/**
 * @private
 */
Ext.define('Ext.event.publisher.ElementPaint', {
    extend: 'Ext.event.publisher.Publisher',
 
    requires: [
        'Ext.util.PaintMonitor',
        'Ext.TaskQueue'
    ],
 
    type: 'paint',
 
    handledEvents: ['painted'],
 
    constructor: function() {
        this.monitors = {};
        this.subscribers = {};
 
        this.callParent(arguments);
    },
 
    subscribe: function(element) {
        var me = this,
            id = element.id,
            subscribers = me.subscribers;
 
        if (subscribers[id]) {
            ++subscribers[id];
        }
        else {
            subscribers[id] = 1;
 
            me.monitors[id] = new Ext.util.PaintMonitor({
                element: element,
                callback: me.onElementPainted,
                scope: me,
                args: [element]
            });
        }
    },
 
    unsubscribe: function(element) {
        var id = element.id,
            subscribers = this.subscribers,
            monitors = this.monitors;
 
        if (subscribers[id] && !--subscribers[id]) {
            delete subscribers[id];
            monitors[id].destroy();
            delete monitors[id];
        }
 
        if (element.activeRead) {
            Ext.TaskQueue.cancelRead(element.activeRead);
        }
    },
    
    fireElementPainted: function(element) {
        delete element.activeRead;
        this.fire(element, 'painted', [element]);
    },
 
    onElementPainted: function(element) {
        if (!element.activeRead) {
            element.activeRead = Ext.TaskQueue.requestRead(
                'fireElementPainted', this, [element]
                //<debug>
                , !!element.$skipResourceCheck
                //</debug>
            );
        }
    }
}, function(ElementPaint) {
    ElementPaint.instance = new ElementPaint();
});