/* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for
* full list of contributors). Published under the Clear BSD license.
* See http://svn.openlayers.org/trunk/openlayers/license.txt for the
* full text of the license. */
/**
* @requires OpenLayers/Util.js
*/
/**
* Namespace: OpenLayers.Event
* Utility functions for event handling.
*/
OpenLayers.Event = {
/**
* Property: observers
* {Object} A hashtable cache of the event observers. Keyed by
* element._eventCacheID
*/
observers: false,
/**
* Constant: KEY_BACKSPACE
* {int}
*/
KEY_BACKSPACE: 8,
/**
* Constant: KEY_TAB
* {int}
*/
KEY_TAB: 9,
/**
* Constant: KEY_RETURN
* {int}
*/
KEY_RETURN: 13,
/**
* Constant: KEY_ESC
* {int}
*/
KEY_ESC: 27,
/**
* Constant: KEY_LEFT
* {int}
*/
KEY_LEFT: 37,
/**
* Constant: KEY_UP
* {int}
*/
KEY_UP: 38,
/**
* Constant: KEY_RIGHT
* {int}
*/
KEY_RIGHT: 39,
/**
* Constant: KEY_DOWN
* {int}
*/
KEY_DOWN: 40,
/**
* Constant: KEY_DELETE
* {int}
*/
KEY_DELETE: 46,
/**
* Method: element
* Cross browser event element detection.
*
* Parameters:
* event - {Event}
*
* Returns:
* {DOMElement} The element that caused the event
*/
element: function(event) {
return event.target || event.srcElement;
},
/**
* Method: isLeftClick
* Determine whether event was caused by a left click.
*
* Parameters:
* event - {Event}
*
* Returns:
* {Boolean}
*/
isLeftClick: function(event) {
return (((event.which) && (event.which == 1)) ||
((event.button) && (event.button == 1)));
},
/**
* Method: isRightClick
* Determine whether event was caused by a right mouse click.
*
* Parameters:
* event - {Event}
*
* Returns:
* {Boolean}
*/
isRightClick: function(event) {
return (((event.which) && (event.which == 3)) ||
((event.button) && (event.button == 2)));
},
/**
* Method: stop
* Stops an event from propagating.
*
* Parameters:
* event - {Event}
* allowDefault - {Boolean} If true, we stop the event chain but
* still allow the default browser
* behaviour (text selection, radio-button
* clicking, etc)
* Default false
*/
stop: function(event, allowDefault) {
if (!allowDefault) {
if (event.preventDefault) {
event.preventDefault();
} else {
event.returnValue = false;
}
}
if (event.stopPropagation) {
event.stopPropagation();
} else {
event.cancelBubble = true;
}
},
/**
* Method: findElement
*
* Parameters:
* event - {Event}
* tagName - {String}
*
* Returns:
* {DOMElement} The first node with the given tagName, starting from the
* node the event was triggered on and traversing the DOM upwards
*/
findElement: function(event, tagName) {
var element = OpenLayers.Event.element(event);
while (element.parentNode && (!element.tagName ||
(element.tagName.toUpperCase() != tagName.toUpperCase()))){
element = element.parentNode;
}
return element;
},
/**
* Method: observe
*
* Parameters:
* elementParam - {DOMElement || String}
* name - {String}
* observer - {function}
* useCapture - {Boolean}
*/
observe: function(elementParam, name, observer, useCapture) {
var element = OpenLayers.Util.getElement(elementParam);
useCapture = useCapture || false;
if (name == 'keypress' &&
(navigator.appVersion.match(/Konqueror|Safari|KHTML/)
|| element.attachEvent)) {
name = 'keydown';
}
//if observers cache has not yet been created, create it
if (!this.observers) {
this.observers = {};
}
//if not already assigned, make a new unique cache ID
if (!element._eventCacheID) {
var idPrefix = "eventCacheID_";
if (element.id) {
idPrefix = element.id + "_" + idPrefix;
}
element._eventCacheID = OpenLayers.Util.createUniqueID(idPrefix);
}
var cacheID = element._eventCacheID;
//if there is not yet a hash entry for this element, add one
if (!this.observers[cacheID]) {
this.observers[cacheID] = [];
}
//add a new observer to this element's list
this.observers[cacheID].push({
'element': element,
'name': name,
'observer': observer,
'useCapture': useCapture
});
//add the actual browser event listener
if (element.addEventListener) {
element.addEventListener(name, observer, useCapture);
} else if (element.attachEvent) {
element.attachEvent('on' + name, observer);
}
},
/**
* Method: stopObservingElement
* Given the id of an element to stop observing, cycle through the
* element's cached observers, calling stopObserving on each one,
* skipping those entries which can no longer be removed.
*
* parameters:
* elementParam - {DOMElement || String}
*/
stopObservingElement: function(elementParam) {
var element = OpenLayers.Util.getElement(elementParam);
var cacheID = element._eventCacheID;
this._removeElementObservers(OpenLayers.Event.observers[cacheID]);
},
/**
* Method: _removeElementObservers
*
* Parameters:
* elementObservers - {Array(Object)} Array of (element, name,
* observer, usecapture) objects,
* taken directly from hashtable
*/
_removeElementObservers: function(elementObservers) {
if (elementObservers) {
for(var i = elementObservers.length-1; i >= 0; i--) {
var entry = elementObservers[i];
var args = new Array(entry.element,
entry.name,
entry.observer,
entry.useCapture);
var removed = OpenLayers.Event.stopObserving.apply(this, args);
}
}
},
/**
* Method: stopObserving
*
* Parameters:
* elementParam - {DOMElement || String}
* name - {String}
* observer - {function}
* useCapture - {Boolean}
*
* Returns:
* {Boolean} Whether or not the event observer was removed
*/
stopObserving: function(elementParam, name, observer, useCapture) {
useCapture = useCapture || false;
var element = OpenLayers.Util.getElement(elementParam);
var cacheID = element._eventCacheID;
if (name == 'keypress') {
if ( navigator.appVersion.match(/Konqueror|Safari|KHTML/) ||
element.detachEvent) {
name = 'keydown';
}
}
// find element's entry in this.observers cache and remove it
var foundEntry = false;
var elementObservers = OpenLayers.Event.observers[cacheID];
if (elementObservers) {
// find the specific event type in the element's list
var i=0;
while(!foundEntry && i < elementObservers.length) {
var cacheEntry = elementObservers[i];
if ((cacheEntry.name == name) &&
(cacheEntry.observer == observer) &&
(cacheEntry.useCapture == useCapture)) {
elementObservers.splice(i, 1);
if (elementObservers.length == 0) {
delete OpenLayers.Event.observers[cacheID];
}
foundEntry = true;
break;
}
i++;
}
}
//actually remove the event listener from browser
if (foundEntry) {
if (element.removeEventListener) {
element.removeEventListener(name, observer, useCapture);
} else if (element && element.detachEvent) {
element.detachEvent('on' + name, observer);
}
}
return foundEntry;
},
/**
* Method: unloadCache
* Cycle through all the element entries in the events cache and call
* stopObservingElement on each.
*/
unloadCache: function() {
// check for OpenLayers.Event before checking for observers, because
// OpenLayers.Event may be undefined in IE if no map instance was
// created
if (OpenLayers.Event && OpenLayers.Event.observers) {
for (var cacheID in OpenLayers.Event.observers) {
var elementObservers = OpenLayers.Event.observers[cacheID];
OpenLayers.Event._removeElementObservers.apply(this,
[elementObservers]);
}
OpenLayers.Event.observers = false;
}
},
CLASS_NAME: "OpenLayers.Event"
};
/* prevent memory leaks in IE */
OpenLayers.Event.observe(window, 'unload', OpenLayers.Event.unloadCache, false);
// FIXME: Remove this in 3.0. In 3.0, Event.stop will no longer be provided
// by OpenLayers.
if (window.Event) {
OpenLayers.Util.applyDefaults(window.Event, OpenLayers.Event);
} else {
var Event = OpenLayers.Event;
}
/**
* Class: OpenLayers.Events
*/
OpenLayers.Events = OpenLayers.Class({
/**
* Constant: BROWSER_EVENTS
* {Array(String)} supported events
*/
BROWSER_EVENTS: [
"mouseover", "mouseout",
"mousedown", "mouseup", "mousemove",
"click", "dblclick", "rightclick", "dblrightclick",
"resize", "focus", "blur"
],
/**
* Property: listeners
* {Object} Hashtable of Array(Function): events listener functions
*/
listeners: null,
/**
* Property: object
* {Object} the code object issuing application events
*/
object: null,
/**
* Property: element
* {DOMElement} the DOM element receiving browser events
*/
element: null,
/**
* Property: eventTypes
* {Array(String)} list of support application events
*/
eventTypes: null,
/**
* Property: eventHandler
* {Function} bound event handler attached to elements
*/
eventHandler: null,
/**
* APIProperty: fallThrough
* {Boolean}
*/
fallThrough: null,
/**
* APIProperty: includeXY
* {Boolean} Should the .xy property automatically be created for browser
* mouse events? In general, this should be false. If it is true, then
* mouse events will automatically generate a '.xy' property on the
* event object that is passed. (Prior to OpenLayers 2.7, this was true
* by default.) Otherwise, you can call the getMousePosition on the
* relevant events handler on the object available via the 'evt.object'
* property of the evt object. So, for most events, you can call:
* function named(evt) {
* this.xy = this.object.events.getMousePosition(evt)
* }
*
* This option typically defaults to false for performance reasons:
* when creating an events object whose primary purpose is to manage
* relatively positioned mouse events within a div, it may make
* sense to set it to true.
*
* This option is also used to control whether the events object caches
* offsets. If this is false, it will not: the reason for this is that
* it is only expected to be called many times if the includeXY property
* is set to true. If you set this to true, you are expected to clear
* the offset cache manually (using this.clearMouseCache()) if:
* the border of the element changes
* the location of the element in the page changes
*/
includeXY: false,
/**
* Method: clearMouseListener
* A version of <clearMouseCache> that is bound to this instance so that
* it can be used with <OpenLayers.Event.observe> and
* <OpenLayers.Event.stopObserving>.
*/
clearMouseListener: null,
/**
* Constructor: OpenLayers.Events
* Construct an OpenLayers.Events object.
*
* Parameters:
* object - {Object} The js object to which this Events object is being
* added element - {DOMElement} A dom element to respond to browser events
* eventTypes - {Array(String)} Array of custom application events
* fallThrough - {Boolean} Allow events to fall through after these have
* been handled?
* options - {Object} Options for the events object.
*/
initialize: function (object, element, eventTypes, fallThrough, options) {
OpenLayers.Util.extend(this, options);
this.object = object;
this.fallThrough = fallThrough;
this.listeners = {};
// keep a bound copy of handleBrowserEvent() so that we can
// pass the same function to both Event.observe() and .stopObserving()
this.eventHandler = OpenLayers.Function.bindAsEventListener(
this.handleBrowserEvent, this
);
// to be used with observe and stopObserving
this.clearMouseListener = OpenLayers.Function.bind(
this.clearMouseCache, this
);
// if eventTypes is specified, create a listeners list for each
// custom application event.
this.eventTypes = [];
if (eventTypes != null) {
for (var i=0, len=eventTypes.length; i<len; i++) {
this.addEventType(eventTypes[i]);
}
}
// if a dom element is specified, add a listeners list
// for browser events on the element and register them
if (element != null) {
this.attachToElement(element);
}
},
/**
* APIMethod: destroy
*/
destroy: function () {
if (this.element) {
OpenLayers.Event.stopObservingElement(this.element);
if(this.element.hasScrollEvent) {
OpenLayers.Event.stopObserving(
window, "scroll", this.clearMouseListener
);
}
}
this.element = null;
this.listeners = null;
this.object = null;
this.eventTypes = null;
this.fallThrough = null;
this.eventHandler = null;
},
/**
* APIMethod: addEventType
* Add a new event type to this events object.
* If the event type has already been added, do nothing.
*
* Parameters:
* eventName - {String}
*/
addEventType: function(eventName) {
if (!this.listeners[eventName]) {
this.eventTypes.push(eventName);
this.listeners[eventName] = [];
}
},
/**
* Method: attachToElement
*
* Parameters:
* element - {HTMLDOMElement} a DOM element to attach browser events to
*/
attachToElement: function (element) {
if(this.element) {
OpenLayers.Event.stopObservingElement(this.element);
}
this.element = element;
for (var i=0, len=this.BROWSER_EVENTS.length; i<len; i++) {
var eventType = this.BROWSER_EVENTS[i];
// every browser event has a corresponding application event
// (whether it's listened for or not).
this.addEventType(eventType);
// use Prototype to register the event cross-browser
OpenLayers.Event.observe(element, eventType, this.eventHandler);
}
// disable dragstart in IE so that mousedown/move/up works normally
OpenLayers.Event.observe(element, "dragstart", OpenLayers.Event.stop);
},
/**
* APIMethod: on
* Convenience method for registering listeners with a common scope.
* Internally, this method calls <register> as shown in the examples
* below.
*
* Example use:
* (code)
* // register a single listener for the "loadstart" event
* events.on({"loadstart", loadStartListener});
*
* // this is equivalent to the following
* events.register("loadstart", undefined, loadStartListener);
*
* // register multiple listeners to be called with the same `this` object
* events.on({
* "loadstart": loadStartListener,
* "loadend": loadEndListener,
* scope: object
* });
*
* // this is equivalent to the following
* events.register("loadstart", object, loadStartListener);
* events.register("loadstart", object, loadEndListener);
* (end)
*/
on: function(object) {
for(var type in object) {
if(type != "scope") {
this.register(type, object.scope, object[type]);
}
}
},
/**
* APIMethod: register
* Register an event on the events object.
*
* When the event is triggered, the 'func' function will be called, in the
* context of 'obj'. Imagine we were to register an event, specifying an
* OpenLayers.Bounds Object as 'obj'. When the event is triggered, the
* context in the callback function will be our Bounds object. This means
* that within our callback function, we can access the properties and
* methods of the Bounds object through the "this" variable. So our
* callback could execute something like:
* : leftStr = "Left: " + this.left;
*
* or
*
* : centerStr = "Center: " + this.getCenterLonLat();
*
* Parameters:
* type - {String} Name of the event to register
* obj - {Object} The object to bind the context to for the callback#.
* If no object is specified, default is the Events's
* 'object' property.
* func - {Function} The callback function. If no callback is
* specified, this function does nothing.
*
*
*/
register: function (type, obj, func) {
if ( (func != null) &&
(OpenLayers.Util.indexOf(this.eventTypes, type) != -1) ) {
if (obj == null) {
obj = this.object;
}
var listeners = this.listeners[type];
listeners.push( {obj: obj, func: func} );
}
},
/**
* APIMethod: registerPriority
* Same as register() but adds the new listener to the *front* of the
* events queue instead of to the end.
*
* TODO: get rid of this in 3.0 - Decide whether listeners should be
* called in the order they were registered or in reverse order.
*
*
* Parameters:
* type - {String} Name of the event to register
* obj - {Object} The object to bind the context to for the callback#.
* If no object is specified, default is the Events's
* 'object' property.
* func - {Function} The callback function. If no callback is
* specified, this function does nothing.
*/
registerPriority: function (type, obj, func) {
if (func != null) {
if (obj == null) {
obj = this.object;
}
var listeners = this.listeners[type];
if (listeners != null) {
listeners.unshift( {obj: obj, func: func} );
}
}
},
/**
* APIMethod: un
* Convenience method for unregistering listeners with a common scope.
* Internally, this method calls <unregister> as shown in the examples
* below.
*
* Example use:
* (code)
* // unregister a single listener for the "loadstart" event
* events.un({"loadstart", loadStartListener});
*
* // this is equivalent to the following
* events.unregister("loadstart", undefined, loadStartListener);
*
* // unregister multiple listeners with the same `this` object
* events.un({
* "loadstart": loadStartListener,
* "loadend": loadEndListener,
* scope: object
* });
*
* // this is equivalent to the following
* events.unregister("loadstart", object, loadStartListener);
* events.unregister("loadstart", object, loadEndListener);
* (end)
*/
un: function(object) {
for(var type in object) {
if(type != "scope") {
this.unregister(type, object.scope, object[type]);
}
}
},
/**
* APIMethod: unregister
*
* Parameters:
* type - {String}
* obj - {Object} If none specified, defaults to this.object
* func - {Function}
*/
unregister: function (type, obj, func) {
if (obj == null) {
obj = this.object;
}
var listeners = this.listeners[type];
if (listeners != null) {
for (var i=0, len=listeners.length; i<len; i++) {
if (listeners[i].obj == obj && listeners[i].func == func) {
listeners.splice(i, 1);
break;
}
}
}
},
/**
* Method: remove
* Remove all listeners for a given event type. If type is not registered,
* does nothing.
*
* Parameters:
* type - {String}
*/
remove: function(type) {
if (this.listeners[type] != null) {
this.listeners[type] = [];
}
},
/**
* APIMethod: triggerEvent
* Trigger a specified registered event.
*
* Parameters:
* type - {String}
* evt - {Event}
*
* Returns:
* {Boolean} The last listener return. If a listener returns false, the
* chain of listeners will stop getting called.
*/
triggerEvent: function (type, evt) {
var listeners = this.listeners[type];
// fast path
if(!listeners || listeners.length == 0) {
return;
}
// prep evt object with object & div references
if (evt == null) {
evt = {};
}
evt.object = this.object;
evt.element = this.element;
if(!evt.type) {
evt.type = type;
}
// execute all callbacks registered for specified type
// get a clone of the listeners array to
// allow for splicing during callbacks
var listeners = listeners.slice(), continueChain;
for (var i=0, len=listeners.length; i<len; i++) {
var callback = listeners[i];
// bind the context to callback.obj
continueChain = callback.func.apply(callback.obj, [evt]);
if ((continueChain != undefined) && (continueChain == false)) {
// if callback returns false, execute no more callbacks.
break;
}
}
// don't fall through to other DOM elements
if (!this.fallThrough) {
OpenLayers.Event.stop(evt, true);
}
return continueChain;
},
/**
* Method: handleBrowserEvent
* Basically just a wrapper to the triggerEvent() function, but takes
* care to set a property 'xy' on the event with the current mouse
* position.
*
* Parameters:
* evt - {Event}
*/
handleBrowserEvent: function (evt) {
if (this.includeXY) {
evt.xy = this.getMousePosition(evt);
}
this.triggerEvent(evt.type, evt);
},
/**
* APIMethod: clearMouseCache
* Clear cached data about the mouse position. This should be called any
* time the element that events are registered on changes position
* within the page.
*/
clearMouseCache: function() {
this.element.scrolls = null;
this.element.lefttop = null;
this.element.offsets = null;
},
/**
* Method: getMousePosition
*
* Parameters:
* evt - {Event}
*
* Returns:
* {<OpenLayers.Pixel>} The current xy coordinate of the mouse, adjusted
* for offsets
*/
getMousePosition: function (evt) {
if (!this.includeXY) {
this.clearMouseCache();
} else if (!this.element.hasScrollEvent) {
OpenLayers.Event.observe(window, "scroll", this.clearMouseListener);
this.element.hasScrollEvent = true;
}
if (!this.element.scrolls) {
this.element.scrolls = [
(document.documentElement.scrollLeft
|| document.body.scrollLeft),
(document.documentElement.scrollTop
|| document.body.scrollTop)
];
}
if (!this.element.lefttop) {
this.element.lefttop = [
(document.documentElement.clientLeft || 0),
(document.documentElement.clientTop || 0)
];
}
if (!this.element.offsets) {
this.element.offsets = OpenLayers.Util.pagePosition(this.element);
this.element.offsets[0] += this.element.scrolls[0];
this.element.offsets[1] += this.element.scrolls[1];
}
return new OpenLayers.Pixel(
(evt.clientX + this.element.scrolls[0]) - this.element.offsets[0]
- this.element.lefttop[0],
(evt.clientY + this.element.scrolls[1]) - this.element.offsets[1]
- this.element.lefttop[1]
);
},
CLASS_NAME: "OpenLayers.Events"
});