Gets or sets whether tab-focus is enabled for the canvas. When tab-focus is enabled, the canvas can receive the keyboard focus when the user navigates among a frame or dialog's controls with the Tab and arrow keys. By default, tab-focus is disabled.
When tab-focus is enabled for a canvas, Tab, arrow, and Enter keyboard events are consumed by a frame's default on-traverse-char method. (In addition, a dialog's default method consumes Escape key events.) Otherwise, on-traverse-char allows the keyboard events to be propagated to the canvas.
Returns #t if tab-focus is enabled for the canvas, #f otherwise.
Enables or disables tab-focus for the canvas.