ext-base-event.js

来自「Ext JS是一个创建丰富互联网应用程序的跨浏览器的JavaScrip库。它包含」· JavaScript 代码 · 共 420 行

/*
 * Ext JS Library 3.0 Pre-alpha
 * Copyright(c) 2006-2008, Ext JS, LLC.
 * [e-mail]
 * 
 * http://extjs.com/license
 */

Ext.lib.Event = function() {
    var loadComplete = false,
    	listeners = [],
    	unloadListeners = [],
    	retryCount = 0,
    	onAvailStack = [],
    	_interval,
    	locked = false,
    	win = window,
    	doc = document,
    	
    	// constants        	
    	POLL_RETRYS = 200,
        POLL_INTERVAL = 20,
        EL = 0,
        TYPE = 1,
        FN = 2,
        WFN = 3,
        OBJ = 3,
        ADJ_SCOPE = 4,            
        // private
        doAdd = function() {
            var ret;
            if (win.addEventListener) {
                ret = function(el, eventName, fn, capture) {
                    if (eventName == 'mouseenter') {
                        fn = fn.createInterceptor(checkRelatedTarget);
                        el.addEventListener('mouseover', fn, (capture));
                    } else if (eventName == 'mouseleave') {
                        fn = fn.createInterceptor(checkRelatedTarget);
                        el.addEventListener('mouseout', fn, (capture));
                    } else {
                        el.addEventListener(eventName, fn, (capture));
                    }
                    return fn;
                };
            } else if (win.attachEvent) {
                ret = function(el, eventName, fn, capture) {
                    el.attachEvent("on" + eventName, fn);
                    return fn;
                };
            } else {
                ret = function(){};
            }
            return ret;
        }(),	
		// private
        doRemove = function(){
            var ret;
            if (win.removeEventListener) {
                ret = function (el, eventName, fn, capture) {
                    if (eventName == 'mouseenter') {
                        eventName = 'mouseover'
                    } else if (eventName == 'mouseleave') {
                        eventName = 'mouseout'
                    }                        
                    el.removeEventListener(eventName, fn, (capture));
                };
            } else if (win.detachEvent) {
                ret = function (el, eventName, fn) {
                    el.detachEvent("on" + eventName, fn);
                };
            } else {
                ret = function(){};
            }
            return ret;
        }();        

    function checkRelatedTarget(e) {
        var related = e.relatedTarget, 
            isXulEl = Object.prototype.toString.apply(related) == '[object XULElement]';
        if (!related) return false;        
        return (!isXulEl && related != this && this.tag != 'document' && !elContains(this, related));
    }
    
    function elContains(parent, child) {
        while(child) {
            if(child === parent) {
                return true;
            }
            try {
                child = child.parentNode;
            } catch(e) {
                // In FF if you mouseout an text input element
                // thats inside a div sometimes it randomly throws
                // Permission denied to get property HTMLDivElement.parentNode
                // See https://bugzilla.mozilla.org/show_bug.cgi?id=208427
                return false;
            }                
            if(child && (child.nodeType != 1)) {
                child = null;
            }
        }
        return false;
    }
     	
    // private	
    function _getCacheIndex(el, eventName, fn) {
        var index = -1;
        Ext.each(listeners, function (v,i) {
            if(v && v[FN] == fn && v[EL] == el && v[TYPE] == eventName) {
	            index = i;
            }
        });
        return index;
    }
                	
	// private
    function _tryPreloadAttach() {
        var ret = false,            	
        	notAvail = [],
            element,
        	tryAgain = !loadComplete || (retryCount > 0);	                	
        
        if (!locked) {
            locked = true;
            
            Ext.each(onAvailStack, function (v,i,a){
            	if(v && (element = doc.getElementById(v.id))){
	            	if(!v.checkReady || loadComplete || element.nextSibling || (doc && doc.body)) {
		            	element = v.override ? (v.override === true ? v.obj : v.override) : element;
		            	v.fn.call(element, v.obj);
		            	onAvailStack[i] = null;
	            	} else {
		            	notAvail.push(item);
	            	}
            	}	
            });

            retryCount = (notAvail.length == 0) ? 0 : retryCount - 1;

            if (tryAgain) {	
                startInterval();
            } else {
                clearInterval(_interval);
                _interval = null;
            }

            ret = !(locked = false);
		}
		return ret;
    }
    
    // private	        	
	function startInterval() {            
        if (!_interval) {                    
            var callback = function() {
                _tryPreloadAttach();
            };
            _interval = setInterval(callback, pub.POLL_INTERVAL);
        }
    }
    
    // private 
    function getScroll() {
        var scroll = Ext.get(doc).getScroll();
        return [scroll.top, scroll.top];
    }
        
    // private
    function getPageCoord (ev, xy) {
        ev = ev.browserEvent || ev;
        var coord  = ev['page' + xy];
        if (!coord && 0 != coord) {
            coord = ev['client' + xy] || 0;

            if (Ext.isIE) {
                coord += getScroll()[xy == "X" ? 0 : 1];
            }
        }

        return coord;
    }

    var pub =  {
        onAvailable : function(p_id, p_fn, p_obj, p_override) {	            
            onAvailStack.push({ 
                id:         p_id,
                fn:         p_fn,
                obj:        p_obj,
                override:   p_override,
                checkReady: false });

            retryCount = this.POLL_RETRYS;
            startInterval();
        },


        addListener: function(el, eventName, fn) {
			var ret;				
			el = Ext.getDom(el);				
			if (el && fn) {
				if ("unload" == eventName) {
				    ret = !!(unloadListeners[unloadListeners.length] = [el, eventName, fn]);					
				} else {
                    listeners.push([el, eventName, fn, ret = doAdd(el, eventName, fn, false)]);
				}
			}
			return !!ret;
        },

        removeListener: function(el, eventName, fn) {
            var ret = false,
            	index, 
            	cacheItem;

            el = Ext.getDom(el);

            if(!fn) { 	                
                ret = this.purgeElement(el, false, eventName);
            } else if ("unload" == eventName) {	
                Ext.each(unloadListeners, function(v, i, a) {
	                if( v && v[0] == el && v[1] == evantName && v[2] == fn) {
		                unloadListeners.splice(i, 1);
	                	ret = true;
                	}
                });
            } else {	
                index = arguments[3] || _getCacheIndex(el, eventName, fn);
                cacheItem = listeners[index];
                
                if (el && cacheItem) {
	                doRemove(el, eventName, cacheItem[WFN], false);		
	                cacheItem[WFN] = cacheItem[FN] = null;		                 
	                listeners.splice(index, 1);		
	                ret = true;
                }
            }
            return ret;
        },

        getTarget : function(ev) {
            ev = ev.browserEvent || ev;                
            return this.resolveTextNode(ev.target || ev.srcElement);
        },

        resolveTextNode : function(node) {
            return Ext.isSafari && node && 3 == node.nodeType ? node.parentNode : node;
        },

        getPageX : function(ev) {
            return getPageCoord(ev, "X");
        },

        getPageY : function(ev) {
            return getPageCoord(ev, "Y");
        },


        getXY : function(ev) {	                           
            return [this.getPageX(ev), this.getPageY(ev)];
        },

        getRelatedTarget : function(ev) {
            ev = ev.browserEvent || ev;
            return this.resolveTextNode(ev.relatedTarget || 
				    (ev.type == "mouseout" ? ev.toElement :
				     ev.type == "mouseover" ? ev.fromElement : null));
        },

// Is this useful?  Removing to save space unless use case exists.
//             getTime: function(ev) {
//                 ev = ev.browserEvent || ev;
//                 if (!ev.time) {
//                     var t = new Date().getTime();
//                     try {
//                         ev.time = t;
//                     } catch(ex) {
//                         return t;
//                     }
//                 }

//                 return ev.time;
//             },

        stopEvent : function(ev) {		                      
            this.stopPropagation(ev);
            this.preventDefault(ev);
        },

        stopPropagation : function(ev) {
            ev = ev.browserEvent || ev;
            if (ev.stopPropagation) {
                ev.stopPropagation();
            } else {
                ev.cancelBubble = true;
            }
        },

        preventDefault : function(ev) {
            ev = ev.browserEvent || ev;
            if (ev.preventDefault) {
                ev.preventDefault();
            } else {
                ev.returnValue = false;
            }
        },
        
        getEvent : function(e) {
            e = e || win.event;
            if (!e) {
                var c = this.getEvent.caller;
                while (c) {
                    e = c.arguments[0];
                    if (e && Event == e.constructor) {
                        break;
                    }
                    c = c.caller;
                }
            }
            return e;
        },

        getCharCode : function(ev) {
            ev = ev.browserEvent || ev;
            return ev.charCode || ev.keyCode || 0;
        },

        //clearCache: function() {},

        _load : function(e) {
            loadComplete = true;
            var EU = Ext.lib.Event;    
            if (Ext.isIE && e !== true) {
                doRemove(win, "load", EU._load);
            }
        },            
        
        purgeElement : function(el, recurse, eventName) {
			var me = this;
			Ext.each( me.getListeners(el, eventName), function(v){
				if(v) me.removeListener(el, v.type, v.fn);
			});

            if (recurse && el && el.childNodes) {
                Ext.each(el.childNodes, function(v){
	                me.purgeElement(v, recurse, eventName);
                });
            }
        },

        getListeners : function(el, eventName) {
            var me = this,
            	results = [], 
            	searchLists = [listeners, unloadListeners];

			if (eventName) {					
				searchLists.splice(eventName == "unload" ? 0 : 1 ,1);
			} else {
				searchLists = searchLists[0].concat(searchLists[1]);	
			}

			Ext.each(searchLists, function(v, i){
				if (v && v[me.EL] == el && (!eventName || eventName == v[me.type])) {
					results.push({
                                type:   v[TYPE],
                                fn:     v[FN],
                                obj:    v[OBJ],
                                adjust: v[ADJ_SCOPE],
                                index:  i
                            });
				}	
			});                

            return results.length ? results : null;
        },

        _unload : function(e) {
             var EU = Ext.lib.Event, 
            	i, 
            	j, 
            	l, 
            	len, 
            	index,
            	scope;
            	

			Ext.each(unloadListeners, function(v) {
				if (v) {
					scope =  v[ADJ_SCOPE] ? (v[ADJ_SCOPE] === true ? v[OBJ] : v[ADJ_SCOPE]) :  win;	
					v[FN].call(scope, EU.getEvent(e), v[OBJ]);	
				}	
			});		

            unloadListeners = null;

            if (listeners && (j = listeners.length)) {                    
                while (j) {                        
                    if (l = listeners[index = --j]) {
                        EU.removeListener(l[EL], l[TYPE], l[FN], index);
                    }                        
                }
                //EU.clearCache();
            }

            doRemove(win, "unload", EU._unload);
        }            
    };        
    
    // Initialize stuff.
    pub.on = pub.addListener;
    pub.un = pub.removeListener;
    if (doc && doc.body) {
        pub._load(true);
    } else {
        doAdd(win, "load", pub._load);
    }
    doAdd(win, "unload", pub._unload);    
    _tryPreloadAttach();
    
    return pub;
}();