// vim: ts=4:sw=4:nu:fdc=4:nospell
/*global Ext */
/**
 * @class Ext.ux.state.TreePanel
 *
 * Ext.tree.TreePanel State Plugin
 * <br><br>
 * Usage:
<pre>
var tree = new Ext.tree.TreePanel({
     root:{
         nodeType:'async'
        ,id:'root'
        ,text:'Root'
    }
    ,loader: {
         url:'get-tree.php'
    }
    <b>,plugins:[new Ext.ux.state.TreePanel()]</b>
});
</pre>
 *
 * @author    Ing. Jozef Sakáloš
 * @copyright (c) 2009, by Ing. Jozef Sakáloš
 * @date      <ul>
 * <li>5. April 2009<li>
 * </ul>
 * @version   1.0
 * @revision  $Id: Ext.ux.state.TreePanel.js 676 2009-04-07 13:03:20Z jozo $
 *
 * @license Ext.ux.state.TreePanel.js is licensed under the terms of
 * the Open Source LGPL 3.0 license.  Commercial use is permitted to the extent
 * that the code/component(s) do NOT become part of another Open Source or Commercially
 * licensed development library or toolkit without explicit permission.
 * 
 * <p>License details: <a href="http://www.gnu.org/licenses/lgpl.html"
 * target="_blank">http://www.gnu.org/licenses/lgpl.html</a></p>
 *
 * @forum     64714
 * @demo      http://examples.extjs.eu/?ex=treestate
 * @download  <ul>
 * <li><a href="http://examples.extjs.eu/Ext.ux.state.TreePanel.js.bz2">Ext.ux.state.TreePanel.js.bz2</a></li>
 * <li><a href="http://examples.extjs.eu/Ext.ux.state.TreePanel.js.gz">Ext.ux.state.TreePanel.js.gz</a></li>
 * <li><a href="http://examples.extjs.eu/Ext.ux.state.TreePanel.js.zip">Ext.ux.state.TreePanel.js.zip</a></li>
 * </ul>
 *
 * @donate
 * <form action="https://www.paypal.com/cgi-bin/webscr" method="post" target="_blank">
 * <input type="hidden" name="cmd" value="_s-xclick">
 * <input type="hidden" name="hosted_button_id" value="3430419">
 * <input type="image" src="https://www.paypal.com/en_US/i/btn/x-click-butcc-donate.gif" 
 * border="0" name="submit" alt="PayPal - The safer, easier way to pay online.">
 * <img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
 * </form>
 */

Ext.ns('Ext.ux.state');

// dummy constructor
Ext.ux.state.TreePanel = function() {};

Ext.override(Ext.ux.state.TreePanel, {
	/**
	 * Initializes the plugin
	 * @param {Ext.tree.TreePanel} tree
	 * @private
	 */
	init:function(tree) {

		// install event handlers on TreePanel
		tree.on({
			// add path of expanded node to stateHash
			 beforeexpandnode:function(n) {
				this.stateHash[n.id] = n.getPath();
			}

			// delete path and all subpaths of collapsed node from stateHash
			,beforecollapsenode:function(n) {
				delete this.stateHash[n.id];
				var cPath = n.getPath();
				for(var p in this.stateHash) {
					if(this.stateHash.hasOwnProperty(p)) {
						if(-1 !== this.stateHash[p].indexOf(cPath)) {
							delete this.stateHash[p];
						}
					}
				}
			}
		});

		// update state on node expand or collapse
		tree.stateEvents = tree.stateEvents || [];
		tree.stateEvents.push('expandnode', 'collapsenode');

		// add state related props to the tree
		Ext.apply(tree, {
			// keeps expanded nodes paths keyed by node.ids
			 stateHash:{}

			// apply state on tree initialization
			,applyState:function(state) {
				if(state) {
					Ext.apply(this, state);

					// it is too early to expand paths here
					// so do it once on root load
					this.root.on({
						load:{single:true, scope:this, fn:function() {
							for(var p in this.stateHash) {
								if(this.stateHash.hasOwnProperty(p)) {
									this.expandPath(this.stateHash[p]);
								}
							}
						}}
					});
				}
			} // eo function applyState

			// returns stateHash for save by state manager
			,getState:function() {
				return {stateHash:this.stateHash};
			} // eo function getState
		});
	} // eo function init

}); // eo override

// eof