Mojo.Event.listen(target, type{string}, handlerFunction, useCapture)

A wrapper around addEventListener that adds some parameter checking.

Parameter	Type	Description
target	Element	Target to observe
type	String	Type of event to observe
handlerFunction	Function	Function that is called when the event occurs
useCapture	Boolean	True causes event to be observed during the capture phase. Optional.

Example usage:

        // Setup the TruncTextField widget
        var scratchEventDiv = this.controller.get('scratch_event');
        this.controller.setupWidget('scratch_event_field', tfAttrs, this.scratchEvent);
        this.controller.instantiateChildWidgets(scratchEventDiv);
        this.scratchEventField = this.controller.get('scratch_event_field');
        this.scratchEventCommitHandler = this.handleEditScratchEventCommit.bind(this);
        this.scratchEventKeyEventHandler = this.handleScratchEventKey.bind(this);
        this.scratchEventTapHandler = this.handleScratchEventTap.bind(this)
        this.scratchEventHoldHandler = this.handleScratchEventHold.bind(this);
        
        // Listen for the key and tap events on the whole scene when a 
        // scratch event is present
        Mojo.Event.listen(scratchEventDiv, "keyup", this.scratchEventKeyEventHandler);
        Mojo.Event.listen(this.controller.sceneElement, 
             Mojo.Event.tap, this.scratchEventTapHandler);
        Mojo.Event.listen(this.controller.sceneElement, 
             Mojo.Event.hold, this.scratchEventHoldHandler);