X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Ftags%2Fstable%2Fsrc%2Fsynfig%2Flayer_pastecanvas.h;h=843ee1efc54bd57f3175a385182a27525dc9f99f;hb=47fce282611fbba1044921d22ca887f9b53ad91a;hp=82cd32dfc9660ffd652a0e094f9c7275700bf715;hpb=d3408370fc3297609b3aa8d4ff7edf1f238df251;p=synfig.git

diff --git a/synfig-core/tags/stable/src/synfig/layer_pastecanvas.h b/synfig-core/tags/stable/src/synfig/layer_pastecanvas.h
index 82cd32d..843ee1e 100644
--- a/synfig-core/tags/stable/src/synfig/layer_pastecanvas.h
+++ b/synfig-core/tags/stable/src/synfig/layer_pastecanvas.h
@@ -1,11 +1,12 @@
 /* === S Y N F I G ========================================================= */
 /*!	\file layer_pastecanvas.h
-**	\brief Template Header
+**	\brief Header file for implementation of the "Paste Canvas" layer
 **
 **	$Id$
 **
 **	\legal
 **	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**	Copyright (c) 2007, 2008 Chris Moore
 **
 **	This package is free software; you can redistribute it and/or
 **	modify it under the terms of the GNU General Public License as
@@ -62,20 +63,45 @@ private:
 
 	mutable Time curr_time;
 
-	bool optimize_layers(synfig::Context context,synfig::CanvasBase&)const;
-
-	bool do_not_muck_with_time_;
+	bool muck_with_time_;
 
 	bool children_lock;
 
 	mutable Rect bounds;
 
 	sigc::connection child_changed_connection;
+
+	// Nasty hack: Remember whether we called an extra ref() when
+	// setting the canvas, so we know whether to call an extra unref()
+	// when finished with the canvas.
+	//
+	// Here's the story:
+	//
+	// The root canvas is destructed first.  That sets the
+	// Layer::canvas_ (the parent canvas) of any PasteCanvas layer it
+	// contains to nil, due to a call to Layer::set_canvas(0),
+	// triggered by the connection made when Layer::set_canvas
+	// originally set its canvas_ member to point to the root canvas.
+	// ~Canvas does begin_delete() which triggers that connection.
+	//
+	// After ~Canvas has run, the members of the root canvas are
+	// freed, including its children_ list.  If this was the last
+	// reference to the child canvas that the pastecanvas uses, that
+	// child canvas will Layer_PasteCanvas::set_sub_canvas(0) on the
+	// PasteCanvas layer to set its canvas (the child, pasted canvas)
+	// not to refer to the soon-to-be destroys child canvas.  But
+	// set_sub_canvas() originally looked at the value of
+	// Layer::canvas_ (the parent canvas, obtained via
+	// Layer::get_canvas()) to decide whether to do an extra ref() on
+	// canvas (the child canvas).  We need to unref() it now if we
+	// did, but we've forgotten whether we did.  So we use this
+	// 'extra_reference' member to store that decision.
+	bool extra_reference;
 public:
 
 	virtual void on_canvas_set();
 
-	void set_do_not_muck_with_time(bool x=true) { do_not_muck_with_time_=true; }
+	void set_muck_with_time(bool x=false) { muck_with_time_=x; }
 
 	etl::handle<synfig::Canvas> get_sub_canvas()const { return canvas; }
 	void set_sub_canvas(etl::handle<synfig::Canvas> x);