photoswipe/src/js/tap.js

JavaScript gallery

/**
 * tap.js:
 *
 * Displatches tap and double-tap events.
 * 
 */

var tapTimer,
	tapReleasePoint = {},
	_dispatchTapEvent = function(origEvent, releasePoint, pointerType) {		
		var e = document.createEvent( 'CustomEvent' ),
			eDetail = {
				origEvent:origEvent, 
				target:origEvent.target, 
				releasePoint: releasePoint, 
				pointerType:pointerType || 'touch'
			};

		e.initCustomEvent( 'pswpTap', true, true, eDetail );
		origEvent.target.dispatchEvent(e);
	};

_registerModule('Tap', {
	publicMethods: {
		initTap: function() {
			_listen('firstTouchStart', self.onTapStart);
			_listen('touchRelease', self.onTapRelease);
			_listen('destroy', function() {
				tapReleasePoint = {};
				tapTimer = null;
			});
		},
		onTapStart: function(touchList) {
			if(touchList.length > 1) {
				clearTimeout(tapTimer);
				tapTimer = null;
			}
		},
		onTapRelease: function(e, releasePoint) {
			if(!releasePoint) {
				return;
			}

			if(!_moved && !_isMultitouch && !_numAnimations) {
				var p0 = releasePoint;
				if(tapTimer) {
					clearTimeout(tapTimer);
					tapTimer = null;

					// Check if taped on the same place
					if ( _isNearbyPoints(p0, tapReleasePoint) ) {
						_shout('doubleTap', p0);
						return;
					}
				}

				if(releasePoint.type === 'mouse') {
					_dispatchTapEvent(e, releasePoint, 'mouse');
					return;
				}

				var clickedTagName = e.target.tagName.toUpperCase();
				// avoid double tap delay on buttons and elements that have class pswp__single-tap
				if(clickedTagName === 'BUTTON' || framework.hasClass(e.target, 'pswp__single-tap') ) {
					_dispatchTapEvent(e, releasePoint);
					return;
				}

				_equalizePoints(tapReleasePoint, p0);

				tapTimer = setTimeout(function() {
					_dispatchTapEvent(e, releasePoint);
					tapTimer = null;
				}, 300);
			}
		}
	}
});