+ }
+
+ void scroll_to (Coord x, Coord y);
+ void add_scroller (ScrollGroup& i);
+
+ virtual Rect visible_area () const = 0;
+ virtual Coord width () const = 0;
+ virtual Coord height () const = 0;
+
+ /** Store the coordinates of the mouse pointer in window coordinates in
+ @param winpos. Return true if the position was within the window,
+ false otherwise.
+ */
+ virtual bool get_mouse_position (Duple& winpos) const = 0;
+
+ /** Signal to be used by items that need to track the mouse position
+ within the window.
+ */
+ sigc::signal<void,Duple const&> MouseMotion;
+
+ sigc::signal<void> PreRender;
+
+ /** Ensures that the position given by @param winpos (in window
+ coordinates) is within the current window area, possibly reduced by
+ @param border.
+ */
+ Duple clamp_to_window (Duple const& winpos, Duple border = Duple());
+
+ void zoomed();
+
+ std::string indent() const;
+ std::string render_indent() const;
+ void dump (std::ostream&) const;