/*

 File: script.js

 Abstract: This example webpage showcases a variety of CSS visual 

 effects.  Buttons and other page elements are styled with CSS gradients

 and shadows, menus are animated with CSS transitions, custom fonts are 

 displayed with CSS web fonts, and elements are positioned, scaled, and 

 rotated on the page using CSS transforms.  The entire interface is drawn

 and animated without using any images or plug-ins.

 Version: 1.1

 Disclaimer: IMPORTANT:  This Apple software is supplied to you by 

 Apple Inc. ("Apple") in consideration of your agreement to the

 following terms, and your use, installation, modification or

 redistribution of this Apple software constitutes acceptance of these

 terms.  If you do not agree with these terms, please do not use,

 install, modify or redistribute this Apple software.

 In consideration of your agreement to abide by the following terms, and

 subject to these terms, Apple grants you a personal, non-exclusive

 license, under Apple's copyrights in this original Apple software (the

 "Apple Software"), to use, reproduce, modify and redistribute the Apple

 Software, with or without modifications, in source and/or binary forms;

 provided that if you redistribute the Apple Software in its entirety and

 without modifications, you must retain this notice and the following

 text and disclaimers in all such redistributions of the Apple Software. 

 Neither the name, trademarks, service marks or logos of Apple Inc. 

 may be used to endorse or promote products derived from the Apple

 Software without specific prior written permission from Apple.  Except

 as expressly stated in this notice, no other rights or licenses, express

 or implied, are granted by Apple herein, including but not limited to

 any patent rights that may be infringed by your derivative works or by

 other works in which the Apple Software may be incorporated.

 The Apple Software is provided by Apple on an "AS IS" basis.  APPLE

 MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION

 THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS

 FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND

 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL

 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,

 MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED

 AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),

 STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE

 POSSIBILITY OF SUCH DAMAGE.

 Copyright (C) 2010 Apple Inc. All Rights Reserved.

 */ 

function load() {

    // Set up the last two menu transitions.

    var blindsSubmenu = document.getElementById("blinds-submenu");

    setIncreasingTransitionDelay(blindsSubmenu, 0.25, 0.15);

    var zoomDownSubmenu = document.getElementById("zoom-down-submenu");

    setIncreasingTransitionDelay(zoomDownSubmenu, 0.25, 0.10);

    // Set up event handlers for collapsing menus on click. We need the 

    // touchend handler because the body isn't clickable on the iPad.

    document.body.addEventListener("click", collapseMenuFromEvent, false);

    document.body.addEventListener("touchend", collapseMenuFromEvent, false);

    // Set up event handlers for expanding menus.

    var menu = document.getElementById("navigation-menu");

    var menuItems = menu.children;

    for(var i = 0; i < menuItems.length; i++) {

        menuItems[i].addEventListener("click", expandMenuFromEvent, true);

        // Prevent the touchend handler on the body from firing when a button is clicked.

        menuItems[i].addEventListener("touchend", function(e) {e.stopPropagation();}, true);

    }

}

function setIncreasingTransitionDelay(containerElement, initialDelay, delayIncrement)

{

    var children = containerElement.children;

    for(var i = 0; i < children.length; i++)

        children[i].style["-webkit-transition-delay"] = (initialDelay + (i * delayIncrement)) + "s";

}

/* Expand the menu item that was clicked on, and expand this button. Also contract other buttons

 * on the menu bar if they're not contracted already.

 */

function expandMenuFromEvent(event)

{

    var currentlyExpandedMenuItem = document.getElementsByClassName("expanded")[0];

    if (currentlyExpandedMenuItem == this)

        return;

    else if (currentlyExpandedMenuItem) // Only allow one menu to be expanded at a time.

        currentlyExpandedMenuItem.removeClassName("expanded");

    else

        document.getElementById("navigation-menu").addClassName("expanded-menu");

    this.addClassName("expanded");

    event.stopPropagation();

}

/* Collapse the currently open menu and return the menu bar to its original appearance.

 */

function collapseMenuFromEvent(event)

{

    var currentlyExpandedMenuItem = document.getElementsByClassName("expanded")[0];

    if (!currentlyExpandedMenuItem)

        return;

    currentlyExpandedMenuItem.removeClassName("expanded");

    var navigationMenu = document.getElementById("navigation-menu");

    navigationMenu.removeClassName("expanded-menu");

}

/**

 *  Indicates whether the element has a given class name within its class attribute.

 */

Element.prototype.hasClassName = function (className) {

  return new RegExp('(?:^|\\s+)' + className + '(?:\\s+|$)').test(this.className);

};

/**

 *  Adds the given class name to the element's class attribute if it's not already there.

 */

Element.prototype.addClassName = function (className) {

  if (!this.hasClassName(className)) {

    this.className = [this.className, className].join(' ').replace(/^\s*|\s*$/g, "");

  }

};

/**

 *  Removes the given class name from the element's class attribute if it's there.

 */

Element.prototype.removeClassName = function (className) {

  if (this.hasClassName(className)) {

    var curClasses = this.className;

    this.className = curClasses.replace(new RegExp('(?:^|\\s+)' + className + '(?:\\s+|$)', 'g'), ' ').replace(/^\s*|\s*$/g, "");

  }

};