/* Utility functions */

function bindEventHandler(element, eventName, handler) {

	if (element.addEventListener) {

		// The standard way

		element.addEventListener(eventName, handler, false);

	} else if (element.attachEvent) {

		// The Microsoft way

		element.attachEvent('on' + eventName, handler);

	}

}



/**

 * The modal dialog class

 * @constructor

 */

function Dialog(options) {

	this.options = {

		width: 400,

		top: 120,

		openOnCreate: true,

		destroyOnClose: true,

		escHandler: this.close,

		buttons: {'OK': this.close}

	};

	// Overwrite the default options

	for (var option in options) {

		this.options[option] = options[option];

	}

	// Create dialog dom

	this._makeNodes();

	if (this.options.openOnCreate) {

		this.open();

	}

}



Dialog.prototype = {

	/* handles to the dom nodes */

	container: null,

	header: null,

	body: null,

	content: null,

	actions: null,

	_overlay: null,

	_wrapper: null,

	_zIndex: 0,

	_escHandler: null,

	

	/**

	 * Shows the dialog

	 */

	open: function() {

		this._makeTop();

		var ws = this._wrapper.style;

		ws.left = (document.body.clientWidth - this.options.width) / 2 + 'px';

		ws.top = (document.body.scrollTop || document.documentElement.scrollTop) + this.options.top + 'px';

		this._overlay.style.display = 'block';

		ws.display = 'block';

		this._wrapper.focus();



		if (this.options.focus) {

			var input = document.getElementById(this.options.focus);

			if (input) {

				input.focus();

			}

		}

	},

	

	/**

	 * Closes the dialog

	 */

	close: function() {

		if (this.options.destroyOnClose) {

			this._destroy();

		} else {

			this._overlay.style.display = 'none';

			this._wrapper.style.display = 'none';

		}

	},



	/**

	 * Add buttons to the dialog actions panel after creation

	 * @param {object} buttons Object with property name as button text and value as click handler

	 * @param {boolean} prepend If true, buttons will be prepended to the panel instead of being appended

	 */

	addButtons: function(buttons, prepend) {

		var actions = this.actions;

		var buttonArray = this._makeButtons(buttons);

		var first = null;

		if (prepend && (first = actions.firstChild) != null) {

			for (var i in buttonArray) {

				actions.insertBefore(buttonArray[i], first);

			}

		} else {

			for (var i in buttonArray) {

				actions.appendChild(buttonArray[i]);

			}

		}

	},



	/**

	 * Change (or set) title after creation

	 * @param {string} title The dialog title

	 */

	setTitle: function(title) {

		if (!this.header) {

			var header = document.createElement('div');

			header.className = 'dialog-header';

			this.container.insertBefore(header, this.body);

			this.header = header;

		}

		this.header.innerHTML = title;

	},



	/**

	 * Makes the dom tree for the dialog

	 */

	_makeNodes: function() {

		if (this._overlay || this._wrapper) {

			return; // Avoid duplicate invocation

		}

		// Make overlay

		this._overlay = document.createElement('div');

		this._overlay.className = 'dialog-overlay';

		document.body.appendChild(this._overlay);



		if (typeof this.options.title == 'string' && this.options.title != '') {

			var header = document.createElement('div');

			header.className = 'dialog-header';

			header.innerHTML = this.options.title;

			this.header = header;

		}



		// {begin dialog body

		var content = document.createElement('div');

		content.className = 'dialog-content';

		content.innerHTML = this.options.content;

		this.content = content;



		//   {begin actions panel

		var actions = document.createElement('div');

		actions.className = 'dialog-actions';

		var buttons = this._makeButtons(this.options.buttons);

		if (buttons.length > 0) {

			for (i=0;i<buttons.size();i=i+1) {
				actions.appendChild(buttons[i]);

			}

		}

		this.actions = actions;

		//   }end actions panel



		var body = document.createElement('div');

		body.className = 'dialog-body';

		body.appendChild(content);

		body.appendChild(actions);

		this.body = body;

		// }end dialog body



		var container = document.createElement('div');

		container.className = 'dialog';

		if (this.header) {

			container.appendChild(header);

		}

		container.appendChild(body);

		this.container = container;



		var wrapper = document.createElement('div');

		wrapper.className = 'dialog-wrapper';

		var ws = wrapper.style;

		ws.position = 'absolute';

		ws.width = this.options.width + 'px';

		ws.display = 'none';

		ws.outline = 'none';

		wrapper.appendChild(container);

		// register keydown event

		if (this.options.escHandler) {

			wrapper.tabIndex = -1;

			this._onKeydown = this._makeHandler(function(e) {

				if (!e) {

					e = window.event;

				}

				if (e.keyCode && e.keyCode == 27) {

					this.options.escHandler.apply(this);

				}

			}, this);

			bindEventHandler(wrapper, 'keydown', this._onKeydown);

		}

		this._wrapper = document.body.appendChild(wrapper);



		if (Dialog.needIEFix) {

			this._fixIE();

		}

	},



	/**

	 * Removes the nodes from document

	 * @param {object} buttons Object with property name as button text and value as click handler

	 * @return {Array} Array of buttons as dom nodes

	 */

	_makeButtons: function(buttons) {

		var buttonArray = new Array();

		for (var buttonText in buttons) {

			var button = document.createElement('button');

			button.className = 'dialog-button';

			button.innerHTML = buttonText;



			bindEventHandler(button, 'click', this._makeHandler(buttons[buttonText], this));



			buttonArray.push(button);

		}

		return buttonArray;

	},



	/** A helper function used by makeButtons */

	_makeHandler: function(method, obj) {

		return function(e) {

			method.call(obj, e);

		}

	},



	/** A helper function used by open */

	_makeTop: function() {

		if (this._zIndex < Dialog.Manager.currentZIndex) {

			this._overlay.style.zIndex = Dialog.Manager.newZIndex();

			this._zIndex = this._wrapper.style.zIndex = Dialog.Manager.newZIndex();

		}

	},



	_fixIE: function() {

		var width = document.documentElement["scrollWidth"] + 'px';

		var height = document.documentElement["scrollHeight"] + 'px';

		var os = this._overlay.style;

		os.position = 'absolute';

		os.width = width;

		os.height = height;



		var iframe = document.createElement('iframe');

		iframe.className = 'iefix';

		iframe.style.width = width;

		iframe.style.height = height;

		this._wrapper.appendChild(iframe);

	},



	/**

	 * Removes the nodes from document

	 */

	_destroy: function() {

		document.body.removeChild(this._wrapper);

		document.body.removeChild(this._overlay);

		this.container = null;

		this.header = null;

		this.body = null;

		this.content = null;

		this.actions = null;

		this._overlay = null;

		this._wrapper = null;

	}

};



Dialog.needIEFix = (function () {

	var userAgent = navigator.userAgent.toLowerCase();

	return /msie/.test(userAgent) && !/opera/.test(userAgent) && !window.XMLHttpRequest;

})();



/** This simple object manages the z indices */

Dialog.Manager = {

	currentZIndex: 3000,

	newZIndex: function() {

		return ++this.currentZIndex;

	}

};