/* Copyright (c) 2006 Yahoo! Inc. All rights reserved. */

/**
 * Emulates OmniOutliner's task view.  The check box marks a task complete.
 * It is a simulated form field with three states ...
 * 0=unchecked, 1=some children checked, 2=all children checked
 * When a task is clicked, the state of the nodes and parent and children
 * are updated, and this behavior cascades.
 *
 * @extends YAHOO.widget.TextNode
 * @constructor
 * @param oData {object} a string or object containing the data that will
 * be used to render this node
 * @param oParent {YAHOO.widget.Node} this node's parent node
 * @param expanded {boolean} the initial expanded/collapsed state
 * @param checked {boolean} the initial checked/unchecked state
 */
YAHOO.widget.TaskNode = function(oData, oParent, expanded, checked) {
    this.logger = new ygLogger("TaskNode");

	if (oParent) { 
		this.init(oData, oParent, expanded);
		this.setUpLabel(oData);
		this.checked = checked;
	}
};

YAHOO.widget.TaskNode.prototype = new YAHOO.widget.TextNode();

/**
 * True if checkstate is 1 (some children checked) or 2 (all children checked),
 * false if 0.
 *
 * @type boolean
 */
YAHOO.widget.TaskNode.prototype.checked = false;

/**
 * checkState
 * 0=unchecked, * 1=some children checked, 2=all children checked
 *
 * @type int
 */
YAHOO.widget.TaskNode.prototype.checkState = 0;

/**
 * The id of the check element
 *
 * @type string
 */
YAHOO.widget.TaskNode.prototype.getCheckElId = function() { 
	return "ygtvcheck" + this.index; 
};

/**
 * Returns the check box element
 *
 * @return the check html element (img)
 */
YAHOO.widget.TaskNode.prototype.getCheckEl = function() { 
	return document.getElementById(this.getCheckElId()); 
};

/**
 * The style of the check element, derived from its current state
 *
 * @return {string} the css style for the current check state
 */
YAHOO.widget.TaskNode.prototype.getCheckStyle = function() { 
	return "ygtvcheck" + this.checkState;
};

/**
 * Returns the link that will invoke this node's check toggle
 *
 * @return {string} returns the link required to adjust the checkbox state
 */
YAHOO.widget.TaskNode.prototype.getCheckLink = function() { 
	return "YAHOO.widget.TreeView.getNode(\'" + this.tree.id + "\'," + 
		this.index + ").checkClick()";
};

/**
 * Invoked when the user clicks the check box
 */
YAHOO.widget.TaskNode.prototype.checkClick = function() { 
	if (this.checkState === 0) {
		this.check();
	} else {
		this.uncheck();
	}
};

/**
 * Refresh the state of this node's parent, and cascade up.
 */
YAHOO.widget.TaskNode.prototype.updateParent = function() { 
	var p = this.parent;

	if (!p || !p.updateParent) {
		this.logger.debug("Abort udpate parent: " + this.index);
		return;
	}

	var somethingChecked = false;
	var somethingNotChecked = false;

	for (var i=0;i< p.children.length;++i) {
		if (p.children[i].checked) {
			somethingChecked = true;
			// checkState will be 1 if the child node has unchecked children
			if (p.children[i].checkState == 1) {
				somethingNotChecked = true;
			}
		} else {
			somethingNotChecked = true;
		}
	}

	if (somethingChecked) {
		p.setCheckState( (somethingNotChecked) ? 1 : 2 );
	} else {
		p.setCheckState(0);
	}

	p.updateCheckHtml();
	p.updateParent();
};

/**
 * If the node has been rendered, update the html to reflect the current
 * state of the node.
 */
YAHOO.widget.TaskNode.prototype.updateCheckHtml = function() { 
	if (this.parent && this.parent.childrenRendered) {
		this.getCheckEl().className = this.getCheckStyle();
	}
};

/**
 * Updates the state.  The checked property is true if the state is 1 or 2
 * 
 * @param the new check state
 */
YAHOO.widget.TaskNode.prototype.setCheckState = function(state) { 
	this.checkState = state;
	this.checked = (state > 0);
};

/**
 * Check this node
 */
YAHOO.widget.TaskNode.prototype.check = function() { 
	this.setCheckState(2);
	for (var i=0; i<this.children.length; ++i) {
		this.children[i].check();
	}
	this.updateCheckHtml();
	this.updateParent();
};

/**
 * Uncheck this node
 */
YAHOO.widget.TaskNode.prototype.uncheck = function() { 
	this.setCheckState(0);
	for (var i=0; i<this.children.length; ++i) {
		this.children[i].uncheck();
	}
	this.updateCheckHtml();
	this.updateParent();
};

// Overrides YAHOO.widget.TextNode
YAHOO.widget.TaskNode.prototype.getNodeHtml = function() { 
	var sb = new Array();

	sb[sb.length] = '<table border="0" cellpadding="0" cellspacing="0">';
	sb[sb.length] = '<tr>';
	
	for (i=0;i<this.depth;++i) {
		sb[sb.length] = '<td class="' + this.getDepthStyle(i) + '">&nbsp;</td>';
	}

	sb[sb.length] = '<td';
	sb[sb.length] = ' id="' + this.getToggleElId() + '"';
	sb[sb.length] = ' class="' + this.getStyle() + '"';
	if (this.hasChildren(true)) {
		sb[sb.length] = ' onmouseover="this.className=';
		sb[sb.length] = 'YAHOO.widget.TreeView.getNode(\'';
		sb[sb.length] = this.tree.id + '\',' + this.index +  ').getHoverStyle()"';
		sb[sb.length] = ' onmouseout="this.className=';
		sb[sb.length] = 'YAHOO.widget.TreeView.getNode(\'';
		sb[sb.length] = this.tree.id + '\',' + this.index +  ').getStyle()"';
	}
	sb[sb.length] = ' onclick="javascript:' + this.getToggleLink() + '">&nbsp;';
	sb[sb.length] = '</td>';

	// check box
	sb[sb.length] = '<td';
	sb[sb.length] = ' id="' + this.getCheckElId() + '"';
	sb[sb.length] = ' class="' + this.getCheckStyle() + '"';
	sb[sb.length] = ' onclick="javascript:' + this.getCheckLink() + '">';
	sb[sb.length] = '&nbsp;</td>';
	

	sb[sb.length] = '<td>';
	sb[sb.length] = '<a';
	sb[sb.length] = ' id="' + this.labelElId + '"';
	sb[sb.length] = ' class="' + this.labelStyle + '"';
	sb[sb.length] = ' href="' + this.href + '"';
	sb[sb.length] = ' target="' + this.target + '"';
	if (this.hasChildren(true)) {
		sb[sb.length] = ' onmouseover="document.getElementById(\'';
		sb[sb.length] = this.getToggleElId() + '\').className=';
		sb[sb.length] = 'YAHOO.widget.TreeView.getNode(\'';
		sb[sb.length] = this.tree.id + '\',' + this.index +  ').getHoverStyle()"';
		sb[sb.length] = ' onmouseout="document.getElementById(\'';
		sb[sb.length] = this.getToggleElId() + '\').className=';
		sb[sb.length] = 'YAHOO.widget.TreeView.getNode(\'';
		sb[sb.length] = this.tree.id + '\',' + this.index +  ').getStyle()"';
	}
	sb[sb.length] = ' >';
	sb[sb.length] = this.label;
	sb[sb.length] = '</a>';
	sb[sb.length] = '</td>';
	sb[sb.length] = '</tr>';
	sb[sb.length] = '</table>';

	return sb.join("");

};