Either "down" for a button pressed or "up" for a button released.
Where the pattern must appear in the history of this input handler. * start - (Default) The first event in the pattern must be the first event in the history of raw Echo Button events. * end - The last event in the pattern must be the last event in the history of raw Echo Button events. * anywhere - The pattern may appear anywhere in the history of raw Echo Button events.
Recognizers are conditions that, at any moment, are either true or false, based on all the raw button events that the Input Handler has received in the time elapsed since the Input Handler session started.
Specifies what raw button presses to put in the inputEvents field of the event. * history - All button presses since this Input Handler was started. * matches - Just the button presses that contributed to this event (that is, were in the recognizers). To receive no raw button presses, leave this array empty or do not specify it at all.