Mouse on Canvas

Some actions need the mouse to be on the Canvas. The video below shows an example. Pressing the Space bar repeatedly makes the Editor switch between Object and Mesh Mode. But, it only works if the mouse is on the Canvas.

The situation is those actions need to be performed only when the Canvas has the focus. But the Engine Interface does not have a way to properly grab or lost focus on the Canvas. Instead, we consider that the Canvas has the focus only when the mouse is on the Canvas.