/* 

*  Mouse wheel support for OS X - implemented in javascript because Adobe

*  hasn't implemented it in the mac version of Flash Player  >:(

*  

*  Copyright (c) 2007-2008 Ali Rantakari ( http://hasseg.org/blog )

*  

*  Requires related ActionScript 3 class:

*  org.hasseg.externalMouseWheel.ExternalMouseWheelSupport

*  

*  

*  Changelog:

*  ---------------------------------------------------------------------------------

*  VERSION 1.0 (Ali Rantakari)

*  July 2007

*  

*  - Initial implementation

*  

*  

*  ---------------------------------------------------------------------------------

*  VERSION 1.5 (Changes by Pavel Fljot, http://inreflected.com)

*  Jan 2008

*  

*  - Added statement to support Safari under Windows

*  

*  

*  ---------------------------------------------------------------------------------

*  VERSION 2.0 (Changes by Ali Rantakari)

*  Apr 2008

*  

*  - Changed structure of JavaScript so that everything is encapsulated

*    inside one top-level function

*  - Added support for modifier keys (ctrl (i.e. command on a Mac,) alt, shift)

*  - Fixed code for determining coordinates on different (recent) browsers

*  - Added support for registering multiple Flash objects and their container DIVs

*  

*  

*  ---------------------------------------------------

*  This code is licensed under the MIT License:

*  

*  Permission is hereby granted, free of charge, to any person obtaining a copy

*  of this software and associated documentation files (the "Software"), to deal

*  in the Software without restriction, including without limitation the rights

*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

*  copies of the Software, and to permit persons to whom the Software is

*  furnished to do so, subject to the following conditions:

*  

*  The above copyright notice and this permission notice shall be included in

*  all copies or substantial portions of the Software.

*  

*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

*  THE SOFTWARE.

*/



var extMouseWheel = function()

{

	// let's not allow other deltas than +/- 3 because that's what flash player does:

	var keepDeltaAtPlusMinusThree = true;

	

	

	// an associative array, where the keys are the ids of flash

	// objects that have registered for the mouse wheel support, and

	// the values their respective container div elements.

	var f = [];

	

	

	

	

	// helper function courtesy of the Adobe peepz

	var thisMovie = function(movieName)

	{

		if (navigator.appName.indexOf("Microsoft") != -1) {

			return window[movieName];

		} else {

			return document[movieName];

		}

	}

	

	// helper functions for getting the position of

	// an element

	// from:  http://blog.firetree.net/2005/07/04/javascript-find-position/

	var findPosX = function(obj)

	{

		var curleft = 0;

		if(obj.offsetParent)

			while(1) 

			{

			  curleft += obj.offsetLeft;

			  if(!obj.offsetParent)

				break;

			  obj = obj.offsetParent;

			}

		else if(obj.x)

			curleft += obj.x;

		return curleft;

	}

	var findPosY = function(obj)

	{

		var curtop = 0;

		if(obj.offsetParent)

			while(1)

			{

			  curtop += obj.offsetTop;

			  if(!obj.offsetParent)

				break;

			  obj = obj.offsetParent;

			}

		else if(obj.y)

			curtop += obj.y;

		return curtop;

	}

	

	// helper function for searching the user-agent string

	var uaContains = function(str)

	{

		return (navigator.userAgent.indexOf(str) != -1);

	}

	

	

	

	

	

	

	// Handler for mouse wheel event:

	var onWheelHandler = function(event)

	{

		var delta = 0;

		if (!event) event = window.event;

		if (event.wheelDelta)

		{

			// Safari

			delta = event.wheelDelta/120;

			if (window.opera) delta = -delta;

		}

		else if (event.detail) // Firefox

			delta = -event.detail*3;

		

		if (keepDeltaAtPlusMinusThree)

		{

			if (delta > 0) delta = 3;

			else if (delta == 0) delta = 0;

			else delta = -3;

		}

		

		if (delta)

		{

			

			var thisFlashMovieId = null;

			for (var j in f)

				if (f[j] != null && f[j] == event.currentTarget) thisFlashMovieId = j;

			

			var thisMouse;

			

			if (uaContains("Camino"))

				thisMouse = {x:event.layerX, y:event.layerY};

			else if (uaContains('Firefox'))

				thisMouse = {x:(event.layerX - findPosX(event.currentTarget)), y:(event.layerY - findPosY(event.currentTarget))};

			else

				thisMouse = {x:event.offsetX, y:event.offsetY};

			

			thisMouse.ctrlKey = (uaContains('Mac')) ? (event.metaKey || event.ctrlKey) : event.ctrlKey;

			thisMouse.altKey = event.altKey;

			thisMouse.shiftKey = event.shiftKey;

			thisMouse.buttonDown = false;

			

			if (thisMovie(thisFlashMovieId).dispatchExternalMouseWheelEvent)

				thisMovie(thisFlashMovieId).dispatchExternalMouseWheelEvent(delta, thisMouse.x, thisMouse.y,

																			thisMouse.ctrlKey, thisMouse.altKey,

																			thisMouse.shiftKey, thisMouse.buttonDown);

		};

		

		// Prevent default actions caused by mouse wheel

		if (event.preventDefault) event.preventDefault();

		event.returnValue = false;

		

	}

	

	

	

	

	

	

	

	

	

	return {

		// initialize mouse wheel capturing by setting the listener

		// (this is called from within the Flash app):

		initCaptureFor: function(aFlashObjectId)

		{

			if (uaContains('Mac') || uaContains('Safari'))

			{

				// find flash object's div container

				var parentdiv = document.getElementById(aFlashObjectId).parentNode;

				while(parentdiv != null && parentdiv.nodeName != "DIV")

					parentdiv = parentdiv.parentNode;

				

				if (parentdiv != undefined && parentdiv != null)

				{

					f[aFlashObjectId] = parentdiv;

					

					if (parentdiv.addEventListener) parentdiv.addEventListener('DOMMouseScroll', onWheelHandler, false); // Firefox

					parentdiv.onmousewheel = onWheelHandler; // Safari

					

					return true;

				}

				else

					return false;

			}

			else

				return false;

		}

	};

	

}();