X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fmidi_region.cc;h=eef2811c5b963c7b438862cb02486ba86f0c783c;hb=c8c6bca6587450ff64303dbc994a4cd28d6ce7aa;hp=cc1ba4b2a86da96a3d86a79710dd838e434396e4;hpb=badc087263990ecf360792c10e4d9f2d60828d43;p=ardour.git

diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index cc1ba4b2a8..eef2811c5b 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000-2006 Paul Davis 
+    Copyright (C) 2000-2006 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
@@ -24,248 +24,382 @@
 
 #include <set>
 
-#include <sigc++/bind.h>
-#include <sigc++/class_slot.h>
+#include <glibmm/threads.h>
+#include <glibmm/fileutils.h>
+#include <glibmm/miscutils.h>
 
-#include <glibmm/thread.h>
+#include "evoral/Beats.hpp"
 
-#include <pbd/basename.h>
-#include <pbd/xml++.h>
-#include <pbd/enumwriter.h>
+#include "pbd/xml++.h"
+#include "pbd/basename.h"
 
-#include <ardour/midi_region.h>
-#include <ardour/session.h>
-#include <ardour/gain.h>
-#include <ardour/dB.h>
-#include <ardour/playlist.h>
-#include <ardour/midi_source.h>
-#include <ardour/types.h>
-#include <ardour/midi_ring_buffer.h>
+#include "ardour/automation_control.h"
+#include "ardour/midi_model.h"
+#include "ardour/midi_region.h"
+#include "ardour/midi_ring_buffer.h"
+#include "ardour/midi_source.h"
+#include "ardour/region_factory.h"
+#include "ardour/session.h"
+#include "ardour/source_factory.h"
+#include "ardour/tempo.h"
+#include "ardour/types.h"
 
-#include "i18n.h"
+#include "pbd/i18n.h"
 #include <locale.h>
 
 using namespace std;
 using namespace ARDOUR;
+using namespace PBD;
 
-/** Basic MidiRegion constructor (one channel) */
-MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nframes_t length)
-	: Region (src, start, length, PBD::basename_nosuffix(src->name()), DataType::MIDI, 0,  Region::Flag(Region::DefaultFlags|Region::External))
+namespace ARDOUR {
+	namespace Properties {
+		PBD::PropertyDescriptor<Evoral::Beats> start_beats;
+		PBD::PropertyDescriptor<Evoral::Beats> length_beats;
+	}
+}
+
+void
+MidiRegion::make_property_quarks ()
 {
-	assert(_name.find("/") == string::npos);
-	midi_source(0)->Switched.connect(sigc::mem_fun(this, &MidiRegion::switch_source));
+	Properties::start_beats.property_id = g_quark_from_static_string (X_("start-beats"));
+	DEBUG_TRACE (DEBUG::Properties, string_compose ("quark for start-beats = %1\n", Properties::start_beats.property_id));
+	Properties::length_beats.property_id = g_quark_from_static_string (X_("length-beats"));
+	DEBUG_TRACE (DEBUG::Properties, string_compose ("quark for length-beats = %1\n", Properties::length_beats.property_id));
 }
 
-/* Basic MidiRegion constructor (one channel) */
-MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (src, start, length, name, DataType::MIDI, layer, flags)
+void
+MidiRegion::register_properties ()
 {
-	assert(_name.find("/") == string::npos);
-	midi_source(0)->Switched.connect(sigc::mem_fun(this, &MidiRegion::switch_source));
+	add_property (_start_beats);
+	add_property (_length_beats);
 }
 
 /* Basic MidiRegion constructor (many channels) */
-MidiRegion::MidiRegion (SourceList& srcs, nframes_t start, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (srcs, start, length, name, DataType::MIDI, layer, flags)
+MidiRegion::MidiRegion (const SourceList& srcs)
+	: Region (srcs)
+	, _start_beats (Properties::start_beats, Evoral::Beats())
+	, _length_beats (Properties::length_beats, midi_source(0)->length_beats())
 {
-	assert(_name.find("/") == string::npos);
-	midi_source(0)->Switched.connect(sigc::mem_fun(this, &MidiRegion::switch_source));
+	register_properties ();
+
+	midi_source(0)->ModelChanged.connect_same_thread (_source_connection, boost::bind (&MidiRegion::model_changed, this));
+	model_changed ();
+	assert(_name.val().find("/") == string::npos);
+	assert(_type == DataType::MIDI);
 }
 
+MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other)
+	: Region (other)
+	, _start_beats (Properties::start_beats, other->_start_beats)
+	, _length_beats (Properties::length_beats, other->_length_beats)
+{
+	//update_length_beats ();
+	register_properties ();
+
+	assert(_name.val().find("/") == string::npos);
+	midi_source(0)->ModelChanged.connect_same_thread (_source_connection, boost::bind (&MidiRegion::model_changed, this));
+	model_changed ();
+}
 
-/** Create a new MidiRegion, that is part of an existing one */
-MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other, nframes_t offset, nframes_t length, const string& name, layer_t layer, Flag flags)
-	: Region (other, offset, length, name, layer, flags)
+/** Create a new MidiRegion that is part of an existing one */
+MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other, frameoffset_t offset, const int32_t sub_num)
+	: Region (other, offset, sub_num)
+	, _start_beats (Properties::start_beats, Evoral::Beats())
+	, _length_beats (Properties::length_beats, other->_length_beats)
 {
-	assert(_name.find("/") == string::npos);
-	midi_source(0)->Switched.connect(sigc::mem_fun(this, &MidiRegion::switch_source));
+	_start_beats = Evoral::Beats (_session.tempo_map().exact_beat_at_frame ((other->_position + offset), sub_num) - other->beat()) + other->_start_beats;
+	update_length_beats (sub_num);
+	register_properties ();
+
+	assert(_name.val().find("/") == string::npos);
+	midi_source(0)->ModelChanged.connect_same_thread (_source_connection, boost::bind (&MidiRegion::model_changed, this));
+	model_changed ();
 }
 
-MidiRegion::MidiRegion (boost::shared_ptr<const MidiRegion> other)
-	: Region (other)
+MidiRegion::~MidiRegion ()
 {
-	assert(_name.find("/") == string::npos);
-	midi_source(0)->Switched.connect(sigc::mem_fun(this, &MidiRegion::switch_source));
 }
 
-MidiRegion::MidiRegion (boost::shared_ptr<MidiSource> src, const XMLNode& node)
-	: Region (src, node)
+/** Export the MIDI data of the MidiRegion to a new MIDI file (SMF).
+ */
+bool
+MidiRegion::do_export (string path) const
 {
-	if (set_state (node)) {
-		throw failed_constructor();
+	boost::shared_ptr<MidiSource> newsrc;
+
+	/* caller must check for pre-existing file */
+	assert (!path.empty());
+	assert (!Glib::file_test (path, Glib::FILE_TEST_EXISTS));
+	newsrc = boost::dynamic_pointer_cast<MidiSource>(
+		SourceFactory::createWritable(DataType::MIDI, _session,
+		                              path, false, _session.frame_rate()));
+
+	BeatsFramesConverter bfc (_session.tempo_map(), _position);
+	Evoral::Beats const bbegin = bfc.from (_start);
+	Evoral::Beats const bend = bfc.from (_start + _length);
+
+	{
+		/* Lock our source since we'll be reading from it.  write_to() will
+		   take a lock on newsrc. */
+		Source::Lock lm (midi_source(0)->mutex());
+		if (midi_source(0)->export_write_to (lm, newsrc, bbegin, bend)) {
+			return false;
+		}
 	}
 
-	midi_source(0)->Switched.connect(sigc::mem_fun(this, &MidiRegion::switch_source));
-	assert(_name.find("/") == string::npos);
-	assert(_type == DataType::MIDI);
+	return true;
+}
+
+
+/** Create a new MidiRegion that has its own version of some/all of the Source used by another.
+ */
+boost::shared_ptr<MidiRegion>
+MidiRegion::clone (string path) const
+{
+	boost::shared_ptr<MidiSource> newsrc;
+
+	/* caller must check for pre-existing file */
+	assert (!path.empty());
+	assert (!Glib::file_test (path, Glib::FILE_TEST_EXISTS));
+	newsrc = boost::dynamic_pointer_cast<MidiSource>(
+		SourceFactory::createWritable(DataType::MIDI, _session,
+					      path, false, _session.frame_rate()));
+	return clone (newsrc);
 }
 
-MidiRegion::MidiRegion (SourceList& srcs, const XMLNode& node)
-	: Region (srcs, node)
+boost::shared_ptr<MidiRegion>
+MidiRegion::clone (boost::shared_ptr<MidiSource> newsrc) const
 {
-	if (set_state (node)) {
-		throw failed_constructor();
+	BeatsFramesConverter bfc (_session.tempo_map(), _position);
+	Evoral::Beats const bbegin = bfc.from (_start);
+	Evoral::Beats const bend = bfc.from (_start + _length);
+
+	{
+		/* Lock our source since we'll be reading from it.  write_to() will
+		   take a lock on newsrc. */
+		Source::Lock lm (midi_source(0)->mutex());
+		if (midi_source(0)->write_to (lm, newsrc, bbegin, bend)) {
+			return boost::shared_ptr<MidiRegion> ();
+		}
 	}
 
-	midi_source(0)->Switched.connect(sigc::mem_fun(this, &MidiRegion::switch_source));
-	assert(_name.find("/") == string::npos);
-	assert(_type == DataType::MIDI);
+	PropertyList plist;
+
+	plist.add (Properties::name, PBD::basename_nosuffix (newsrc->name()));
+	plist.add (Properties::whole_file, true);
+	plist.add (Properties::start, _start);
+	plist.add (Properties::start_beats, _start_beats);
+	plist.add (Properties::length, _length);
+	plist.add (Properties::length_beats, _length_beats);
+	plist.add (Properties::layer, 0);
+
+	boost::shared_ptr<MidiRegion> ret (boost::dynamic_pointer_cast<MidiRegion> (RegionFactory::create (newsrc, plist, true)));
+	ret->set_beat (beat());
+
+	return ret;
 }
 
-MidiRegion::~MidiRegion ()
+void
+MidiRegion::post_set (const PropertyChange& pc)
 {
+	Region::post_set (pc);
+
+	if (pc.contains (Properties::length) && !pc.contains (Properties::length_beats)) {
+		/* update non-musically */
+		update_length_beats (0);
+	} else if (pc.contains (Properties::start) && !pc.contains (Properties::start_beats)) {
+		set_start_beats_from_start_frames ();
+	}
 }
 
-nframes_t
-MidiRegion::read_at (MidiRingBuffer& out, nframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode) const
+void
+MidiRegion::set_start_beats_from_start_frames ()
 {
-	return _read_at (_sources, out, position, dur, chan_n, mode);
+	_start_beats = Evoral::Beats (beat() - _session.tempo_map().beat_at_frame (_position - _start));
 }
 
-nframes_t
-MidiRegion::master_read_at (MidiRingBuffer& out, nframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode) const
+void
+MidiRegion::set_length_internal (framecnt_t len, const int32_t sub_num)
 {
-	return _read_at (_master_sources, out, position, dur, chan_n, mode);
+	Region::set_length_internal (len, sub_num);
+	update_length_beats (sub_num);
 }
 
-nframes_t
-MidiRegion::_read_at (const SourceList& srcs, MidiRingBuffer& dst, nframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode) const
+void
+MidiRegion::update_after_tempo_map_change (bool /* send */)
 {
-	// cerr << _name << "._read_at(" << position << ") - " << _position << endl;
-
-	nframes_t internal_offset = 0;
-	nframes_t src_offset      = 0;
-	nframes_t to_read         = 0;
-	
-	/* precondition: caller has verified that we cover the desired section */
+	boost::shared_ptr<Playlist> pl (playlist());
 
-	assert(chan_n == 0);
-	
-	if (position < _position) {
-		internal_offset = 0;
-		src_offset = _position - position;
-		dur -= src_offset;
-	} else {
-		internal_offset = position - _position;
-		src_offset = 0;
+	if (!pl || position_lock_style() != MusicTime) {
+		return;
 	}
 
-	if (internal_offset >= _length) {
-		return 0; /* read nothing */
-	}
-	
+	const framepos_t old_pos = _position;
+	const framepos_t old_length = _length;
+	const framepos_t old_start = _start;
 
-	if ((to_read = min (dur, _length - internal_offset)) == 0) {
-		return 0; /* read nothing */
-	}
+	Region::update_after_tempo_map_change (false);
 
-	// FIXME: non-opaque MIDI regions not yet supported
-	assert(opaque());
+	/* _start has now been updated. */
+	_length = _session.tempo_map().frame_at_beat (beat() + _length_beats.val().to_double()) - _position;
 
-	if (muted()) {
-		return 0; /* read nothing */
+	PropertyChange s_and_l;
+	if (old_start != _start) {
+		s_and_l.add (Properties::start);
 	}
-
-	_read_data_count = 0;
-
-	boost::shared_ptr<MidiSource> src = midi_source(chan_n);
-	src->set_note_mode(mode);
-
-	if (src->read (dst, _start + internal_offset, to_read, _position) != to_read) {
-		return 0; /* "read nothing" */
+	if (old_length != _length) {
+		s_and_l.add (Properties::length);
+	}
+	if (old_pos != _position) {
+		s_and_l.add (Properties::position);
 	}
 
-	_read_data_count += src->read_data_count();
+	send_change (s_and_l);
+}
 
-	return to_read;
+void
+MidiRegion::update_length_beats (const int32_t sub_num)
+{
+	_length_beats = Evoral::Beats (_session.tempo_map().exact_beat_at_frame (_position + _length, sub_num) - beat());
 }
-	
-XMLNode&
-MidiRegion::state (bool full)
-{
-	XMLNode& node (Region::state (full));
-	char buf[64];
-	char buf2[64];
-	LocaleGuard lg (X_("POSIX"));
-	
-	node.add_property ("flags", enum_2_string (_flags));
-
-	// XXX these should move into Region
-	
-	for (uint32_t n=0; n < _sources.size(); ++n) {
-		snprintf (buf2, sizeof(buf2), "source-%d", n);
-		_sources[n]->id().print (buf, sizeof(buf));
-		node.add_property (buf2, buf);
-	}
 
-	for (uint32_t n=0; n < _master_sources.size(); ++n) {
-		snprintf (buf2, sizeof(buf2), "master-source-%d", n);
-		_master_sources[n]->id().print (buf, sizeof (buf));
-		node.add_property (buf2, buf);
-	}
+void
+MidiRegion::set_position_internal (framepos_t pos, bool allow_bbt_recompute, const int32_t sub_num)
+{
+	Region::set_position_internal (pos, allow_bbt_recompute, sub_num);
+
+	/* set _start to new position in tempo map */
+	_start = _position - _session.tempo_map().frame_at_beat (beat() - _start_beats.val().to_double());
 
-	if (full && _extra_xml) {
-		node.add_child_copy (*_extra_xml);
+	/* in construction from src */
+	if (_length_beats == Evoral::Beats()) {
+		update_length_beats (sub_num);
 	}
 
-	return node;
+	/* leave _length_beats alone, and change _length to reflect the state of things
+	   at the new position (tempo map may dictate a different number of frames).
+	*/
+	Region::set_length_internal (_session.tempo_map().frame_at_beat (beat() + _length_beats.val().to_double()) - _position, sub_num);
 }
 
-int
-MidiRegion::set_live_state (const XMLNode& node, Change& what_changed, bool send)
+framecnt_t
+MidiRegion::read_at (Evoral::EventSink<framepos_t>& out,
+                     framepos_t                     position,
+                     framecnt_t                     dur,
+                     uint32_t                       chan_n,
+                     NoteMode                       mode,
+                     MidiStateTracker*              tracker,
+                     MidiChannelFilter*             filter) const
 {
-	const XMLProperty *prop;
-	LocaleGuard lg (X_("POSIX"));
+	return _read_at (_sources, out, position, dur, chan_n, mode, tracker, filter);
+}
 
-	Region::set_live_state (node, what_changed, false);
+framecnt_t
+MidiRegion::master_read_at (MidiRingBuffer<framepos_t>& out, framepos_t position, framecnt_t dur, uint32_t chan_n, NoteMode mode) const
+{
+	return _read_at (_master_sources, out, position, dur, chan_n, mode); /* no tracker */
+}
 
-	uint32_t old_flags = _flags;
-		
-	if ((prop = node.property ("flags")) != 0) {
-		_flags = Flag (string_2_enum (prop->value(), _flags));
+framecnt_t
+MidiRegion::_read_at (const SourceList&              /*srcs*/,
+                      Evoral::EventSink<framepos_t>& dst,
+                      framepos_t                     position,
+                      framecnt_t                     dur,
+                      uint32_t                       chan_n,
+                      NoteMode                       mode,
+                      MidiStateTracker*              tracker,
+                      MidiChannelFilter*             filter) const
+{
+	frameoffset_t internal_offset = 0;
+	framecnt_t    to_read         = 0;
 
-		//_flags = Flag (strtol (prop->value().c_str(), (char **) 0, 16));
+	/* precondition: caller has verified that we cover the desired section */
+
+	assert(chan_n == 0);
 
-		_flags = Flag (_flags & ~Region::LeftOfSplit);
-		_flags = Flag (_flags & ~Region::RightOfSplit);
+	if (muted()) {
+		return 0; /* read nothing */
 	}
 
-	if ((old_flags ^ _flags) & Muted) {
-		what_changed = Change (what_changed|MuteChanged);
+	if (position < _position) {
+		/* we are starting the read from before the start of the region */
+		internal_offset = 0;
+		dur -= _position - position;
+	} else {
+		/* we are starting the read from after the start of the region */
+		internal_offset = position - _position;
 	}
-	if ((old_flags ^ _flags) & Opaque) {
-		what_changed = Change (what_changed|OpacityChanged);
+
+	if (internal_offset >= _length) {
+		return 0; /* read nothing */
 	}
-	if ((old_flags ^ _flags) & Locked) {
-		what_changed = Change (what_changed|LockChanged);
+
+	if ((to_read = min (dur, _length - internal_offset)) == 0) {
+		return 0; /* read nothing */
 	}
 
-	if (send) {
-		send_change (what_changed);
+	boost::shared_ptr<MidiSource> src = midi_source(chan_n);
+
+	Glib::Threads::Mutex::Lock lm(src->mutex());
+
+	src->set_note_mode(lm, mode);
+
+	/*
+	  cerr << "MR " << name () << " read @ " << position << " * " << to_read
+	  << " _position = " << _position
+	  << " _start = " << _start
+	  << " intoffset = " << internal_offset
+	  << endl;
+	*/
+
+	/* This call reads events from a source and writes them to `dst' timed in session frames */
+
+	if (src->midi_read (
+		    lm, // source lock
+			dst, // destination buffer
+			_position - _start, // start position of the source in session frames
+			_start + internal_offset, // where to start reading in the source
+			to_read, // read duration in frames
+			tracker,
+			filter,
+			_filtered_parameters,
+			beat(),
+			_start_beats.val().to_double()
+		    ) != to_read) {
+		return 0; /* "read nothing" */
 	}
 
-	return 0;
+	return to_read;
+}
+
+XMLNode&
+MidiRegion::state ()
+{
+	return Region::state ();
 }
 
 int
-MidiRegion::set_state (const XMLNode& node)
+MidiRegion::set_state (const XMLNode& node, int version)
 {
-	/* Region::set_state() calls the virtual set_live_state(),
-	   which will get us back to AudioRegion::set_live_state()
-	   to handle the relevant stuff.
-	*/
+	int ret = Region::set_state (node, version);
+
+	if (ret == 0) {
+		/* set length beats to the frame (non-musical) */
+		if (position_lock_style() == AudioTime) {
+			update_length_beats (0);
+		}
+	}
 
-	return Region::set_state (node);
+	return ret;
 }
 
 void
 MidiRegion::recompute_at_end ()
 {
 	/* our length has changed
-	 * (non destructively) "chop" notes that pass the end boundary, to
-	 * prevent stuck notes.
+	 * so what? stuck notes are dealt with via a note state tracker
 	 */
-}	
+}
 
 void
 MidiRegion::recompute_at_start ()
@@ -280,34 +414,34 @@ MidiRegion::recompute_at_start ()
 }
 
 int
-MidiRegion::separate_by_channel (Session& session, vector<MidiRegion*>& v) const
+MidiRegion::separate_by_channel (ARDOUR::Session&, vector< boost::shared_ptr<Region> >&) const
 {
-	// Separate by MIDI channel?  bit different from audio since this is separating based
-	// on the actual contained data and destructively modifies and creates new sources..
-	
-#if 0
-	SourceList srcs;
-	string new_name;
-
-	for (SourceList::const_iterator i = _master_sources.begin(); i != _master_sources.end(); ++i) {
-
-		srcs.clear ();
-		srcs.push_back (*i);
+	// TODO
+	return -1;
+}
 
-		/* generate a new name */
-		
-		if (session.region_name (new_name, _name)) {
-			return -1;
-		}
+boost::shared_ptr<Evoral::Control>
+MidiRegion::control (const Evoral::Parameter& id, bool create)
+{
+	return model()->control(id, create);
+}
 
-		/* create a copy with just one source */
+boost::shared_ptr<const Evoral::Control>
+MidiRegion::control (const Evoral::Parameter& id) const
+{
+	return model()->control(id);
+}
 
-		v.push_back (new MidiRegion (srcs, _start, _length, new_name, _layer, _flags));
-	}
-#endif
+boost::shared_ptr<MidiModel>
+MidiRegion::model()
+{
+	return midi_source()->model();
+}
 
-	// Actually, I would prefer not if that's alright
-	return -1;
+boost::shared_ptr<const MidiModel>
+MidiRegion::model() const
+{
+	return midi_source()->model();
 }
 
 boost::shared_ptr<MidiSource>
@@ -317,18 +451,145 @@ MidiRegion::midi_source (uint32_t n) const
 	return boost::dynamic_pointer_cast<MidiSource>(source(n));
 }
 
-
 void
-MidiRegion::switch_source(boost::shared_ptr<Source> src)
+MidiRegion::model_changed ()
 {
-	boost::shared_ptr<MidiSource> msrc = boost::dynamic_pointer_cast<MidiSource>(src);
-	if (!msrc)
+	if (!model()) {
 		return;
+	}
+
+	/* build list of filtered Parameters, being those whose automation state is not `Play' */
+
+	_filtered_parameters.clear ();
+
+	Automatable::Controls const & c = model()->controls();
+
+	for (Automatable::Controls::const_iterator i = c.begin(); i != c.end(); ++i) {
+		boost::shared_ptr<AutomationControl> ac = boost::dynamic_pointer_cast<AutomationControl> (i->second);
+		assert (ac);
+		if (ac->alist()->automation_state() != Play) {
+			_filtered_parameters.insert (ac->parameter ());
+		}
+	}
+
+	/* watch for changes to controls' AutoState */
+	midi_source()->AutomationStateChanged.connect_same_thread (
+		_model_connection, boost::bind (&MidiRegion::model_automation_state_changed, this, _1)
+		);
+}
+
+void
+MidiRegion::model_automation_state_changed (Evoral::Parameter const & p)
+{
+	/* Update our filtered parameters list after a change to a parameter's AutoState */
 
-	// MIDI regions have only one source
-	_sources.clear();
-	_sources.push_back(msrc);
+	boost::shared_ptr<AutomationControl> ac = model()->automation_control (p);
+	if (!ac || ac->alist()->automation_state() == Play) {
+		/* It should be "impossible" for ac to be NULL, but if it is, don't
+		   filter the parameter so events aren't lost. */
+		_filtered_parameters.erase (p);
+	} else {
+		_filtered_parameters.insert (p);
+	}
+
+	/* the source will have an iterator into the model, and that iterator will have been set up
+	   for a given set of filtered_parameters, so now that we've changed that list we must invalidate
+	   the iterator.
+	*/
+	Glib::Threads::Mutex::Lock lm (midi_source(0)->mutex(), Glib::Threads::TRY_LOCK);
+	if (lm.locked()) {
+		/* TODO: This is too aggressive, we need more fine-grained invalidation. */
+		midi_source(0)->invalidate (lm);
+	}
+}
+
+/** This is called when a trim drag has resulted in a -ve _start time for this region.
+ *  Fix it up by adding some empty space to the source.
+ */
+void
+MidiRegion::fix_negative_start ()
+{
+	BeatsFramesConverter c (_session.tempo_map(), _position);
+
+	model()->insert_silence_at_start (c.from (-_start));
+	_start = 0;
+	_start_beats = Evoral::Beats();
+}
 
-	set_name(msrc->name());
+void
+MidiRegion::set_start_internal (framecnt_t s, const int32_t sub_num)
+{
+	Region::set_start_internal (s, sub_num);
+
+	if (position_lock_style() == AudioTime) {
+		set_start_beats_from_start_frames ();
+		}
 }
 
+void
+MidiRegion::trim_to_internal (framepos_t position, framecnt_t length, const int32_t sub_num)
+{
+	framepos_t new_start;
+
+	if (locked()) {
+		return;
+	}
+
+	PropertyChange what_changed;
+
+	/* beat has been set exactly by set_position_internal, but the source starts on a frame.
+	   working in beats seems the correct thing to do, but reports of a missing first note
+	   on playback suggest otherwise. for now, we work in exact beats.
+	*/
+	const double pos_beat = _session.tempo_map().exact_beat_at_frame (position, sub_num);
+	const double beat_delta = pos_beat - beat();
+
+	/* Set position before length, otherwise for MIDI regions this bad thing happens:
+	 * 1. we call set_length_internal; length in beats is computed using the region's current
+	 *    (soon-to-be old) position
+	 * 2. we call set_position_internal; position is set and length in frames re-computed using
+	 *    length in beats from (1) but at the new position, which is wrong if the region
+	 *    straddles a tempo/meter change.
+	 */
+
+	if (_position != position) {
+		set_position_internal (position, true, sub_num);
+		what_changed.add (Properties::position);
+	}
+
+	const double new_start_beat = _start_beats.val().to_double() + beat_delta;
+	new_start = _position - _session.tempo_map().frame_at_beat (beat() - new_start_beat);
+
+	if (!verify_start_and_length (new_start, length)) {
+		return;
+	}
+
+	if (_start != new_start) {
+		_start_beats = Evoral::Beats (new_start_beat);
+		what_changed.add (Properties::start_beats);
+
+		set_start_internal (new_start, sub_num);
+		what_changed.add (Properties::start);
+	}
+
+	if (_length != length) {
+		set_length_internal (length, sub_num);
+		what_changed.add (Properties::length);
+		what_changed.add (Properties::length_beats);
+	}
+
+	set_whole_file (false);
+
+	PropertyChange start_and_length;
+
+	start_and_length.add (Properties::start);
+	start_and_length.add (Properties::length);
+
+	if (what_changed.contains (start_and_length)) {
+		first_edit ();
+	}
+
+	if (!what_changed.empty()) {
+		send_change (what_changed);
+	}
+}