Better solution to find a valid canvas for the displayed valuenodes

[synfig.git] / synfig-studio / trunk / src / gtkmm / widget_curves.cpp

diff --git a/synfig-studio/trunk/src/gtkmm/widget_curves.cpp b/synfig-studio/trunk/src/gtkmm/widget_curves.cpp
index efd2cd1..6077772 100644 (file)
--- a/synfig-studio/trunk/src/gtkmm/widget_curves.cpp
+++ b/synfig-studio/trunk/src/gtkmm/widget_curves.cpp
@@ -474,6 +474,9 @@ Widget_Curves::redraw(GdkEventExpose */*bleh*/)
        if(!time_adjustment_ || !range_adjustment_ || !h || !w)
                return false;
 
+       if(!curve_list_.size())
+               return false;
+
        Glib::RefPtr<Gdk::GC> gc(Gdk::GC::create(get_window()));
 
        const Real t_begin(time_adjustment_->get_lower());
@@ -501,12 +504,19 @@ Widget_Curves::redraw(GdkEventExpose */*bleh*/)
        gc->set_rgb_fg_color(Gdk::Color("#0000ff")); // It should be user selectable
        get_window()->draw_rectangle(gc, false, round_to_int((time_adjustment_->get_value()-t_begin)/dt), 0, 0, h);
 
-       // This is not the best solution but I guess that if the first valuenode
-       // has canvas then show the keyframes. Maybe I can loop all them until I find
-       // a valid canvas and use it for look to the keyframes.
-       synfig::Canvas::Handle canvas(curve_list_.begin()->value_desc.get_canvas());
+       // This try to find a valid vanvas to show the keyframes of those
+       // valuenodes. If not canvas found then no keyframes marks are shown.
+       synfig::Canvas::Handle canvas=0;
+       for(curve_iter=curve_list_.begin();curve_iter!=curve_list_.end();++curve_iter)
+       {
+               canvas=curve_iter->value_desc.get_canvas();
+               if(canvas)
+                       break;
+       }
+
        if(canvas)
        {
+       // Draw vertical lines for the keyframes marks.
                const synfig::KeyframeList& keyframe_list(canvas->keyframe_list());
                synfig::KeyframeList::const_iterator iter;