kity
Version:
Kity Graphic Library
297 lines (177 loc) • 6.48 kB
JavaScript
/*
* kity event 实现
*/
define(function(require, exports, module) {
// polyfill
(function() {
function CustomEvent(event, params) {
params = params || {
bubbles: false,
cancelable: false,
detail: undefined
};
var evt = document.createEvent('CustomEvent');
evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
return evt;
}
CustomEvent.prototype = window.Event.prototype;
window.CustomEvent = CustomEvent;
})();
var Utils = require('../core/utils'),
ShapeEvent = require('./shapeevent');
// 内部处理器缓存
var INNER_HANDLER_CACHE = {},
// 用户处理器缓存
USER_HANDLER_CACHE = {},
guid = 0;
// 添加事件统一入口
function _addEvent(type, handler, isOnce) {
isOnce = !!isOnce;
if (Utils.isString(type)) {
type = type.match(/\S+/g);
}
Utils.each(type, function(currentType) {
listen.call(this, this.node, currentType, handler, isOnce);
}, this);
return this;
}
// 移除事件统一入口
function _removeEvent(type, handler) {
var userHandlerList = null,
eventId = this._EVNET_UID,
isRemoveAll = handler === undefined;
userHandlerList = USER_HANDLER_CACHE[eventId][type];
//移除指定的监听器
if (!isRemoveAll) {
isRemoveAll = true;
Utils.each(userHandlerList, function removeKityEvent(fn, index) {
if (fn === handler) {
// 不能结束， 需要查找完整个list， 避免丢失移除多次绑定同一个处理器的情况
delete userHandlerList[index];
} else {
isRemoveAll = false;
}
});
}
//删除所有监听器
if (isRemoveAll) {
deleteDomEvent(this.node, type, INNER_HANDLER_CACHE[eventId][type]);
delete USER_HANDLER_CACHE[eventId][type];
delete INNER_HANDLER_CACHE[eventId][type];
}
return this;
}
// 执行绑定, 该方法context为shape或者mixin了eventhandler的对象
function listen(node, type, handler, isOnce) {
var eid = this._EVNET_UID,
targetObject = this;
// 初始化内部监听器
if (!INNER_HANDLER_CACHE[eid]) {
INNER_HANDLER_CACHE[eid] = {};
}
if (!INNER_HANDLER_CACHE[eid][type]) {
// 内部监听器
INNER_HANDLER_CACHE[eid][type] = function kityEventHandler(e) {
e = new ShapeEvent(e || window.event);
Utils.each(USER_HANDLER_CACHE[eid][type], function executeKityEvent(fn) {
var result;
if (fn) {
result = fn.call(targetObject, e);
//once 绑定， 执行完后删除
if (isOnce) {
targetObject.off(type, fn);
}
}
// 如果用户handler里return了false， 则该节点上的此后的同类型事件将不再执行
return result;
}, targetObject);
};
}
// 初始化用户监听器列表
if (!USER_HANDLER_CACHE[eid]) {
USER_HANDLER_CACHE[eid] = {};
}
if (!USER_HANDLER_CACHE[eid][type]) {
USER_HANDLER_CACHE[eid][type] = [handler];
// 绑定对应类型的事件
// dom对象利用dom event进行处理， 非dom对象， 由消息分发机制处理
if (!!node && ('on' + type) in node) {
bindDomEvent(node, type, INNER_HANDLER_CACHE[eid][type]);
}
} else {
USER_HANDLER_CACHE[eid][type].push(handler);
}
}
// 绑定dom事件
function bindDomEvent(node, type, handler) {
if (node.addEventListener) {
node.addEventListener(type, handler, false);
} else {
node.attachEvent('on' + type, handler);
}
}
// 删除dom事件
function deleteDomEvent(node, type, handler) {
if (node.removeEventListener) {
node.removeEventListener(type, handler, false);
} else {
node.detachEvent(type, handler);
}
}
// 触发dom事件
function triggerDomEvent(node, type, params) {
var event = new CustomEvent(type, {
bubbles: true,
cancelable: true
});
event._kityParam = params;
node.dispatchEvent(event);
}
// 发送消息
function sendMessage(messageObj, type, msg) {
var event = null,
handler = null;
var handlers = INNER_HANDLER_CACHE[messageObj._EVNET_UID];
if (!handlers) return;
handler = handlers[type];
if (!handler) {
return;
}
event = Utils.extend({
type: type,
target: messageObj
}, msg || {});
handler.call(messageObj, event);
}
// 对外接口
return require('../core/class').createClass('EventHandler', {
constructor: function() {
this._EVNET_UID = ++guid;
},
addEventListener: function(type, handler) {
return _addEvent.call(this, type, handler, false);
},
addOnceEventListener: function(type, handler) {
return _addEvent.call(this, type, handler, true);
},
removeEventListener: function(type, handler) {
return _removeEvent.call(this, type, handler);
},
on: function(type, handler) {
return this.addEventListener.apply(this, arguments);
},
once: function(type, handler) {
return this.addOnceEventListener.apply(this, arguments);
},
off: function() {
return this.removeEventListener.apply(this, arguments);
},
fire: function(type, params) {
return this.trigger.apply(this, arguments);
},
trigger: function(type, params) {
sendMessage(this, type, params);
return this;
}
});
});