var STOP = 1;
var FORCED_STOP = 2;
/**
* Manager
* @param {HTMLElement} element
* @param {Object} [options]
* @constructor
*/
function Manager(element, options) {
this.options = assign({}, Hammer.defaults, options || {});
this.options.inputTarget = this.options.inputTarget || element;
this.handlers = {};
this.session = {};
this.recognizers = [];
this.oldCssProps = {};
this.element = element;
this.input = createInputInstance(this);
this.touchAction = new TouchAction(this, this.options.touchAction);
toggleCssProps(this, true);
each(this.options.recognizers, function(item) {
var recognizer = this.add(new (item[0])(item[1]));
item[2] && recognizer.recognizeWith(item[2]);
item[3] && recognizer.requireFailure(item[3]);
}, this);
}
Manager.prototype = {
/**
* set options
* @param {Object} options
* @returns {Manager}
*/
set: function(options) {
assign(this.options, options);
// Options that need a little more setup
if (options.touchAction) {
this.touchAction.update();
}
if (options.inputTarget) {
// Clean up existing event listeners and reinitialize
this.input.destroy();
this.input.target = options.inputTarget;
this.input.init();
}
return this;
},
/**
* stop recognizing for this session.
* This session will be discarded, when a new [input]start event is fired.
* When forced, the recognizer cycle is stopped immediately.
* @param {Boolean} [force]
*/
stop: function(force) {
this.session.stopped = force ? FORCED_STOP : STOP;
},
/**
* run the recognizers!
* called by the inputHandler function on every movement of the pointers (touches)
* it walks through all the recognizers and tries to detect the gesture that is being made
* @param {Object} inputData
*/
recognize: function(inputData) {
var session = this.session;
if (session.stopped) {
return;
}
// run the touch-action polyfill
this.touchAction.preventDefaults(inputData);
var recognizer;
var recognizers = this.recognizers;
// this holds the recognizer that is being recognized.
// so the recognizer's state needs to be BEGAN, CHANGED, ENDED or RECOGNIZED
// if no recognizer is detecting a thing, it is set to `null`
var curRecognizer = session.curRecognizer;
// reset when the last recognizer is recognized
// or when we're in a new session
if (!curRecognizer || (curRecognizer && curRecognizer.state & STATE_RECOGNIZED)) {
curRecognizer = session.curRecognizer = null;
}
var i = 0;
while (i < recognizers.length) {
recognizer = recognizers[i];
// find out if we are allowed try to recognize the input for this one.
// 1. allow if the session is NOT forced stopped (see the .stop() method)
// 2. allow if we still haven't recognized a gesture in this session, or the this recognizer is the one
// that is being recognized.
// 3. allow if the recognizer is allowed to run simultaneous with the current recognized recognizer.
// this can be setup with the `recognizeWith()` method on the recognizer.
if (session.stopped !== FORCED_STOP && ( // 1
!curRecognizer || recognizer == curRecognizer || // 2
recognizer.canRecognizeWith(curRecognizer))) { // 3
recognizer.recognize(inputData);
} else {
recognizer.reset();
}
// if the recognizer has been recognizing the input as a valid gesture, we want to store this one as the
// current active recognizer. but only if we don't already have an active recognizer
if (!curRecognizer && recognizer.state & (STATE_BEGAN | STATE_CHANGED | STATE_ENDED)) {
curRecognizer = session.curRecognizer = recognizer;
}
i++;
}
},
/**
* get a recognizer by its event name.
* @param {Recognizer|String} recognizer
* @returns {Recognizer|Null}
*/
get: function(recognizer) {
if (recognizer instanceof Recognizer) {
return recognizer;
}
var recognizers = this.recognizers;
for (var i = 0; i < recognizers.length; i++) {
if (recognizers[i].options.event == recognizer) {
return recognizers[i];
}
}
return null;
},
/**
* add a recognizer to the manager
* existing recognizers with the same event name will be removed
* @param {Recognizer} recognizer
* @returns {Recognizer|Manager}
*/
add: function(recognizer) {
if (invokeArrayArg(recognizer, 'add', this)) {
return this;
}
// remove existing
var existing = this.get(recognizer.options.event);
if (existing) {
this.remove(existing);
}
this.recognizers.push(recognizer);
recognizer.manager = this;
this.touchAction.update();
return recognizer;
},
/**
* remove a recognizer by name or instance
* @param {Recognizer|String} recognizer
* @returns {Manager}
*/
remove: function(recognizer) {
if (invokeArrayArg(recognizer, 'remove', this)) {
return this;
}
recognizer = this.get(recognizer);
// let's make sure this recognizer exists
if (recognizer) {
var recognizers = this.recognizers;
var index = inArray(recognizers, recognizer);
if (index !== -1) {
recognizers.splice(index, 1);
this.touchAction.update();
}
}
return this;
},
/**
* bind event
* @param {String} events
* @param {Function} handler
* @returns {EventEmitter} this
*/
on: function(events, handler) {
if (events === undefined) {
return;
}
if (handler === undefined) {
return;
}
var handlers = this.handlers;
each(splitStr(events), function(event) {
handlers[event] = handlers[event] || [];
handlers[event].push(handler);
});
return this;
},
/**
* unbind event, leave emit blank to remove all handlers
* @param {String} events
* @param {Function} [handler]
* @returns {EventEmitter} this
*/
off: function(events, handler) {
if (events === undefined) {
return;
}
var handlers = this.handlers;
each(splitStr(events), function(event) {
if (!handler) {
delete handlers[event];
} else {
handlers[event] && handlers[event].splice(inArray(handlers[event], handler), 1);
}
});
return this;
},
/**
* emit event to the listeners
* @param {String} event
* @param {Object} data
*/
emit: function(event, data) {
// we also want to trigger dom events
if (this.options.domEvents) {
triggerDomEvent(event, data);
}
// no handlers, so skip it all
var handlers = this.handlers[event] && this.handlers[event].slice();
if (!handlers || !handlers.length) {
return;
}
data.type = event;
data.preventDefault = function() {
data.srcEvent.preventDefault();
};
var i = 0;
while (i < handlers.length) {
handlers[i](data);
i++;
}
},
/**
* destroy the manager and unbinds all events
* it doesn't unbind dom events, that is the user own responsibility
*/
destroy: function() {
this.element && toggleCssProps(this, false);
this.handlers = {};
this.session = {};
this.input.destroy();
this.element = null;
}
};
/**
* add/remove the css properties as defined in manager.options.cssProps
* @param {Manager} manager
* @param {Boolean} add
*/
function toggleCssProps(manager, add) {
var element = manager.element;
if (!element.style) {
return;
}
var prop;
each(manager.options.cssProps, function(value, name) {
prop = prefixed(element.style, name);
if (add) {
manager.oldCssProps[prop] = element.style[prop];
element.style[prop] = value;
} else {
element.style[prop] = manager.oldCssProps[prop] || '';
}
});
if (!add) {
manager.oldCssProps = {};
}
}
/**
* trigger dom event
* @param {String} event
* @param {Object} data
*/
function triggerDomEvent(event, data) {
var gestureEvent = document.createEvent('Event');
gestureEvent.initEvent(event, true, true);
gestureEvent.gesture = data;
data.target.dispatchEvent(gestureEvent);
}