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eventcontract.js
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eventcontract.js
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// Copyright 2005 Google Inc. All Rights Reserved.
/**
*
* @fileoverview Implements the local event handling contract. This
* allows DOM objects in a container that enters into this contract to
* define event handlers which are executed in a local context.
*
* One EventContract instance can manage the contract for multiple
* containers, which are added using the addContainer() method.
*
* Events can be registered using the addEvent() method.
*
* A Dispatcher is added using the dispatchTo() method. Until there is
* a dispatcher, events are queued. The idea is that the EventContract
* class is inlined in the HTML of the top level page and instantiated
* right after the start of <body>. The Dispatcher class is contained
* in the external deferred js, and instantiated and registered with
* EventContract when the external javascript in the page loads. The
* external javascript will also register the jsaction handlers, which
* then pick up the queued events at the time of registration.
*
* Since this class is meant to be inlined in the main page HTML, the
* size of the binary compiled from this file MUST be kept as small as
* possible and thus its dependencies to a minimum.
*/
goog.provide('jsaction.EventContract');
goog.provide('jsaction.EventContractContainer');
goog.require('goog.dom.TagName');
goog.require('jsaction.Attribute');
goog.require('jsaction.Cache');
goog.require('jsaction.Char');
goog.require('jsaction.EventType');
goog.require('jsaction.Property');
goog.require('jsaction.domGenerator');
goog.require('jsaction.event');
/**
* EventContract intercepts events in the bubbling phase at the
* boundary of a container element, and maps them to generic actions
* which are specified using the custom jsaction attribute in
* HTML. Behavior of the application is then specified in terms of
* handler for such actions, cf. jsaction.Dispatcher in dispatcher.js.
*
* This has several benefits: (1) No DOM event handlers need to be
* registered on the specific elements in the UI. (2) The set of
* events that the application has to handle can be specified in terms
* of the semantics of the application, rather than in terms of DOM
* events. (3) Invocation of handlers can be delayed and handlers can
* be delay loaded in a generic way.
*
* @constructor
*/
jsaction.EventContract = function() {
/**
* A list of functions. Each function will initialize a newly
* registered contract for one event. See addContainer().
*
* @type {!Array.<!jsaction.ContainerInitializerFunction>}
* @private
*/
this.installers_ = [];
/**
* The containers signed up for this event contract. See addContainer().
*
* @type {!Array.<!jsaction.EventContractContainer>}
* @private
*/
this.containers_ = [];
/**
* The list of containers that are children of an existing container. If
* STOP_PROPAGATION is false then we do not install event listeners on these
* (since that would cause the event to be triggered more than once). We do
* want to keep track of these containers such that we properly handle
* additions/removals.
* If STOP_PROPAGATION is true it is safe to add event listeners on all the
* containers.
* @type {!Array.<!jsaction.EventContractContainer>}
* @private
*/
this.nestedContainers_ = [];
/**
* The DOM events which this contract covers. Used to prevent double
* registration of event types. The value of the map is the
* internally created DOM event handler function that handles the
* DOM events. See addEvent().
*
* @type {!Object.<string, !jsaction.EventHandlerFunction>}
* @private
*/
this.events_ = {};
/**
* The dispatcher function. Events are passed to this function for
* handling once it was set using the dispatchTo() method. Usually
* the dispatcher is the bound dispatch() method of a
* jsaction.Dispatcher instance. This is done because the function
* is passed from another jsbinary, so passing the instance and
* invoking the method here would require to leave the method
* unobfuscated.
*
* @type {?function((!jsaction.EventInfo|!Array.<!jsaction.EventInfo>),
* boolean=)}
* @private
*/
this.dispatcher_ = null;
/**
* The queue of events. Events are queued while there is no
* dispatcher set.
* @type {Array.<!jsaction.EventInfo>}
* @private
*/
this.queue_ = [];
if (jsaction.EventContract.CUSTOM_EVENT_SUPPORT) {
this.addEvent(jsaction.EventType.CUSTOM);
}
};
/**
* @define {boolean} Controls the use of event.path logic for the dom
* walking in createEventInfo_.
*/
goog.define('jsaction.EventContract.USE_EVENT_PATH', false);
/**
* Whether the user agent is running on iOS.
* @type {boolean}
* @private
*/
jsaction.EventContract.isIos_ = typeof navigator != 'undefined' &&
/iPhone|iPad|iPod/.test(navigator.userAgent);
/**
* @define {boolean} Support for jsnamespace attribute. This flag can be
* overriden in a build rule to trim down the EventContract's binary size.
*/
goog.define('jsaction.EventContract.JSNAMESPACE_SUPPORT', true);
/**
* @define {boolean} Support for accessible click actions. This flag can be
* overriden in a build rule.
*/
goog.define('jsaction.EventContract.A11Y_CLICK_SUPPORT', false);
/**
* @define {boolean} Support for the non-bubbling mouseenter and mouseleave
* events. This flag can be overridden in a build rule.
*/
goog.define('jsaction.EventContract.MOUSE_SPECIAL_SUPPORT', false);
/**
* @define {boolean} Simulate click events based on touch events for browsers
* that have a 300ms delay before they send the click event. This is
* currently EXPERIMENTAL.
*/
goog.define('jsaction.EventContract.FAST_CLICK_SUPPORT', false);
/**
* @define {boolean} Call stopPropagation on handled events. When integrating
* with non-jsaction event handler based code, you will likely want to turn
* this flag off. While most event handlers will continue to work, jsaction
* binds focus and blur events in the capture phase and thus with
* stopPropagation, none of your non-jsaction-handlers will ever see it.
*/
goog.define('jsaction.EventContract.STOP_PROPAGATION', true);
/**
* @define {boolean} Support for custom events, which are type
* jsaction.EventType.CUSTOM. These are native DOM events with an
* additional type field and an optional payload.
*/
goog.define('jsaction.EventContract.CUSTOM_EVENT_SUPPORT', false);
/**
* Specifies a click jsaction event type triggered by an Enter/Space DOM
* keypress.
* @private {string}
* @const
*/
jsaction.EventContract.CLICKKEY_ = 'clickkey';
/**
* Helper function to trim whitespace from the beginning and the end
* of the string. This deliberately doesn't use the closure equivalent
* to keep dependencies small.
*
* @param {string} str Input string.
* @return {string} Trimmed string.
* @private
*/
jsaction.EventContract.stringTrim_ = function(str) {
var trimmedLeft = str.replace(/^\s+/, '');
return trimmedLeft.replace(/\s+$/, '');
};
/**
* This regular expression matches a semicolon.
* @type {RegExp}
* @private
* @const
*/
jsaction.EventContract.REGEXP_SEMICOLON_ = /\s*;\s*/;
/**
* The default event type.
* @type {string}
* @private
*/
jsaction.EventContract.defaultEventType_ = jsaction.EventType.CLICK;
/**
* An element that received a touchstart event that we might want to translate
* into a click event if a touchend event arrives.
* @private {Element}
*/
jsaction.EventContract.fastClickNode_;
/**
* Elements for which we emitted "fast click" events, so that we need to ignore
* subsequent click events. Elements are removed when the click events arrive.
* At this point there may be a memory leak if we emit fast clicks in scenarios
* that do not trigger a native click event.
* @private {!Array.<!Element>}
* @const
*/
jsaction.EventContract.fastClickedNodes_ = [];
/**
* A timer that we schedule after a touchstart. If the timer fires before the
* touchend event, the press is considered a long-press that does not get
* translated into a click.
* @private {number}
*/
jsaction.EventContract.fastClickTimeout_;
/**
* Gets the default event type.
* @return {string} The default event type.
*/
jsaction.EventContract.getDefaultEventType = function() {
return jsaction.EventContract.defaultEventType_;
};
/**
* Sets a new default event type.
* @param {string} eventType The new default event type.
*/
jsaction.EventContract.setDefaultEventType = function(eventType) {
jsaction.EventContract.defaultEventType_ = eventType;
};
/**
* Returns a function that handles events on a container and invokes a local
* event handler (bound using the actions map) on the source node or any of
* its ancestors up to the container to which the returned event handler
* belongs. The local event handler is passed an ActionFlow which allows
* access to the node, event, and values defined on the node. If there are no
* jsaction handlers bound that can handle this event, the flow representing
* the event is stored in a queue for replaying at a later time.
*
* @param {!jsaction.EventContract} eventContract The EventContract
* instance to create this handler for.
* @param {string} eventType The type of the event - e.g. 'click'.
* Note that event.type can differ from eventType. In some browsers (e.g.
* Firefox) the event handling code registers handlers for 'focusin' and
* 'focusout' to handle 'focus' and 'blur' respectively. In those cases,
* event.type might be 'focus', but eventType will be 'focusin'.
* @return {jsaction.EventHandlerFunction} The DOM event handler to
* use for the given event type on all containers.
* @private
*/
jsaction.EventContract.eventHandler_ = function(eventContract, eventType) {
/**
* See description above.
* @param {!Event} e Event.
* @this {!Element}
*/
return function(e) {
var container = this;
// Store eventType's value in a local variable so that multiple calls do not
// modify the shared eventType variable.
var eventTypeForDispatch = eventType;
if (jsaction.EventContract.CUSTOM_EVENT_SUPPORT &&
eventTypeForDispatch == jsaction.EventType.CUSTOM) {
// For custom events, use a secondary dispatch based on the internal
// custom type of the event.
if (!e.detail || !e.detail['_type']) {
// This should never happen.
return;
}
eventTypeForDispatch = e.detail['_type'];
}
var eventInfo = jsaction.EventContract.createEventInfo_(
eventTypeForDispatch, e, container);
if (eventContract.dispatcher_) {
var globalEventInfo = jsaction.EventContract.createEventInfoInternal_(
eventInfo['eventType'], eventInfo['event'],
eventInfo['targetElement'], eventInfo['action'],
eventInfo['actionElement'], eventInfo['timeStamp']);
// In some cases, createEventInfo_() will rewrite click events to
// clickonly. Revert back to a regular click, otherwise we won't be able
// to execute global event handlers registered on click events.
if (globalEventInfo['eventType'] == jsaction.EventType.CLICKONLY) {
globalEventInfo['eventType'] = jsaction.EventType.CLICK;
}
eventContract.dispatcher_(
globalEventInfo, /* dispatch global event */ true);
}
// Return early if no action element found while walking up the DOM tree.
if (!eventInfo['actionElement']) {
return;
}
if (jsaction.EventContract.STOP_PROPAGATION) {
// Since we found a jsaction, prevent other handlers from seeing
// this event.
jsaction.event.stopPropagation(e);
}
// Prevent browser from following <a> node links if a jsaction is
// present. Note that the targetElement may be a child of an anchor that has
// a jsaction attached. For that reason, we need to check the actionElement
// rather than the targetElement.
if (eventInfo['actionElement'].tagName == goog.dom.TagName.A &&
eventInfo['eventType'] == jsaction.EventType.CLICK) {
jsaction.event.preventDefault(e);
}
if (eventContract.dispatcher_) {
eventContract.dispatcher_(eventInfo);
} else {
var copiedEvent = jsaction.event.maybeCopyEvent(e);
// The event is queued since there is no dispatcher registered
// yet. Potentially make a copy of the event in order to extend its
// life. The copy will later be used when attempting to replay.
eventInfo['event'] = copiedEvent;
eventContract.queue_.push(eventInfo);
}
};
};
/**
* Searches for a jsaction that the DOM event maps to and creates an
* object containing event information used for dispatching by
* jsaction.Dispatcher. The dispatch information returned consists of
* the event type, target element, action and the Event instance
* supplied by the DOM. The jsaction for the DOM event is the first
* jsaction attribute above the target Node of the event, and below
* the container Node, that specifies a jsaction for the event
* type. If no such jsaction is found, the actionElement properties is null.
*
* @param {string} eventType The type of the event, e.g. 'click', as
* specified by event contract. This may differ from the DOM event
* type, because event contract may use more generic event types.
* @param {!Event} e The Event instance received by the container from
* the DOM.
* @param {!Node} container The container which limits the search for
* jsactions which can handle the event.
* @return {jsaction.EventInfo} The event info object. If its actionElement
* property is null, no jsaction was found above the target Node of the
* event.
* @private
*/
jsaction.EventContract.createEventInfo_ = function(eventType, e, container) {
// We distinguish modified and plain clicks in order to support the
// default browser behavior of modified clicks on links; usually to
// open the URL of the link in new tab or new window on ctrl/cmd
// click. A DOM 'click' event is mapped to the jsaction 'click'
// event iff there is no modifier present on the event. If there is
// a modifier, it's mapped to 'clickmod' instead.
//
// It's allowed to omit the event in the jsaction attribute. In that
// case, 'click' is assumed. Thus the following two are equivalent:
//
// <a href="someurl" jsaction="gna.fu">
// <a href="someurl" jsaction="click:gna.fu">
//
// For unmodified clicks, EventContract invokes the jsaction
// 'gna.fu'. For modified clicks, EventContract won't find a
// suitable action and and leave the event to be handled by the
// browser.
//
// In order to also invoke a jsaction handler for a modifier click,
// 'clickmod' needs to be used:
//
// <a href="someurl" jsaction="clickmod:gna.fu">
//
// EventContract invokes the jsaction 'gna.fu' for modified
// clicks. Unmodified clicks are left to the browser.
//
// In order to set up the event contract to handle both clickonly and
// clickmod, only addEvent(jsaction.EventType.CLICK) is necessary.
//
// In order to set up the event contract to handle click,
// addEvent() is necessary for CLICK, KEYDOWN, and KEYPRESS event types. If
// the jsaction.EventContract.A11Y_CLICK_SUPPORT flag is turned on, addEvent()
// will set up the appropriate key event handler automatically.
if (eventType == jsaction.EventType.CLICK &&
jsaction.event.isModifiedClickEvent(e)) {
eventType = jsaction.EventType.CLICKMOD;
} else if (jsaction.EventContract.A11Y_CLICK_SUPPORT &&
jsaction.event.isActionKeyEvent(e)) {
eventType = jsaction.EventContract.CLICKKEY_;
}
var target = /** @type {!Element} */(e.srcElement || e.target);
var eventInfo = jsaction.EventContract.createEventInfoInternal_(
eventType, e, target, '', null);
// NOTE(user): In order to avoid complicating the code that calculates the
// event's path, we need a common interface to iterating over event.path or
// walking the DOM. We use the generator pattern here, as generating the
// path array ahead of time for DOM walks will result in degraded
// performance.
/** @type {jsaction.ActionInfo} */
var actionInfo;
// NOTE(user): This is a work around some issues with custom dispatchers.
var element;
if (jsaction.EventContract.USE_EVENT_PATH) {
var generator = jsaction.domGenerator.getGenerator(
e, target, /** @type {!Element} */(container));
for (var node; node = generator.next();) {
element = node;
actionInfo = jsaction.EventContract.getAction_(
element, eventType, e, container);
eventInfo = jsaction.EventContract.createEventInfoInternal_(
actionInfo.eventType, e, target, actionInfo.action || '', element,
eventInfo['timeStamp']);
// TODO(user): If we can get rid of the break on actionInfo.ignore
// these loops can collapse down to one and the contents can live in
// a function.
// Stop walking the DOM prematurely if we will ignore this event. This is
// used solely for fastbutton's implementation.
if (actionInfo.ignore ||
// An event is handled by at most one jsaction. Thus we stop at
// the first matching jsaction specified in a jsaction attribute
// up the ancestor chain of the event target node.
actionInfo.action) {
break;
}
}
} else {
for (var node = target; node && node != container;
// Walk to the parent node, unless the node has a different owner in
// which case we walk to the owner.
node = node[jsaction.Property.OWNER] || node.parentNode) {
element = node;
actionInfo = jsaction.EventContract.getAction_(
element, eventType, e, container);
eventInfo = jsaction.EventContract.createEventInfoInternal_(
actionInfo.eventType, e, target, actionInfo.action || '', element,
eventInfo['timeStamp']);
// Stop walking the DOM prematurely if we will ignore this event. This is
// used solely for fastbutton's implementation.
if (actionInfo.ignore ||
// An event is handled by at most one jsaction. Thus we stop at
// the first matching jsaction specified in a jsaction attribute
// up the ancestor chain of the event target node.
actionInfo.action) {
break;
}
}
}
if (actionInfo && actionInfo.action) {
// Prevent scrolling if the Space key was pressed and prevent the browser's
// default action for native HTML controls.
if (jsaction.EventContract.A11Y_CLICK_SUPPORT &&
eventType == jsaction.EventContract.CLICKKEY_ &&
(jsaction.event.isSpaceKeyEvent(e) ||
jsaction.event.shouldCallPreventDefaultOnNativeHtmlControl(e))) {
jsaction.event.preventDefault(e);
}
if (jsaction.EventContract.MOUSE_SPECIAL_SUPPORT &&
(eventType == jsaction.EventType.MOUSEENTER ||
eventType == jsaction.EventType.MOUSELEAVE)) {
// We attempt to handle the mouseenter/mouseleave events here by
// detecting whether the mouseover/mouseout events correspond to
// entering/leaving an element.
if (jsaction.event.isMouseSpecialEvent(e, element)) {
// If both mouseover/mouseout and mouseenter/mouseleave events are
// enabled, two separate handlers for mouseover/mouseout are
// registered. Both handlers will see the same event instance
// so we create a copy to avoid interfering with the dispatching of
// the mouseover/mouseout event.
var copiedEvent = jsaction.event.createMouseSpecialEvent(
e, /** @type {!Element} */(element));
eventInfo['event'] = /** @type {!Event} */(copiedEvent);
// Since the mouseenter/mouseleave events do not bubble, the target
// of the event is technically the node on which the jsaction is
// specified (the actionElement).
eventInfo['targetElement'] = element;
}
}
return eventInfo;
}
// Reset action-related properties of the current eventInfo, to ensure we
// won't dispatch a non-existing action.
eventInfo['action'] = '';
eventInfo['actionElement'] = null;
return eventInfo;
};
/**
* @param {string} eventType
* @param {!Event} e
* @param {!Element} targetElement
* @param {string} action
* @param {Element} actionElement
* @param {number=} opt_timeStamp
* @return {jsaction.EventInfo}
* @private
*/
jsaction.EventContract.createEventInfoInternal_ = function(
eventType, e, targetElement, action, actionElement, opt_timeStamp) {
// Event#timeStamp is broken on Firefox for synthetic events. See
// https://bugzilla.mozilla.org/show_bug.cgi?id=238041 for details. Since
// Firefox marks Event#timeStamp as read-only, the only workaround is to
// expose a timestamp directly in eventInfo, to be consistent across all
// browsers.
return /** @type {jsaction.EventInfo} */ ({
'eventType': eventType,
'event': e,
'targetElement': targetElement,
'action': action,
'actionElement': actionElement,
'timeStamp': opt_timeStamp || goog.now()
});
};
/**
* Accesses the event handler attribute value of a DOM node. It guards
* against weird situations (described in the body) that occur in
* connection with nodes that are removed from their document.
* @param {!Element} node The DOM node.
* @param {string} attribute The name of the attribute to access.
* @return {?string} The attribute value if it was found, null
* otherwise.
* @private
*/
jsaction.EventContract.getAttr_ = function(node, attribute) {
var value = null;
// NOTE(user): Nodes in IE do not always have a getAttribute
// method defined. This is the case where sourceElement has in
// fact been removed from the DOM before eventContract begins
// handling - where a parentNode does not have getAttribute
// defined.
// NOTE(user): We must use the 'in' operator instead of the regular dot
// notation, since the latter fails in IE8 if the getAttribute method is not
// defined. See b/7139109.
if ('getAttribute' in node) {
value = node.getAttribute(attribute);
}
return value;
};
/**
* Accesses the jsaction map on a node and retrieves the name of the
* action the given event is mapped to, if any. It parses the
* attribute value and stores it in a property on the node for
* subsequent retrieval without re-parsing and re-accessing the
* attribute. In order to fully qualify jsaction names using a
* namespace, the DOM is searched starting at the current node and
* going through ancestor nodes until a jsnamespace attribute is
* found.
*
* @param {!Element} node The DOM node to retrieve the jsaction map
* from.
* @param {string} eventType The type of the event for which to
* retrieve the action.
* @param {!Event} event The current browser event.
* @param {!Node} container The node which limits the namespace lookup
* for a jsaction name. The container node itself will not be
* searched.
* @return {jsaction.ActionInfo} The action info.
* @private
*/
jsaction.EventContract.getAction_ = function(node, eventType, event,
container) {
var actionMap = jsaction.Cache.get(node);
if (!actionMap) {
actionMap = {};
jsaction.Cache.set(node, actionMap);
var attvalue = jsaction.EventContract.getAttr_(
node, jsaction.Attribute.JSACTION);
if (attvalue) {
var values = attvalue.split(jsaction.EventContract.REGEXP_SEMICOLON_);
for (var i = 0, I = values ? values.length : 0; i < I; i++) {
var value = values[i];
if (!value) {
continue;
}
var colon = value.indexOf(jsaction.Char.EVENT_ACTION_SEPARATOR);
var hasColon = colon != -1;
var type = hasColon ?
jsaction.EventContract.stringTrim_(value.substr(0, colon)) :
jsaction.EventContract.defaultEventType_;
var action = jsaction.EventContract.getQualifiedName_(
hasColon ? jsaction.EventContract.stringTrim_(
value.substr(colon + 1)) : value,
node, container);
actionMap[type] = action;
}
}
}
if (jsaction.EventContract.A11Y_CLICK_SUPPORT) {
if (eventType == jsaction.EventContract.CLICKKEY_) {
// A 'click' triggered by a DOM keypress should be mapped to the 'click'
// jsaction.
eventType = jsaction.EventType.CLICK;
} else if (eventType == jsaction.EventType.CLICK &&
!actionMap[jsaction.EventType.CLICK]) {
// A 'click' triggered by a DOM click should be mapped to the 'click'
// jsaction, if available, or else fallback to the 'clickonly' jsaction.
// If 'click' and 'clickonly' jsactions are used together, 'click' will
// prevail.
eventType = jsaction.EventType.CLICKONLY;
}
}
if (jsaction.EventContract.FAST_CLICK_SUPPORT &&
// Don't want fast click behavior? Just bind clickonly instead.
actionMap[jsaction.EventType.CLICK]) {
var fastType = jsaction.EventContract.getFastClickEventType_(node,
eventType, event, actionMap);
if (!fastType) {
// Null means to stop looking for further events, as the logic event
// has already been handled or the event started a sequence that may
// eventually lead to a logic click event.
return {
eventType: eventType,
action: '',
ignore: true
};
} else {
eventType = fastType;
}
}
// An empty action indicates that no jsaction attribute was found in the given
// DOM node.
var actionName = actionMap[eventType] || '';
return {
eventType: eventType,
action: actionName,
ignore: false
};
};
/**
* Returns the qualified jsaction name, i.e. the name of the jsaction
* including the namespace part before the dot. If the given jsaction
* name doesn't already contain the namespace, the function iterates
* over ancestor nodes until a jsnamespace attribute is found, and
* uses the value of that attribute as the namespace.
*
* @param {string} name The jsaction name to resolve the namespace of.
* @param {Element} start The node from which to start searching for a
* jsnamespace attribute.
* @param {Node} container The node which limits the search for a
* jsnamespace attribute. This node will be searched.
* @return {string} The qualified name of the jsaction. If no
* namespace is found, returns the unqualified name in case it
* exists in the global namespace.
* @private
*/
jsaction.EventContract.getQualifiedName_ = function(name, start, container) {
if (jsaction.EventContract.JSNAMESPACE_SUPPORT) {
if (jsaction.EventContract.isQualifiedName_(name)) {
return name;
}
for (var node = start; node; node = node.parentNode) {
var ns = jsaction.EventContract.getNamespace_(
/** @type {!Element} */(node));
if (ns) {
return ns + jsaction.Char.NAMESPACE_ACTION_SEPARATOR + name;
}
// If this node is the container, stop.
if (node == container) {
break;
}
}
}
return name;
};
/**
* Converts a sequence of touchstart and touchend events into a click event
* and will then ignore a subsequent click event (within 400ms).
* @param {!Element} node The current node with a jsaction annotation.
* @param {string} eventType
* @param {!Event} event The current browser event.
* @param {!Object.<string, string>} actionMap
* @return {?string} The mapped event type or null if the event should be
* ignored.
* @private
*/
jsaction.EventContract.getFastClickEventType_ = function(node, eventType, event,
actionMap) {
// TODO(user): Disable fast click emulation for browsers that don't need
// it (Currently Chrome 32 and IE10 with layer.style.msTouchAction == 'none').
var fastClickNode = jsaction.EventContract.fastClickNode_;
// A click event is being emitted onto what was previously the target of
// a fast click: Ignore this click.
if (eventType == jsaction.EventType.CLICK) {
for (var i = 0; i < jsaction.EventContract.fastClickedNodes_.length; ++i) {
if (jsaction.EventContract.fastClickedNodes_[i] == node) {
jsaction.EventContract.fastClickedNodes_.splice(i, 1);
return null;
}
}
return eventType;
}
if (event.targetTouches && event.targetTouches.length > 1) {
// Click emulation does not make sense for multi touch.
return eventType;
}
var target = event.target;
if (target) {
// Don't do anything special for clicks on elements with elaborate built in
// click and focus behavior.
var type = (target.type || target.tagName || '').toUpperCase();
if (type == 'TEXTAREA' || type == 'TEXT' || type == 'PASSWORD' ||
type == 'SEARCH') {
return eventType;
}
}
// When a touchstart is fired, remember the action node in a global variable.
// When a subsequent touchend arrives, it'll be interpreted as a click.
if (eventType == jsaction.EventType.TOUCHSTART &&
// If the jsaction binds touchstart or touchend explicitly, we don't do
// anything special with it
!actionMap[jsaction.EventType.TOUCHSTART] &&
!actionMap[jsaction.EventType.TOUCHEND]) {
jsaction.EventContract.fastClickNode_ = node;
clearTimeout(jsaction.EventContract.fastClickTimeout_);
// If touchend doesn't arrive within a reasonable amount of time, this is
// a long click and not a click, so we throw the state away and will ignore
// a later touchend.
jsaction.EventContract.fastClickTimeout_ = setTimeout(
jsaction.EventContract.resetFastClickNode_, 400);
return null;
}
// If a touchend was fired on what had a previous touchstart, count the event
// as a click.
else if (eventType == jsaction.EventType.TOUCHEND &&
fastClickNode == node) {
jsaction.EventContract.patchTouchEventToBeClickLike_(event);
eventType = jsaction.EventType.CLICK;
jsaction.EventContract.fastClickedNodes_.push(node);
}
// Touchmove is fired when the user scrolls. In this case a previous
// touchstart is ignored.
else if (eventType == jsaction.EventType.TOUCHMOVE && fastClickNode) {
jsaction.EventContract.resetFastClickNode_();
}
return eventType;
};
/**
* Cancels the expectation that there might come a touchend to after a
* touchstart, so we can synthesize a click.
* @private
*/
jsaction.EventContract.resetFastClickNode_ = function() {
jsaction.EventContract.fastClickNode_ = null;
};
/**
* To be called after it was decided that a click event should be synthesized
* from a touchend event.
* Takes a touch event, adds common fields found in mouse events and changes the
* type to 'click', so that the resulting event looks more like a real click
* event.
* @param {!Event} event A touch event.
* @private
*/
jsaction.EventContract.patchTouchEventToBeClickLike_ = function(event) {
event['originalEventType'] = event.type;
event.type = jsaction.EventType.CLICK;
var touch = (event.changedTouches && event.changedTouches[0]) ||
(event.touches && event.touches[0]);
if (touch) {
event.clientX = touch.clientX;
event.clientY = touch.clientY;
event.screenX = touch.screenX;
event.screenY = touch.screenY;
event.pageX = touch.pageX;
event.pageY = touch.pageY;
}
};
if (jsaction.EventContract.JSNAMESPACE_SUPPORT) {
/**
* Checks if a jsaction name contains a namespace part.
* @param {string} name The name of a jsaction.
* @return {boolean} Whether the name contains a namespace part.
* @private
*/
jsaction.EventContract.isQualifiedName_ = function(name) {
return name.indexOf(jsaction.Char.NAMESPACE_ACTION_SEPARATOR) >= 0;
};
/**
* Returns the value of the jsnamespace attribute of the given node.
* Also caches the value for subsequent lookups.
* @param {!Element} node The node whose jsnamespace attribute is being
* asked for.
* @return {?string} The value of the jsnamespace attribute, or null if not
* found.
* @private
*/
jsaction.EventContract.getNamespace_ = function(node) {
var jsnamespace = jsaction.Cache.getNamespace(node);
// Only query for the attribute if it has not been queried for
// before. jsaction.EventContract.getAttr_() returns null if an
// attribute is not present. Thus, jsnamespace is string|null if
// the query took place in the past, or undefined if the query did
// not take place.
if (!goog.isDef(jsnamespace)) {
jsnamespace =
jsaction.EventContract.getAttr_(node, jsaction.Attribute.JSNAMESPACE);
jsaction.Cache.setNamespace(node, jsnamespace);
}
return jsnamespace;
};
}
/**
* Factory for container installer functions. The returned function
* will install the given handler for the event given by name here on
* the container passed to the returned function. It is used to
* register all currently known events on a newly registered
* container.
*
* @param {string} name The name of the event.
* @param {jsaction.EventHandlerFunction} handler An event handler.
* @return {jsaction.ContainerInitializerFunction} A function that, when
* applied to an Element, installs the given event handler for the
* event type given by name.
* @private
*/
jsaction.EventContract.containerHandlerInstaller_ = function(name, handler) {
/**
* @param {!Element} div The container to install this handler on.
* @return {jsaction.EventHandlerInfo} The event name and the
* handler installed by the function.
*/
return function(div) {
return jsaction.event.addEventListener(div, name, handler);
};
};
/**
* Enables jsaction handlers to be called for the event type given by
* name.
*
* If the event is already registered, this does nothing.
*
* @param {string} name Event name.
*/
jsaction.EventContract.prototype.addEvent = function(name) {
if (this.events_.hasOwnProperty(name)) {
return;
}
if (!jsaction.EventContract.MOUSE_SPECIAL_SUPPORT &&
(name == jsaction.EventType.MOUSEENTER ||
name == jsaction.EventType.MOUSELEAVE)) {
return;
}
var handler = jsaction.EventContract.eventHandler_(this, name);
// Install the callback which handles events on the container.
var installer = jsaction.EventContract.containerHandlerInstaller_(
name, handler);
// Store the callback to allow us to replay events.
this.events_[name] = handler;
this.installers_.push(installer);
for (var i = 0; i < this.containers_.length; ++i) {
this.containers_[i].installHandler(installer);
}
// Automatically install a keypress/keydown event handler if support for
// accessible clicks is turned on.
if (jsaction.EventContract.A11Y_CLICK_SUPPORT &&
name == jsaction.EventType.CLICK) {
this.addEvent(jsaction.EventType.KEYDOWN);
}
if (jsaction.EventContract.FAST_CLICK_SUPPORT &&
name == jsaction.EventType.CLICK) {
this.addEvent(jsaction.EventType.TOUCHSTART);
this.addEvent(jsaction.EventType.TOUCHEND);
this.addEvent(jsaction.EventType.TOUCHMOVE);
}
};
/**
* Returns the event handler function for a given event type.
* @param {string} name Event name.
* @return {jsaction.EventHandlerFunction|undefined} The event handler
* function or undefined if it does not exist.
*/
jsaction.EventContract.prototype.handler = function(name) {
return this.events_[name];
};
/**
* Signs the event contract for a new container. All registered events
* are enabled for this container too. Containers have to be kept disjoint,
* so if the newly added container is a parent/child of existing containers,
* they will be merged.
*
* The caller of addContainer can keep a reference to this if it desires
* to remove the container later.
*
* @param {!Element} div The container element. Usually a DIV, but not
* constrained to.
* @return {!jsaction.EventContractContainer} The container object that was
* created.
*/
jsaction.EventContract.prototype.addContainer = function(div) {
var container = new jsaction.EventContractContainer(div);
if (!jsaction.EventContract.STOP_PROPAGATION) {
if (this.hasContainerFor_(div)) {
// This container has an ancestor that is already a contract container.
// Don't install event listeners on it when STOP_PROPAGATION is false
// in order to prevent an event from being handled multiple times. We
// still want to keep track of it in order to be able to correctly
// add/remove containers.
this.nestedContainers_.push(container);
return container;
}