Include widget y() and h() in event_widget() test.

Timeline/Sequence.C

@@ -176,7 +176,8 @@ Sequence::event_widget ( void )
 {
     nframes_t ets = timeline->xoffset + timeline->x_to_ts( Fl::event_x() - x() );
     for ( list <Sequence_Widget *>::const_reverse_iterator r = _widgets.rbegin();  r != _widgets.rend(); r++ )
-        if ( ets > (*r)->start() && ets < (*r)->start() + (*r)->length() )
+        if ( ets > (*r)->start() && ets < (*r)->start() + (*r)->length()
+             && Fl::event_y() >= (*r)->y() && Fl::event_y() <= (*r)->y() + (*r)->h() )
             return (*r);
 
     return NULL;