cleanup up cleanup at session destruction; clarify the meaning of 3 signals (DropRefe...
[ardour.git] / libs / ardour / audio_playlist.cc
index 7c4052d8ac9e6a0c3b4bab65df83231ff924aa15..1ecba28653f615f44838ed73c4a0c83c42bd8a45 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2003 Paul Davis 
+    Copyright (C) 2003 Paul Davis
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id$
 */
 
 #include <algorithm>
 
 #include <cstdlib>
 
-#include <sigc++/bind.h>
 
-#include <ardour/types.h>
-#include <ardour/configuration.h>
-#include <ardour/audioplaylist.h>
-#include <ardour/audioregion.h>
-#include <ardour/crossfade.h>
-#include <ardour/crossfade_compare.h>
-#include <ardour/session.h>
+#include "ardour/types.h"
+#include "ardour/configuration.h"
+#include "ardour/audioplaylist.h"
+#include "ardour/audioregion.h"
+#include "ardour/crossfade.h"
+#include "ardour/crossfade_compare.h"
+#include "ardour/session.h"
+#include "pbd/enumwriter.h"
 
 #include "i18n.h"
 
 using namespace ARDOUR;
-using namespace sigc;
 using namespace std;
 using namespace PBD;
 
-AudioPlaylist::State::~State ()
-{
-}
-
 AudioPlaylist::AudioPlaylist (Session& session, const XMLNode& node, bool hidden)
        : Playlist (session, node, DataType::AUDIO, hidden)
 {
        const XMLProperty* prop = node.property("type");
        assert(!prop || DataType(prop->value()) == DataType::AUDIO);
 
-       in_set_state = true;
-       set_state (node);
-       in_set_state = false;
-
-       save_state (_("initial state"));
-
-       if (!hidden) {
-               PlaylistCreated (this); /* EMIT SIGNAL */
-       }
+       in_set_state++;
+       set_state (node, Stateful::loading_state_version);
+       in_set_state--;
 }
 
 AudioPlaylist::AudioPlaylist (Session& session, string name, bool hidden)
        : Playlist (session, name, DataType::AUDIO, hidden)
 {
-       save_state (_("initial state"));
-
-       if (!hidden) {
-               PlaylistCreated (this); /* EMIT SIGNAL */
-       }
-
 }
 
-AudioPlaylist::AudioPlaylist (const AudioPlaylist& other, string name, bool hidden)
+AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, string name, bool hidden)
        : Playlist (other, name, hidden)
 {
-       save_state (_("initial state"));
-
-       RegionList::const_iterator in_o  = other.regions.begin();
+       RegionList::const_iterator in_o  = other->regions.begin();
        RegionList::iterator in_n = regions.begin();
 
-       while (in_o != other.regions.end()) {
+       while (in_o != other->regions.end()) {
                boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(*in_o);
 
                // We look only for crossfades which begin with the current region, so we don't get doubles
-               for (list<Crossfade *>::const_iterator xfades = other._crossfades.begin(); xfades != other._crossfades.end(); ++xfades) {
+               for (Crossfades::const_iterator xfades = other->_crossfades.begin(); xfades != other->_crossfades.end(); ++xfades) {
                        if ((*xfades)->in() == ar) {
                                // We found one! Now copy it!
 
-                               RegionList::const_iterator out_o = other.regions.begin();
+                               RegionList::const_iterator out_o = other->regions.begin();
                                RegionList::const_iterator out_n = regions.begin();
 
-                               while (out_o != other.regions.end()) {
-                                       
+                               while (out_o != other->regions.end()) {
+
                                        boost::shared_ptr<AudioRegion>ar2 = boost::dynamic_pointer_cast<AudioRegion>(*out_o);
-                                       
+
                                        if ((*xfades)->out() == ar2) {
                                                boost::shared_ptr<AudioRegion>in  = boost::dynamic_pointer_cast<AudioRegion>(*in_n);
                                                boost::shared_ptr<AudioRegion>out = boost::dynamic_pointer_cast<AudioRegion>(*out_n);
-                                               Crossfade *new_fade = new Crossfade (*(*xfades), in, out);
-                                               add_crossfade(*new_fade);
+                                               boost::shared_ptr<Crossfade> new_fade = boost::shared_ptr<Crossfade> (new Crossfade (*xfades, in, out));
+                                               add_crossfade(new_fade);
                                                break;
                                        }
-                                       
+
                                        out_o++;
                                        out_n++;
                                }
@@ -112,50 +92,17 @@ AudioPlaylist::AudioPlaylist (const AudioPlaylist& other, string name, bool hidd
                in_o++;
                in_n++;
        }
-
-       if (!hidden) {
-               PlaylistCreated (this); /* EMIT SIGNAL */
-       }
 }
 
-AudioPlaylist::AudioPlaylist (const AudioPlaylist& other, nframes_t start, nframes_t cnt, string name, bool hidden)
+AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, nframes_t start, nframes_t cnt, string name, bool hidden)
        : Playlist (other, start, cnt, name, hidden)
 {
-       save_state (_("initial state"));
-
        /* this constructor does NOT notify others (session) */
 }
 
 AudioPlaylist::~AudioPlaylist ()
 {
-       set<Crossfade*> all_xfades;
-
-       GoingAway (); /* EMIT SIGNAL */
-
-       /* drop connections to signals */
-
-       notify_callbacks ();
-
-       for (Crossfades::iterator x = _crossfades.begin(); x != _crossfades.end(); ++x) {
-               all_xfades.insert (*x);
-       }
-
-       for (StateMap::iterator i = states.begin(); i != states.end(); ++i) {
-
-               AudioPlaylist::State* apstate = dynamic_cast<AudioPlaylist::State*> (*i);
-
-               for (Crossfades::iterator xf = apstate->crossfades.begin(); xf != apstate->crossfades.end(); ++xf) {
-                       all_xfades.insert (*xf);
-               }
-
-               delete apstate;
-       }
-
-       /* delete every crossfade */
-
-       for (set<Crossfade *>::iterator axf = all_xfades.begin(); axf != all_xfades.end(); ++axf) {
-               delete *axf;
-       }
+       _crossfades.clear ();
 }
 
 struct RegionSortByLayer {
@@ -174,9 +121,9 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
        nframes_t skip_frames;
 
        /* optimizing this memset() away involves a lot of conditionals
-          that may well cause more of a hit due to cache misses 
+          that may well cause more of a hit due to cache misses
           and related stuff than just doing this here.
-          
+
           it would be great if someone could measure this
           at some point.
 
@@ -188,23 +135,31 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
 
        memset (buf, 0, sizeof (Sample) * cnt);
 
-       /* this function is never called from a realtime thread, so 
+       /* this function is never called from a realtime thread, so
           its OK to block (for short intervals).
        */
 
-       Glib::Mutex::Lock rm (region_lock);
+       Glib::RecMutex::Lock rm (region_lock);
 
        end =  start + cnt - 1;
-
        read_frames = 0;
        skip_frames = 0;
        _read_data_count = 0;
 
+       _read_data_count = 0;
+
+       RegionList* rlist = regions_to_read (start, start+cnt);
+
+       if (rlist->empty()) {
+               delete rlist;
+               return cnt;
+       }
+
        map<uint32_t,vector<boost::shared_ptr<Region> > > relevant_regions;
-       map<uint32_t,vector<Crossfade*> > relevant_xfades;
+       map<uint32_t,vector<boost::shared_ptr<Crossfade> > > relevant_xfades;
        vector<uint32_t> relevant_layers;
 
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+       for (RegionList::iterator i = rlist->begin(); i != rlist->end(); ++i) {
                if ((*i)->coverage (start, end) != OverlapNone) {
                        relevant_regions[(*i)->layer()].push_back (*i);
                        relevant_layers.push_back ((*i)->layer());
@@ -231,7 +186,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
        for (vector<uint32_t>::iterator l = relevant_layers.begin(); l != relevant_layers.end(); ++l) {
 
                vector<boost::shared_ptr<Region> > r (relevant_regions[*l]);
-               vector<Crossfade*>& x (relevant_xfades[*l]);
+               vector<boost::shared_ptr<Crossfade> >& x (relevant_xfades[*l]);
 
                for (vector<boost::shared_ptr<Region> >::iterator i = r.begin(); i != r.end(); ++i) {
                        boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(*i);
@@ -239,8 +194,8 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
                        ar->read_at (buf, mixdown_buffer, gain_buffer, start, cnt, chan_n, read_frames, skip_frames);
                        _read_data_count += ar->read_data_count();
                }
-               
-               for (vector<Crossfade*>::iterator i = x.begin(); i != x.end(); ++i) {
+
+               for (vector<boost::shared_ptr<Crossfade> >::iterator i = x.begin(); i != x.end(); ++i) {
                        (*i)->read_at (buf, mixdown_buffer, gain_buffer, start, cnt, chan_n);
 
                        /* don't JACK up _read_data_count, since its the same data as we just
@@ -249,6 +204,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
                }
        }
 
+       delete rlist;
        return ret;
 }
 
@@ -256,25 +212,25 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
 void
 AudioPlaylist::remove_dependents (boost::shared_ptr<Region> region)
 {
-       Crossfades::iterator i, tmp;
        boost::shared_ptr<AudioRegion> r = boost::dynamic_pointer_cast<AudioRegion> (region);
-       
+
+       if (in_set_state) {
+               return;
+       }
+
        if (r == 0) {
                fatal << _("programming error: non-audio Region passed to remove_overlap in audio playlist")
                      << endmsg;
                return;
        }
 
-       for (i = _crossfades.begin(); i != _crossfades.end(); ) {
-               tmp = i;
-               tmp++;
+       for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); ) {
 
                if ((*i)->involves (r)) {
-                       /* do not delete crossfades */
-                       _crossfades.erase (i);
+                       i = _crossfades.erase (i);
+               } else {
+                       ++i;
                }
-               
-               i = tmp;
        }
 }
 
@@ -296,7 +252,7 @@ AudioPlaylist::flush_notifications ()
        }
 
        _pending_xfade_adds.clear ();
-       
+
        in_flush = false;
 }
 
@@ -304,7 +260,7 @@ void
 AudioPlaylist::refresh_dependents (boost::shared_ptr<Region> r)
 {
        boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(r);
-       set<Crossfade*> updated;
+       set<boost::shared_ptr<Crossfade> > updated;
 
        if (ar == 0) {
                return;
@@ -313,7 +269,7 @@ AudioPlaylist::refresh_dependents (boost::shared_ptr<Region> r)
        for (Crossfades::iterator x = _crossfades.begin(); x != _crossfades.end();) {
 
                Crossfades::iterator tmp;
-               
+
                tmp = x;
                ++tmp;
 
@@ -321,10 +277,16 @@ AudioPlaylist::refresh_dependents (boost::shared_ptr<Region> r)
 
                if ((*x)->involves (ar)) {
 
-                       if (find (updated.begin(), updated.end(), *x) == updated.end()) {
-                               if ((*x)->refresh ()) {
-                                       /* not invalidated by the refresh */
-                                       updated.insert (*x);
+                       pair<set<boost::shared_ptr<Crossfade> >::iterator, bool> const u = updated.insert (*x);
+
+                       if (u.second) {
+                               /* x was successfully inserted into the set, so it has not already been updated */
+                               try {
+                                       (*x)->refresh ();
+                               }
+
+                               catch (Crossfade::NoCrossfadeHere& err) {
+                                       // relax, Invalidated during refresh
                                }
                        }
                }
@@ -345,29 +307,29 @@ AudioPlaylist::finalize_split_region (boost::shared_ptr<Region> o, boost::shared
                tmp = x;
                ++tmp;
 
-               Crossfade *fade = 0;
-               
+               boost::shared_ptr<Crossfade> fade;
+
                if ((*x)->_in == orig) {
                        if (! (*x)->covers(right->position())) {
-                               fade = new Crossfade (**x, left, (*x)->_out);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, left, (*x)->_out));
                        } else {
                                // Overlap, the crossfade is copied on the left side of the right region instead
-                               fade = new Crossfade (**x, right, (*x)->_out);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, right, (*x)->_out));
                        }
                }
-               
+
                if ((*x)->_out == orig) {
                        if (! (*x)->covers(right->position())) {
-                               fade = new Crossfade (**x, (*x)->_in, right);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, (*x)->_in, right));
                        } else {
                                // Overlap, the crossfade is copied on the right side of the left region instead
-                               fade = new Crossfade (**x, (*x)->_in, left);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, (*x)->_in, left));
                        }
                }
-               
+
                if (fade) {
                        _crossfades.remove (*x);
-                       add_crossfade (*fade);
+                       add_crossfade (fade);
                }
                x = tmp;
        }
@@ -380,7 +342,8 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
        boost::shared_ptr<AudioRegion> region;
        boost::shared_ptr<AudioRegion> top;
        boost::shared_ptr<AudioRegion> bottom;
-       Crossfade*   xfade;
+       boost::shared_ptr<Crossfade>   xfade;
+       RegionList*  touched_regions = 0;
 
        if (in_set_state || in_partition) {
                return;
@@ -396,12 +359,15 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
                refresh_dependents (r);
        }
 
-       if (!Config->get_auto_xfade()) {
+
+       if (!_session.config.get_auto_xfade()) {
                return;
        }
 
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 
+               nframes_t xfade_length;
+
                other = boost::dynamic_pointer_cast<AudioRegion> (*i);
 
                if (other == region) {
@@ -412,6 +378,7 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
                        continue;
                }
 
+
                if (other->layer() < region->layer()) {
                        top = region;
                        bottom = other;
@@ -420,78 +387,151 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
                        bottom = region;
                }
 
+               if (!top->opaque()) {
+                       continue;
+               }
+
+               OverlapType c = top->coverage (bottom->position(), bottom->last_frame());
+
+               delete touched_regions;
+               touched_regions = 0;
+
                try {
-                               
-                       if (top->coverage (bottom->position(), bottom->last_frame()) != OverlapNone) {
-                               
-                               /* check if the upper region is within the lower region */
-                               
-                               if (top->first_frame() > bottom->first_frame() &&
-                                   top->last_frame() < bottom->last_frame()) {
-                                       
-                                       
-                                       /*     [ -------- top ------- ]
-                                        * {=========== bottom =============}
-                                        */
-                                       
-                                       /* to avoid discontinuities at the region boundaries of an internal
-                                          overlap (this region is completely within another), we create
-                                          two hidden crossfades at each boundary. this is not dependent
-                                          on the auto-xfade option, because we require it as basic
-                                          audio engineering.
+                       switch (c) {
+                       case OverlapNone:
+                               break;
+
+                       case OverlapInternal:
+                                /* {=============== top  =============}
+                                 *     [ ----- bottom  ------- ]
+                                 */
+                               break;
+
+                       case OverlapExternal:
+
+                               /*     [ -------- top ------- ]
+                                * {=========== bottom =============}
+                                */
+
+                               /* to avoid discontinuities at the region boundaries of an internal
+                                  overlap (this region is completely within another), we create
+                                  two hidden crossfades at each boundary. this is not dependent
+                                  on the auto-xfade option, because we require it as basic
+                                  audio engineering.
+                               */
+
+                               xfade_length = min ((nframes_t) 720, top->length());
+
+                               if (top_region_at (top->first_frame()) == top) {
+
+                                       xfade = boost::shared_ptr<Crossfade> (new Crossfade (top, bottom, xfade_length, top->first_frame(), StartOfIn));
+                                       add_crossfade (xfade);
+                               }
+
+                               if (top_region_at (top->last_frame() - 1) == top) {
+
+                                       /*
+                                          only add a fade out if there is no region on top of the end of 'top' (which
+                                          would cover it).
                                        */
-                                       
-                                       nframes_t xfade_length = min ((nframes_t) 720, top->length());
-                                       
-                                                           /*  in,      out */
-                                       xfade = new Crossfade (top, bottom, xfade_length, top->first_frame(), StartOfIn);
-                                       add_crossfade (*xfade);
-                                       xfade = new Crossfade (bottom, top, xfade_length, top->last_frame() - xfade_length, EndOfOut);
-                                       add_crossfade (*xfade);
-                                       
+
+                                       xfade = boost::shared_ptr<Crossfade> (new Crossfade (bottom, top, xfade_length, top->last_frame() - xfade_length, EndOfOut));
+                                       add_crossfade (xfade);
+                               }
+                               break;
+                       case OverlapStart:
+
+                               /*                   { ==== top ============ }
+                                *   [---- bottom -------------------]
+                                */
+
+                               if (_session.config.get_xfade_model() == FullCrossfade) {
+                                       touched_regions = regions_touched (top->first_frame(), bottom->last_frame());
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
+                               } else {
+
+                                       touched_regions = regions_touched (top->first_frame(),
+                                                                          top->first_frame() + min ((nframes_t)_session.config.get_short_xfade_seconds() * _session.frame_rate(),
+                                                                                                    top->length()));
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
+                               }
+                               break;
+                       case OverlapEnd:
+
+
+                               /* [---- top ------------------------]
+                                *                { ==== bottom ============ }
+                                */
+
+                               if (_session.config.get_xfade_model() == FullCrossfade) {
+
+                                       touched_regions = regions_touched (bottom->first_frame(), top->last_frame());
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other,
+                                                                                                    _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
+
                                } else {
-               
-                                       xfade = new Crossfade (other, region, Config->get_xfade_model(), Config->get_crossfades_active());
-                                       add_crossfade (*xfade);
+                                       touched_regions = regions_touched (bottom->first_frame(),
+                                                                          bottom->first_frame() + min ((nframes_t)_session.config.get_short_xfade_seconds() * _session.frame_rate(),
+                                                                                                       bottom->length()));
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
                                }
-                       } 
+                               break;
+                       default:
+                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other,
+                                                                                    _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                               add_crossfade (xfade);
+                       }
                }
-               
+
                catch (failed_constructor& err) {
                        continue;
                }
-               
+
                catch (Crossfade::NoCrossfadeHere& err) {
                        continue;
                }
-               
+
        }
+
+       delete touched_regions;
 }
 
 void
-AudioPlaylist::add_crossfade (Crossfade& xfade)
+AudioPlaylist::add_crossfade (boost::shared_ptr<Crossfade> xfade)
 {
        Crossfades::iterator ci;
 
        for (ci = _crossfades.begin(); ci != _crossfades.end(); ++ci) {
-               if (*(*ci) == xfade) { // Crossfade::operator==()
+               if (*(*ci) == *xfade) { // Crossfade::operator==()
                        break;
                }
        }
-       
+
        if (ci != _crossfades.end()) {
-               delete &xfade;
+               // it will just go away
        } else {
-               _crossfades.push_back (&xfade);
+               _crossfades.push_back (xfade);
 
-               xfade.Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
-               xfade.StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
+               xfade->Invalidated.connect_same_thread (*this, boost::bind (&AudioPlaylist::crossfade_invalidated, this, _1));
+               xfade->StateChanged.connect_same_thread (*this, boost::bind (&AudioPlaylist::crossfade_changed, this, _1));
 
-               notify_crossfade_added (&xfade);
+               notify_crossfade_added (xfade);
        }
 }
-       
-void AudioPlaylist::notify_crossfade_added (Crossfade *x)
+
+void AudioPlaylist::notify_crossfade_added (boost::shared_ptr<Crossfade> x)
 {
        if (g_atomic_int_get(&block_notifications)) {
                _pending_xfade_adds.insert (_pending_xfade_adds.end(), x);
@@ -501,9 +541,10 @@ void AudioPlaylist::notify_crossfade_added (Crossfade *x)
 }
 
 void
-AudioPlaylist::crossfade_invalidated (Crossfade* xfade)
+AudioPlaylist::crossfade_invalidated (boost::shared_ptr<Region> r)
 {
        Crossfades::iterator i;
+       boost::shared_ptr<Crossfade> xfade = boost::dynamic_pointer_cast<Crossfade> (r);
 
        xfade->in()->resume_fade_in ();
        xfade->out()->resume_fade_out ();
@@ -514,15 +555,17 @@ AudioPlaylist::crossfade_invalidated (Crossfade* xfade)
 }
 
 int
-AudioPlaylist::set_state (const XMLNode& node)
+AudioPlaylist::set_state (const XMLNode& node, int version)
 {
        XMLNode *child;
        XMLNodeList nlist;
        XMLNodeConstIterator niter;
 
-       if (!in_set_state) {
-               Playlist::set_state (node);
-       }
+       in_set_state++;
+
+       Playlist::set_state (node, version);
+
+       freeze ();
 
        nlist = node.children();
 
@@ -530,155 +573,37 @@ AudioPlaylist::set_state (const XMLNode& node)
 
                child = *niter;
 
-               if (child->name() == "Crossfade") {
-
-                       Crossfade *xfade;
-                       
-                       try {
-                               xfade = new Crossfade (*((const Playlist *)this), *child);
-                       }
-
-                       catch (failed_constructor& err) {
-                         //    cout << string_compose (_("could not create crossfade object in playlist %1"),
-                         //      _name) 
-                         //    << endl;
-                               continue;
-                       }
-
-                       Crossfades::iterator ci;
-
-                       for (ci = _crossfades.begin(); ci != _crossfades.end(); ++ci) {
-                               if (*(*ci) == *xfade) {
-                                       break;
-                               }
-                       }
-
-                       if (ci == _crossfades.end()) {
-                               _crossfades.push_back (xfade);
-                               xfade->Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
-                               xfade->StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
-                               NewCrossfade(xfade);
-                       } else {
-                               delete xfade;
-                       }
-               }
-
-       }
-
-       return 0;
-}
-
-void
-AudioPlaylist::drop_all_states ()
-{
-       set<Crossfade*> all_xfades;
-       set<boost::shared_ptr<Region> > all_regions;
-
-       /* find every region we've ever used, and add it to the set of 
-          all regions. same for xfades;
-       */
-
-       for (StateMap::iterator i = states.begin(); i != states.end(); ++i) {
-               
-               AudioPlaylist::State* apstate = dynamic_cast<AudioPlaylist::State*> (*i);
-
-               for (RegionList::iterator r = apstate->regions.begin(); r != apstate->regions.end(); ++r) {
-                       all_regions.insert (*r);
-               }
-
-               for (Crossfades::iterator xf = apstate->crossfades.begin(); xf != apstate->crossfades.end(); ++xf) {
-                       all_xfades.insert (*xf);
-               }
-       }
-
-       /* now remove from the "all" lists every region that is in the current list. */
-
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-               set<boost::shared_ptr<Region> >::iterator x = all_regions.find (*i);
-               if (x != all_regions.end()) {
-                       all_regions.erase (x);
-               }
-       }
-
-       /* ditto for every crossfade */
-
-       for (list<Crossfade*>::iterator i = _crossfades.begin(); i != _crossfades.end(); ++i) {
-               set<Crossfade*>::iterator x = all_xfades.find (*i);
-               if (x != all_xfades.end()) {
-                       all_xfades.erase (x);
+               if (child->name() != "Crossfade") {
+                       continue;
                }
-       }
-
-       /* delete every crossfade that is left (ditto as per regions) */
-
-       for (set<Crossfade *>::iterator axf = all_xfades.begin(); axf != all_xfades.end(); ++axf) {
-               delete *axf;
-       }
-
-       /* Now do the generic thing ... */
-
-       StateManager::drop_all_states ();
-}
-
-StateManager::State*
-AudioPlaylist::state_factory (std::string why) const
-{
-       State* state = new State (why);
-
-       state->regions = regions;
-       state->region_states.clear ();
-       for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
-               state->region_states.push_back ((*i)->get_memento());
-       }
-
-       state->crossfades = _crossfades;
-       state->crossfade_states.clear ();
-       for (Crossfades::const_iterator i = _crossfades.begin(); i != _crossfades.end(); ++i) {
-               state->crossfade_states.push_back ((*i)->get_memento());
-       }
-       return state;
-}
-
-Change
-AudioPlaylist::restore_state (StateManager::State& state)
-{ 
-       { 
-               RegionLock rlock (this);
-               State* apstate = dynamic_cast<State*> (&state);
-
-               in_set_state = true;
 
-               regions = apstate->regions;
-
-               for (list<UndoAction>::iterator s = apstate->region_states.begin(); s != apstate->region_states.end(); ++s) {
-                       (*s) ();
+               try {
+                       boost::shared_ptr<Crossfade> xfade = boost::shared_ptr<Crossfade> (new Crossfade (*((const Playlist *)this), *child));
+                       _crossfades.push_back (xfade);
+                       xfade->Invalidated.connect_same_thread (*this, boost::bind (&AudioPlaylist::crossfade_invalidated, this, _1));
+                       xfade->StateChanged.connect_same_thread (*this, boost::bind (&AudioPlaylist::crossfade_changed, this, _1));
+                       NewCrossfade(xfade);
                }
 
-               _crossfades = apstate->crossfades;
-               
-               for (list<UndoAction>::iterator s = apstate->crossfade_states.begin(); s != apstate->crossfade_states.end(); ++s) {
-                       (*s) ();
+               catch (failed_constructor& err) {
+                       //      cout << string_compose (_("could not create crossfade object in playlist %1"),
+                       //        _name)
+                       //    << endl;
+                       continue;
                }
-
-               in_set_state = false;
        }
 
-       notify_length_changed ();
-       return Change (~0);
-}
+       thaw ();
+       in_set_state--;
 
-UndoAction
-AudioPlaylist::get_memento () const
-{
-       return sigc::bind (mem_fun (*(const_cast<AudioPlaylist*> (this)), &StateManager::use_state), _current_state_id);
+       return 0;
 }
 
 void
-AudioPlaylist::clear (bool with_save)
+AudioPlaylist::clear (bool with_signals)
 {
        _crossfades.clear ();
-       
-       Playlist::clear (with_save);
+       Playlist::clear (with_signals);
 }
 
 XMLNode&
@@ -691,7 +616,7 @@ AudioPlaylist::state (bool full_state)
                        node.add_child_nocopy ((*i)->get_state());
                }
        }
-       
+
        return node;
 }
 
@@ -699,7 +624,7 @@ void
 AudioPlaylist::dump () const
 {
        boost::shared_ptr<Region>r;
-       Crossfade *x;
+       boost::shared_ptr<Crossfade> x;
 
        cerr << "Playlist \"" << _name << "\" " << endl
             << regions.size() << " regions "
@@ -708,9 +633,9 @@ AudioPlaylist::dump () const
 
        for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
                r = *i;
-               cerr << "  " << r->name() << " @ " << r << " [" 
-                    << r->start() << "+" << r->length() 
-                    << "] at " 
+               cerr << "  " << r->name() << " @ " << r << " ["
+                    << r->start() << "+" << r->length()
+                    << "] at "
                     << r->position()
                     << " on layer "
                     << r->layer ()
@@ -719,13 +644,13 @@ AudioPlaylist::dump () const
 
        for (Crossfades::const_iterator i = _crossfades.begin(); i != _crossfades.end(); ++i) {
                x = *i;
-               cerr << "  xfade [" 
+               cerr << "  xfade ["
                     << x->out()->name()
                     << ','
                     << x->in()->name()
                     << " @ "
                     << x->position()
-                    << " length = " 
+                    << " length = "
                     << x->length ()
                     << " active ? "
                     << (x->active() ? "yes" : "no")
@@ -739,7 +664,7 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
        boost::shared_ptr<AudioRegion> r = boost::dynamic_pointer_cast<AudioRegion> (region);
        bool changed = false;
        Crossfades::iterator c, ctmp;
-       set<Crossfade*> unique_xfades;
+       set<boost::shared_ptr<Crossfade> > unique_xfades;
 
        if (r == 0) {
                fatal << _("programming error: non-audio Region passed to remove_overlap in audio playlist")
@@ -748,85 +673,48 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
                return false;
        }
 
-       { 
+       {
                RegionLock rlock (this);
-               RegionList::iterator i;
-               RegionList::iterator tmp;
 
-               for (i = regions.begin(); i != regions.end(); ) {
-                       
-                       tmp = i;
+               for (RegionList::iterator i = regions.begin(); i != regions.end(); ) {
+
+                       RegionList::iterator tmp = i;
                        ++tmp;
-                       
+
                        if ((*i) == region) {
                                regions.erase (i);
                                changed = true;
                        }
-                       
-                       i = tmp;
-               }
-       }
-
-       for (c = _crossfades.begin(); c != _crossfades.end(); ) {
-               ctmp = c;
-               ++ctmp;
 
-               if ((*c)->involves (r)) {
-                       unique_xfades.insert (*c);
-                       _crossfades.erase (c);
+                       i = tmp;
                }
-               
-               c = ctmp;
-       }
-
-       for (StateMap::iterator s = states.begin(); s != states.end(); ) {
-               StateMap::iterator tmp;
 
-               tmp = s;
-               ++tmp;
-
-               State* astate = dynamic_cast<State*> (*s);
-               
-               for (c = astate->crossfades.begin(); c != astate->crossfades.end(); ) {
+               for (set<boost::shared_ptr<Region> >::iterator x = all_regions.begin(); x != all_regions.end(); ) {
 
-                       ctmp = c;
-                       ++ctmp;
+                       set<boost::shared_ptr<Region> >::iterator xtmp = x;
+                       ++xtmp;
 
-                       if ((*c)->involves (r)) {
-                               unique_xfades.insert (*c);
-                               _crossfades.erase (c);
+                       if ((*x) == region) {
+                               all_regions.erase (x);
+                               changed = true;
                        }
 
-                       c = ctmp;
+                       x = xtmp;
                }
 
-               list<UndoAction>::iterator rsi, rsitmp;
-               RegionList::iterator ri, ritmp;
-
-               for (ri = astate->regions.begin(), rsi = astate->region_states.begin(); 
-                    ri != astate->regions.end() && rsi != astate->region_states.end();) {
-
-
-                       ritmp = ri;
-                       ++ritmp;
-
-                       rsitmp = rsi; 
-                       ++rsitmp;
+               region->set_playlist (boost::shared_ptr<Playlist>());
+       }
 
-                       if (region == (*ri)) {
-                               astate->regions.erase (ri);
-                               astate->region_states.erase (rsi);
-                       }
+       for (c = _crossfades.begin(); c != _crossfades.end(); ) {
+               ctmp = c;
+               ++ctmp;
 
-                       ri = ritmp;
-                       rsi = rsitmp;
+               if ((*c)->involves (r)) {
+                       unique_xfades.insert (*c);
+                       _crossfades.erase (c);
                }
-               
-               s = tmp;
-       }
 
-       for (set<Crossfade*>::iterator c = unique_xfades.begin(); c != unique_xfades.end(); ++c) {
-               delete *c;
+               c = ctmp;
        }
 
        if (changed) {
@@ -838,7 +726,7 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 }
 
 void
-AudioPlaylist::crossfade_changed (Change ignored)
+AudioPlaylist::crossfade_changed (Change)
 {
        if (in_flush || in_set_state) {
                return;
@@ -850,8 +738,6 @@ AudioPlaylist::crossfade_changed (Change ignored)
           that occured.
        */
 
-       maybe_save_state (_("xfade change"));
-
        notify_modified ();
 }
 
@@ -873,13 +759,11 @@ AudioPlaylist::region_changed (Change what_changed, boost::shared_ptr<Region> re
 
        parent_wants_notify = Playlist::region_changed (what_changed, region);
 
-       maybe_save_state (_("region modified"));
-
        if ((parent_wants_notify || (what_changed & our_interests))) {
                notify_modified ();
        }
 
-       return true; 
+       return true;
 }
 
 void
@@ -895,7 +779,15 @@ AudioPlaylist::crossfades_at (nframes_t frame, Crossfades& clist)
 
                if (frame >= start && frame <= end) {
                        clist.push_back (*i);
-               } 
+               }
        }
 }
 
+void
+AudioPlaylist::foreach_crossfade (boost::function<void (boost::shared_ptr<Crossfade>)> s)
+{
+       RegionLock rl (this, false);
+       for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); ++i) {
+               s (*i);
+       }
+}