Small cleanups to dragging code. Fix assertion failure on dragging a regions' parent entry from the region list to the canvas (which may be #2811). Fixes to drags of regions onto and then back off canvas; should fix #3109.

git-svn-id: svn://localhost/ardour2/branches/3.0@7068 d708f5d6-7413-0410-9779-e7cbd77b26cf

gtk2_ardour/editor_canvas.cc

@@ -438,6 +438,7 @@ Editor::track_canvas_map_handler (GdkEventAny* /*ev*/)
 	return false;
 }
 
+/** This is called when something is dropped onto the track canvas */
 void
 Editor::track_canvas_drag_data_received (const RefPtr<Gdk::DragContext>& context,
 					 int x, int y,

gtk2_ardour/editor_canvas_events.cc

@@ -996,6 +996,10 @@ Editor::track_canvas_drag_motion (Glib::RefPtr<Gdk::DragContext> const & /*c*/,
 
 		boost::shared_ptr<Region> region = _regions->get_dragged_region ();
 
+		if (!region) {
+			return true;
+		}
+
 		boost::shared_ptr<Region> region_copy = RegionFactory::create (region);
 
 		if (boost::dynamic_pointer_cast<AudioRegion> (region_copy) != 0 &&

gtk2_ardour/editor_drag.cc

@@ -67,24 +67,14 @@ DragManager::~DragManager ()
 	abort ();
 }
 
+/** Call abort for each active drag */
 void
 DragManager::abort ()
-{
-	for (list<Drag*>::const_iterator i = _drags.begin(); i != _drags.end(); ++i) {
-		(*i)->end_grab (0);
-		delete *i;
-	}
-
-	_drags.clear ();
-}
-
-void
-DragManager::break_drag ()
 {
 	_ending = true;
 	
 	for (list<Drag*>::const_iterator i = _drags.begin(); i != _drags.end(); ++i) {
-		(*i)->break_drag ();
+		(*i)->abort ();
 		delete *i;
 	}
 
@@ -119,6 +109,9 @@ DragManager::start_grab (GdkEvent* e)
 	}
 }
 
+/** Call end_grab for each active drag.
+ *  @return true if any drag reported movement having occurred.
+ */
 bool
 DragManager::end_grab (GdkEvent* e)
 {
@@ -243,7 +236,10 @@ Drag::start_grab (GdkEvent* event, Gdk::Cursor *cursor)
 	}
 }
 
-/** @param event GDK event, or 0.
+/** Call to end a drag `successfully'.  Ungrabs item and calls
+ *  subclass' finished() method.
+ *
+ *  @param event GDK event, or 0.
  *  @return true if some movement occurred, otherwise false.
  */
 bool
@@ -323,8 +319,9 @@ Drag::motion_handler (GdkEvent* event, bool from_autoscroll)
 	return false;
 }
 
+/** Call to abort a drag.  Ungrabs item and calls subclass's aborted () */
 void
-Drag::break_drag ()
+Drag::abort ()
 {
 	if (_item) {
 		_item->ungrab (0);
@@ -1450,7 +1447,9 @@ RegionInsertDrag::finished (GdkEvent* /*event*/, bool /*movement_occurred*/)
 void
 RegionInsertDrag::aborted ()
 {
-	/* XXX: TODO */
+	delete _primary;
+	_primary = 0;
+	_views.clear ();
 }
 
 RegionSpliceDrag::RegionSpliceDrag (Editor* e, ArdourCanvas::Item* i, RegionView* p, list<RegionView*> const & v)

gtk2_ardour/editor_drag.h

@@ -50,14 +50,13 @@ public:
 	bool motion_handler (GdkEvent *, bool);
 
 	void abort ();
-	void break_drag ();
 	void add (Drag *);
 	void set (Drag *, GdkEvent *, Gdk::Cursor* c = 0);
 	void start_grab (GdkEvent *);
 	bool end_grab (GdkEvent *);
 	bool have_item (ArdourCanvas::Item *) const;
 
-	/** @return true if an end drag or break_drag is in progress */
+	/** @return true if an end drag or abort is in progress */
 	bool ending () const {
 		return _ending;
 	}
@@ -84,7 +83,7 @@ public:
 private:
 	Editor* _editor;
 	std::list<Drag*> _drags;
-	bool _ending; ///< true if end_grab or break_drag is in progress, otherwise false
+	bool _ending; ///< true if end_grab or abort is in progress, otherwise false
 	double _current_pointer_x; ///< trackview x of the current pointer
 	double _current_pointer_y; ///< trackview y of the current pointer
 	nframes64_t _current_pointer_frame; ///< frame that the pointer is now at
@@ -108,7 +107,7 @@ public:
 
 	void swap_grab (ArdourCanvas::Item *, Gdk::Cursor *, uint32_t);
 	bool motion_handler (GdkEvent*, bool);
-	void break_drag ();
+	void abort ();
 
 	nframes64_t adjusted_frame (nframes64_t, GdkEvent const *, bool snap = true) const;
 	nframes64_t adjusted_current_frame (GdkEvent const *, bool snap = true) const;

gtk2_ardour/editor_markers.cc

@@ -1119,7 +1119,7 @@ Editor::new_transport_marker_menu_popdown ()
 	// hide rects
 	transport_bar_drag_rect->hide();
 
-	_drags->break_drag ();
+	_drags->abort ();
 }
 
 void

gtk2_ardour/editor_mouse.cc

@@ -2551,7 +2551,7 @@ void
 Editor::escape ()
 {
 	if (_drags->active ()) {
-		_drags->break_drag ();
+		_drags->abort ();
 	} else {
 		selection->clear ();
 	}

gtk2_ardour/editor_ops.cc

@@ -3760,7 +3760,7 @@ Editor::cut_copy (CutCopyOp op)
 			Glib::signal_idle().connect (sigc::bind (sigc::mem_fun(*this, &Editor::really_remove_marker), loc));
 		}
 
-		_drags->break_drag ();
+		_drags->abort ();
 		return;
 	}
 
@@ -3841,7 +3841,7 @@ Editor::cut_copy (CutCopyOp op)
 	}
 
 	if (op == Cut || op == Clear) {
-		_drags->break_drag ();
+		_drags->abort ();
 	}
 }
 

gtk2_ardour/editor_regions.cc

@@ -44,6 +44,7 @@
 #include "region_view.h"
 #include "utils.h"
 #include "editor_regions.h"
+#include "editor_drag.h"
 
 #include "i18n.h"
 
@@ -1097,6 +1098,8 @@ EditorRegions::drag_data_received (const RefPtr<Gdk::DragContext>& context,
 	vector<ustring> paths;
 
 	if (data.get_target() == "GTK_TREE_MODEL_ROW") {
+		/* something is being dragged over the region list */
+		_editor->_drags->abort ();
 		_display.on_drag_data_received (context, x, y, data, info, time);
 		return;
 	}
@@ -1155,12 +1158,18 @@ EditorRegions::name_edit (const Glib::ustring& path, const Glib::ustring& new_te
 
 }
 
+/** @return Region that has been dragged out of the list, or 0 */
 boost::shared_ptr<Region>
 EditorRegions::get_dragged_region ()
 {
 	list<boost::shared_ptr<Region> > regions;
 	TreeView* source;
 	_display.get_object_drag_data (regions, &source);
+
+	if (regions.empty()) {
+		return boost::shared_ptr<Region> ();
+	}
+	
 	assert (regions.size() == 1);
 	return regions.front ();
 }