delite/activationTracker
delite/activationTracker is a utility module that is used to track and manage active widgets on a page.
At any point in time there is a set of (for lack of a better word) "active" or "focused" widgets, meaning the currently focused widget and that widget's ancestors. "Ancestor" can mean either DOM ancestor (ex: TextBox → Form), or a logical parent-child relationship (ex: TooltipDialog → DropDownButton).
For example, if activationTracker is on a TextBox inside a TabContainer inside a TooltipDialog triggered by a DropDownButton, the stack would be TextBox → ContentPane → TabContainer → TooltipDialog → DropDownButton.
on() interface
Call activationTracker.on("active-widget-stack", callback) to track the stack of currently focused widgets.
Call activationTracker.on("deactivated", func) or activationTracker.on("activated", ...) to monitor when
when widgets become active/inactive.
delite-activated and delite-deactivated events
Also, if delite/activationTracker is loaded, every widget will emit a non-bubbling delite-activated event
when it becomes activate (i.e. when it or logical descendant widget is focused or clicked), and a non-bubbling
delite-deactivated event when the opposite happens.
