add basic data members and methods for adding an explicit size allocation for Canvas::Item

1 files changed, 13 insertions, 1 deletions

diff --git a/libs/canvas/canvas/item.h b/libs/canvas/canvas/item.h
index 517b4401ba..a480ec38a1 100644
--- a/libs/canvas/canvas/item.h
+++ b/libs/canvas/canvas/item.h
@@ -136,7 +136,18 @@ public:
 
 	ScrollGroup* scroll_parent() const { return _scroll_parent; }
 
-	Rect bounding_box () const;
+	/* item implementations can override this if they need to */
+	virtual Rect size_request() const { return bounding_box (true); }
+	void size_allocate (Rect const&);
+
+	/** bounding box is the public API to get the size of the item.
+	   If @param for_own_purposes is false, then it will return the
+	   allocated bounding box (if there is one) in preference to the
+	   one that would naturally be computed by the item.
+	*/
+	Rect bounding_box (bool for_own_purposes = false) const;
+	Rect allocation() const { return _allocation; }
+
         Coord height() const;
         Coord width() const;
 
@@ -281,6 +292,7 @@ protected:
 	mutable Rect _bounding_box;
 	/** true if _bounding_box might be out of date, false if its definitely not */
 	mutable bool _bounding_box_dirty;
+	Rect _allocation;
 
 	/* XXX: this is a bit grubby */
 	std::map<std::string, void *> _data;