The Tap event will fire when any of the following occurs:
On a device that supports mouse and TapOnDown is set to true: When the user presses down the left button and the mouse is over a TargetElement.
On a device that supports mouse and TapOnDown is set to false: When the user presses and then releases the left button and the mouse is over a TargetElement.
On a device that supports touch and TapOnDown is set to true: When the user presses a finger down on TargetElement.
On a device that supports touch and TapOnDown is set to false: When the user presses and then releases a finger on a TargetElement.