framework/images/webapp/images/dojo/src/widget/TreeCommon.js

/*
	Copyright (c) 2004-2006, The Dojo Foundation
	All Rights Reserved.

	Licensed under the Academic Free License version 2.1 or above OR the
	modified BSD license. For more information on Dojo licensing, see:

		http://dojotoolkit.org/community/licensing.shtml
*/


dojo.provide("dojo.widget.TreeCommon");
dojo.require("dojo.widget.*"); // for dojo.widget.manager

dojo.declare(
	"dojo.widget.TreeCommon",
	null,
{
	listenTreeEvents: [],
	listenedTrees: {},

	/**
	 * evaluates to false => skip unlistening nodes
	 * provided => use it
	 */
	listenNodeFilter: null,

	listenTree: function(tree) {

		//dojo.debug("listenTree in "+this+" tree "+tree);

		var _this = this;

		if (this.listenedTrees[tree.widgetId]) {
			return; // already listening
		}

		dojo.lang.forEach(this.listenTreeEvents, function(event) {
			var eventHandler =  "on" + event.charAt(0).toUpperCase() + event.substr(1);
			//dojo.debug("subscribe: event "+tree.eventNames[event]+" widget "+_this+" handler "+eventHandler);
			dojo.event.topic.subscribe(tree.eventNames[event], _this, eventHandler);
		});


		var filter;

		if (this.listenNodeFilter) {
			this.processDescendants(tree, this.listenNodeFilter, this.listenNode, true);
		}

		/**
		 * remember that I listen to this tree. No unbinding/binding/deselection
		 * needed when transfer between listened trees
		 */
		this.listenedTrees[tree.widgetId] = true;

	},

	// interface functions
	listenNode: function() {},
	unlistenNode: function() {},

	unlistenTree: function(tree, nodeFilter) {

		var _this = this;

		if (!this.listenedTrees[tree.widgetId]) {
			return;
		}

		dojo.lang.forEach(this.listenTreeEvents, function(event) {
			var eventHandler =  "on" + event.charAt(0).toUpperCase() + event.substr(1);
			dojo.event.topic.unsubscribe(tree.eventNames[event], _this, eventHandler);
		});


		if (this.listenNodeFilter) {
			this.processDescendants(tree, this.listenNodeFilter, this.unlistenNode, true);
		}

		delete this.listenedTrees[tree.widgetId];

	},


	/**
	 * check condition for node.domNode -> .. -> any node chain
	 */
	checkPathCondition: function(domElement, condition) {

		while (domElement && !domElement.widgetId) {
			if (condition.call(null, domElement)) {
				return true;
			}

			domElement = domElement.parentNode;
		}

		return false;
	},


	/**
	 * get node widget id by its descendant dom node
	 */
	domElement2TreeNode: function(domElement) {

		while (domElement && !domElement.widgetId) {
			domElement = domElement.parentNode;
		}

		if (!domElement) {
			return null;
		}

		var widget = dojo.widget.byId(domElement.widgetId);

		if (!widget.isTreeNode) {
			return null;
		}

		return widget;
	},

	/**
	 * it is here, not in Widget, because mostly tree needs it
	 */
	processDescendants: function(elem, filter, func, skipFirst) {

		var _this = this;

		if (!skipFirst) {
			if (!filter.call(_this,elem)) {
				return;
			}
			func.call(_this,elem);
		}


		var stack = [elem];
		while (elem = stack.pop()) {
			dojo.lang.forEach(elem.children, function(elem) {
				if (filter.call(_this, elem)) {
					func.call(_this, elem);
					stack.push(elem);
				}
			});
		}
    }
});