定制事件

http://www.extjs.com/learn/Tutorial:Events_Explained
参考样例：

OrgChart = Ext.extend(Ext.Panel, {
    initComponent:function() {
        // call parent init component
        OrgChart.superclass.initComponent.apply(this, arguments);
 
        // add custom events
        this.addEvents('assigned', 'dismissed');
    }
 
    ,assign:function(employee, position) {
        // do whatever is necessary to assign the employee to position
 
        // fire assigned event
        this.fireEvent('assigned', this, employee, position);
    }
 
    ,dismiss:function(empoyee, position) {
        // do whatever is necessary to dismiss employee from position
 
        // fire dismissed event
        this.fireEvent('dismissed', this, employee, position);
    }
});