Extjs4 下拉框清空已选数据插件

Ext.define('Ext.ux.ClearValuePlugin', {
alias: 'plugin.clearvalueplugin',
trigger1Cls: Ext.baseCSSPrefix + 'form-clear-trigger',
trigger2Cls: Ext.baseCSSPrefix + 'form-arrow-trigger',
hasSearch: false,
constructor: function(config) {
var me = this;
Ext.apply(me, config);
},
init: function(combo) {
var me = this;
combo.hasSearch = me.hasSearch;
combo.trigger1Cls = me.trigger1Cls;
combo.trigger2Cls = me.trigger2Cls;
combo.onTrigger1Click = me.onTrigger1Click;
combo.onTrigger2Click = me.onTrigger2Click;
combo.on('afterrender', me.afterRender, combo);
},
afterRender: function() {
this.triggerCell.item(0).setDisplayed(false);
},
onTrigger1Click: function() {
var me = this;
if (me.hasSearch) {
me.clearValue();
me.hasSearch = false;
me.triggerCell.item(0).setDisplayed(false);
me.updateLayout();
}
},
onTrigger2Click: function() {
this.onTriggerClick();
this.hasSearch = true;
this.triggerCell.item(0).setDisplayed(true);
}
});

plugins: ['clearvalueplugin']