string fix up
[ardour.git] / libs / ardour / playlist.cc
index a072d4977b3f248e782d92a942efbc2d20a43201..47462a3575be3b19274698290d9dbf861f68a3d8 100644 (file)
 
 */
 
+#include <stdint.h>
 #include <set>
-#include <fstream>
 #include <algorithm>
-#include <unistd.h>
-#include <cerrno>
 #include <string>
-#include <climits>
 
-#include <sigc++/bind.h>
+#include <boost/lexical_cast.hpp>
 
-#include "pbd/failed_constructor.h"
-#include "pbd/stl_delete.h"
+#include "pbd/convert.h"
+#include "pbd/stateful_diff_command.h"
 #include "pbd/xml++.h"
-#include "pbd/stacktrace.h"
 
+#include "ardour/debug.h"
 #include "ardour/playlist.h"
 #include "ardour/session.h"
 #include "ardour/region.h"
 #include "ardour/region_factory.h"
+#include "ardour/region_sorters.h"
 #include "ardour/playlist_factory.h"
+#include "ardour/playlist_source.h"
 #include "ardour/transient_detector.h"
+#include "ardour/session_playlists.h"
+#include "ardour/source_factory.h"
 
 #include "i18n.h"
 
@@ -45,6 +46,12 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
+namespace ARDOUR {
+       namespace Properties {
+               PBD::PropertyDescriptor<bool> regions;
+       }
+}
+
 struct ShowMeTheList {
     ShowMeTheList (boost::shared_ptr<Playlist> pl, const string& n) : playlist (pl), name (n) {}
     ~ShowMeTheList () {
@@ -54,67 +61,102 @@ struct ShowMeTheList {
     string name;
 };
 
-struct RegionSortByLayer {
-    bool operator() (boost::shared_ptr<Region> a, boost::shared_ptr<Region> b) {
-           return a->layer() < b->layer();
-    }
-};
 
-struct RegionSortByLayerWithPending {
-       bool operator () (boost::shared_ptr<Region> a, boost::shared_ptr<Region> b) {
 
-               double p = a->layer ();
-               if (a->pending_explicit_relayer()) {
-                       p += 0.5;
-               }
+void
+Playlist::make_property_quarks ()
+{
+       Properties::regions.property_id = g_quark_from_static_string (X_("regions"));
+       DEBUG_TRACE (DEBUG::Properties, string_compose ("quark for regions = %1\n",
+                                                       Properties::regions.property_id));
+}
 
-               double q = b->layer ();
-               if (b->pending_explicit_relayer()) {
-                       q += 0.5;
-               }
+RegionListProperty::RegionListProperty (Playlist& pl)
+       : SequenceProperty<std::list<boost::shared_ptr<Region> > > (Properties::regions.property_id, boost::bind (&Playlist::update, &pl, _1))
+       , _playlist (pl)
+{
 
-               return p < q;
-       }
-};
+}
 
-struct RegionSortByPosition {
-    bool operator() (boost::shared_ptr<Region> a, boost::shared_ptr<Region> b) {
-           return a->position() < b->position();
-    }
-};
+RegionListProperty::RegionListProperty (RegionListProperty const & p)
+       : PBD::SequenceProperty<std::list<boost::shared_ptr<Region> > > (p)
+       , _playlist (p._playlist)
+{
 
-struct RegionSortByLastLayerOp {
-    bool operator() (boost::shared_ptr<Region> a, boost::shared_ptr<Region> b) {
-           return a->last_layer_op() < b->last_layer_op();
-    }
-};
+}
+
+RegionListProperty *
+RegionListProperty::clone () const
+{
+       return new RegionListProperty (*this);
+}
+
+RegionListProperty *
+RegionListProperty::create () const
+{
+       return new RegionListProperty (_playlist);
+}
+
+void
+RegionListProperty::get_content_as_xml (boost::shared_ptr<Region> region, XMLNode & node) const
+{
+       /* All regions (even those which are deleted) have their state saved by other
+          code, so we can just store ID here.
+       */
+
+       node.add_property ("id", region->id().to_s ());
+}
+
+boost::shared_ptr<Region>
+RegionListProperty::get_content_from_xml (XMLNode const & node) const
+{
+       XMLProperty const * prop = node.property ("id");
+       assert (prop);
+
+       PBD::ID id (prop->value ());
+
+       boost::shared_ptr<Region> ret = _playlist.region_by_id (id);
+
+       if (!ret) {
+               ret = RegionFactory::region_by_id (id);
+       }
 
+       return ret;
+}
 
 Playlist::Playlist (Session& sess, string nom, DataType type, bool hide)
        : SessionObject(sess, nom)
+       , regions (*this)
        , _type(type)
 {
        init (hide);
        first_set_state = false;
        _name = nom;
-
+       _set_sort_id ();
 }
 
 Playlist::Playlist (Session& sess, const XMLNode& node, DataType type, bool hide)
        : SessionObject(sess, "unnamed playlist")
+       , regions (*this)
        , _type(type)
 {
+#ifndef NDEBUG
        const XMLProperty* prop = node.property("type");
        assert(!prop || DataType(prop->value()) == _type);
+#endif
 
        init (hide);
        _name = "unnamed"; /* reset by set_state */
+       _set_sort_id ();
 
        /* set state called by derived class */
 }
 
 Playlist::Playlist (boost::shared_ptr<const Playlist> other, string namestr, bool hide)
-       : SessionObject(other->_session, namestr), _type(other->_type), _orig_diskstream_id(other->_orig_diskstream_id)
+       : SessionObject(other->_session, namestr)
+       , regions (*this)
+       , _type(other->_type)
+       , _orig_track_id (other->_orig_track_id)
 {
        init (hide);
 
@@ -138,78 +180,83 @@ Playlist::Playlist (boost::shared_ptr<const Playlist> other, string namestr, boo
        in_flush = false;
        in_partition = false;
        subcnt = 0;
-       _read_data_count = 0;
        _frozen = other->_frozen;
-
-       layer_op_counter = other->layer_op_counter;
-       freeze_length = other->freeze_length;
 }
 
-Playlist::Playlist (boost::shared_ptr<const Playlist> other, nframes_t start, nframes_t cnt, string str, bool hide)
-       : SessionObject(other->_session, str), _type(other->_type), _orig_diskstream_id(other->_orig_diskstream_id)
+Playlist::Playlist (boost::shared_ptr<const Playlist> other, framepos_t start, framecnt_t cnt, string str, bool hide)
+       : SessionObject(other->_session, str)
+       , regions (*this)
+       , _type(other->_type)
+       , _orig_track_id (other->_orig_track_id)
 {
-       RegionLock rlock2 (const_cast<Playlist*> (other.get()));
+       RegionReadLock rlock2 (const_cast<Playlist*> (other.get()));
 
-       nframes_t end = start + cnt - 1;
+       framepos_t end = start + cnt - 1;
 
        init (hide);
 
        in_set_state++;
 
-       for (RegionList::const_iterator i = other->regions.begin(); i != other->regions.end(); i++) {
+       for (RegionList::const_iterator i = other->regions.begin(); i != other->regions.end(); ++i) {
 
                boost::shared_ptr<Region> region;
                boost::shared_ptr<Region> new_region;
-               nframes_t offset = 0;
-               nframes_t position = 0;
-               nframes_t len = 0;
+               frameoffset_t offset = 0;
+               framepos_t position = 0;
+               framecnt_t len = 0;
                string    new_name;
-               OverlapType overlap;
+               Evoral::OverlapType overlap;
 
                region = *i;
 
                overlap = region->coverage (start, end);
 
                switch (overlap) {
-               case OverlapNone:
+               case Evoral::OverlapNone:
                        continue;
 
-               case OverlapInternal:
+               case Evoral::OverlapInternal:
                        offset = start - region->position();
                        position = 0;
                        len = cnt;
                        break;
 
-               case OverlapStart:
+               case Evoral::OverlapStart:
                        offset = 0;
                        position = region->position() - start;
                        len = end - region->position();
                        break;
 
-               case OverlapEnd:
+               case Evoral::OverlapEnd:
                        offset = start - region->position();
                        position = 0;
                        len = region->length() - offset;
                        break;
 
-               case OverlapExternal:
+               case Evoral::OverlapExternal:
                        offset = 0;
                        position = region->position() - start;
                        len = region->length();
                        break;
                }
 
-               _session.region_name (new_name, region->name(), false);
+               RegionFactory::region_name (new_name, region->name(), false);
+
+               PropertyList plist;
+
+               plist.add (Properties::start, region->start() + offset);
+               plist.add (Properties::length, len);
+               plist.add (Properties::name, new_name);
+               plist.add (Properties::layer, region->layer());
+               plist.add (Properties::layering_index, region->layering_index());
 
-               new_region = RegionFactory::RegionFactory::create (region, offset, len, new_name, region->layer(), region->flags());
+               new_region = RegionFactory::create (region, plist);
 
                add_region_internal (new_region, position);
        }
 
        in_set_state--;
        first_set_state = false;
-
-       /* this constructor does NOT notify others (session) */
 }
 
 void
@@ -234,20 +281,23 @@ Playlist::release ()
 void
 Playlist::copy_regions (RegionList& newlist) const
 {
-       RegionLock rlock (const_cast<Playlist *> (this));
+       RegionReadLock rlock (const_cast<Playlist *> (this));
 
        for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
-               newlist.push_back (RegionFactory::RegionFactory::create (*i));
+               newlist.push_back (RegionFactory::create (*i, true));
        }
 }
 
 void
 Playlist::init (bool hide)
 {
+       add_property (regions);
+       _xml_node_name = X_("Playlist");
+
        g_atomic_int_set (&block_notifications, 0);
        g_atomic_int_set (&ignore_state_changes, 0);
-       pending_modified = false;
-       pending_length = false;
+       pending_contents_change = false;
+       pending_layering = false;
        first_set_state = true;
        _refcnt = 0;
        _hidden = hide;
@@ -255,23 +305,27 @@ Playlist::init (bool hide)
        _shuffling = false;
        _nudging = false;
        in_set_state = 0;
+       in_undo = false;
        _edit_mode = Config->get_edit_mode();
        in_flush = false;
        in_partition = false;
        subcnt = 0;
-       _read_data_count = 0;
        _frozen = false;
-       layer_op_counter = 0;
-       freeze_length = 0;
-       _explicit_relayering = false;
+       _capture_insertion_underway = false;
+       _combine_ops = 0;
 
-       Modified.connect (mem_fun (*this, &Playlist::mark_session_dirty));
+       _session.history().BeginUndoRedo.connect_same_thread (*this, boost::bind (&Playlist::begin_undo, this));
+       _session.history().EndUndoRedo.connect_same_thread (*this, boost::bind (&Playlist::end_undo, this));
+
+       ContentsChanged.connect_same_thread (*this, boost::bind (&Playlist::mark_session_dirty, this));
 }
 
 Playlist::~Playlist ()
 {
+       DEBUG_TRACE (DEBUG::Destruction, string_compose ("Playlist %1 destructor\n", _name));
+
        {
-               RegionLock rl (this);
+               RegionReadLock rl (this);
 
                for (set<boost::shared_ptr<Region> >::iterator i = all_regions.begin(); i != all_regions.end(); ++i) {
                        (*i)->set_playlist (boost::shared_ptr<Playlist>());
@@ -281,6 +335,32 @@ Playlist::~Playlist ()
        /* GoingAway must be emitted by derived classes */
 }
 
+void
+Playlist::_set_sort_id ()
+{
+       /*
+         Playlists are given names like <track name>.<id>
+         or <track name>.<edit group name>.<id> where id
+         is an integer. We extract the id and sort by that.
+       */
+
+       size_t dot_position = _name.val().find_last_of(".");
+
+       if (dot_position == string::npos) {
+               _sort_id = 0;
+       } else {
+               string t = _name.val().substr(dot_position + 1);
+
+               try {
+                       _sort_id = boost::lexical_cast<int>(t);
+               }
+
+               catch (boost::bad_lexical_cast e) {
+                       _sort_id = 0;
+               }
+       }
+}
+
 bool
 Playlist::set_name (const string& str)
 {
@@ -292,9 +372,13 @@ Playlist::set_name (const string& str)
 
        if (_refcnt > 2) {
                return false;
-       } else {
-               return SessionObject::set_name(str);
        }
+
+       bool ret =  SessionObject::set_name(str);
+       if (ret) {
+               _set_sort_id ();
+       }
+       return ret;
 }
 
 /***********************************************************************
@@ -305,6 +389,20 @@ Playlist::set_name (const string& str)
  the lock (e.g. to read from the playlist).
  ***********************************************************************/
 
+void
+Playlist::begin_undo ()
+{
+       in_undo = true;
+       freeze ();
+}
+
+void
+Playlist::end_undo ()
+{
+       thaw (true);
+       in_undo = false;
+}
+
 void
 Playlist::freeze ()
 {
@@ -312,11 +410,12 @@ Playlist::freeze ()
        g_atomic_int_inc (&ignore_state_changes);
 }
 
+/** @param from_undo true if this thaw is triggered by the end of an undo on this playlist */
 void
-Playlist::thaw ()
+Playlist::thaw (bool from_undo)
 {
        g_atomic_int_dec_and_test (&ignore_state_changes);
-       release_notifications ();
+       release_notifications (from_undo);
 }
 
 
@@ -324,25 +423,36 @@ void
 Playlist::delay_notifications ()
 {
        g_atomic_int_inc (&block_notifications);
-       freeze_length = _get_maximum_extent();
 }
 
+/** @param from_undo true if this release is triggered by the end of an undo on this playlist */
 void
-Playlist::release_notifications ()
+Playlist::release_notifications (bool from_undo)
 {
        if (g_atomic_int_dec_and_test (&block_notifications)) {
-               flush_notifications ();
+               flush_notifications (from_undo);
+       }
+}
+
+void
+Playlist::notify_contents_changed ()
+{
+       if (holding_state ()) {
+               pending_contents_change = true;
+       } else {
+               pending_contents_change = false;
+               ContentsChanged(); /* EMIT SIGNAL */
        }
 }
 
 void
-Playlist::notify_modified ()
+Playlist::notify_layering_changed ()
 {
        if (holding_state ()) {
-               pending_modified = true;
+               pending_layering = true;
        } else {
-               pending_modified = false;
-               Modified(); /* EMIT SIGNAL */
+               pending_layering = false;
+               LayeringChanged(); /* EMIT SIGNAL */
        }
 }
 
@@ -351,24 +461,21 @@ Playlist::notify_region_removed (boost::shared_ptr<Region> r)
 {
        if (holding_state ()) {
                pending_removes.insert (r);
-               pending_modified = true;
-               pending_length = true;
+               pending_contents_change = true;
        } else {
                /* this might not be true, but we have to act
                   as though it could be.
                */
-               pending_length = false;
-               LengthChanged (); /* EMIT SIGNAL */
-               pending_modified = false;
+               pending_contents_change = false;
                RegionRemoved (boost::weak_ptr<Region> (r)); /* EMIT SIGNAL */
-               Modified (); /* EMIT SIGNAL */
+               ContentsChanged (); /* EMIT SIGNAL */
        }
 }
 
 void
 Playlist::notify_region_moved (boost::shared_ptr<Region> r)
 {
-       Evoral::RangeMove<nframes_t> const move (r->last_position (), r->length (), r->position ());
+       Evoral::RangeMove<framepos_t> const move (r->last_position (), r->length (), r->position ());
 
        if (holding_state ()) {
 
@@ -376,52 +483,82 @@ Playlist::notify_region_moved (boost::shared_ptr<Region> r)
 
        } else {
 
-               list< Evoral::RangeMove<nframes_t> > m;
+               list< Evoral::RangeMove<framepos_t> > m;
                m.push_back (move);
-               RangesMoved (m);
+               RangesMoved (m, false);
        }
 
 }
 
 void
-Playlist::notify_region_added (boost::shared_ptr<Region> r)
+Playlist::notify_region_start_trimmed (boost::shared_ptr<Region> r)
 {
-       /* the length change might not be true, but we have to act
-          as though it could be.
-       */
+       if (r->position() >= r->last_position()) {
+               /* trimmed shorter */
+               return;
+       }
+
+       Evoral::Range<framepos_t> const extra (r->position(), r->last_position());
+
+       if (holding_state ()) {
+
+               pending_region_extensions.push_back (extra);
 
-       if (holding_state()) {
-               pending_adds.insert (r);
-               pending_modified = true;
-               pending_length = true;
        } else {
-               pending_length = false;
-               LengthChanged (); /* EMIT SIGNAL */
-               pending_modified = false;
-               RegionAdded (boost::weak_ptr<Region> (r)); /* EMIT SIGNAL */
-               Modified (); /* EMIT SIGNAL */
+
+               list<Evoral::Range<framepos_t> > r;
+               r.push_back (extra);
+               RegionsExtended (r);
+
        }
 }
 
 void
-Playlist::notify_length_changed ()
+Playlist::notify_region_end_trimmed (boost::shared_ptr<Region> r)
 {
+       if (r->length() < r->last_length()) {
+               /* trimmed shorter */
+       }
+
+       Evoral::Range<framepos_t> const extra (r->position() + r->last_length(), r->position() + r->length());
+
        if (holding_state ()) {
-               pending_length = true;
+
+               pending_region_extensions.push_back (extra);
+
+       } else {
+
+               list<Evoral::Range<framepos_t> > r;
+               r.push_back (extra);
+               RegionsExtended (r);
+       }
+}
+
+
+void
+Playlist::notify_region_added (boost::shared_ptr<Region> r)
+{
+       /* the length change might not be true, but we have to act
+          as though it could be.
+       */
+
+       if (holding_state()) {
+               pending_adds.insert (r);
+               pending_contents_change = true;
        } else {
-               pending_length = false;
-               LengthChanged(); /* EMIT SIGNAL */
-               pending_modified = false;
-               Modified (); /* EMIT SIGNAL */
+               r->clear_changes ();
+               pending_contents_change = false;
+               RegionAdded (boost::weak_ptr<Region> (r)); /* EMIT SIGNAL */
+               ContentsChanged (); /* EMIT SIGNAL */
        }
 }
 
+/** @param from_undo true if this flush is triggered by the end of an undo on this playlist */
 void
-Playlist::flush_notifications ()
+Playlist::flush_notifications (bool from_undo)
 {
-       set<boost::shared_ptr<Region> > dependent_checks_needed;
        set<boost::shared_ptr<Region> >::iterator s;
-       uint32_t n = 0;
+       bool regions_changed = false;
 
        if (in_flush) {
                return;
@@ -429,6 +566,14 @@ Playlist::flush_notifications ()
 
        in_flush = true;
 
+       if (!pending_bounds.empty() || !pending_removes.empty() || !pending_adds.empty()) {
+               regions_changed = true;
+       }
+
+       /* XXX: it'd be nice if we could use pending_bounds for
+          RegionsExtended and RegionsMoved.
+       */
+
        /* we have no idea what order the regions ended up in pending
           bounds (it could be based on selection order, for example).
           so, to preserve layering in the "most recently moved is higher"
@@ -438,1160 +583,1203 @@ Playlist::flush_notifications ()
        // RegionSortByLayer cmp;
        // pending_bounds.sort (cmp);
 
-       for (RegionList::iterator r = pending_bounds.begin(); r != pending_bounds.end(); ++r) {
-               if (_session.config.get_layer_model() == MoveAddHigher) {
-                       timestamp_layer_op (*r);
-               }
-
-               pending_length = true;
-               dependent_checks_needed.insert (*r);
+       list<Evoral::Range<framepos_t> > crossfade_ranges;
 
-               n++;
+       for (RegionList::iterator r = pending_bounds.begin(); r != pending_bounds.end(); ++r) {
+               crossfade_ranges.push_back ((*r)->last_range ());
+               crossfade_ranges.push_back ((*r)->range ());
        }
 
        for (s = pending_removes.begin(); s != pending_removes.end(); ++s) {
+               crossfade_ranges.push_back ((*s)->range ());
                remove_dependents (*s);
                RegionRemoved (boost::weak_ptr<Region> (*s)); /* EMIT SIGNAL */
-               n++;
        }
-
+       
        for (s = pending_adds.begin(); s != pending_adds.end(); ++s) {
-               RegionAdded (boost::weak_ptr<Region> (*s)); /* EMIT SIGNAL */
-               dependent_checks_needed.insert (*s);
-               n++;
+               crossfade_ranges.push_back ((*s)->range ());
+               /* don't emit RegionAdded signal until relayering is done,
+                  so that the region is fully setup by the time
+                  anyone hears that its been added
+               */
        }
 
-       if ((freeze_length != _get_maximum_extent()) || pending_length) {
-               pending_length = 0;
-               LengthChanged(); /* EMIT SIGNAL */
-               n++;
+       if (((regions_changed || pending_contents_change) && !in_set_state) || pending_layering) {
+               relayer ();
        }
 
-       if (n || pending_modified) {
-               if (!in_set_state) {
-                       relayer ();
-               }
-               pending_modified = false;
-               Modified (); /* EMIT SIGNAL */
-       }
+        if (regions_changed || pending_contents_change) {
+                pending_contents_change = false;
+                ContentsChanged (); /* EMIT SIGNAL */
+        }
 
-       for (s = dependent_checks_needed.begin(); s != dependent_checks_needed.end(); ++s) {
-               check_dependents (*s, false);
-       }
+        for (s = pending_adds.begin(); s != pending_adds.end(); ++s) {
+                (*s)->clear_changes ();
+                RegionAdded (boost::weak_ptr<Region> (*s)); /* EMIT SIGNAL */
+        }
 
-       if (!pending_range_moves.empty ()) {
-               RangesMoved (pending_range_moves);
-       }
+        coalesce_and_check_crossfades (crossfade_ranges);
 
-       pending_adds.clear ();
-       pending_removes.clear ();
-       pending_bounds.clear ();
-       pending_range_moves.clear ();
+        if (!pending_range_moves.empty ()) {
+                /* We don't need to check crossfades for these as pending_bounds has
+                   already covered it.
+                */
+                RangesMoved (pending_range_moves, from_undo);
+        }
 
-       in_flush = false;
-}
+        if (!pending_region_extensions.empty ()) {
+                RegionsExtended (pending_region_extensions);
+        }
 
-/*************************************************************
-  PLAYLIST OPERATIONS
- *************************************************************/
+        clear_pending ();
 
-void
-Playlist::add_region (boost::shared_ptr<Region> region, nframes_t position, float times, bool auto_partition)
-{
-       RegionLock rlock (this);
-       times = fabs (times);
+        in_flush = false;
+ }
 
-       int itimes = (int) floor (times);
+ void
+ Playlist::clear_pending ()
+ {
+        pending_adds.clear ();
+        pending_removes.clear ();
+        pending_bounds.clear ();
+        pending_range_moves.clear ();
+        pending_region_extensions.clear ();
+        pending_contents_change = false;
+ }
 
-       nframes_t pos = position;
+ /*************************************************************
+   PLAYLIST OPERATIONS
+  *************************************************************/
 
-       if(times == 1 && auto_partition){
-               partition(pos, (nframes_t) (pos + region->length()), true);
-       }
+/** Note: this calls set_layer (..., DBL_MAX) so it will reset the layering index of region */
+ void
+ Playlist::add_region (boost::shared_ptr<Region> region, framepos_t position, float times, bool auto_partition)
+ {
+        RegionWriteLock rlock (this);
+        times = fabs (times);
 
-       if (itimes >= 1) {
-               add_region_internal (region, pos);
-               pos += region->length();
-               --itimes;
-       }
+        int itimes = (int) floor (times);
 
+        framepos_t pos = position;
 
-       /* note that itimes can be zero if we being asked to just
-          insert a single fraction of the region.
-       */
+        if (times == 1 && auto_partition){
+                partition(pos - 1, (pos + region->length()), true);
+        }
 
-       for (int i = 0; i < itimes; ++i) {
-               boost::shared_ptr<Region> copy = RegionFactory::create (region);
-               add_region_internal (copy, pos);
-               pos += region->length();
-       }
+        if (itimes >= 1) {
+                add_region_internal (region, pos);
+                set_layer (region, DBL_MAX);
+                pos += region->length();
+                --itimes;
+        }
 
-       nframes_t length = 0;
 
-       if (floor (times) != times) {
-               length = (nframes_t) floor (region->length() * (times - floor (times)));
-               string name;
-               _session.region_name (name, region->name(), false);
-               boost::shared_ptr<Region> sub = RegionFactory::create (region, 0, length, name, region->layer(), region->flags());
-               add_region_internal (sub, pos);
-       }
+        /* note that itimes can be zero if we being asked to just
+           insert a single fraction of the region.
+        */
 
-       possibly_splice_unlocked (position, (pos + length) - position, boost::shared_ptr<Region>());
-}
+        for (int i = 0; i < itimes; ++i) {
+                boost::shared_ptr<Region> copy = RegionFactory::create (region, true);
+                add_region_internal (copy, pos);
+                set_layer (copy, DBL_MAX);
+                pos += region->length();
+        }
 
-void
-Playlist::set_region_ownership ()
-{
-       RegionLock rl (this);
-       RegionList::iterator i;
-       boost::weak_ptr<Playlist> pl (shared_from_this());
+        framecnt_t length = 0;
 
-       for (i = regions.begin(); i != regions.end(); ++i) {
-               (*i)->set_playlist (pl);
-       }
-}
+        if (floor (times) != times) {
+                length = (framecnt_t) floor (region->length() * (times - floor (times)));
+                string name;
+                RegionFactory::region_name (name, region->name(), false);
 
-bool
-Playlist::add_region_internal (boost::shared_ptr<Region> region, nframes_t position)
-{
-       if (region->data_type() != _type){
-               return false;
-       }
+                {
+                        PropertyList plist;
 
-       RegionSortByPosition cmp;
+                        plist.add (Properties::start, region->start());
+                        plist.add (Properties::length, length);
+                        plist.add (Properties::name, name);
+                        plist.add (Properties::layer, region->layer());
 
-       nframes_t old_length = 0;
+                        boost::shared_ptr<Region> sub = RegionFactory::create (region, plist);
+                        add_region_internal (sub, pos);
+                        set_layer (sub, DBL_MAX);
+                }
+        }
 
-       if (!holding_state()) {
-                old_length = _get_maximum_extent();
-       }
+        possibly_splice_unlocked (position, (pos + length) - position, boost::shared_ptr<Region>());
+ }
 
-       if (!first_set_state) {
-               boost::shared_ptr<Playlist> foo (shared_from_this());
-               region->set_playlist (boost::weak_ptr<Playlist>(foo));
-       }
+ void
+ Playlist::set_region_ownership ()
+ {
+        RegionWriteLock rl (this);
+        RegionList::iterator i;
+        boost::weak_ptr<Playlist> pl (shared_from_this());
 
-       region->set_position (position, this);
+        for (i = regions.begin(); i != regions.end(); ++i) {
+                (*i)->set_playlist (pl);
+        }
+ }
 
-       timestamp_layer_op (region);
+ bool
+ Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t position)
+ {
+        if (region->data_type() != _type) {
+                return false;
+        }
 
-       regions.insert (upper_bound (regions.begin(), regions.end(), region, cmp), region);
-       all_regions.insert (region);
+        RegionSortByPosition cmp;
+
+        if (!first_set_state) {
+                boost::shared_ptr<Playlist> foo (shared_from_this());
+                region->set_playlist (boost::weak_ptr<Playlist>(foo));
+        }
+
+        region->set_position (position);
+
+        regions.insert (upper_bound (regions.begin(), regions.end(), region, cmp), region);
+        all_regions.insert (region);
+
+        possibly_splice_unlocked (position, region->length(), region);
+
+        if (!holding_state ()) {
+                /* layers get assigned from XML state, and are not reset during undo/redo */
+                relayer ();
+        }
+
+        /* we need to notify the existence of new region before checking dependents. Ick. */
+
+        notify_region_added (region);
+
+        region->PropertyChanged.connect_same_thread (region_state_changed_connections, boost::bind (&Playlist::region_changed_proxy, this, _1, boost::weak_ptr<Region> (region)));
+
+        return true;
+ }
+
+ void
+ Playlist::replace_region (boost::shared_ptr<Region> old, boost::shared_ptr<Region> newr, framepos_t pos)
+ {
+        RegionWriteLock rlock (this);
+
+        bool old_sp = _splicing;
+        _splicing = true;
+
+        remove_region_internal (old);
+        add_region_internal (newr, pos);
+        set_layer (newr, old->layer ());
+
+        _splicing = old_sp;
+
+        possibly_splice_unlocked (pos, old->length() - newr->length());
+ }
+
+ void
+ Playlist::remove_region (boost::shared_ptr<Region> region)
+ {
+        RegionWriteLock rlock (this);
+        remove_region_internal (region);
+ }
+
+ int
+ Playlist::remove_region_internal (boost::shared_ptr<Region> region)
+ {
+        RegionList::iterator i;
+
+        if (!in_set_state) {
+                /* unset playlist */
+                region->set_playlist (boost::weak_ptr<Playlist>());
+        }
+
+        /* XXX should probably freeze here .... */
+
+        for (i = regions.begin(); i != regions.end(); ++i) {
+                if (*i == region) {
+
+                        framepos_t pos = (*i)->position();
+                        framecnt_t distance = (*i)->length();
+
+                        regions.erase (i);
+
+                        possibly_splice_unlocked (pos, -distance);
+
+                        if (!holding_state ()) {
+                                relayer ();
+                                remove_dependents (region);
+                        }
+
+                        notify_region_removed (region);
+                        break;
+                }
+        }
+
+        return -1;
+ }
+
+ void
+ Playlist::get_equivalent_regions (boost::shared_ptr<Region> other, vector<boost::shared_ptr<Region> >& results)
+ {
+        if (Config->get_use_overlap_equivalency()) {
+                for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+                        if ((*i)->overlap_equivalent (other)) {
+                                results.push_back (*i);
+                        }
+                }
+        } else {
+                for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+                        if ((*i)->equivalent (other)) {
+                                results.push_back (*i);
+                        }
+                }
+        }
+ }
+
+ void
+ Playlist::get_region_list_equivalent_regions (boost::shared_ptr<Region> other, vector<boost::shared_ptr<Region> >& results)
+ {
+        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+
+                if ((*i) && (*i)->region_list_equivalent (other)) {
+                        results.push_back (*i);
+                }
+        }
+ }
+
+ void
+ Playlist::get_source_equivalent_regions (boost::shared_ptr<Region> other, vector<boost::shared_ptr<Region> >& results)
+ {
+        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+
+                if ((*i) && (*i)->any_source_equivalent (other)) {
+                        results.push_back (*i);
+                }
+        }
+ }
+
+ void
+ Playlist::partition (framepos_t start, framepos_t end, bool cut)
+ {
+        RegionList thawlist;
+
+        partition_internal (start, end, cut, thawlist);
+
+        for (RegionList::iterator i = thawlist.begin(); i != thawlist.end(); ++i) {
+                (*i)->resume_property_changes ();
+        }
+ }
+
+/** Go through each region on the playlist and cut them at start and end, removing the section between
+ *  start and end if cutting == true.  Regions that lie entirely within start and end are always
+ *  removed.
+ */
 
-       possibly_splice_unlocked (position, region->length(), region);
+ void
+ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, RegionList& thawlist)
+ {
+        RegionList new_regions;
 
-       if (!holding_state () && !in_set_state) {
-               /* layers get assigned from XML state */
-               relayer ();
-       }
+        {
+                RegionWriteLock rlock (this);
 
-       /* we need to notify the existence of new region before checking dependents. Ick. */
+                boost::shared_ptr<Region> region;
+                boost::shared_ptr<Region> current;
+                string new_name;
+                RegionList::iterator tmp;
+                Evoral::OverlapType overlap;
+                framepos_t pos1, pos2, pos3, pos4;
 
-       notify_region_added (region);
+                in_partition = true;
 
-       if (!holding_state ()) {
+                /* need to work from a copy, because otherwise the regions we add during the process
+                   get operated on as well.
+                */
 
-               check_dependents (region, false);
+                RegionList copy = regions.rlist();
 
-               if (old_length != _get_maximum_extent()) {
-                       notify_length_changed ();
-               }
-       }
+                for (RegionList::iterator i = copy.begin(); i != copy.end(); i = tmp) {
 
-       region_state_changed_connections.push_back (
-               region->StateChanged.connect (sigc::bind (mem_fun (this, &Playlist::region_changed_proxy),
-                                                         boost::weak_ptr<Region> (region)))
-               );
+                        tmp = i;
+                        ++tmp;
 
-       return true;
-}
+                        current = *i;
 
-void
-Playlist::replace_region (boost::shared_ptr<Region> old, boost::shared_ptr<Region> newr, nframes_t pos)
-{
-       RegionLock rlock (this);
+                        if (current->first_frame() >= start && current->last_frame() < end) {
 
-       bool old_sp = _splicing;
-       _splicing = true;
+                                if (cutting) {
+                                        remove_region_internal (current);
+                                }
 
-       remove_region_internal (old);
-       add_region_internal (newr, pos);
+                                continue;
+                        }
 
-       _splicing = old_sp;
+                        /* coverage will return OverlapStart if the start coincides
+                           with the end point. we do not partition such a region,
+                           so catch this special case.
+                        */
 
-       possibly_splice_unlocked (pos, (nframes64_t) old->length() - (nframes64_t) newr->length());
-}
+                        if (current->first_frame() >= end) {
+                                continue;
+                        }
 
-void
-Playlist::remove_region (boost::shared_ptr<Region> region)
-{
-       RegionLock rlock (this);
-       remove_region_internal (region);
-}
+                        if ((overlap = current->coverage (start, end)) == Evoral::OverlapNone) {
+                                continue;
+                        }
 
-int
-Playlist::remove_region_internal (boost::shared_ptr<Region> region)
-{
-       RegionList::iterator i;
-       nframes_t old_length = 0;
+                        pos1 = current->position();
+                        pos2 = start;
+                        pos3 = end;
+                        pos4 = current->last_frame();
 
-       if (!holding_state()) {
-               old_length = _get_maximum_extent();
-       }
+                        if (overlap == Evoral::OverlapInternal) {
+                                /* split: we need 3 new regions, the front, middle and end.
+                                   cut:   we need 2 regions, the front and end.
+                                */
 
-       if (!in_set_state) {
-               /* unset playlist */
-               region->set_playlist (boost::weak_ptr<Playlist>());
-       }
+                                /*
+                                         start                 end
+                          ---------------*************************------------
+                                         P1  P2              P3  P4
+                          SPLIT:
+                          ---------------*****++++++++++++++++====------------
+                          CUT
+                          ---------------*****----------------====------------
 
-       for (i = regions.begin(); i != regions.end(); ++i) {
-               if (*i == region) {
+                                */
 
-                       nframes_t pos = (*i)->position();
-                       nframes64_t distance = (*i)->length();
+                                if (!cutting) {
+                                        /* "middle" ++++++ */
 
-                       regions.erase (i);
+                                        RegionFactory::region_name (new_name, current->name(), false);
 
-                       possibly_splice_unlocked (pos, -distance);
+                                        PropertyList plist;
 
-                       if (!holding_state ()) {
-                               relayer ();
-                               remove_dependents (region);
+                                        plist.add (Properties::start, current->start() + (pos2 - pos1));
+                                        plist.add (Properties::length, pos3 - pos2);
+                                        plist.add (Properties::name, new_name);
+                                        plist.add (Properties::layer, current->layer ());
+                                        plist.add (Properties::layering_index, current->layering_index ());
+                                        plist.add (Properties::automatic, true);
+                                        plist.add (Properties::left_of_split, true);
+                                        plist.add (Properties::right_of_split, true);
 
-                               if (old_length != _get_maximum_extent()) {
-                                       notify_length_changed ();
-                               }
-                       }
+                                        region = RegionFactory::create (current, plist);
+                                        add_region_internal (region, start);
+                                        new_regions.push_back (region);
+                                }
 
-                       notify_region_removed (region);
-                       return 0;
-               }
-       }
+                                /* "end" ====== */
 
+                                RegionFactory::region_name (new_name, current->name(), false);
 
+                                PropertyList plist;
 
-       return -1;
-}
+                                plist.add (Properties::start, current->start() + (pos3 - pos1));
+                                plist.add (Properties::length, pos4 - pos3);
+                                plist.add (Properties::name, new_name);
+                                plist.add (Properties::layer, current->layer ());
+                                plist.add (Properties::layering_index, current->layering_index ());
+                                plist.add (Properties::automatic, true);
+                                plist.add (Properties::right_of_split, true);
 
-void
-Playlist::get_equivalent_regions (boost::shared_ptr<Region> other, vector<boost::shared_ptr<Region> >& results)
-{
-       if (Config->get_use_overlap_equivalency()) {
-               for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-                       if ((*i)->overlap_equivalent (other)) {
-                               results.push_back ((*i));
-                       }
-               }
-       } else {
-               for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-                       if ((*i)->equivalent (other)) {
-                               results.push_back ((*i));
-                       }
-               }
-       }
-}
+                                region = RegionFactory::create (current, plist);
 
-void
-Playlist::get_region_list_equivalent_regions (boost::shared_ptr<Region> other, vector<boost::shared_ptr<Region> >& results)
-{
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+                                add_region_internal (region, end);
+                                new_regions.push_back (region);
 
-               if ((*i) && (*i)->region_list_equivalent (other)) {
-                       results.push_back (*i);
-               }
-       }
-}
+                                /* "front" ***** */
 
-void
-Playlist::partition (nframes_t start, nframes_t end, bool cut)
-{
-       RegionList thawlist;
+                                current->suspend_property_changes ();
+                                thawlist.push_back (current);
+                                current->cut_end (pos2 - 1);
 
-       partition_internal (start, end, cut, thawlist);
+                        } else if (overlap == Evoral::OverlapEnd) {
 
-       for (RegionList::iterator i = thawlist.begin(); i != thawlist.end(); ++i) {
-               (*i)->thaw ("separation");
-       }
-}
+                                /*
+                                                              start           end
+                                    ---------------*************************------------
+                                                   P1           P2         P4   P3
+                                    SPLIT:
+                                    ---------------**************+++++++++++------------
+                                    CUT:
+                                    ---------------**************-----------------------
+                                */
 
-void
-Playlist::partition_internal (nframes_t start, nframes_t end, bool cutting, RegionList& thawlist)
-{
-       RegionList new_regions;
+                                if (!cutting) {
 
-       {
-               RegionLock rlock (this);
+                                        /* end +++++ */
 
-               boost::shared_ptr<Region> region;
-               boost::shared_ptr<Region> current;
-               string new_name;
-               RegionList::iterator tmp;
-               OverlapType overlap;
-               nframes_t pos1, pos2, pos3, pos4;
+                                        RegionFactory::region_name (new_name, current->name(), false);
 
-               in_partition = true;
+                                        PropertyList plist;
 
-               /* need to work from a copy, because otherwise the regions we add during the process
-                  get operated on as well.
-               */
+                                        plist.add (Properties::start, current->start() + (pos2 - pos1));
+                                        plist.add (Properties::length, pos4 - pos2);
+                                        plist.add (Properties::name, new_name);
+                                        plist.add (Properties::layer, current->layer ());
+                                        plist.add (Properties::layering_index, current->layering_index ());
+                                        plist.add (Properties::automatic, true);
+                                        plist.add (Properties::left_of_split, true);
 
-               RegionList copy = regions;
+                                        region = RegionFactory::create (current, plist);
 
-               for (RegionList::iterator i = copy.begin(); i != copy.end(); i = tmp) {
+                                        add_region_internal (region, start);
+                                        new_regions.push_back (region);
+                                }
 
-                       tmp = i;
-                       ++tmp;
+                                /* front ****** */
 
-                       current = *i;
+                                current->suspend_property_changes ();
+                                thawlist.push_back (current);
+                                current->cut_end (pos2 - 1);
 
-                       if (current->first_frame() >= start && current->last_frame() < end) {
+                        } else if (overlap == Evoral::OverlapStart) {
 
-                               if (cutting) {
-                                       remove_region_internal (current);
-                               }
+                                /* split: we need 2 regions: the front and the end.
+                                   cut: just trim current to skip the cut area
+                                */
 
-                               continue;
-                       }
+                                /*
+                                                        start           end
+                                    ---------------*************************------------
+                                       P2          P1 P3                   P4
 
-                       /* coverage will return OverlapStart if the start coincides
-                          with the end point. we do not partition such a region,
-                          so catch this special case.
-                       */
+                                    SPLIT:
+                                    ---------------****+++++++++++++++++++++------------
+                                    CUT:
+                                    -------------------*********************------------
 
-                       if (current->first_frame() >= end) {
-                               continue;
-                       }
+                                */
 
-                       if ((overlap = current->coverage (start, end)) == OverlapNone) {
-                               continue;
-                       }
+                                if (!cutting) {
+                                        /* front **** */
+                                        RegionFactory::region_name (new_name, current->name(), false);
 
-                       pos1 = current->position();
-                       pos2 = start;
-                       pos3 = end;
-                       pos4 = current->last_frame();
-
-                       if (overlap == OverlapInternal) {
-                               /* split: we need 3 new regions, the front, middle and end.
-                                  cut:   we need 2 regions, the front and end.
-                               */
-
-                               /*
-                                        start                 end
-                         ---------------*************************------------
-                                        P1  P2              P3  P4
-                         SPLIT:
-                         ---------------*****++++++++++++++++====------------
-                         CUT
-                         ---------------*****----------------====------------
-
-                               */
-
-                               if (!cutting) {
-                                       /* "middle" ++++++ */
-
-                                       _session.region_name (new_name, current->name(), false);
-                                       region = RegionFactory::create (current, pos2 - pos1, pos3 - pos2, new_name,
-                                                                       regions.size(), Region::Flag(current->flags()|Region::Automatic|Region::LeftOfSplit|Region::RightOfSplit));
-                                       add_region_internal (region, start);
-                                       new_regions.push_back (region);
-                               }
+                                        PropertyList plist;
 
-                               /* "end" ====== */
+                                        plist.add (Properties::start, current->start());
+                                        plist.add (Properties::length, pos3 - pos1);
+                                        plist.add (Properties::name, new_name);
+                                        plist.add (Properties::layer, current->layer ());
+                                        plist.add (Properties::layering_index, current->layering_index ());
+                                        plist.add (Properties::automatic, true);
+                                        plist.add (Properties::right_of_split, true);
 
-                               _session.region_name (new_name, current->name(), false);
-                               region = RegionFactory::create (current, pos3 - pos1, pos4 - pos3, new_name,
-                                                               regions.size(), Region::Flag(current->flags()|Region::Automatic|Region::RightOfSplit));
+                                        region = RegionFactory::create (current, plist);
 
-                               add_region_internal (region, end);
-                               new_regions.push_back (region);
+                                        add_region_internal (region, pos1);
+                                        new_regions.push_back (region);
+                                }
 
-                               /* "front" ***** */
+                                /* end */
 
-                               current->freeze ();
-                               thawlist.push_back (current);
-                               current->trim_end (pos2, this);
+                                current->suspend_property_changes ();
+                                thawlist.push_back (current);
+                                current->trim_front (pos3);
+                        } else if (overlap == Evoral::OverlapExternal) {
 
-                       } else if (overlap == OverlapEnd) {
+                                /* split: no split required.
+                                   cut: remove the region.
+                                */
 
-                               /*
-                                                             start           end
-                                   ---------------*************************------------
-                                                  P1           P2         P4   P3
-                                    SPLIT:
-                                   ---------------**************+++++++++++------------
-                                    CUT:
-                                   ---------------**************-----------------------
-                               */
+                                /*
+                                       start                                      end
+                                    ---------------*************************------------
+                                       P2          P1 P3                   P4
 
-                               if (!cutting) {
+                                    SPLIT:
+                                    ---------------*************************------------
+                                    CUT:
+                                    ----------------------------------------------------
 
-                                       /* end +++++ */
+                                */
 
-                                       _session.region_name (new_name, current->name(), false);
-                                       region = RegionFactory::create (current, pos2 - pos1, pos4 - pos2, new_name, (layer_t) regions.size(),
-                                                                       Region::Flag(current->flags()|Region::Automatic|Region::LeftOfSplit));
+                                if (cutting) {
+                                        remove_region_internal (current);
+                                }
 
-                                       add_region_internal (region, start);
-                                       new_regions.push_back (region);
-                               }
+                                new_regions.push_back (current);
+                        }
+                }
 
-                               /* front ****** */
+                in_partition = false;
+        }
+ }
 
-                               current->freeze ();
-                               thawlist.push_back (current);
-                               current->trim_end (pos2, this);
+ boost::shared_ptr<Playlist>
+ Playlist::cut_copy (boost::shared_ptr<Playlist> (Playlist::*pmf)(framepos_t, framecnt_t,bool), list<AudioRange>& ranges, bool result_is_hidden)
+ {
+        boost::shared_ptr<Playlist> ret;
+        boost::shared_ptr<Playlist> pl;
+        framepos_t start;
+
+        if (ranges.empty()) {
+                return boost::shared_ptr<Playlist>();
+        }
+
+        start = ranges.front().start;
+
+        for (list<AudioRange>::iterator i = ranges.begin(); i != ranges.end(); ++i) {
+
+                pl = (this->*pmf)((*i).start, (*i).length(), result_is_hidden);
+
+                if (i == ranges.begin()) {
+                        ret = pl;
+                } else {
+
+                        /* paste the next section into the nascent playlist,
+                           offset to reflect the start of the first range we
+                           chopped.
+                        */
+
+                        ret->paste (pl, (*i).start - start, 1.0f);
+                }
+        }
+
+        return ret;
+ }
+
+ boost::shared_ptr<Playlist>
+ Playlist::cut (list<AudioRange>& ranges, bool result_is_hidden)
+ {
+        boost::shared_ptr<Playlist> (Playlist::*pmf)(framepos_t,framecnt_t,bool) = &Playlist::cut;
+        return cut_copy (pmf, ranges, result_is_hidden);
+ }
+
+ boost::shared_ptr<Playlist>
+ Playlist::copy (list<AudioRange>& ranges, bool result_is_hidden)
+ {
+        boost::shared_ptr<Playlist> (Playlist::*pmf)(framepos_t,framecnt_t,bool) = &Playlist::copy;
+        return cut_copy (pmf, ranges, result_is_hidden);
+ }
+
+ boost::shared_ptr<Playlist>
+ Playlist::cut (framepos_t start, framecnt_t cnt, bool result_is_hidden)
+ {
+        boost::shared_ptr<Playlist> the_copy;
+        RegionList thawlist;
+        char buf[32];
+
+        snprintf (buf, sizeof (buf), "%" PRIu32, ++subcnt);
+        string new_name = _name;
+        new_name += '.';
+        new_name += buf;
+
+        if ((the_copy = PlaylistFactory::create (shared_from_this(), start, cnt, new_name, result_is_hidden)) == 0) {
+                return boost::shared_ptr<Playlist>();
+        }
+
+        partition_internal (start, start+cnt-1, true, thawlist);
+
+        for (RegionList::iterator i = thawlist.begin(); i != thawlist.end(); ++i) {
+                (*i)->resume_property_changes();
+        }
+
+        return the_copy;
+ }
+
+ boost::shared_ptr<Playlist>
+ Playlist::copy (framepos_t start, framecnt_t cnt, bool result_is_hidden)
+ {
+        char buf[32];
+
+        snprintf (buf, sizeof (buf), "%" PRIu32, ++subcnt);
+        string new_name = _name;
+        new_name += '.';
+        new_name += buf;
+
+        cnt = min (_get_extent().second - start, cnt);
+        return PlaylistFactory::create (shared_from_this(), start, cnt, new_name, result_is_hidden);
+ }
+
+ int
+ Playlist::paste (boost::shared_ptr<Playlist> other, framepos_t position, float times)
+ {
+        times = fabs (times);
+
+        {
+                RegionReadLock rl2 (other.get());
+
+                int itimes = (int) floor (times);
+                framepos_t pos = position;
+                framecnt_t const shift = other->_get_extent().second;
+                layer_t top = top_layer ();
+
+                {
+                        RegionWriteLock rl1 (this);
+                        while (itimes--) {
+                                for (RegionList::iterator i = other->regions.begin(); i != other->regions.end(); ++i) {
+                                        boost::shared_ptr<Region> copy_of_region = RegionFactory::create (*i, true);
+                                        
+                                        /* put these new regions on top of all existing ones, but preserve
+                                           the ordering they had in the original playlist.
+                                        */
+                                        
+                                        add_region_internal (copy_of_region, (*i)->position() + pos);
+                                        set_layer (copy_of_region, copy_of_region->layer() + top);
+                                }
+                                pos += shift;
+                        }
+                }
+        }
+
+        return 0;
+ }
+
+
+ void
+ Playlist::duplicate (boost::shared_ptr<Region> region, framepos_t position, float times)
+ {
+        times = fabs (times);
+
+        RegionWriteLock rl (this);
+        int itimes = (int) floor (times);
+        framepos_t pos = position + 1;
+
+        while (itimes--) {
+                boost::shared_ptr<Region> copy = RegionFactory::create (region, true);
+                add_region_internal (copy, pos);
+                set_layer (copy, DBL_MAX);
+                pos += region->length();
+        }
+
+        if (floor (times) != times) {
+                framecnt_t length = (framecnt_t) floor (region->length() * (times - floor (times)));
+                string name;
+                RegionFactory::region_name (name, region->name(), false);
+
+                {
+                        PropertyList plist;
+
+                        plist.add (Properties::start, region->start());
+                        plist.add (Properties::length, length);
+                        plist.add (Properties::name, name);
+
+                        boost::shared_ptr<Region> sub = RegionFactory::create (region, plist);
+                        add_region_internal (sub, pos);
+                        set_layer (sub, DBL_MAX);
+                }
+        }
+ }
+
+ void
+ Playlist::shift (framepos_t at, frameoffset_t distance, bool move_intersected, bool ignore_music_glue)
+ {
+        RegionWriteLock rlock (this);
+        RegionList copy (regions.rlist());
+        RegionList fixup;
+
+        for (RegionList::iterator r = copy.begin(); r != copy.end(); ++r) {
+
+                if ((*r)->last_frame() < at) {
+                        /* too early */
+                        continue;
+                }
+
+                if (at > (*r)->first_frame() && at < (*r)->last_frame()) {
+                        /* intersected region */
+                        if (!move_intersected) {
+                                continue;
+                        }
+                }
+
+                /* do not move regions glued to music time - that
+                   has to be done separately.
+                */
+
+                if (!ignore_music_glue && (*r)->position_lock_style() != AudioTime) {
+                        fixup.push_back (*r);
+                        continue;
+                }
+
+                (*r)->set_position ((*r)->position() + distance);
+        }
+
+        /* XXX: may not be necessary; Region::post_set should do this, I think */
+        for (RegionList::iterator r = fixup.begin(); r != fixup.end(); ++r) {
+                (*r)->recompute_position_from_lock_style ();
+        }
+ }
+
+ void
+ Playlist::split (framepos_t at)
+ {
+        RegionWriteLock rlock (this);
+        RegionList copy (regions.rlist());
+
+        /* use a copy since this operation can modify the region list
+         */
+
+        for (RegionList::iterator r = copy.begin(); r != copy.end(); ++r) {
+                _split_region (*r, at);
+        }
+ }
+
+ void
+ Playlist::split_region (boost::shared_ptr<Region> region, framepos_t playlist_position)
+ {
+        RegionWriteLock rl (this);
+        _split_region (region, playlist_position);
+ }
+
+ void
+ Playlist::_split_region (boost::shared_ptr<Region> region, framepos_t playlist_position)
+ {
+        if (!region->covers (playlist_position)) {
+                return;
+        }
+
+        if (region->position() == playlist_position ||
+            region->last_frame() == playlist_position) {
+                return;
+        }
+
+        boost::shared_ptr<Region> left;
+        boost::shared_ptr<Region> right;
+        frameoffset_t before;
+        frameoffset_t after;
+        string before_name;
+        string after_name;
+
+        /* split doesn't change anything about length, so don't try to splice */
+
+        bool old_sp = _splicing;
+        _splicing = true;
+
+        before = playlist_position - region->position();
+        after = region->length() - before;
+
+        RegionFactory::region_name (before_name, region->name(), false);
+
+        {
+                PropertyList plist;
+
+                plist.add (Properties::position, region->position ());
+                plist.add (Properties::length, before);
+                plist.add (Properties::name, before_name);
+                plist.add (Properties::left_of_split, true);
+                plist.add (Properties::layering_index, region->layering_index ());
+                plist.add (Properties::layer, region->layer ());
+
+                /* note: we must use the version of ::create with an offset here,
+                   since it supplies that offset to the Region constructor, which
+                   is necessary to get audio region gain envelopes right.
+                */
+                left = RegionFactory::create (region, 0, plist);
+        }
+
+        RegionFactory::region_name (after_name, region->name(), false);
+
+        {
+                PropertyList plist;
+
+                plist.add (Properties::position, region->position() + before);
+                plist.add (Properties::length, after);
+                plist.add (Properties::name, after_name);
+                plist.add (Properties::right_of_split, true);
+                plist.add (Properties::layering_index, region->layering_index ());
+                plist.add (Properties::layer, region->layer ());
+
+                /* same note as above */
+                right = RegionFactory::create (region, before, plist);
+        }
+
+        add_region_internal (left, region->position());
+        add_region_internal (right, region->position() + before);
+        remove_region_internal (region);
+
+        _splicing = old_sp;
+ }
+
+ void
+ Playlist::possibly_splice (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
+ {
+        if (_splicing || in_set_state) {
+                /* don't respond to splicing moves or state setting */
+                return;
+        }
+
+        if (_edit_mode == Splice) {
+                splice_locked (at, distance, exclude);
+        }
+ }
+
+ void
+ Playlist::possibly_splice_unlocked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
+ {
+        if (_splicing || in_set_state) {
+                /* don't respond to splicing moves or state setting */
+                return;
+        }
+
+        if (_edit_mode == Splice) {
+                splice_unlocked (at, distance, exclude);
+        }
+ }
+
+ void
+ Playlist::splice_locked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
+ {
+        {
+                RegionWriteLock rl (this);
+                core_splice (at, distance, exclude);
+        }
+ }
+
+ void
+ Playlist::splice_unlocked (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
+ {
+        core_splice (at, distance, exclude);
+ }
+
+ void
+ Playlist::core_splice (framepos_t at, framecnt_t distance, boost::shared_ptr<Region> exclude)
+ {
+        _splicing = true;
+
+        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+
+                if (exclude && (*i) == exclude) {
+                        continue;
+                }
+
+                if ((*i)->position() >= at) {
+                        framepos_t new_pos = (*i)->position() + distance;
+                        if (new_pos < 0) {
+                                new_pos = 0;
+                        } else if (new_pos >= max_framepos - (*i)->length()) {
+                                new_pos = max_framepos - (*i)->length();
+                        }
+
+                        (*i)->set_position (new_pos);
+                }
+        }
+
+        _splicing = false;
+
+        notify_contents_changed ();
+ }
+
+ void
+ Playlist::region_bounds_changed (const PropertyChange& what_changed, boost::shared_ptr<Region> region)
+ {
+        if (in_set_state || _splicing || _nudging || _shuffling) {
+                return;
+        }
+
+        if (what_changed.contains (Properties::position)) {
+
+                /* remove it from the list then add it back in
+                   the right place again.
+                */
+
+                RegionSortByPosition cmp;
+
+                RegionList::iterator i = find (regions.begin(), regions.end(), region);
+
+                if (i == regions.end()) {
+                        /* the region bounds are being modified but its not currently
+                           in the region list. we will use its bounds correctly when/if
+                           it is added
+                        */
+                        return;
+                }
+
+                regions.erase (i);
+                regions.insert (upper_bound (regions.begin(), regions.end(), region, cmp), region);
+        }
+
+        if (what_changed.contains (Properties::position) || what_changed.contains (Properties::length)) {
+
+                frameoffset_t delta = 0;
+
+                if (what_changed.contains (Properties::position)) {
+                        delta = region->position() - region->last_position();
+                }
+
+                if (what_changed.contains (Properties::length)) {
+                        delta += region->length() - region->last_length();
+                }
+
+                if (delta) {
+                        possibly_splice (region->last_position() + region->last_length(), delta, region);
+                }
+
+                if (holding_state ()) {
+                        pending_bounds.push_back (region);
+                } else {
+                        notify_contents_changed ();
+                        relayer ();
+                        list<Evoral::Range<framepos_t> > xf;
+                        xf.push_back (Evoral::Range<framepos_t> (region->last_range()));
+                        xf.push_back (Evoral::Range<framepos_t> (region->range()));
+                        coalesce_and_check_crossfades (xf);
+                }
+        }
+ }
+
+ void
+ Playlist::region_changed_proxy (const PropertyChange& what_changed, boost::weak_ptr<Region> weak_region)
+ {
+        boost::shared_ptr<Region> region (weak_region.lock());
+
+        if (!region) {
+                return;
+        }
+
+        /* this makes a virtual call to the right kind of playlist ... */
+
+        region_changed (what_changed, region);
+ }
+
+ bool
+ Playlist::region_changed (const PropertyChange& what_changed, boost::shared_ptr<Region> region)
+ {
+        PropertyChange our_interests;
+        PropertyChange bounds;
+        PropertyChange pos_and_length;
+        bool save = false;
+
+        if (in_set_state || in_flush) {
+                return false;
+        }
+
+        our_interests.add (Properties::muted);
+        our_interests.add (Properties::layer);
+        our_interests.add (Properties::opaque);
+
+        bounds.add (Properties::start);
+        bounds.add (Properties::position);
+        bounds.add (Properties::length);
+
+        pos_and_length.add (Properties::position);
+        pos_and_length.add (Properties::length);
+
+        if (what_changed.contains (bounds)) {
+                region_bounds_changed (what_changed, region);
+                save = !(_splicing || _nudging);
+        }
+
+        if (what_changed.contains (Properties::position) && !what_changed.contains (Properties::length)) {
+                notify_region_moved (region);
+        } else if (!what_changed.contains (Properties::position) && what_changed.contains (Properties::length)) {
+                notify_region_end_trimmed (region);
+        } else if (what_changed.contains (Properties::position) && what_changed.contains (Properties::length)) {
+                notify_region_start_trimmed (region);
+        }
+
+        /* don't notify about layer changes, since we are the only object that can initiate
+           them, and we notify in ::relayer()
+        */
 
-                       } else if (overlap == OverlapStart) {
+        if (what_changed.contains (our_interests)) {
+                save = true;
+        }
 
-                               /* split: we need 2 regions: the front and the end.
-                                  cut: just trim current to skip the cut area
-                               */
+        return save;
+ }
 
-                               /*
-                                                       start           end
-                                   ---------------*************************------------
-                                      P2          P1 P3                   P4
+ void
+ Playlist::drop_regions ()
+ {
+        RegionWriteLock rl (this);
+        regions.clear ();
+        all_regions.clear ();
+ }
 
-                                   SPLIT:
-                                   ---------------****+++++++++++++++++++++------------
-                                   CUT:
-                                   -------------------*********************------------
+ void
+ Playlist::sync_all_regions_with_regions ()
+ {
+        RegionWriteLock rl (this);
 
-                               */
+        all_regions.clear ();
 
-                               if (!cutting) {
-                                       /* front **** */
-                                       _session.region_name (new_name, current->name(), false);
-                                       region = RegionFactory::create (current, 0, pos3 - pos1, new_name,
-                                                                       regions.size(), Region::Flag(current->flags()|Region::Automatic|Region::RightOfSplit));
+        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+                all_regions.insert (*i);
+        }
+ }
 
-                                       add_region_internal (region, pos1);
-                                       new_regions.push_back (region);
-                               }
+ void
+ Playlist::clear (bool with_signals)
+ {
+        {
+                RegionWriteLock rl (this);
 
-                               /* end */
+                region_state_changed_connections.drop_connections ();
 
-                               current->freeze ();
-                               thawlist.push_back (current);
-                               current->trim_front (pos3, this);
-                       } else if (overlap == OverlapExternal) {
+                for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+                        pending_removes.insert (*i);
+                }
 
-                               /* split: no split required.
-                                  cut: remove the region.
-                               */
+                regions.clear ();
 
-                               /*
-                                      start                                      end
-                                   ---------------*************************------------
-                                      P2          P1 P3                   P4
+                for (set<boost::shared_ptr<Region> >::iterator s = pending_removes.begin(); s != pending_removes.end(); ++s) {
+                        remove_dependents (*s);
+                }
+        }
 
-                                   SPLIT:
-                                   ---------------*************************------------
-                                   CUT:
-                                   ----------------------------------------------------
+        if (with_signals) {
 
-                               */
+                for (set<boost::shared_ptr<Region> >::iterator s = pending_removes.begin(); s != pending_removes.end(); ++s) {
+                        RegionRemoved (boost::weak_ptr<Region> (*s)); /* EMIT SIGNAL */
+                }
 
-                               if (cutting) {
-                                       remove_region_internal (current);
-                               }
+                pending_removes.clear ();
+                pending_contents_change = false;
+                ContentsChanged ();
+        }
 
-                               new_regions.push_back (current);
-                       }
-               }
+ }
 
-               in_partition = false;
-       }
+ /***********************************************************************
+  FINDING THINGS
+  **********************************************************************/
 
-       for (RegionList::iterator i = new_regions.begin(); i != new_regions.end(); ++i) {
-               check_dependents (*i, false);
-       }
+boost::shared_ptr<RegionList>
+Playlist::regions_at (framepos_t frame)
+{
+       RegionReadLock rlock (this);
+       return find_regions_at (frame);
 }
 
-boost::shared_ptr<Playlist>
-Playlist::cut_copy (boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t, nframes_t,bool), list<AudioRange>& ranges, bool result_is_hidden)
-{
-       boost::shared_ptr<Playlist> ret;
-       boost::shared_ptr<Playlist> pl;
-       nframes_t start;
+ uint32_t
+ Playlist::count_regions_at (framepos_t frame) const
+ {
+        RegionReadLock rlock (const_cast<Playlist*>(this));
+        uint32_t cnt = 0;
 
-       if (ranges.empty()) {
-               return boost::shared_ptr<Playlist>();
-       }
+        for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
+                if ((*i)->covers (frame)) {
+                        cnt++;
+                }
+        }
 
-       start = ranges.front().start;
+        return cnt;
+ }
 
-       for (list<AudioRange>::iterator i = ranges.begin(); i != ranges.end(); ++i) {
+ boost::shared_ptr<Region>
+ Playlist::top_region_at (framepos_t frame)
 
-               pl = (this->*pmf)((*i).start, (*i).length(), result_is_hidden);
+ {
+        RegionReadLock rlock (this);
+        boost::shared_ptr<RegionList> rlist = find_regions_at (frame);
+        boost::shared_ptr<Region> region;
 
-               if (i == ranges.begin()) {
-                       ret = pl;
-               } else {
+        if (rlist->size()) {
+                RegionSortByLayer cmp;
+                rlist->sort (cmp);
+                region = rlist->back();
+        }
 
-                       /* paste the next section into the nascent playlist,
-                          offset to reflect the start of the first range we
-                          chopped.
-                       */
+        return region;
+ }
 
-                       ret->paste (pl, (*i).start - start, 1.0f);
-               }
-       }
+ boost::shared_ptr<Region>
+ Playlist::top_unmuted_region_at (framepos_t frame)
 
-       return ret;
-}
+ {
+        RegionReadLock rlock (this);
+        boost::shared_ptr<RegionList> rlist = find_regions_at (frame);
 
-boost::shared_ptr<Playlist>
-Playlist::cut (list<AudioRange>& ranges, bool result_is_hidden)
-{
-       boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t,nframes_t,bool) = &Playlist::cut;
-       return cut_copy (pmf, ranges, result_is_hidden);
-}
+        for (RegionList::iterator i = rlist->begin(); i != rlist->end(); ) {
 
-boost::shared_ptr<Playlist>
-Playlist::copy (list<AudioRange>& ranges, bool result_is_hidden)
-{
-       boost::shared_ptr<Playlist> (Playlist::*pmf)(nframes_t,nframes_t,bool) = &Playlist::copy;
-       return cut_copy (pmf, ranges, result_is_hidden);
-}
+                RegionList::iterator tmp = i;
+                ++tmp;
 
-boost::shared_ptr<Playlist>
-Playlist::cut (nframes_t start, nframes_t cnt, bool result_is_hidden)
-{
-       boost::shared_ptr<Playlist> the_copy;
-       RegionList thawlist;
-       char buf[32];
+                if ((*i)->muted()) {
+                        rlist->erase (i);
+                }
 
-       snprintf (buf, sizeof (buf), "%" PRIu32, ++subcnt);
-       string new_name = _name;
-       new_name += '.';
-       new_name += buf;
+                i = tmp;
+        }
 
-       if ((the_copy = PlaylistFactory::create (shared_from_this(), start, cnt, new_name, result_is_hidden)) == 0) {
-               return boost::shared_ptr<Playlist>();
-       }
+        boost::shared_ptr<Region> region;
 
-       partition_internal (start, start+cnt-1, true, thawlist);
+        if (rlist->size()) {
+                RegionSortByLayer cmp;
+                rlist->sort (cmp);
+                region = rlist->back();
+        }
 
-       for (RegionList::iterator i = thawlist.begin(); i != thawlist.end(); ++i) {
-               (*i)->thaw ("playlist cut");
-       }
+        return region;
+ }
 
-       return the_copy;
+boost::shared_ptr<RegionList>
+Playlist::find_regions_at (framepos_t frame)
+{
+       /* Caller must hold lock */
+       
+       boost::shared_ptr<RegionList> rlist (new RegionList);
+       
+       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+               if ((*i)->covers (frame)) {
+                       rlist->push_back (*i);
+               }
+       }
+       
+       return rlist;
 }
 
-boost::shared_ptr<Playlist>
-Playlist::copy (nframes_t start, nframes_t cnt, bool result_is_hidden)
+boost::shared_ptr<RegionList>
+Playlist::regions_with_start_within (Evoral::Range<framepos_t> range)
 {
-       char buf[32];
+       RegionReadLock rlock (this);
+       boost::shared_ptr<RegionList> rlist (new RegionList);
 
-       snprintf (buf, sizeof (buf), "%" PRIu32, ++subcnt);
-       string new_name = _name;
-       new_name += '.';
-       new_name += buf;
+       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+               if ((*i)->first_frame() >= range.from && (*i)->first_frame() <= range.to) {
+                       rlist->push_back (*i);
+               }
+       }
 
-       cnt = min (_get_maximum_extent() - start, cnt);
-       return PlaylistFactory::create (shared_from_this(), start, cnt, new_name, result_is_hidden);
+       return rlist;
 }
 
-int
-Playlist::paste (boost::shared_ptr<Playlist> other, nframes_t position, float times)
+boost::shared_ptr<RegionList>
+Playlist::regions_with_end_within (Evoral::Range<framepos_t> range)
 {
-       times = fabs (times);
-       nframes_t old_length;
+       RegionReadLock rlock (this);
+       boost::shared_ptr<RegionList> rlist (new RegionList);
 
-       {
-               RegionLock rl1 (this);
-               RegionLock rl2 (other.get());
+       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+               if ((*i)->last_frame() >= range.from && (*i)->last_frame() <= range.to) {
+                       rlist->push_back (*i);
+               }
+       }
 
-               old_length = _get_maximum_extent();
+       return rlist;
+}
 
-               int itimes = (int) floor (times);
-               nframes_t pos = position;
-               nframes_t shift = other->_get_maximum_extent();
-               layer_t top_layer = regions.size();
-
-               while (itimes--) {
-                       for (RegionList::iterator i = other->regions.begin(); i != other->regions.end(); ++i) {
-                               boost::shared_ptr<Region> copy_of_region = RegionFactory::create (*i);
-
-                               /* put these new regions on top of all existing ones, but preserve
-                                  the ordering they had in the original playlist.
-                               */
-
-                               copy_of_region->set_layer (copy_of_region->layer() + top_layer);
-                               add_region_internal (copy_of_region, copy_of_region->position() + pos);
-                       }
-                       pos += shift;
-               }
-
-
-               /* XXX shall we handle fractional cases at some point? */
-
-               if (old_length != _get_maximum_extent()) {
-                       notify_length_changed ();
-               }
-
-
-       }
-
-       return 0;
-}
-
-
-void
-Playlist::duplicate (boost::shared_ptr<Region> region, nframes_t position, float times)
-{
-       times = fabs (times);
-
-       RegionLock rl (this);
-       int itimes = (int) floor (times);
-       nframes_t pos = position;
-
-       while (itimes--) {
-               boost::shared_ptr<Region> copy = RegionFactory::create (region);
-               add_region_internal (copy, pos);
-               pos += region->length();
-       }
-
-       if (floor (times) != times) {
-               nframes_t length = (nframes_t) floor (region->length() * (times - floor (times)));
-               string name;
-               _session.region_name (name, region->name(), false);
-               boost::shared_ptr<Region> sub = RegionFactory::create (region, 0, length, name, region->layer(), region->flags());
-               add_region_internal (sub, pos);
-       }
-}
-
-void
-Playlist::shift (nframes64_t at, nframes64_t distance, bool move_intersected, bool ignore_music_glue)
-{
-       RegionLock rlock (this);
-       RegionList copy (regions);
-       RegionList fixup;
-
-       for (RegionList::iterator r = copy.begin(); r != copy.end(); ++r) {
-
-               if ((*r)->last_frame() < at) {
-                       /* too early */
-                       continue;
-               }
-
-               if (at > (*r)->first_frame() && at < (*r)->last_frame()) {
-                       /* intersected region */
-                       if (!move_intersected) {
-                               continue;
-                       }
-               }
-
-               /* do not move regions glued to music time - that
-                  has to be done separately.
-               */
-
-               if (!ignore_music_glue && (*r)->positional_lock_style() != Region::AudioTime) {
-                       fixup.push_back (*r);
-                       continue;
-               }
-
-               (*r)->set_position ((*r)->position() + distance, this);
-       }
-
-       for (RegionList::iterator r = fixup.begin(); r != fixup.end(); ++r) {
-               (*r)->recompute_position_from_lock_style ();
-       }
-}
-
-void
-Playlist::split (nframes64_t at)
-{
-       RegionLock rlock (this);
-       RegionList copy (regions);
-
-       /* use a copy since this operation can modify the region list
-        */
-
-       for (RegionList::iterator r = copy.begin(); r != copy.end(); ++r) {
-               _split_region (*r, at);
-       }
-}
-
-void
-Playlist::split_region (boost::shared_ptr<Region> region, nframes_t playlist_position)
-{
-       RegionLock rl (this);
-       _split_region (region, playlist_position);
-}
-
-void
-Playlist::_split_region (boost::shared_ptr<Region> region, nframes_t playlist_position)
-{
-       if (!region->covers (playlist_position)) {
-               return;
-       }
-
-       if (region->position() == playlist_position ||
-           region->last_frame() == playlist_position) {
-               return;
-       }
-
-       boost::shared_ptr<Region> left;
-       boost::shared_ptr<Region> right;
-       nframes_t before;
-       nframes_t after;
-       string before_name;
-       string after_name;
-
-       /* split doesn't change anything about length, so don't try to splice */
-
-       bool old_sp = _splicing;
-       _splicing = true;
-
-       before = playlist_position - region->position();
-       after = region->length() - before;
-
-       _session.region_name (before_name, region->name(), false);
-       left = RegionFactory::create (region, 0, before, before_name, region->layer(), Region::Flag (region->flags()|Region::LeftOfSplit));
-
-       _session.region_name (after_name, region->name(), false);
-       right = RegionFactory::create (region, before, after, after_name, region->layer(), Region::Flag (region->flags()|Region::RightOfSplit));
-
-       add_region_internal (left, region->position());
-       add_region_internal (right, region->position() + before);
-
-       uint64_t orig_layer_op = region->last_layer_op();
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-               if ((*i)->last_layer_op() > orig_layer_op) {
-                       (*i)->set_last_layer_op( (*i)->last_layer_op() + 1 );
-               }
-       }
-
-       left->set_last_layer_op ( orig_layer_op );
-       right->set_last_layer_op ( orig_layer_op + 1);
-
-       layer_op_counter++;
-
-       finalize_split_region (region, left, right);
-
-       remove_region_internal (region);
-
-       _splicing = old_sp;
-}
-
-void
-Playlist::possibly_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
-{
-       if (_splicing || in_set_state) {
-               /* don't respond to splicing moves or state setting */
-               return;
-       }
-
-       if (_edit_mode == Splice) {
-               splice_locked (at, distance, exclude);
-       }
-}
-
-void
-Playlist::possibly_splice_unlocked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
-{
-       if (_splicing || in_set_state) {
-               /* don't respond to splicing moves or state setting */
-               return;
-       }
-
-       if (_edit_mode == Splice) {
-               splice_unlocked (at, distance, exclude);
-       }
-}
-
-void
-Playlist::splice_locked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
-{
-       {
-               RegionLock rl (this);
-               core_splice (at, distance, exclude);
-       }
-}
-
-void
-Playlist::splice_unlocked (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
-{
-       core_splice (at, distance, exclude);
-}
-
-void
-Playlist::core_splice (nframes_t at, nframes64_t distance, boost::shared_ptr<Region> exclude)
-{
-       _splicing = true;
-
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-
-               if (exclude && (*i) == exclude) {
-                       continue;
-               }
-
-               if ((*i)->position() >= at) {
-                       nframes64_t new_pos = (*i)->position() + distance;
-                       if (new_pos < 0) {
-                               new_pos = 0;
-                       } else if (new_pos >= max_frames - (*i)->length()) {
-                               new_pos = max_frames - (*i)->length();
-                       }
-
-                       (*i)->set_position (new_pos, this);
-               }
-       }
-
-       _splicing = false;
-
-       notify_length_changed ();
-}
-
-void
-Playlist::region_bounds_changed (Change what_changed, boost::shared_ptr<Region> region)
-{
-       if (in_set_state || _splicing || _nudging || _shuffling) {
-               return;
-       }
-
-       if (what_changed & ARDOUR::PositionChanged) {
-
-               /* remove it from the list then add it back in
-                  the right place again.
-               */
-
-               RegionSortByPosition cmp;
-
-               RegionList::iterator i = find (regions.begin(), regions.end(), region);
-
-               if (i == regions.end()) {
-                       warning << string_compose (_("%1: bounds changed received for region (%2)not in playlist"),
-                                           _name, region->name())
-                               << endmsg;
-                       return;
-               }
-
-               regions.erase (i);
-               regions.insert (upper_bound (regions.begin(), regions.end(), region, cmp), region);
-       }
-
-       if (what_changed & Change (ARDOUR::PositionChanged|ARDOUR::LengthChanged)) {
-
-               nframes64_t delta = 0;
-
-               if (what_changed & ARDOUR::PositionChanged) {
-                       delta = (nframes64_t) region->position() - (nframes64_t) region->last_position();
-               }
-
-               if (what_changed & ARDOUR::LengthChanged) {
-                       delta += (nframes64_t) region->length() - (nframes64_t) region->last_length();
-               }
-
-               if (delta) {
-                       possibly_splice (region->last_position() + region->last_length(), delta, region);
-               }
-
-               if (holding_state ()) {
-                       pending_bounds.push_back (region);
-               } else {
-                       if (_session.config.get_layer_model() == MoveAddHigher) {
-                               /* it moved or changed length, so change the timestamp */
-                               timestamp_layer_op (region);
-                       }
-
-                       notify_length_changed ();
-                       relayer ();
-                       check_dependents (region, false);
-               }
-       }
-}
-
-void
-Playlist::region_changed_proxy (Change what_changed, boost::weak_ptr<Region> weak_region)
-{
-       boost::shared_ptr<Region> region (weak_region.lock());
-
-       if (!region) {
-               return;
-       }
-
-
-       /* this makes a virtual call to the right kind of playlist ... */
-
-       region_changed (what_changed, region);
-}
-
-bool
-Playlist::region_changed (Change what_changed, boost::shared_ptr<Region> region)
-{
-       Change our_interests = Change (Region::MuteChanged|Region::LayerChanged|Region::OpacityChanged);
-       bool save = false;
-
-       if (in_set_state || in_flush) {
-               return false;
-       }
-
-       if (what_changed & BoundsChanged) {
-               region_bounds_changed (what_changed, region);
-               save = !(_splicing || _nudging);
-       }
-
-       if ((what_changed & our_interests) &&
-           !(what_changed & Change (ARDOUR::PositionChanged|ARDOUR::LengthChanged))) {
-               check_dependents (region, false);
-       }
-
-       if (what_changed & Change (ARDOUR::PositionChanged)) {
-               notify_region_moved (region);
-       }
-
-       if (what_changed & our_interests) {
-               save = true;
-       }
-
-       return save;
-}
-
-void
-Playlist::drop_regions ()
-{
-       RegionLock rl (this);
-       regions.clear ();
-       all_regions.clear ();
-}
-
-void
-Playlist::clear (bool with_signals)
-{
-       {
-               RegionLock rl (this);
-
-               for (
-                       std::list<sigc::connection>::iterator i = region_state_changed_connections.begin ();
-                       i != region_state_changed_connections.end ();
-                       ++i
-               ) {
-                       i->disconnect ();
-               }
-
-               for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-                       pending_removes.insert (*i);
-               }
-
-               regions.clear ();
-       }
-
-       if (with_signals) {
-               pending_length = false;
-               LengthChanged ();
-               pending_modified = false;
-               Modified ();
-       }
-
-}
-
-/***********************************************************************
- FINDING THINGS
- **********************************************************************/
-
-Playlist::RegionList *
-Playlist::regions_at (nframes_t frame)
-
-{
-       RegionLock rlock (this);
-       return find_regions_at (frame);
-}
-
-boost::shared_ptr<Region>
-Playlist::top_region_at (nframes_t frame)
-
-{
-       RegionLock rlock (this);
-       RegionList *rlist = find_regions_at (frame);
-       boost::shared_ptr<Region> region;
-
-       if (rlist->size()) {
-               RegionSortByLayer cmp;
-               rlist->sort (cmp);
-               region = rlist->back();
-       }
-
-       delete rlist;
-       return region;
-}
-
-boost::shared_ptr<Region>
-Playlist::top_unmuted_region_at (nframes_t frame)
-
-{
-       RegionLock rlock (this);
-       RegionList *rlist = find_regions_at (frame);
-
-       for (RegionList::iterator i = rlist->begin(); i != rlist->end(); ) {
-
-               RegionList::iterator tmp = i;
-               ++tmp;
-
-               if ((*i)->muted()) {
-                       rlist->erase (i);
-               }
-
-               i = tmp;
-       }
-
-       boost::shared_ptr<Region> region;
-
-       if (rlist->size()) {
-               RegionSortByLayer cmp;
-               rlist->sort (cmp);
-               region = rlist->back();
-       }
-
-       delete rlist;
-       return region;
-}
-
-Playlist::RegionList*
-Playlist::regions_to_read (nframes_t start, nframes_t end)
-{
-       /* Caller must hold lock */
-
-       RegionList covering;
-       set<nframes_t> to_check;
-       set<boost::shared_ptr<Region> > unique;
-       RegionList here;
-
-       to_check.insert (start);
-       to_check.insert (end);
-
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-
-               /* find all/any regions that span start+end */
-
-               switch ((*i)->coverage (start, end)) {
-               case OverlapNone:
-                       break;
-
-               case OverlapInternal:
-                       covering.push_back (*i);
-                       break;
-
-               case OverlapStart:
-                       to_check.insert ((*i)->position());
-                       covering.push_back (*i);
-                       break;
-
-               case OverlapEnd:
-                       to_check.insert ((*i)->last_frame());
-                       covering.push_back (*i);
-                       break;
-
-               case OverlapExternal:
-                       covering.push_back (*i);
-                       to_check.insert ((*i)->position());
-                       to_check.insert ((*i)->last_frame());
-                       break;
-               }
-
-               /* don't go too far */
-
-               if ((*i)->position() > end) {
-                       break;
-               }
-       }
-
-       RegionList* rlist = new RegionList;
-
-       /* find all the regions that cover each position .... */
-
-       if (covering.size() == 1) {
-
-               rlist->push_back (covering.front());
-
-       } else {
-
-               for (set<nframes_t>::iterator t = to_check.begin(); t != to_check.end(); ++t) {
-
-                       here.clear ();
-
-                       for (RegionList::iterator x = covering.begin(); x != covering.end(); ++x) {
-
-                               if ((*x)->covers (*t)) {
-                                       here.push_back (*x);
-                               }
-                       }
-
-                       RegionSortByLayer cmp;
-                       here.sort (cmp);
-
-                       /* ... and get the top/transparent regions at "here" */
-
-                       for (RegionList::reverse_iterator c = here.rbegin(); c != here.rend(); ++c) {
-
-                               unique.insert (*c);
-
-                               if ((*c)->opaque()) {
-
-                                       /* the other regions at this position are hidden by this one */
-
-                                       break;
-                               }
-                       }
-               }
-
-               for (set<boost::shared_ptr<Region> >::iterator s = unique.begin(); s != unique.end(); ++s) {
-                       rlist->push_back (*s);
-               }
-
-               if (rlist->size() > 1) {
-                       /* now sort by time order */
-
-                       RegionSortByPosition cmp;
-                       rlist->sort (cmp);
-               }
-       }
-
-       return rlist;
-}
-
-Playlist::RegionList *
-Playlist::find_regions_at (nframes_t frame)
+/** @param start Range start.
+ *  @param end Range end.
+ *  @return regions which have some part within this range.
+ */
+boost::shared_ptr<RegionList>
+Playlist::regions_touched (framepos_t start, framepos_t end)
 {
-       /* Caller must hold lock */
-
-       RegionList *rlist = new RegionList;
-
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-               if ((*i)->covers (frame)) {
-                       rlist->push_back (*i);
-               }
-       }
-
-       return rlist;
+       RegionReadLock rlock (this);
+       return regions_touched_locked (start, end);
 }
 
-Playlist::RegionList *
-Playlist::regions_touched (nframes_t start, nframes_t end)
+boost::shared_ptr<RegionList>
+Playlist::regions_touched_locked (framepos_t start, framepos_t end)
 {
-       RegionLock rlock (this);
-       RegionList *rlist = new RegionList;
-
+       boost::shared_ptr<RegionList> rlist (new RegionList);
+       
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-               if ((*i)->coverage (start, end) != OverlapNone) {
+               if ((*i)->coverage (start, end) != Evoral::OverlapNone) {
                        rlist->push_back (*i);
                }
        }
-
+       
        return rlist;
 }
 
-nframes64_t
-Playlist::find_next_transient (nframes64_t from, int dir)
+framepos_t
+Playlist::find_next_transient (framepos_t from, int dir)
 {
-       RegionLock rlock (this);
+       RegionReadLock rlock (this);
        AnalysisFeatureList points;
        AnalysisFeatureList these_points;
-
+       
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
                if (dir > 0) {
                        if ((*i)->last_frame() < from) {
@@ -1602,30 +1790,30 @@ Playlist::find_next_transient (nframes64_t from, int dir)
                                continue;
                        }
                }
-
+               
                (*i)->get_transients (these_points);
-
+               
                /* add first frame, just, err, because */
-
+               
                these_points.push_back ((*i)->first_frame());
-
+               
                points.insert (points.end(), these_points.begin(), these_points.end());
                these_points.clear ();
        }
-
+       
        if (points.empty()) {
                return -1;
        }
-
+       
        TransientDetector::cleanup_transients (points, _session.frame_rate(), 3.0);
        bool reached = false;
-
+       
        if (dir > 0) {
                for (AnalysisFeatureList::iterator x = points.begin(); x != points.end(); ++x) {
                        if ((*x) >= from) {
                                reached = true;
                        }
-
+                       
                        if (reached && (*x) > from) {
                                return *x;
                        }
@@ -1635,33 +1823,33 @@ Playlist::find_next_transient (nframes64_t from, int dir)
                        if ((*x) <= from) {
                                reached = true;
                        }
-
+                       
                        if (reached && (*x) < from) {
                                return *x;
                        }
                }
        }
-
+       
        return -1;
 }
 
 boost::shared_ptr<Region>
-Playlist::find_next_region (nframes_t frame, RegionPoint point, int dir)
+Playlist::find_next_region (framepos_t frame, RegionPoint point, int dir)
 {
-       RegionLock rlock (this);
+       RegionReadLock rlock (this);
        boost::shared_ptr<Region> ret;
-       nframes_t closest = max_frames;
-
+       framepos_t closest = max_framepos;
+       
        bool end_iter = false;
-
+       
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-
+               
                if(end_iter) break;
-
-               nframes_t distance;
+               
+               frameoffset_t distance;
                boost::shared_ptr<Region> r = (*i);
-               nframes_t pos = 0;
-
+               framepos_t pos = 0;
+               
                switch (point) {
                case Start:
                        pos = r->first_frame ();
@@ -1671,13 +1859,12 @@ Playlist::find_next_region (nframes_t frame, RegionPoint point, int dir)
                        break;
                case SyncPoint:
                        pos = r->sync_position ();
-                       // r->adjust_to_sync (r->first_frame());
                        break;
                }
-
+               
                switch (dir) {
                case 1: /* forwards */
-
+                       
                        if (pos > frame) {
                                if ((distance = pos - frame) < closest) {
                                        closest = distance;
@@ -1685,199 +1872,244 @@ Playlist::find_next_region (nframes_t frame, RegionPoint point, int dir)
                                        end_iter = true;
                                }
                        }
-
+                       
                        break;
-
+                       
                default: /* backwards */
-
+                       
                        if (pos < frame) {
                                if ((distance = frame - pos) < closest) {
                                        closest = distance;
                                        ret = r;
                                }
-                       }
-                       else {
+                       } else {
                                end_iter = true;
                        }
-
+                       
                        break;
                }
        }
-
+       
        return ret;
 }
 
-nframes64_t
-Playlist::find_next_region_boundary (nframes64_t frame, int dir)
-{
-       RegionLock rlock (this);
+ framepos_t
+ Playlist::find_next_region_boundary (framepos_t frame, int dir)
+ {
+        RegionReadLock rlock (this);
 
-       nframes64_t closest = max_frames;
-       nframes64_t ret = -1;
+        framepos_t closest = max_framepos;
+        framepos_t ret = -1;
 
-       if (dir > 0) {
+        if (dir > 0) {
 
-               for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+                for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 
-                       boost::shared_ptr<Region> r = (*i);
-                       nframes64_t distance;
+                        boost::shared_ptr<Region> r = (*i);
+                        frameoffset_t distance;
 
-                       if (r->first_frame() > frame) {
+                        if (r->first_frame() > frame) {
 
-                               distance = r->first_frame() - frame;
+                                distance = r->first_frame() - frame;
 
-                               if (distance < closest) {
-                                       ret = r->first_frame();
-                                       closest = distance;
-                               }
-                       }
+                                if (distance < closest) {
+                                        ret = r->first_frame();
+                                        closest = distance;
+                                }
+                        }
 
-                       if (r->last_frame () > frame) {
+                        if (r->last_frame () > frame) {
 
-                               distance = r->last_frame () - frame;
+                                distance = r->last_frame () - frame;
 
-                               if (distance < closest) {
-                                       ret = r->last_frame ();
-                                       closest = distance;
-                               }
-                       }
-               }
+                                if (distance < closest) {
+                                        ret = r->last_frame ();
+                                        closest = distance;
+                                }
+                        }
+                }
 
-       } else {
+        } else {
 
-               for (RegionList::reverse_iterator i = regions.rbegin(); i != regions.rend(); ++i) {
+                for (RegionList::reverse_iterator i = regions.rbegin(); i != regions.rend(); ++i) {
 
-                       boost::shared_ptr<Region> r = (*i);
-                       nframes64_t distance;
+                        boost::shared_ptr<Region> r = (*i);
+                        frameoffset_t distance;
 
-                       if (r->last_frame() < frame) {
+                        if (r->last_frame() < frame) {
 
-                               distance = frame - r->last_frame();
+                                distance = frame - r->last_frame();
 
-                               if (distance < closest) {
-                                       ret = r->last_frame();
-                                       closest = distance;
-                               }
-                       }
+                                if (distance < closest) {
+                                        ret = r->last_frame();
+                                        closest = distance;
+                                }
+                        }
 
-                       if (r->first_frame() < frame) {
+                        if (r->first_frame() < frame) {
 
-                               distance = frame - r->first_frame();
+                                distance = frame - r->first_frame();
 
-                               if (distance < closest) {
-                                       ret = r->first_frame();
-                                       closest = distance;
-                               }
-                       }
-               }
-       }
+                                if (distance < closest) {
+                                        ret = r->first_frame();
+                                        closest = distance;
+                                }
+                        }
+                }
+        }
 
-       return ret;
-}
+        return ret;
+ }
 
-/***********************************************************************/
 
+ /***********************************************************************/
 
 
 
-void
-Playlist::mark_session_dirty ()
-{
-       if (!in_set_state && !holding_state ()) {
-               _session.set_dirty();
-       }
-}
 
-int
-Playlist::set_state (const XMLNode& node, int version)
-{
-       XMLNode *child;
-       XMLNodeList nlist;
-       XMLNodeConstIterator niter;
-       XMLPropertyList plist;
-       XMLPropertyConstIterator piter;
-       XMLProperty *prop;
-       boost::shared_ptr<Region> region;
-       string region_name;
+ void
+ Playlist::mark_session_dirty ()
+ {
+        if (!in_set_state && !holding_state ()) {
+                _session.set_dirty();
+        }
+ }
 
-       in_set_state++;
+ void
+ Playlist::rdiff (vector<Command*>& cmds) const
+ {
+        RegionReadLock rlock (const_cast<Playlist *> (this));
+        Stateful::rdiff (cmds);
+ }
 
-       if (node.name() != "Playlist") {
-               in_set_state--;
-               return -1;
-       }
+ void
+ Playlist::clear_owned_changes ()
+ {
+        RegionReadLock rlock (this);
+        Stateful::clear_owned_changes ();
+ }
 
-       freeze ();
+ void
+ Playlist::update (const RegionListProperty::ChangeRecord& change)
+ {
+        DEBUG_TRACE (DEBUG::Properties, string_compose ("Playlist %1 updates from a change record with %2 adds %3 removes\n",
+                                                        name(), change.added.size(), change.removed.size()));
 
-       plist = node.properties();
+        freeze ();
+        /* add the added regions */
+        for (RegionListProperty::ChangeContainer::const_iterator i = change.added.begin(); i != change.added.end(); ++i) {
+                add_region_internal ((*i), (*i)->position());
+        }
+        /* remove the removed regions */
+        for (RegionListProperty::ChangeContainer::const_iterator i = change.removed.begin(); i != change.removed.end(); ++i) {
+                remove_region (*i);
+        }
 
-       for (piter = plist.begin(); piter != plist.end(); ++piter) {
+        thaw ();
+ }
 
-               prop = *piter;
+ int
+ Playlist::set_state (const XMLNode& node, int version)
+ {
+        XMLNode *child;
+        XMLNodeList nlist;
+        XMLNodeConstIterator niter;
+        XMLPropertyList plist;
+        XMLPropertyConstIterator piter;
+        XMLProperty *prop;
+        boost::shared_ptr<Region> region;
+        string region_name;
+        bool seen_region_nodes = false;
+        int ret = 0;
 
-               if (prop->name() == X_("name")) {
-                       _name = prop->value();
-               } else if (prop->name() == X_("orig_diskstream_id")) {
-                       _orig_diskstream_id = prop->value ();
-               } else if (prop->name() == X_("frozen")) {
-                       _frozen = string_is_affirmative (prop->value());
-               }
-       }
+        in_set_state++;
 
-       clear (false);
+        if (node.name() != "Playlist") {
+                in_set_state--;
+                return -1;
+        }
 
-       nlist = node.children();
+        freeze ();
 
-       for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+        plist = node.properties();
 
-               child = *niter;
+        set_id (node);
 
-               if (child->name() == "Region") {
+        for (piter = plist.begin(); piter != plist.end(); ++piter) {
 
-                       if ((prop = child->property ("id")) == 0) {
-                               error << _("region state node has no ID, ignored") << endmsg;
-                               continue;
-                       }
+                prop = *piter;
 
-                       ID id = prop->value ();
+                if (prop->name() == X_("name")) {
+                        _name = prop->value();
+                        _set_sort_id ();
+                } else if (prop->name() == X_("orig-diskstream-id")) {
+                        /* XXX legacy session: fix up later */
+                        _orig_track_id = prop->value ();
+                } else if (prop->name() == X_("orig-track-id")) {
+                        _orig_track_id = prop->value ();
+                } else if (prop->name() == X_("frozen")) {
+                        _frozen = string_is_affirmative (prop->value());
+                } else if (prop->name() == X_("combine-ops")) {
+                        _combine_ops = atoi (prop->value());
+                }
+        }
 
-                       if ((region = region_by_id (id))) {
+        clear (true);
 
-                               Change what_changed = Change (0);
+        nlist = node.children();
 
-                               if (region->set_live_state (*child, version, what_changed, true)) {
-                                       error << _("Playlist: cannot reset region state from XML") << endmsg;
-                                       continue;
-                               }
+        for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
 
-                       } else if ((region = RegionFactory::create (_session, *child, true)) == 0) {
-                               error << _("Playlist: cannot create region from XML") << endmsg;
-                               continue;
-                       }
+                child = *niter;
 
-                       add_region (region, region->position(), 1.0);
+                if (child->name() == "Region") {
+
+                        seen_region_nodes = true;
+
+                        if ((prop = child->property ("id")) == 0) {
+                                error << _("region state node has no ID, ignored") << endmsg;
+                                continue;
+                        }
+
+                        ID id = prop->value ();
+
+                        if ((region = region_by_id (id))) {
+
+                                region->suspend_property_changes ();
+
+                                if (region->set_state (*child, version)) {
+                                        region->resume_property_changes ();
+                                        continue;
+                                }
+
+                        } else if ((region = RegionFactory::create (_session, *child, true)) != 0) {
+                                region->suspend_property_changes ();
+                        } else {
+                                error << _("Playlist: cannot create region from XML") << endmsg;
+                               return -1;
+                       }
 
-                       // So that layer_op ordering doesn't get screwed up
-                       region->set_last_layer_op( region->layer());
+                        {
+                                RegionWriteLock rlock (this);
+                                add_region_internal (region, region->position());
+                        }
+                       
+                       region->resume_property_changes ();
 
                }
        }
 
-       notify_modified ();
-
-       thaw ();
-
-       /* update dependents, which was not done during add_region_internal
-          due to in_set_state being true
-       */
-
-       for (RegionList::iterator r = regions.begin(); r != regions.end(); ++r) {
-               check_dependents (*r, false);
+       if (seen_region_nodes && regions.empty()) {
+               ret = -1;
        }
+               
+       thaw ();
+       notify_contents_changed ();
 
        in_set_state--;
        first_set_state = false;
-       return 0;
+
+       return ret;
 }
 
 XMLNode&
@@ -1900,15 +2132,20 @@ Playlist::state (bool full_state)
        XMLNode *node = new XMLNode (X_("Playlist"));
        char buf[64];
 
+       node->add_property (X_("id"), id().to_s());
        node->add_property (X_("name"), _name);
        node->add_property (X_("type"), _type.to_string());
 
-       _orig_diskstream_id.print (buf, sizeof (buf));
-       node->add_property (X_("orig_diskstream_id"), buf);
+       _orig_track_id.print (buf, sizeof (buf));
+       node->add_property (X_("orig-track-id"), buf);
        node->add_property (X_("frozen"), _frozen ? "yes" : "no");
 
        if (full_state) {
-               RegionLock rlock (this, false);
+               RegionReadLock rlock (this);
+
+               snprintf (buf, sizeof (buf), "%u", _combine_ops);
+               node->add_property ("combine-ops", buf);
+
                for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
                        node->add_child_nocopy ((*i)->get_state());
                }
@@ -1924,38 +2161,55 @@ Playlist::state (bool full_state)
 bool
 Playlist::empty() const
 {
-       RegionLock rlock (const_cast<Playlist *>(this), false);
+       RegionReadLock rlock (const_cast<Playlist *>(this));
        return regions.empty();
 }
 
 uint32_t
 Playlist::n_regions() const
 {
-       RegionLock rlock (const_cast<Playlist *>(this), false);
+       RegionReadLock rlock (const_cast<Playlist *>(this));
        return regions.size();
 }
 
-nframes_t
-Playlist::get_maximum_extent () const
+/** @return true if the all_regions list is empty, ie this playlist
+ *  has never had a region added to it.
+ */
+bool
+Playlist::all_regions_empty() const
+{
+       RegionReadLock rl (const_cast<Playlist *> (this));
+       return all_regions.empty();
+}
+
+pair<framepos_t, framepos_t>
+Playlist::get_extent () const
 {
-       RegionLock rlock (const_cast<Playlist *>(this), false);
-       return _get_maximum_extent ();
+       RegionReadLock rlock (const_cast<Playlist *>(this));
+       return _get_extent ();
 }
 
-ARDOUR::nframes_t
-Playlist::_get_maximum_extent () const
+pair<framepos_t, framepos_t>
+Playlist::_get_extent () const
 {
-       RegionList::const_iterator i;
-       nframes_t max_extent = 0;
-       nframes_t end = 0;
+       pair<framepos_t, framepos_t> ext (max_framepos, 0);
+
+       if (regions.empty()) {
+               ext.first = 0;
+               return ext;
+       }
 
-       for (i = regions.begin(); i != regions.end(); ++i) {
-               if ((end = (*i)->position() + (*i)->length()) > max_extent) {
-                       max_extent = end;
+       for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
+               pair<framepos_t, framepos_t> const e ((*i)->position(), (*i)->position() + (*i)->length());
+               if (e.first < ext.first) {
+                       ext.first = e.first;
+               }
+               if (e.second > ext.second) {
+                       ext.second = e.second;
                }
        }
 
-       return max_extent;
+       return ext;
 }
 
 string
@@ -1964,8 +2218,8 @@ Playlist::bump_name (string name, Session &session)
        string newname = name;
 
        do {
-               newname = bump_name_once (newname);
-       } while (session.playlist_by_name (newname)!=NULL);
+               newname = bump_name_once (newname, '.');
+       } while (session.playlists->by_name (newname)!=NULL);
 
        return newname;
 }
@@ -1974,7 +2228,7 @@ Playlist::bump_name (string name, Session &session)
 layer_t
 Playlist::top_layer() const
 {
-       RegionLock rlock (const_cast<Playlist *> (this));
+       RegionReadLock rlock (const_cast<Playlist *> (this));
        layer_t top = 0;
 
        for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
@@ -1989,18 +2243,61 @@ Playlist::set_edit_mode (EditMode mode)
        _edit_mode = mode;
 }
 
-/********************
- * Region Layering
- ********************/
+struct RelayerSort {
+       bool operator () (boost::shared_ptr<Region> a, boost::shared_ptr<Region> b) {
+               return a->layering_index() < b->layering_index();
+       }
+};
+
+/** Set a new layer for a region.  This adjusts the layering indices of all
+ *  regions in the playlist to put the specified region in the appropriate
+ *  place.  The actual layering will be fixed up when relayer() happens.
+ */
+
+void
+Playlist::set_layer (boost::shared_ptr<Region> region, double new_layer)
+{
+       /* Remove the layer we are setting from our region list, and sort it */
+       RegionList copy = regions.rlist();
+       copy.remove (region);
+       copy.sort (RelayerSort ());
+
+       /* Put region back in the right place */
+       RegionList::iterator i = copy.begin();
+       while (i != copy.end ()) {
+               if ((*i)->layer() > new_layer) {
+                       break;
+               }
+               ++i;
+       }
+       
+       copy.insert (i, region);
+
+       setup_layering_indices (copy);
+}
+
+void
+Playlist::setup_layering_indices (RegionList const & regions)
+{
+       uint64_t j = 0;
+       list<Evoral::Range<framepos_t> > xf;
 
+       for (RegionList::const_iterator k = regions.begin(); k != regions.end(); ++k) {
+               (*k)->set_layering_index (j++);
+       }
+}
+
+/** Take the layering indices of each of our regions, compute the layers
+ *  that they should be on, and write the layers back to the regions.
+ */
 void
 Playlist::relayer ()
 {
-       /* don't send multiple Modified notifications
-          when multiple regions are relayered.
-       */
+       /* never compute layers when setting from XML */
 
-       freeze ();
+       if (in_set_state) {
+               return;
+       }
 
        /* Build up a new list of regions on each layer, stored in a set of lists
           each of which represent some period of time on some layer.  The idea
@@ -2011,50 +2308,46 @@ Playlist::relayer ()
        int const divisions = 512;
 
        /* find the start and end positions of the regions on this playlist */
-       nframes_t start = UINT_MAX;
-       nframes_t end = 0;
+       framepos_t start = INT64_MAX;
+       framepos_t end = 0;
        for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
                start = min (start, (*i)->position());
                end = max (end, (*i)->position() + (*i)->length());
        }
 
-       /* hence the size of each time division */
-       double const division_size = (end - start) / double (divisions);
-
-       vector<vector<RegionList> > layers;
-       layers.push_back (vector<RegionList> (divisions));
-
-       /* we want to go through regions from desired lowest to desired highest layer,
-          which depends on the layer model
-       */
-
-       RegionList copy = regions;
-
-       /* sort according to the model and the layering mode that we're in */
-
-       if (_explicit_relayering) {
-
-               copy.sort (RegionSortByLayerWithPending ());
+       /* hence the size of each time division */
+       double const division_size = (end - start) / double (divisions);
 
-       } else if (_session.config.get_layer_model() == MoveAddHigher || _session.config.get_layer_model() == AddHigher) {
+       vector<vector<RegionList> > layers;
+       layers.push_back (vector<RegionList> (divisions));
 
-               copy.sort (RegionSortByLastLayerOp ());
+       /* Sort our regions into layering index order */
+       RegionList copy = regions.rlist();
+       copy.sort (RelayerSort ());
 
+       DEBUG_TRACE (DEBUG::Layering, "relayer() using:\n");
+       for (RegionList::iterator i = copy.begin(); i != copy.end(); ++i) {
+               DEBUG_TRACE (DEBUG::Layering, string_compose ("\t%1 %2\n", (*i)->name(), (*i)->layering_index()));
        }
 
        for (RegionList::iterator i = copy.begin(); i != copy.end(); ++i) {
 
-               /* reset the pending explicit relayer flag for every region, now that we're relayering */
-               (*i)->set_pending_explicit_relayer (false);
-
-               /* find the time divisions that this region covers */
-               int const start_division = floor ( ((*i)->position() - start) / division_size);
-               int end_division = floor ( ((*i)->position() + (*i)->length() - start) / division_size );
-               if (end_division == divisions) {
-                       end_division--;
+               /* find the time divisions that this region covers; if there are no regions on the list,
+                  division_size will equal 0 and in this case we'll just say that
+                  start_division = end_division = 0.
+               */
+               int start_division = 0;
+               int end_division = 0;
+
+               if (division_size > 0) {
+                       start_division = floor ( ((*i)->position() - start) / division_size);
+                       end_division = floor ( ((*i)->position() + (*i)->length() - start) / division_size );
+                       if (end_division == divisions) {
+                               end_division--;
+                       }
                }
 
-               assert (end_division < divisions);
+               assert (divisions == 0 || end_division < divisions);
 
                /* find the lowest layer that this region can go on */
                size_t j = layers.size();
@@ -2100,163 +2393,70 @@ Playlist::relayer ()
                (*i)->set_layer (j);
        }
 
-       /* sending Modified means that various kinds of layering
-          models operate correctly at the GUI
-          level. slightly inefficient, but only slightly.
-
-          We force a Modified signal here in case no layers actually
-          changed.
+       /* It's a little tricky to know when we could avoid calling this; e.g. if we are
+          relayering because we just removed the only region on the top layer, nothing will
+          appear to have changed, but the StreamView must still sort itself out.  We could
+          probably keep a note of the top layer last time we relayered, and check that,
+          but premature optimisation &c...
        */
+       notify_layering_changed ();
 
-       notify_modified ();
-
-       thaw ();
+       /* This relayer() may have been called as a result of a region removal, in which
+          case we need to setup layering indices to account for the one that has just
+          gone away.
+       */
+       setup_layering_indices (copy);
 }
 
-/* XXX these layer functions are all deprecated */
-
 void
 Playlist::raise_region (boost::shared_ptr<Region> region)
 {
-       uint32_t rsz = regions.size();
-       layer_t target = region->layer() + 1U;
-
-       if (target >= rsz) {
-               /* its already at the effective top */
-               return;
-       }
-
-       move_region_to_layer (target, region, 1);
+       set_layer (region, region->layer() + 1.5);
+       relayer ();
 }
 
 void
 Playlist::lower_region (boost::shared_ptr<Region> region)
 {
-       if (region->layer() == 0) {
-               /* its already at the bottom */
-               return;
-       }
-
-       layer_t target = region->layer() - 1U;
-
-       move_region_to_layer (target, region, -1);
+       set_layer (region, region->layer() - 1.5);
+       relayer ();
 }
 
 void
 Playlist::raise_region_to_top (boost::shared_ptr<Region> region)
 {
-       /* does nothing useful if layering mode is later=higher */
-       if ((_session.config.get_layer_model() == MoveAddHigher) ||
-           (_session.config.get_layer_model() == AddHigher)) {
-               timestamp_layer_op (region);
-               relayer ();
-       }
+       set_layer (region, DBL_MAX);
+       relayer ();
 }
 
 void
 Playlist::lower_region_to_bottom (boost::shared_ptr<Region> region)
 {
-       /* does nothing useful if layering mode is later=higher */
-       if ((_session.config.get_layer_model() == MoveAddHigher) ||
-           (_session.config.get_layer_model() == AddHigher)) {
-               region->set_last_layer_op (0);
-               relayer ();
-       }
-}
-
-int
-Playlist::move_region_to_layer (layer_t target_layer, boost::shared_ptr<Region> region, int dir)
-{
-       RegionList::iterator i;
-       typedef pair<boost::shared_ptr<Region>,layer_t> LayerInfo;
-       list<LayerInfo> layerinfo;
-       layer_t dest;
-
-       {
-               RegionLock rlock (const_cast<Playlist *> (this));
-
-               for (i = regions.begin(); i != regions.end(); ++i) {
-
-                       if (region == *i) {
-                               continue;
-                       }
-
-                       if (dir > 0) {
-
-                               /* region is moving up, move all regions on intermediate layers
-                                  down 1
-                               */
-
-                               if ((*i)->layer() > region->layer() && (*i)->layer() <= target_layer) {
-                                       dest = (*i)->layer() - 1;
-                               } else {
-                                       /* not affected */
-                                       continue;
-                               }
-                       } else {
-
-                               /* region is moving down, move all regions on intermediate layers
-                                  up 1
-                               */
-
-                               if ((*i)->layer() < region->layer() && (*i)->layer() >= target_layer) {
-                                       dest = (*i)->layer() + 1;
-                               } else {
-                                       /* not affected */
-                                       continue;
-                               }
-                       }
-
-                       LayerInfo newpair;
-
-                       newpair.first = *i;
-                       newpair.second = dest;
-
-                       layerinfo.push_back (newpair);
-               }
-       }
-
-       /* now reset the layers without holding the region lock */
-
-       for (list<LayerInfo>::iterator x = layerinfo.begin(); x != layerinfo.end(); ++x) {
-               x->first->set_layer (x->second);
-       }
-
-       region->set_layer (target_layer);
-
-#if 0
-       /* now check all dependents */
-
-       for (list<LayerInfo>::iterator x = layerinfo.begin(); x != layerinfo.end(); ++x) {
-               check_dependents (x->first, false);
-       }
-
-       check_dependents (region, false);
-#endif
-
-       return 0;
+       set_layer (region, -0.5);
+       relayer ();
 }
 
 void
-Playlist::nudge_after (nframes_t start, nframes_t distance, bool forwards)
+Playlist::nudge_after (framepos_t start, framecnt_t distance, bool forwards)
 {
        RegionList::iterator i;
-       nframes_t new_pos;
        bool moved = false;
 
        _nudging = true;
 
        {
-               RegionLock rlock (const_cast<Playlist *> (this));
+               RegionWriteLock rlock (const_cast<Playlist *> (this));
 
                for (i = regions.begin(); i != regions.end(); ++i) {
 
                        if ((*i)->position() >= start) {
 
+                               framepos_t new_pos;
+
                                if (forwards) {
 
-                                       if ((*i)->last_frame() > max_frames - distance) {
-                                               new_pos = max_frames - (*i)->length();
+                                       if ((*i)->last_frame() > max_framepos - distance) {
+                                               new_pos = max_framepos - (*i)->length();
                                        } else {
                                                new_pos = (*i)->position() + distance;
                                        }
@@ -2270,7 +2470,7 @@ Playlist::nudge_after (nframes_t start, nframes_t distance, bool forwards)
                                        }
                                }
 
-                               (*i)->set_position (new_pos, this);
+                               (*i)->set_position (new_pos);
                                moved = true;
                        }
                }
@@ -2278,15 +2478,29 @@ Playlist::nudge_after (nframes_t start, nframes_t distance, bool forwards)
 
        if (moved) {
                _nudging = false;
-               notify_length_changed ();
+               notify_contents_changed ();
+       }
+
+}
+
+bool
+Playlist::uses_source (boost::shared_ptr<const Source> src) const
+{
+       RegionReadLock rlock (const_cast<Playlist*> (this));
+
+       for (set<boost::shared_ptr<Region> >::const_iterator r = all_regions.begin(); r != all_regions.end(); ++r) {
+               if ((*r)->uses_source (src)) {
+                       return true;
+               }
        }
 
+       return false;
 }
 
 boost::shared_ptr<Region>
 Playlist::find_region (const ID& id) const
 {
-       RegionLock rlock (const_cast<Playlist*> (this));
+       RegionReadLock rlock (const_cast<Playlist*> (this));
 
        /* searches all regions currently in use by the playlist */
 
@@ -2299,12 +2513,27 @@ Playlist::find_region (const ID& id) const
        return boost::shared_ptr<Region> ();
 }
 
+uint32_t
+Playlist::region_use_count (boost::shared_ptr<Region> r) const
+{
+       RegionReadLock rlock (const_cast<Playlist*> (this));
+       uint32_t cnt = 0;
+
+       for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
+               if ((*i) == r) {
+                       cnt++;
+               }
+       }
+
+       return cnt;
+}
+
 boost::shared_ptr<Region>
-Playlist::region_by_id (ID id)
+Playlist::region_by_id (const ID& id) const
 {
        /* searches all regions ever added to this playlist */
 
-       for (set<boost::shared_ptr<Region> >::iterator i = all_regions.begin(); i != all_regions.end(); ++i) {
+       for (set<boost::shared_ptr<Region> >::const_iterator i = all_regions.begin(); i != all_regions.end(); ++i) {
                if ((*i)->id() == id) {
                        return *i;
                }
@@ -2339,20 +2568,10 @@ Playlist::set_frozen (bool yn)
        _frozen = yn;
 }
 
-void
-Playlist::timestamp_layer_op (boost::shared_ptr<Region> region)
-{
-//     struct timeval tv;
-//     gettimeofday (&tv, 0);
-       region->set_last_layer_op (++layer_op_counter);
-}
-
-
 void
 Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
 {
        bool moved = false;
-       nframes_t new_pos;
 
        if (region->locked()) {
                return;
@@ -2361,7 +2580,7 @@ Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
        _shuffling = true;
 
        {
-               RegionLock rlock (const_cast<Playlist*> (this));
+               RegionWriteLock rlock (const_cast<Playlist*> (this));
 
 
                if (dir > 0) {
@@ -2379,6 +2598,8 @@ Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
                                                        break;
                                                }
 
+                                               framepos_t new_pos;
+
                                                if ((*next)->position() != region->last_frame() + 1) {
                                                        /* they didn't used to touch, so after shuffle,
                                                           just have them swap positions.
@@ -2393,8 +2614,8 @@ Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
                                                        new_pos = region->position() + (*next)->length();
                                                }
 
-                                               (*next)->set_position (region->position(), this);
-                                               region->set_position (new_pos, this);
+                                               (*next)->set_position (region->position());
+                                               region->set_position (new_pos);
 
                                                /* avoid a full sort */
 
@@ -2420,6 +2641,7 @@ Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
                                                        break;
                                                }
 
+                                               framepos_t new_pos;
                                                if (region->position() != (*prev)->last_frame() + 1) {
                                                        /* they didn't used to touch, so after shuffle,
                                                           just have them swap positions.
@@ -2433,8 +2655,8 @@ Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
                                                        new_pos = (*prev)->position() + region->length();
                                                }
 
-                                               region->set_position ((*prev)->position(), this);
-                                               (*prev)->set_position (new_pos, this);
+                                               region->set_position ((*prev)->position());
+                                               (*prev)->set_position (new_pos);
 
                                                /* avoid a full sort */
 
@@ -2455,9 +2677,7 @@ Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
        if (moved) {
 
                relayer ();
-               check_dependents (region, false);
-
-               notify_modified();
+               notify_contents_changed();
        }
 
 }
@@ -2465,7 +2685,7 @@ Playlist::shuffle (boost::shared_ptr<Region> region, int dir)
 bool
 Playlist::region_is_shuffle_constrained (boost::shared_ptr<Region>)
 {
-       RegionLock rlock (const_cast<Playlist*> (this));
+       RegionReadLock rlock (const_cast<Playlist*> (this));
 
        if (regions.size() > 1) {
                return true;
@@ -2477,45 +2697,416 @@ Playlist::region_is_shuffle_constrained (boost::shared_ptr<Region>)
 void
 Playlist::update_after_tempo_map_change ()
 {
-       RegionLock rlock (const_cast<Playlist*> (this));
-       RegionList copy (regions);
+       RegionWriteLock rlock (const_cast<Playlist*> (this));
+       RegionList copy (regions.rlist());
 
        freeze ();
 
        for (RegionList::iterator i = copy.begin(); i != copy.end(); ++i) {
-               (*i)->update_position_after_tempo_map_change ();
+               (*i)->update_after_tempo_map_change ();
        }
 
        thaw ();
 }
 
 void
-Playlist::foreach_region (sigc::slot<void, boost::shared_ptr<Region> > s)
+Playlist::foreach_region (boost::function<void(boost::shared_ptr<Region>)> s)
 {
-       RegionLock rl (this, false);
+       RegionWriteLock rl (this, false);
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
                s (*i);
        }
 }
 
+bool
+Playlist::has_region_at (framepos_t const p) const
+{
+       RegionReadLock (const_cast<Playlist *> (this));
+
+       RegionList::const_iterator i = regions.begin ();
+       while (i != regions.end() && !(*i)->covers (p)) {
+               ++i;
+       }
+
+       return (i != regions.end());
+}
+
+/** Remove any region that uses a given source */
 void
-Playlist::set_explicit_relayering (bool e)
+Playlist::remove_region_by_source (boost::shared_ptr<Source> s)
 {
-       if (e == false && _explicit_relayering == true) {
+       RegionWriteLock rl (this);
 
-               /* We are changing from explicit to implicit relayering; layering may have been changed whilst
-                  we were in explicit mode, and we don't want that to be undone next time an implicit relayer
-                  occurs.  Hence now we'll set up region last_layer_op values so that an implicit relayer
-                  at this point would keep regions on the same layers.
+       RegionList::iterator i = regions.begin();
+       while (i != regions.end()) {
+               RegionList::iterator j = i;
+               ++j;
 
-                  From then on in, it's just you and your towel.
-               */
+               if ((*i)->uses_source (s)) {
+                       remove_region_internal (*i);
+               }
 
-               RegionLock rl (this);
-               for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-                       (*i)->set_last_layer_op ((*i)->layer ());
+               i = j;
+       }
+}
+
+/** Look from a session frame time and find the start time of the next region
+ *  which is on the top layer of this playlist.
+ *  @param t Time to look from.
+ *  @return Position of next top-layered region, or max_framepos if there isn't one.
+ */
+framepos_t
+Playlist::find_next_top_layer_position (framepos_t t) const
+{
+       RegionReadLock rlock (const_cast<Playlist *> (this));
+
+       layer_t const top = top_layer ();
+
+       RegionList copy = regions.rlist ();
+       copy.sort (RegionSortByPosition ());
+
+       for (RegionList::const_iterator i = copy.begin(); i != copy.end(); ++i) {
+               if ((*i)->position() >= t && (*i)->layer() == top) {
+                       return (*i)->position();
+               }
+       }
+
+       return max_framepos;
+}
+
+boost::shared_ptr<Region>
+Playlist::combine (const RegionList& r)
+{
+       PropertyList plist;
+       uint32_t channels = 0;
+       uint32_t layer = 0;
+       framepos_t earliest_position = max_framepos;
+       vector<TwoRegions> old_and_new_regions;
+       vector<boost::shared_ptr<Region> > originals;
+       vector<boost::shared_ptr<Region> > copies;
+       string parent_name;
+       string child_name;
+       uint32_t max_level = 0;
+
+       /* find the maximum depth of all the regions we're combining */
+
+       for (RegionList::const_iterator i = r.begin(); i != r.end(); ++i) {
+               max_level = max (max_level, (*i)->max_source_level());
+       }
+
+       parent_name = RegionFactory::compound_region_name (name(), combine_ops(), max_level, true);
+       child_name = RegionFactory::compound_region_name (name(), combine_ops(), max_level, false);
+
+       boost::shared_ptr<Playlist> pl = PlaylistFactory::create (_type, _session, parent_name, true);
+
+       for (RegionList::const_iterator i = r.begin(); i != r.end(); ++i) {
+               earliest_position = min (earliest_position, (*i)->position());
+       }
+
+       /* enable this so that we do not try to create xfades etc. as we add
+        * regions
+        */
+
+       pl->in_partition = true;
+
+       for (RegionList::const_iterator i = r.begin(); i != r.end(); ++i) {
+
+               /* copy the region */
+
+               boost::shared_ptr<Region> original_region = (*i);
+               boost::shared_ptr<Region> copied_region = RegionFactory::create (original_region, false);
+
+               old_and_new_regions.push_back (TwoRegions (original_region,copied_region));
+               originals.push_back (original_region);
+               copies.push_back (copied_region);
+
+               RegionFactory::add_compound_association (original_region, copied_region);
+
+               /* make position relative to zero */
+
+               pl->add_region (copied_region, original_region->position() - earliest_position);
+               copied_region->set_layer (original_region->layer ());
+
+               /* use the maximum number of channels for any region */
+
+               channels = max (channels, original_region->n_channels());
+
+               /* it will go above the layer of the highest existing region */
+
+               layer = max (layer, original_region->layer());
+       }
+
+       pl->in_partition = false;
+
+       pre_combine (copies);
+
+       /* now create a new PlaylistSource for each channel in the new playlist */
+
+       SourceList sources;
+       pair<framepos_t,framepos_t> extent = pl->get_extent();
+
+       for (uint32_t chn = 0; chn < channels; ++chn) {
+               sources.push_back (SourceFactory::createFromPlaylist (_type, _session, pl, id(), parent_name, chn, 0, extent.second, false, false));
+
+       }
+
+       /* now a new whole-file region using the list of sources */
+
+       plist.add (Properties::start, 0);
+       plist.add (Properties::length, extent.second);
+       plist.add (Properties::name, parent_name);
+       plist.add (Properties::whole_file, true);
+
+       boost::shared_ptr<Region> parent_region = RegionFactory::create (sources, plist, true);
+
+       /* now the non-whole-file region that we will actually use in the
+        * playlist
+        */
+
+       plist.clear ();
+       plist.add (Properties::start, 0);
+       plist.add (Properties::length, extent.second);
+       plist.add (Properties::name, child_name);
+       plist.add (Properties::layer, layer+1);
+
+       boost::shared_ptr<Region> compound_region = RegionFactory::create (parent_region, plist, true);
+
+       /* remove all the selected regions from the current playlist
+        */
+
+       freeze ();
+
+       for (RegionList::const_iterator i = r.begin(); i != r.end(); ++i) {
+               remove_region (*i);
+       }
+
+       /* do type-specific stuff with the originals and the new compound
+          region
+       */
+
+       post_combine (originals, compound_region);
+
+       /* add the new region at the right location */
+
+       add_region (compound_region, earliest_position);
+
+       _combine_ops++;
+
+       thaw ();
+
+       return compound_region;
+}
+
+void
+Playlist::uncombine (boost::shared_ptr<Region> target)
+{
+       boost::shared_ptr<PlaylistSource> pls;
+       boost::shared_ptr<const Playlist> pl;
+       vector<boost::shared_ptr<Region> > originals;
+       vector<TwoRegions> old_and_new_regions;
+
+       // (1) check that its really a compound region
+
+       if ((pls = boost::dynamic_pointer_cast<PlaylistSource>(target->source (0))) == 0) {
+               return;
+       }
+
+       pl = pls->playlist();
+
+       framepos_t adjusted_start = 0; // gcc isn't smart enough
+       framepos_t adjusted_end = 0;   // gcc isn't smart enough
+
+       /* the leftmost (earliest) edge of the compound region
+          starts at zero in its source, or larger if it
+          has been trimmed or content-scrolled.
+
+          the rightmost (latest) edge of the compound region
+          relative to its source is the starting point plus
+          the length of the region.
+       */
+
+       // (2) get all the original regions
+
+       const RegionList& rl (pl->region_list().rlist());
+       RegionFactory::CompoundAssociations& cassocs (RegionFactory::compound_associations());
+       frameoffset_t move_offset = 0;
+
+       /* there are two possibilities here:
+          1) the playlist that the playlist source was based on
+          is us, so just add the originals (which belonged to
+          us anyway) back in the right place.
+
+          2) the playlist that the playlist source was based on
+          is NOT us, so we need to make copies of each of
+          the original regions that we find, and add them
+          instead.
+       */
+       bool same_playlist = (pls->original() == id());
+
+       for (RegionList::const_iterator i = rl.begin(); i != rl.end(); ++i) {
+
+               boost::shared_ptr<Region> current (*i);
+
+               RegionFactory::CompoundAssociations::iterator ca = cassocs.find (*i);
+
+               if (ca == cassocs.end()) {
+                       continue;
+               }
+
+               boost::shared_ptr<Region> original (ca->second);
+               bool modified_region;
+
+               if (i == rl.begin()) {
+                       move_offset = (target->position() - original->position()) - target->start();
+                       adjusted_start = original->position() + target->start();
+                       adjusted_end = adjusted_start + target->length();
+               }
+
+               if (!same_playlist) {
+                       framepos_t pos = original->position();
+                       /* make a copy, but don't announce it */
+                       original = RegionFactory::create (original, false);
+                       /* the pure copy constructor resets position() to zero,
+                          so fix that up.
+                       */
+                       original->set_position (pos);
+               }
+
+               /* check to see how the original region (in the
+                * playlist before compounding occured) overlaps
+                * with the new state of the compound region.
+                */
+
+               original->clear_changes ();
+               modified_region = false;
+
+               switch (original->coverage (adjusted_start, adjusted_end)) {
+               case Evoral::OverlapNone:
+                       /* original region does not cover any part
+                          of the current state of the compound region
+                       */
+                       continue;
+
+               case Evoral::OverlapInternal:
+                       /* overlap is just a small piece inside the
+                        * original so trim both ends
+                        */
+                       original->trim_to (adjusted_start, adjusted_end - adjusted_start);
+                       modified_region = true;
+                       break;
+
+               case Evoral::OverlapExternal:
+                       /* overlap fully covers original, so leave it
+                          as is
+                       */
+                       break;
+
+               case Evoral::OverlapEnd:
+                       /* overlap starts within but covers end,
+                          so trim the front of the region
+                       */
+                       original->trim_front (adjusted_start);
+                       modified_region = true;
+                       break;
+
+               case Evoral::OverlapStart:
+                       /* overlap covers start but ends within, so
+                        * trim the end of the region.
+                        */
+                       original->trim_end (adjusted_end);
+                       modified_region = true;
+                       break;
+               }
+
+               if (move_offset) {
+                       /* fix the position to match any movement of the compound region.
+                        */
+                       original->set_position (original->position() + move_offset);
+                       modified_region = true;
+               }
+
+               if (modified_region) {
+                       _session.add_command (new StatefulDiffCommand (original));
+               }
+
+               /* and add to the list of regions waiting to be
+                * re-inserted
+                */
+
+               originals.push_back (original);
+               old_and_new_regions.push_back (TwoRegions (*i, original));
+       }
+
+       pre_uncombine (originals, target);
+
+       in_partition = true;
+       freeze ();
+
+       // (3) remove the compound region
+
+       remove_region (target);
+
+       // (4) add the constituent regions
+
+       for (vector<boost::shared_ptr<Region> >::iterator i = originals.begin(); i != originals.end(); ++i) {
+               add_region ((*i), (*i)->position());
+       }
+
+       in_partition = false;
+       thaw ();
+}
+
+uint32_t
+Playlist::max_source_level () const
+{
+       RegionReadLock rlock (const_cast<Playlist *> (this));
+       uint32_t lvl = 0;
+
+       for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
+               lvl = max (lvl, (*i)->max_source_level());
+       }
+
+       return lvl;
+}
+
+void
+Playlist::set_orig_track_id (const PBD::ID& id)
+{
+       _orig_track_id = id;
+}
+
+/** Take a list of ranges, coalesce any that can be coalesced, then call
+ *  check_crossfades for each one.
+ */
+void
+Playlist::coalesce_and_check_crossfades (list<Evoral::Range<framepos_t> > ranges)
+{
+       /* XXX: it's a shame that this coalesce algorithm also exists in
+          TimeSelection::consolidate().
+       */
+
+       /* XXX: xfade: this is implemented in Evoral::RangeList */
+
+restart:
+       for (list<Evoral::Range<framepos_t> >::iterator i = ranges.begin(); i != ranges.end(); ++i) {
+               for (list<Evoral::Range<framepos_t> >::iterator j = ranges.begin(); j != ranges.end(); ++j) {
+
+                       if (i == j) {
+                               continue;
+                       }
+
+                       if (Evoral::coverage (i->from, i->to, j->from, j->to) != Evoral::OverlapNone) {
+                               i->from = min (i->from, j->from);
+                               i->to = max (i->to, j->to);
+                               ranges.erase (j);
+                               goto restart;
+                       }
                }
        }
+}
 
-       _explicit_relayering = e;
+void
+Playlist::set_capture_insertion_in_progress (bool yn)
+{
+       _capture_insertion_underway = yn;
 }