merge #1141 and clean it up

src/core/Events.js

@@ -10,9 +10,10 @@ L.Mixin.Events = {
 
 	addEventListener: function (types, fn, context) { // (String, Function[, Object]) or (Object[, Object])
 		var events = this[key] = this[key] || {},
-			type, i, len;
+			type, i, len, evt,
+			contextId, objKey, objLenKey, eventsObj;
 
-		// Types can be a map of types/handlers
+		// types can be a map of types/handlers
 		if (typeof types === 'object') {
 			for (type in types) {
 				if (types.hasOwnProperty(type)) {
@@ -23,26 +24,50 @@ L.Mixin.Events = {
 			return this;
 		}
 
+		// types can be a string of space-separated words
 		types = L.Util.splitWords(types);
 
 		for (i = 0, len = types.length; i < len; i++) {
-			events[types[i]] = events[types[i]] || [];
+			evt = {
-			events[types[i]].push({
 				action: fn,
 				context: context || this
-			});
+			};
+			contextId = context && context._leaflet_id;
+
+			if (contextId) {
+				// store listeners of a particular context in a separate hash (if it has an id)
+				// gives a major performance boost when removing thousands of map layers
+
+				objKey = types[i] + '_idx',
+				objLenKey = objKey + '_len',
+				eventsObj = events[objKey] = events[objKey] || {};
+
+				if (eventsObj[contextId]) {
+					eventsObj[contextId].push(evt);
+				} else {
+					eventsObj[contextId] = [evt];
+					events[objLenKey] = (events[objLenKey] || 0) + 1;
+				}
+
+			} else {
+				events[types[i]] = events[types[i]] || [];
+				events[types[i]].push(evt);
+			}
 		}
 
 		return this;
 	},
 
 	hasEventListeners: function (type) { // (String) -> Boolean
-		return (key in this) && (type in this[key]) && (this[key][type].length > 0);
+		return (key in this) &&
+		        (((type in this[key]) && this[key][type].length > 0) ||
+		        (this[key][type + '_idx_len'] > 0));
 	},
 
 	removeEventListener: function (types, fn, context) { // (String[, Function, Object]) or (Object[, Object])
 		var events = this[key],
-			type, i, len, listeners, j;
+			type, i, len, listeners, j,
+			contextId, objKey, objLenKey;
 
 		if (typeof types === 'object') {
 			for (type in types) {
@@ -50,25 +75,35 @@ L.Mixin.Events = {
 					this.removeEventListener(type, types[type], fn);
 				}
 			}
-
 			return this;
 		}
 
 		types = L.Util.splitWords(types);
 
 		for (i = 0, len = types.length; i < len; i++) {
-
 			if (this.hasEventListeners(types[i])) {
-				listeners = events[types[i]];
+
+				// if the context has an id, use it to find the listeners
+				contextId = context && context._leaflet_id;
+				objKey = types[i] + '_idx';
+
+				if (contextId && events[objKey]) {
+					listeners =  events[objKey][contextId] || [];
+				} else {
+					listeners = events[types[i]] || [];
+				}
 
 				for (j = listeners.length - 1; j >= 0; j--) {
-					if (
+					if ((!fn || listeners[j].action === fn) && (!context || (listeners[j].context === context))) {
-						(!fn || listeners[j].action === fn) &&
-						(!context || (listeners[j].context === context))
-					) {
 						listeners.splice(j, 1);
 					}
 				}
+
+				if (contextId && listeners.length === 0) {
+					objLenKey = objKey + '_len';
+					delete events[objKey][contextId];
+					events[objLenKey] = (events[objLenKey] || 1) - 1;
+				}
 			}
 		}
 
@@ -80,16 +115,37 @@ L.Mixin.Events = {
 			return this;
 		}
 
-		var event = L.extend({
+		var event = L.Util.extend({
 			type: type,
 			target: this
 		}, data);
 
-		var listeners = this[key][type].slice();
+		var listeners, i, len, eventsObj, contextId;
 
-		for (var i = 0, len = listeners.length; i < len; i++) {
+		if (this[key][type]) {
+			listeners = this[key][type].slice();
+
+			for (i = 0, len = listeners.length; i < len; i++) {
 				listeners[i].action.call(listeners[i].context || this, event);
 			}
+		}
+
+		// fire event for the context-indexed listeners as well
+		
+		eventsObj = this[key][type + '_idx'];
+
+		if (eventsObj) {
+			for (contextId in eventsObj) {
+				if (eventsObj.hasOwnProperty(contextId)) {
+					listeners = eventsObj[contextId];
+					if (listeners) {
+						for (i = 0, len = listeners.length; i < len; i++) {
+							listeners[i].action.call(listeners[i].context || this, event);
+						}
+					}
+				}
+			}
+		}
 
 		return this;
 	}