Add some utility functions for dealing with widget hierarchy

[libs/gltk.git] / source / widget.cpp

diff --git a/source/widget.cpp b/source/widget.cpp
index 13c5174df43e33cc6db256bbbe47ec45d3de7c4a..a9c233b5d8c370a0ece166c00bc81a8fb1b1f0ff 100644 (file)
--- a/source/widget.cpp
+++ b/source/widget.cpp
@@ -75,6 +75,21 @@ void Widget::set_geometry(const Geometry &g)
        }
 }
 
+void Widget::map_coords_to_ancestor(int &x, int &y, const Widget &ancestor) const
+{
+       for(const Widget *w=this; w; w=w->get_parent())
+       {
+               if(w==&ancestor)
+                       return;
+
+               const Geometry &wgeom = w->get_geometry();
+               x += wgeom.x;
+               y += wgeom.y;
+       }
+
+       throw hierarchy_error("not an ancestor");
+}
+
 void Widget::set_parent(Container *p)
 {
        if(parent && p)