Changes

Note that the pointer count will always be greater than or equal to 1 when an onTouch() method is called (since at least one touch must have occurred for the callback to be triggered).

A touch on a view, particularly one involving motion across the screen, will generate a stream of events before the point of contact with the screen is lifted. As such, it is likely that an application will need to track individual touches over multiple touch events. While the ID of a specific touch gesture will not change from one event to the next, it is important to keep in mind that the index value will change as other touch events come and go. When working with a touch gesture over multiple events, therefore, it is essential that the ID value be used as the touch reference in order to make sure the same touch is being tracked. When calling methods that require an index value, this should be obtained by converting the ID for a touch to the corresponding index value via a call to the findPointerIndex() method of the MotionEvent object.

}

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The final task before testing the application is to implement the handleTouch() method called by the onTouch() callback method. The code for this method reads as follows:

Since action types equate to integer values, a switch statement is used to convert the action type to a more meaningful string value, which is stored in the previously declared actionString variable:

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switch (action)