/*

Important:

This is sample code demonstrating API, technology or techniques in development.

Although this sample code has been reviewed for technical accuracy, it is not 

final. Apple is supplying this information to help you plan for the adoption of 

the technologies and programming interfaces described herein. This information 

is subject to change, and software implemented based on this sample code should 

be tested with final operating system software and final documentation. Newer 

versions of this sample code may be provided with future seeds of the API or 

technology. For information about updates to this and other developer 

documentation, view the New & Updated sidebars in subsequent documentation seeds.

*/

/*

File: nano.js

Abstract: Defines JavaScript functionality for the iPodNano sample.

Version: 1.0

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

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

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

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

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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

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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

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Copyright (C) 2008 Apple Inc. All Rights Reserved.

*/

var movies = 

[

    "media/lasttime_180x102.mp4",

    "media/lasttime_180x102.mp4",

    "media/lasttime_180x102.mp4",

    "media/lasttime_180x102.mp4",

    "media/lasttime_180x102.mp4"

];

var nanoDivs = null;

var currentNano = null;

var stackClosed = true;

// we use the same video for all five iPods so set each to a different time

function videoPlayable(evt) 

{

    var video = evt.target;

    var time = (Math.random() * video.duration);

    video.currentTime = time;

    video.removeEventListener("canshowcurrentframe", videoPlayable);

}

// the document has loaded, set everything up

function initialize(evt) 

{

    var ndx, count;

    var nanoContainer = document.getElementById('nanoStack');

    // cache the nano divs

    nanoDivs = [];

    var childNodes = nanoContainer.childNodes;

    for ( ndx = 0, count = childNodes.length; ndx < count; ndx++) 

    {

        var child = childNodes[ndx];

        if ( "nano" == child.className )

            nanoDivs[nanoDivs.length] = child;

    }

    // setup each of the video elements

    var videos = document.getElementsByTagName("video");

    for ( ndx = 0, count = videos.length; ndx < count; ndx++ ) 

    {

        var video = videos[ndx];

        if ( ndx > 0 ) 

        {

            // listen for the only ready state event we are guaranteed to see (it is fired

            //  as part of the "load" processing. see section 3.12.10.6 of the HTML5 spec)

            video.addEventListener("canshowcurrentframe", videoPlayable, true);

            video.volume = 0.0;

        }

        video.autoplay = true;

        video.playCount = 10000;

        video.src = movies[ndx];

    }

}

// toggle the nanos between stacked and expanded

function toggleNanoStack() 

{

    var ndx, count;

    var nanoContainer = document.getElementById('nanoStack');

    if ( "closed" == nanoContainer.className ) 

    {

        // open the container 

        stackClosed = false;

        nanoContainer.className = "open";

        for ( ndx = 0, count = nanoDivs.length; ndx< count; ndx++) 

        {

            var nano = nanoDivs[ndx];

            if ( 0 == ndx)

                currentNano = nano;

            nano.addEventListener("click",nanoClicked);

        }

    }

    else 

    {

        // close the container

        stackClosed = true;

        nanoContainer.className = "closed";

        for ( ndx = 0, count = nanoDivs.length; ndx < count; ndx++) 

        {

            var nano = nanoDivs[ndx];

            nano.className = "nano";

            nano.removeEventListener("click", nanoClicked);

        }

        setCurrentNano(nanoDivs[0]);

    }

}

// fade audio down in the previously focused movie, up in the new one

function fadeAudio(previous, current) 

{

     var previousVideo = previous.getElementsByTagName("video")[0];

     var currentVideo = current.getElementsByTagName("video")[0];

     var steps = 10;

     var increment = 1.0 / steps;

     var frequency = (1000 * .7) / steps;

     var _fadeAudio = function() 

     {

         var newVolume;

         newVolume = currentVideo.volume + increment;

         currentVideo.volume = (newVolume <= 0.5) ? newVolume : 0.5;

         newVolume = previousVideo.volume - increment;

         previousVideo.volume = (newVolume >= 0.0) ? newVolume : 0.0;

         if ( 0 == previousVideo.volume ) 

         {

             if ( arguments.callee.interval )

             {

                 clearInterval(arguments.callee.interval);

                 arguments.callee.interval = null;

             }

         }

     }

     _fadeAudio.interval = setInterval(_fadeAudio, frequency);

}

// bring one of the nanos to the front of the stack

function setCurrentNano(target) 

{

    var targetVideo = target.getElementsByTagName("video")[0];

    var previousNano = currentNano;

    if ( "nano selected" != target.className ) 

    {

        // clicked on a non-focused nano, start playing, and bring to front if expanded

        targetVideo.play();

        if ( !stackClosed )

            target.className = "nano selected";

        if ( currentNano && (target != currentNano) )

            currentNano.className = "nano";

        currentNano = target;

    }

    else if ( currentNano == target )

    {

        // already selected, push it back into the pack and select the first one as

        //  it is now the only one fully visible

        target.className = "nano";

        currentNano = nanoDivs[0];

    }

    fadeAudio(previousNano, currentNano);

}

// nano click handler, only active when stack is expanded

function nanoClicked(evt) 

{

    var target = evt.target;

    if ( "VIDEO" == target.tagName.toUpperCase() ) 

        target = target.parentNode;

    if ( "DIV" != target.tagName.toUpperCase() ) 

        return;

    setCurrentNano(target);

}

function videoForControl(element) 

{

    return element.parentNode.getElementsByTagName("video")[0];

}

function playPause(element) 

{

    var video = videoForControl(element);            

    if ( video.paused )

        video.play();

    else

        video.pause();

}

function jumpForward(element)

{

    videoForControl(element).currentTime += 10;

}

function jumpBackward(element)

{

    videoForControl(element).currentTime -= 10;

}

window.addEventListener("load", initialize);