add extjs 6.0.1 sources

[extjs.git] / extjs / packages / core / src / dom / GarbageCollector.js

/**\r
 * @private\r
 * Garbage collector for Ext.dom.Element instances.  Automatically cleans up Elements\r
 * that are no longer in the dom, but were not properly destroyed using\r
 * {@link Ext.dom.Element#destroy destroy()}.  Recommended practice is for Components to\r
 * clean up their own elements, but the GarbageCollector runs on regularly scheduled\r
 * intervals to attempt to clean up orphaned Elements that may have slipped through the cracks.\r
 */\r
Ext.define('Ext.dom.GarbageCollector', {\r
    singleton: true,\r
\r
    /**\r
     * @property {Number}\r
     * The interval at which to run Element garbage collection. Set this property directly\r
     * to tune the interval.\r
     *\r
     *     Ext.dom.GarbageCollector.interval = 60000; // run garbage collection every one minute\r
     */\r
    interval: 30000,\r
\r
    constructor: function() {\r
        var me = this;\r
        me.collect = Ext.Function.bind(me.collect, me);\r
        me.lastTime = Ext.now();\r
        me.resume();\r
    },\r
\r
    /**\r
     * Collects orphaned Ext.dom.Elements by removing their listeners and evicting them\r
     * from the cache.  Runs on a regularly scheduled {@link #interval} but can be called\r
     * directly to force garbage collection.\r
     * @return {String[]} An array containing the IDs of the elements that were garbage\r
     * collected, prefixed by their tag names.  Only applies in dev mode.  Returns nothing\r
     * in a production build.\r
     */\r
    collect: function() {\r
        var me = this,\r
            cache = Ext.cache,\r
            eid, dom, el, t, isGarbage, tagName;\r
        \r
        //<debug>\r
        var collectedIds = [];\r
        //</debug>\r
        \r
\r
        for (eid in cache) {\r
            if (!cache.hasOwnProperty(eid)) {\r
                continue;\r
            }\r
\r
            el = cache[eid];\r
\r
            if (el.skipGarbageCollection) {\r
                continue;\r
            }\r
\r
            dom = el.dom;\r
\r
            //<debug>\r
            // Should always have a DOM node\r
            if (!dom) {\r
                Ext.raise('Missing DOM node in element garbage collection: ' + eid);\r
            }\r
            //</debug>\r
            \r
            try {\r
                // In IE, accessing any properties of the window object of an orphaned iframe\r
                // can result in a "Permission Denied" error.  The same error also occurs\r
                // when accessing any properties of orphaned documentElement or body inside\r
                // of an iframe (documentElement and body become orphaned when the iframe\r
                // contentWindow is unloaded)\r
                isGarbage = Ext.isGarbage(dom);\r
            } catch (e) {\r
                // if an error was thrown in isGarbage it is most likely because we are\r
                // dealing with an inaccessible window or documentElement inside an orphaned\r
                // iframe in IE.  In this case we can't do anything except remove the\r
                // cache entry.\r
                delete cache[eid];\r
                //<debug>\r
                collectedIds.push('#' + el.id);\r
                //</debug>\r
                continue;\r
            }\r
            \r
            if (isGarbage) {\r
                if (el && el.dom) {\r
                    //<debug>\r
                    tagName = el.dom.tagName;\r
                    //</debug>\r
                    el.collect();\r
                    //<debug>\r
                    collectedIds.push((tagName ? tagName : '') + '#' + el.id);\r
                    //</debug>\r
                }\r
            }\r
        }\r
        //<feature legacyBrowser>\r
        // Cleanup IE Object leaks\r
        if (Ext.isIE9m) {\r
            t = {};\r
            for (eid in cache) {\r
                if (cache.hasOwnProperty(eid)) {\r
                    t[eid] = cache[eid];\r
                }\r
            }\r
            Ext.cache = Ext.dom.Element.cache = t;\r
        }\r
        //</feature>\r
\r
        me.lastTime = Ext.now();\r
\r
        //<debug>\r
        return collectedIds;\r
        //</debug>\r
    },\r
\r
    /**\r
     * Pauses the timer and stops garbage collection\r
     */\r
    pause: function() {\r
        clearTimeout(this.timerId);\r
    },\r
\r
    /**\r
     * Resumes garbage collection at the specified {@link #interval}\r
     */\r
    resume: function() {\r
        var me = this,\r
            lastTime = me.lastTime;\r
\r
        if (Ext.enableGarbageCollector && (Ext.now() - lastTime > me.interval)) {\r
            me.collect();\r
        }\r
\r
        me.timerId = Ext.interval(me.collect, me.interval);\r
    }\r
});