7500: TopBoxInputEventBridge
7501
7508: move event code to TopBoxInputBridge
7509: HitPoint
7515: IHitElement
7517: fix OnMouseDown,GetElementGlobalLocation
7518: fix
7522:HitPointChain abstraction
7529:
7531: errs!
7532P: LayoutFarm.RenderTree

rename from LeanRenderer
7534
7538: merge WinGraphic with MyCanvas
7540: clean MyCanvas
7542: refactor LayoutFarm.Drawing
7543: fix MyCanvas origin
Merge branch 'v_wingfx' into v_hitchain
Merge branch 'v_hitchain' into v_event_bridge
7548: HitObjectWrapper
7550