From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 8 Aug 2013 16:02:10 +0000 (+0300)
Subject: Add some utility functions for dealing with widget hierarchy
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=e6a6b3fbd760e487c5df1a6d70ed0700d151710b;p=libs%2Fgltk.git

Add some utility functions for dealing with widget hierarchy
---

diff --git a/source/widget.cpp b/source/widget.cpp
index 13c5174..a9c233b 100644
--- 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)
diff --git a/source/widget.h b/source/widget.h
index 5c81b80..dfef4ba 100644
--- a/source/widget.h
+++ b/source/widget.h
@@ -68,6 +68,8 @@ public:
 	void set_geometry(const Geometry &);
 	const Geometry &get_geometry() const { return geom; }
 
+	void map_coords_to_ancestor(int &, int &, const Widget &) const;
+
 protected:
 	/** Sets the widget's parent Container.  The widget must be unparented when
 	calling this function with a non-null parameter. */
@@ -75,6 +77,16 @@ protected:
 public:
 	Container *get_parent() const { return parent; }
 
+	/** Finds the closest ancestor of a specific type. */
+	template<typename T>
+	T *find_ancestor() const
+	{
+		for(Widget *w=parent; w; w=w->get_parent())
+			if(T *tw = dynamic_cast<T *>(w))
+				return tw;
+		return 0;
+	}
+
 	/** Sets the widget style.  The name of the resource to be looked up is
 	constructed by concatenating the widget class and the style name with a
 	dash. */