Tweak transmission of MMC on locate. Should fix #3121.
[ardour.git] / libs / ardour / playlist.cc
index e128489820b3f150b9fdff8fbd58fedbb14a9a9b..cc9dc62ec79c027fcc3f8417c11ab7821bb5d190 100644 (file)
@@ -17,6 +17,9 @@
 
 */
 
+#define __STDC_LIMIT_MACROS
+#include <stdint.h>
+
 #include <set>
 #include <fstream>
 #include <algorithm>
 #include <string>
 #include <climits>
 
+#include <boost/lexical_cast.hpp>
 
 #include "pbd/failed_constructor.h"
-#include "pbd/stl_delete.h"
+#include "pbd/stateful_diff_command.h"
 #include "pbd/xml++.h"
-#include "pbd/stacktrace.h"
 
 #include "ardour/debug.h"
 #include "ardour/playlist.h"
@@ -46,6 +49,12 @@ 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 () {
@@ -90,34 +99,103 @@ struct RegionSortByLastLayerOp {
     }
 };
 
+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));
+}
+
+RegionListProperty::RegionListProperty (Playlist& pl)
+        : SequenceProperty<std::list<boost::shared_ptr<Region> > > (Properties::regions.property_id, boost::bind (&Playlist::update, &pl, _1))
+        , _playlist (pl)
+{
+}
+
+boost::shared_ptr<Region>
+RegionListProperty::lookup_id (const ID& id)
+{
+        boost::shared_ptr<Region> ret =  _playlist.region_by_id (id);
+        
+        if (!ret) {
+                ret = RegionFactory::region_by_id (id);
+        }
+
+        return ret;
+}
+
+RegionListProperty*
+RegionListProperty::copy_for_history () const
+{
+        RegionListProperty* copy = new RegionListProperty (_playlist);
+        /* this is all we need */
+        copy->_change = _change;
+        return copy;
+}
+
+void 
+RegionListProperty::diff (PropertyList& undo, PropertyList& redo, Command* cmd) const
+{
+        if (changed()) {
+               /* list of the removed/added regions since clear_history() was last called */
+                RegionListProperty* a = copy_for_history ();
+
+               /* the same list, but with removed/added lists swapped (for undo purposes) */
+                RegionListProperty* b = copy_for_history ();
+                b->invert_changes ();
+
+                if (cmd) {
+                        /* whenever one of the regions emits DropReferences, make sure
+                           that the Destructible we've been told to notify hears about
+                           it. the Destructible is likely to be the Command being built
+                           with this diff().
+                        */
+                        
+                        for (set<boost::shared_ptr<Region> >::iterator i = a->change().added.begin(); i != a->change().added.end(); ++i) {
+                                (*i)->DropReferences.connect_same_thread (*cmd, boost::bind (&Destructible::drop_references, cmd));
+                        }
+                }
+
+                undo.add (b);
+                redo.add (a);
+        }
+}
 
 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")
-       , _type(type)
+        , 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)
+        , regions (*this)
        , _type(other->_type)
-       , _orig_diskstream_id(other->_orig_diskstream_id)
+       , _orig_diskstream_id (other->_orig_diskstream_id)
 {
        init (hide);
 
@@ -150,8 +228,9 @@ Playlist::Playlist (boost::shared_ptr<const Playlist> other, string namestr, boo
 
 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_diskstream_id(other->_orig_diskstream_id)
+       , _orig_diskstream_id (other->_orig_diskstream_id)
 {
        RegionLock rlock2 (const_cast<Playlist*> (other.get()));
 
@@ -204,11 +283,11 @@ Playlist::Playlist (boost::shared_ptr<const Playlist> other, framepos_t start, f
                        break;
                }
 
-               _session.region_name (new_name, region->name(), false);
+               RegionFactory::region_name (new_name, region->name(), false);
 
                PropertyList plist; 
 
-               plist.add (Properties::start, offset);
+               plist.add (Properties::start, region->start() + offset);
                plist.add (Properties::length, len);
                plist.add (Properties::name, new_name);
                plist.add (Properties::layer, region->layer());
@@ -256,6 +335,9 @@ Playlist::copy_regions (RegionList& newlist) const
 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_contents_change = false;
@@ -268,6 +350,7 @@ Playlist::init (bool hide)
        _shuffling = false;
        _nudging = false;
        in_set_state = 0;
+        in_update = false;
        _edit_mode = Config->get_edit_mode();
        in_flush = false;
        in_partition = false;
@@ -299,6 +382,32 @@ 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)
 {
@@ -310,9 +419,13 @@ 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;
 }
 
 /***********************************************************************
@@ -326,6 +439,7 @@ Playlist::set_name (const string& str)
 void
 Playlist::begin_undo ()
 {
+        in_update = true;
        freeze ();
 }
 
@@ -333,6 +447,7 @@ void
 Playlist::end_undo ()
 {
        thaw ();
+        in_update = false;
 }
 
 void
@@ -354,7 +469,7 @@ void
 Playlist::delay_notifications ()
 {
        g_atomic_int_inc (&block_notifications);
-       freeze_length = _get_maximum_extent();
+       freeze_length = _get_extent().second;
 }
 
 void
@@ -362,7 +477,8 @@ Playlist::release_notifications ()
 {
        if (g_atomic_int_dec_and_test (&block_notifications)) {
                flush_notifications ();
-       }
+        }
+
 }
 
 void
@@ -430,12 +546,13 @@ 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;
                pending_length = true;
        } else {
+                r->clear_history ();
                pending_length = false;
                LengthChanged (); /* EMIT SIGNAL */
                pending_contents_change = false;
@@ -475,7 +592,7 @@ Playlist::flush_notifications ()
        if (!pending_bounds.empty() || !pending_removes.empty() || !pending_adds.empty()) {
                regions_changed = true;
                if (!pending_length) {
-                       old_length = _get_maximum_extent ();
+                       old_length = _get_extent ().second;
                        check_length = true;
                }
        }
@@ -504,18 +621,21 @@ Playlist::flush_notifications ()
 
        for (s = pending_adds.begin(); s != pending_adds.end(); ++s) {
                // cerr << _name << " sends RegionAdded\n";
-               RegionAdded (boost::weak_ptr<Region> (*s)); /* EMIT SIGNAL */
+                /* don't emit RegionAdded signal until relayering is done,
+                   so that the region is fully setup by the time
+                   anyone hear's that its been added
+                */
                dependent_checks_needed.insert (*s);
        }
 
        if (check_length) {
-               if (old_length != _get_maximum_extent()) {
+               if (old_length != _get_extent().second) {
                        pending_length = true;
                        // cerr << _name << " length has changed\n";
                }
        }
 
-       if (pending_length || (freeze_length != _get_maximum_extent())) {
+       if (pending_length || (freeze_length != _get_extent().second)) {
                pending_length = false;
                // cerr << _name << " sends LengthChanged\n";
                LengthChanged(); /* EMIT SIGNAL */
@@ -531,6 +651,11 @@ Playlist::flush_notifications ()
                // cerr << _name << "done contents change @ " << get_microseconds() << endl;
        }
 
+       for (s = pending_adds.begin(); s != pending_adds.end(); ++s) {
+                (*s)->clear_history ();
+               RegionAdded (boost::weak_ptr<Region> (*s)); /* EMIT SIGNAL */
+        }
+
        for (s = dependent_checks_needed.begin(); s != dependent_checks_needed.end(); ++s) {
                check_dependents (*s, false);
        }
@@ -596,12 +721,12 @@ Playlist::add_region (boost::shared_ptr<Region> region, framepos_t position, flo
        if (floor (times) != times) {
                length = (framecnt_t) floor (region->length() * (times - floor (times)));
                string name;
-               _session.region_name (name, region->name(), false);
+               RegionFactory::region_name (name, region->name(), false);
 
                {
                        PropertyList plist;
                        
-                       plist.add (Properties::start, 0);
+                       plist.add (Properties::start, region->start());
                        plist.add (Properties::length, length);
                        plist.add (Properties::name, name);
                        plist.add (Properties::layer, region->layer());
@@ -638,7 +763,7 @@ Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t posi
        framecnt_t old_length = 0;
 
        if (!holding_state()) {
-                old_length = _get_maximum_extent();
+                old_length = _get_extent().second;
        }
 
        if (!first_set_state) {
@@ -655,8 +780,8 @@ Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t posi
 
        possibly_splice_unlocked (position, region->length(), region);
 
-       if (!holding_state () && !in_set_state) {
-               /* layers get assigned from XML state */
+       if (!holding_state ()) {
+               /* layers get assigned from XML state, and are not reset during undo/redo */
                relayer ();
        }
 
@@ -668,7 +793,7 @@ Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t posi
 
                check_dependents (region, false);
 
-               if (old_length != _get_maximum_extent()) {
+               if (old_length != _get_extent().second) {
                        notify_length_changed ();
                }
        }
@@ -709,7 +834,7 @@ Playlist::remove_region_internal (boost::shared_ptr<Region> region)
        int ret = -1;
 
        if (!holding_state()) {
-               old_length = _get_maximum_extent();
+               old_length = _get_extent().second;
        }
 
        if (!in_set_state) {
@@ -730,10 +855,10 @@ Playlist::remove_region_internal (boost::shared_ptr<Region> region)
                        possibly_splice_unlocked (pos, -distance);
 
                        if (!holding_state ()) {
-                               relayer ();
+                                relayer ();
                                remove_dependents (region);
 
-                               if (old_length != _get_maximum_extent()) {
+                               if (old_length != _get_extent().second) {
                                        notify_length_changed ();
                                }
                        }
@@ -786,7 +911,7 @@ Playlist::partition (framepos_t start, framepos_t end, bool cut)
        partition_internal (start, end, cut, thawlist);
 
        for (RegionList::iterator i = thawlist.begin(); i != thawlist.end(); ++i) {
-               (*i)->thaw ();
+               (*i)->resume_property_changes ();
        }
 }
 
@@ -811,7 +936,7 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
                   get operated on as well.
                */
 
-               RegionList copy = regions;
+               RegionList copy = regions.rlist();
 
                for (RegionList::iterator i = copy.begin(); i != copy.end(); i = tmp) {
 
@@ -866,11 +991,11 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
                                if (!cutting) {
                                        /* "middle" ++++++ */
 
-                                       _session.region_name (new_name, current->name(), false);
+                                       RegionFactory::region_name (new_name, current->name(), false);
 
                                        PropertyList plist;
                                        
-                                       plist.add (Properties::start, pos2 - pos1);
+                                       plist.add (Properties::start, current->start() + (pos2 - pos1));
                                        plist.add (Properties::length, pos3 - pos2);
                                        plist.add (Properties::name, new_name);
                                        plist.add (Properties::layer, regions.size());
@@ -885,11 +1010,11 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
 
                                /* "end" ====== */
 
-                               _session.region_name (new_name, current->name(), false);
+                               RegionFactory::region_name (new_name, current->name(), false);
 
                                PropertyList plist;
                                
-                               plist.add (Properties::start, pos3 - pos1);
+                               plist.add (Properties::start, current->start() + (pos3 - pos1));
                                plist.add (Properties::length, pos4 - pos3);
                                plist.add (Properties::name, new_name);
                                plist.add (Properties::layer, regions.size());
@@ -903,9 +1028,9 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
 
                                /* "front" ***** */
 
-                               current->freeze ();
+                               current->suspend_property_changes ();
                                thawlist.push_back (current);
-                               current->trim_end (pos2, this);
+                               current->cut_end (pos2 - 1, this);
 
                        } else if (overlap == OverlapEnd) {
 
@@ -923,11 +1048,11 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
 
                                        /* end +++++ */
 
-                                       _session.region_name (new_name, current->name(), false);
+                                       RegionFactory::region_name (new_name, current->name(), false);
                                        
                                        PropertyList plist;
                                        
-                                       plist.add (Properties::start, pos2 - pos1);
+                                       plist.add (Properties::start, current->start() + (pos2 - pos1));
                                        plist.add (Properties::length, pos4 - pos2);
                                        plist.add (Properties::name, new_name);
                                        plist.add (Properties::layer, regions.size());
@@ -942,9 +1067,9 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
 
                                /* front ****** */
 
-                               current->freeze ();
+                               current->suspend_property_changes ();
                                thawlist.push_back (current);
-                               current->trim_end (pos2, this);
+                               current->cut_end (pos2 - 1, this);
 
                        } else if (overlap == OverlapStart) {
 
@@ -966,11 +1091,11 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
 
                                if (!cutting) {
                                        /* front **** */
-                                       _session.region_name (new_name, current->name(), false);
+                                       RegionFactory::region_name (new_name, current->name(), false);
 
                                        PropertyList plist;
                                        
-                                       plist.add (Properties::start, 0);
+                                       plist.add (Properties::start, current->start());
                                        plist.add (Properties::length, pos3 - pos1);
                                        plist.add (Properties::name, new_name);
                                        plist.add (Properties::layer, regions.size());
@@ -985,7 +1110,7 @@ Playlist::partition_internal (framepos_t start, framepos_t end, bool cutting, Re
 
                                /* end */
 
-                               current->freeze ();
+                               current->suspend_property_changes ();
                                thawlist.push_back (current);
                                current->trim_front (pos3, this);
                        } else if (overlap == OverlapExternal) {
@@ -1088,7 +1213,7 @@ Playlist::cut (framepos_t start, framecnt_t cnt, bool result_is_hidden)
        partition_internal (start, start+cnt-1, true, thawlist);
 
        for (RegionList::iterator i = thawlist.begin(); i != thawlist.end(); ++i) {
-               (*i)->thaw ();
+               (*i)->resume_property_changes();
        }
 
        return the_copy;
@@ -1104,7 +1229,7 @@ Playlist::copy (framepos_t start, framecnt_t cnt, bool result_is_hidden)
        new_name += '.';
        new_name += buf;
 
-       cnt = min (_get_maximum_extent() - start, cnt);
+       cnt = min (_get_extent().second - start, cnt);
        return PlaylistFactory::create (shared_from_this(), start, cnt, new_name, result_is_hidden);
 }
 
@@ -1117,11 +1242,11 @@ Playlist::paste (boost::shared_ptr<Playlist> other, framepos_t position, float t
                RegionLock rl1 (this);
                RegionLock rl2 (other.get());
 
-               framecnt_t old_length = _get_maximum_extent();
+               framecnt_t const old_length = _get_extent().second;
 
                int itimes = (int) floor (times);
                framepos_t pos = position;
-               framecnt_t shift = other->_get_maximum_extent();
+               framecnt_t const shift = other->_get_extent().second;
                layer_t top_layer = regions.size();
 
                while (itimes--) {
@@ -1141,7 +1266,7 @@ Playlist::paste (boost::shared_ptr<Playlist> other, framepos_t position, float t
 
                /* XXX shall we handle fractional cases at some point? */
 
-               if (old_length != _get_maximum_extent()) {
+               if (old_length != _get_extent().second) {
                        notify_length_changed ();
                }
 
@@ -1170,12 +1295,12 @@ Playlist::duplicate (boost::shared_ptr<Region> region, framepos_t position, floa
        if (floor (times) != times) {
                framecnt_t length = (framecnt_t) floor (region->length() * (times - floor (times)));
                string name;
-               _session.region_name (name, region->name(), false);
+               RegionFactory::region_name (name, region->name(), false);
                
                {
                        PropertyList plist;
                        
-                       plist.add (Properties::start, 0);
+                       plist.add (Properties::start, region->start());
                        plist.add (Properties::length, length);
                        plist.add (Properties::name, name);
                        
@@ -1189,7 +1314,7 @@ void
 Playlist::shift (framepos_t at, frameoffset_t distance, bool move_intersected, bool ignore_music_glue)
 {
        RegionLock rlock (this);
-       RegionList copy (regions);
+       RegionList copy (regions.rlist());
        RegionList fixup;
 
        for (RegionList::iterator r = copy.begin(); r != copy.end(); ++r) {
@@ -1210,7 +1335,7 @@ Playlist::shift (framepos_t at, frameoffset_t distance, bool move_intersected, b
                   has to be done separately.
                */
 
-               if (!ignore_music_glue && (*r)->positional_lock_style() != Region::AudioTime) {
+               if (!ignore_music_glue && (*r)->position_lock_style() != AudioTime) {
                        fixup.push_back (*r);
                        continue;
                }
@@ -1227,7 +1352,7 @@ void
 Playlist::split (framepos_t at)
 {
        RegionLock rlock (this);
-       RegionList copy (regions);
+       RegionList copy (regions.rlist());
 
        /* use a copy since this operation can modify the region list
         */
@@ -1271,12 +1396,12 @@ Playlist::_split_region (boost::shared_ptr<Region> region, framepos_t playlist_p
        before = playlist_position - region->position();
        after = region->length() - before;
 
-       _session.region_name (before_name, region->name(), false);
+       RegionFactory::region_name (before_name, region->name(), false);
 
        {
                PropertyList plist;
                
-               plist.add (Properties::start, 0);
+               plist.add (Properties::start, region->start());
                plist.add (Properties::length, before);
                plist.add (Properties::name, before_name);
                plist.add (Properties::left_of_split, true);
@@ -1284,12 +1409,12 @@ Playlist::_split_region (boost::shared_ptr<Region> region, framepos_t playlist_p
                left = RegionFactory::create (region, plist);
        }
 
-       _session.region_name (after_name, region->name(), false);
+       RegionFactory::region_name (after_name, region->name(), false);
 
        {
                PropertyList plist;
                
-               plist.add (Properties::start, before);
+               plist.add (Properties::start, region->start() + before);
                plist.add (Properties::length, after);
                plist.add (Properties::name, after_name);
                plist.add (Properties::right_of_split, true);
@@ -1406,9 +1531,10 @@ Playlist::region_bounds_changed (const PropertyChange& what_changed, boost::shar
                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;
+                        /* 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;
                }
 
@@ -1530,9 +1656,19 @@ Playlist::clear (bool with_signals)
                }
 
                regions.clear ();
+
+                for (set<boost::shared_ptr<Region> >::iterator s = pending_removes.begin(); s != pending_removes.end(); ++s) {
+                        remove_dependents (*s);
+                }
        }
 
        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 */
+                }
+
+                pending_removes.clear ();
                pending_length = false;
                LengthChanged ();
                pending_contents_change = false;
@@ -1614,6 +1750,8 @@ Playlist::regions_to_read (framepos_t start, framepos_t end)
        to_check.insert (start);
        to_check.insert (end);
 
+        DEBUG_TRACE (DEBUG::AudioPlayback, ">>>>> REGIONS TO READ\n");
+
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 
                /* find all/any regions that span start+end */
@@ -1624,22 +1762,38 @@ Playlist::regions_to_read (framepos_t start, framepos_t end)
 
                case OverlapInternal:
                        covering.push_back (*i);
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("toread: will cover %1 (OInternal)\n", (*i)->name()));
                        break;
 
                case OverlapStart:
                        to_check.insert ((*i)->position());
+                        if ((*i)->position() != 0) {
+                                to_check.insert ((*i)->position()-1);
+                        }
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("toread: will check %1 for %2\n", (*i)->position(), (*i)->name()));
                        covering.push_back (*i);
                        break;
 
                case OverlapEnd:
                        to_check.insert ((*i)->last_frame());
+                       to_check.insert ((*i)->last_frame()+1);
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("toread: will cover %1 (OEnd)\n", (*i)->name()));
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("\ttoread: will check %1 for %2\n", (*i)->last_frame(), (*i)->name()));
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("\ttoread: will check %1 for %2\n", (*i)->last_frame(), (*i)->name()));
                        covering.push_back (*i);
                        break;
 
                case OverlapExternal:
                        covering.push_back (*i);
                        to_check.insert ((*i)->position());
+                        if ((*i)->position() != 0) {
+                                to_check.insert ((*i)->position()-1);
+                        }
                        to_check.insert ((*i)->last_frame());
+                       to_check.insert ((*i)->last_frame()+1);
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("toread: will cover %1 (OExt)\n", (*i)->name()));
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("\ttoread: will check %1 for %2\n", (*i)->position(), (*i)->name()));
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("\ttoread: will check %1 for %2\n", (*i)->last_frame(), (*i)->name()));
                        break;
                }
 
@@ -1657,6 +1811,7 @@ Playlist::regions_to_read (framepos_t start, framepos_t end)
        if (covering.size() == 1) {
 
                rlist->push_back (covering.front());
+                DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("Just one covering region (%1)\n", covering.front()->name()));
 
        } else {
 
@@ -1665,11 +1820,21 @@ Playlist::regions_to_read (framepos_t start, framepos_t end)
 
                        here.clear ();
 
+                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("++++ Considering %1\n", *t));
+
                        for (RegionList::iterator x = covering.begin(); x != covering.end(); ++x) {
 
                                if ((*x)->covers (*t)) {
                                        here.push_back (*x);
-                               }
+                                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("region %1 covers %2\n",
+                                                                                           (*x)->name(),
+                                                                                           (*t)));
+                               } else {
+                                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("region %1 does NOT covers %2\n",
+                                                                                           (*x)->name(),
+                                                                                           (*t)));
+                                }
+                                        
                        }
 
                        RegionSortByLayer cmp;
@@ -1684,7 +1849,8 @@ Playlist::regions_to_read (framepos_t start, framepos_t end)
                                if ((*c)->opaque()) {
 
                                        /* the other regions at this position are hidden by this one */
-
+                                        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("%1 is opaque, ignore all others\n",
+                                                                                           (*c)->name()));
                                        break;
                                }
                        }
@@ -1702,6 +1868,8 @@ Playlist::regions_to_read (framepos_t start, framepos_t end)
                }
        }
 
+        DEBUG_TRACE (DEBUG::AudioPlayback, string_compose ("<<<<< REGIONS TO READ returns %1\n", rlist->size()));
+
        return rlist;
 }
 
@@ -1939,6 +2107,85 @@ Playlist::mark_session_dirty ()
        }
 }
 
+bool
+Playlist::set_property (const PropertyBase& prop)
+{
+        if (prop == Properties::regions.property_id) {
+                const RegionListProperty::ChangeRecord& change (dynamic_cast<const RegionListProperty*>(&prop)->change());
+                regions.update (change);
+                return (!change.added.empty() && !change.removed.empty());
+        }
+        return false;
+}
+
+void
+Playlist::rdiff (vector<StatefulDiffCommand*>& cmds) const
+{
+       RegionLock rlock (const_cast<Playlist *> (this));
+
+       for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
+               if ((*i)->changed ()) {
+                        StatefulDiffCommand* sdc = new StatefulDiffCommand (*i);
+                        cmds.push_back (sdc);
+                }
+       }
+}
+
+void
+Playlist::clear_owned_history ()
+{
+       RegionLock rlock (this);
+
+       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+                (*i)->clear_history ();
+        }
+}
+
+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()));
+        
+        freeze ();
+        /* add the added regions */
+        for (RegionListProperty::ChangeContainer::iterator i = change.added.begin(); i != change.added.end(); ++i) {
+                add_region ((*i), (*i)->position());
+        }
+        /* remove the removed regions */
+        for (RegionListProperty::ChangeContainer::iterator i = change.removed.begin(); i != change.removed.end(); ++i) {
+                remove_region (*i);
+        }
+
+        thaw ();
+}
+
+PropertyList*
+Playlist::property_factory (const XMLNode& history_node) const
+{
+        const XMLNodeList& children (history_node.children());
+        PropertyList* prop_list = 0;
+
+        for (XMLNodeList::const_iterator i = children.begin(); i != children.end(); ++i) {
+
+                if ((*i)->name() == capitalize (regions.property_name())) {
+                        
+                        RegionListProperty* rlp = new RegionListProperty (*const_cast<Playlist*> (this));
+
+                        if (rlp->load_history_state (**i)) {
+                                if (!prop_list) {
+                                        prop_list = new PropertyList();
+                                }
+                                prop_list->add (rlp);
+                        } else {
+                                delete rlp;
+                        }
+                }
+        }
+
+        return prop_list;
+}
+
 int
 Playlist::set_state (const XMLNode& node, int version)
 {
@@ -1968,6 +2215,9 @@ Playlist::set_state (const XMLNode& node, int version)
 
                if (prop->name() == X_("name")) {
                        _name = prop->value();
+                        _set_sort_id ();
+               } else if (prop->name() == X_("id")) {
+                        _id = prop->value();
                } else if (prop->name() == X_("orig_diskstream_id")) {
                        _orig_diskstream_id = prop->value ();
                } else if (prop->name() == X_("frozen")) {
@@ -1975,7 +2225,7 @@ Playlist::set_state (const XMLNode& node, int version)
                }
        }
 
-       clear (false);
+       clear (true);
 
        nlist = node.children();
 
@@ -1994,25 +2244,25 @@ Playlist::set_state (const XMLNode& node, int version)
 
                        if ((region = region_by_id (id))) {
 
-                               region->freeze ();
+                               region->suspend_property_changes ();
 
                                if (region->set_state (*child, version)) {
-                                       region->thaw ();
+                                       region->resume_property_changes ();
                                        continue;
                                }
                                
                        } else if ((region = RegionFactory::create (_session, *child, true)) != 0) {
-                               region->freeze ();
+                               region->suspend_property_changes ();
                        } else {
                                error << _("Playlist: cannot create region from XML") << endmsg;
                                continue;
                        }
-
+                        
                        add_region (region, region->position(), 1.0);
 
                        // So that layer_op ordering doesn't get screwed up
                        region->set_last_layer_op( region->layer());
-                       region->thaw ();
+                       region->resume_property_changes ();
                }
        }
 
@@ -2024,7 +2274,6 @@ Playlist::set_state (const XMLNode& node, int version)
                check_dependents (*r, false);
        }
 
-       clear_pending (); // this makes thaw() do nothing
        thaw ();
        notify_contents_changed ();
 
@@ -2053,6 +2302,7 @@ 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());
 
@@ -2088,27 +2338,29 @@ Playlist::n_regions() const
        return regions.size();
 }
 
-framecnt_t
-Playlist::get_maximum_extent () const
+pair<framecnt_t, framecnt_t>
+Playlist::get_extent () const
 {
        RegionLock rlock (const_cast<Playlist *>(this), false);
-       return _get_maximum_extent ();
+       return _get_extent ();
 }
 
-framecnt_t
-Playlist::_get_maximum_extent () const
+pair<framecnt_t, framecnt_t>
+Playlist::_get_extent () const
 {
-       RegionList::const_iterator i;
-       framecnt_t max_extent = 0;
-       framepos_t end = 0;
+       pair<framecnt_t, framecnt_t> ext (max_frames, 0);
 
-       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<framecnt_t, framecnt_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
@@ -2117,7 +2369,7 @@ Playlist::bump_name (string name, Session &session)
        string newname = name;
 
        do {
-               newname = bump_name_once (newname);
+               newname = bump_name_once (newname, '.');
        } while (session.playlists->by_name (newname)!=NULL);
 
        return newname;
@@ -2149,6 +2401,12 @@ Playlist::set_edit_mode (EditMode mode)
 void
 Playlist::relayer ()
 {
+        /* never compute layers when changing state for undo/redo or setting from XML */
+
+        if (in_update || in_set_state) {
+                return;
+        }
+
        bool changed = false;
 
        /* Build up a new list of regions on each layer, stored in a set of lists
@@ -2160,7 +2418,7 @@ Playlist::relayer ()
        int const divisions = 512;
 
        /* find the start and end positions of the regions on this playlist */
-       framepos_t start = UINT_MAX;
+       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());
@@ -2177,7 +2435,7 @@ Playlist::relayer ()
           which depends on the layer model
        */
 
-       RegionList copy = regions;
+       RegionList copy = regions.rlist();
 
        /* sort according to the model and the layering mode that we're in */
 
@@ -2191,19 +2449,28 @@ Playlist::relayer ()
 
        }
 
+
        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();
@@ -2291,22 +2558,48 @@ 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 ();
+       switch (_session.config.get_layer_model()) {
+       case LaterHigher:
+               return;
+       default:
+               break;
        }
+
+       layer_t top = regions.size() - 1;
+
+       if (region->layer() >= top) {
+               /* already on the top */
+               return;
+       }
+
+       move_region_to_layer (top, region, 1);
+       /* mark the region's last_layer_op as now, so that it remains on top when
+          doing future relayers (until something else takes over)
+        */
+       timestamp_layer_op (region);
 }
 
 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 ();
+       switch (_session.config.get_layer_model()) {
+       case LaterHigher:
+               return;
+       default:
+               break;
+       }
+
+       if (region->layer() == 0) {
+               /* already on the bottom */
+               return;
        }
+
+       move_region_to_layer (0, region, -1);
+       /* force region's last layer op to zero so that it stays at the bottom
+          when doing future relayers
+       */
+       region->set_last_layer_op (0);
 }
 
 int
@@ -2447,7 +2740,7 @@ Playlist::find_region (const ID& id) const
 }
 
 boost::shared_ptr<Region>
-Playlist::region_by_id (ID id)
+Playlist::region_by_id (const ID& id)
 {
        /* searches all regions ever added to this playlist */
 
@@ -2489,8 +2782,6 @@ Playlist::set_frozen (bool 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);
 }
 
@@ -2627,7 +2918,7 @@ void
 Playlist::update_after_tempo_map_change ()
 {
        RegionLock rlock (const_cast<Playlist*> (this));
-       RegionList copy (regions);
+       RegionList copy (regions.rlist());
 
        freeze ();
 
@@ -2682,3 +2973,22 @@ Playlist::has_region_at (framepos_t const p) const
 
        return (i != regions.end());
 }
+
+/** Remove any region that uses a given source */
+void
+Playlist::remove_region_by_source (boost::shared_ptr<Source> s)
+{
+       RegionLock rl (this);
+       
+       RegionList::iterator i = regions.begin();
+       while (i != regions.end()) {
+               RegionList::iterator j = i;
+               ++j;
+               
+               if ((*i)->uses_source (s)) {
+                       remove_region_internal (*i);
+               }
+
+               i = j;
+       }
+}