// SprySlidingPanels.js - version 0.5 - Spry Pre-Release 1.6.1
//
// Copyright (c) 2006. Adobe Systems Incorporated.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//   * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//   * Neither the name of Adobe Systems Incorporated nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

var Spry;
if (!Spry) Spry = {};
if (!Spry.Widget) Spry.Widget = {};

Spry.Widget.SlidingPanels = function(element, opts)
{
    this.element = this.getElement(element);
    this.enableAnimation = true;
    this.currentPanel = null;
    this.enableKeyboardNavigation = true;
    this.hasFocus = false;
    this.previousPanelKeyCode = Spry.Widget.SlidingPanels.KEY_LEFT;
    this.nextPanelKeyCode = Spry.Widget.SlidingPanels.KEY_RIGHT;

    this.currentPanelClass = "SlidingPanelsCurrentPanel";
    this.focusedClass = "SlidingPanelsFocused";
    this.animatingClass = "SlidingPanelsAnimating";

    Spry.Widget.SlidingPanels.setOptions(this, opts);

    if (this.element)
        this.element.style.overflow = "hidden";

    // Developers can specify the default panel as an index,
    // id or an actual element node. Make sure to normalize
    // it into an element node because that is what we expect
    // internally.

    if (this.defaultPanel)
    {
        if (typeof this.defaultPanel == "number")
            this.currentPanel = this.getContentPanels()[this.defaultPanel];
        else
            this.currentPanel = this.getElement(this.defaultPanel);
    }

    // If we still don't have a current panel, use the first one!

    if (!this.currentPanel)
        this.currentPanel = this.getContentPanels()[0];

    // Since we rely on the positioning information of the
    // panels, we need to wait for the onload event to fire before
    // we can attempt to show the initial panel. Once the onload
    // fires, we know that all CSS files have loaded. This is
    // especially important for Safari.

    if (Spry.Widget.SlidingPanels.onloadDidFire)
        this.attachBehaviors();
    else
        Spry.Widget.SlidingPanels.loadQueue.push(this);
};

Spry.Widget.SlidingPanels.prototype.onFocus = function(e)
{
    this.hasFocus = true;
    this.addClassName(this.element, this.focusedClass);
    return false;
};

Spry.Widget.SlidingPanels.prototype.onBlur = function(e)
{
    this.hasFocus = false;
    this.removeClassName(this.element, this.focusedClass);
    return false;
};

Spry.Widget.SlidingPanels.KEY_LEFT = 37;
Spry.Widget.SlidingPanels.KEY_UP = 38;
Spry.Widget.SlidingPanels.KEY_RIGHT = 39;
Spry.Widget.SlidingPanels.KEY_DOWN = 40;

Spry.Widget.SlidingPanels.prototype.onKeyDown = function(e)
{
    var key = e.keyCode;
    if (!this.hasFocus || (key != this.previousPanelKeyCode && key != this.nextPanelKeyCode))
        return true;

    if (key == this.nextPanelKeyCode)
        this.showNextPanel();
    else /* if (key == this.previousPanelKeyCode) */
        this.showPreviousPanel();

    if (e.preventDefault) e.preventDefault();
    else e.returnValue = false;
    if (e.stopPropagation) e.stopPropagation();
    else e.cancelBubble = true;

    return false;
};

Spry.Widget.SlidingPanels.prototype.attachBehaviors = function()
{
    var ele = this.element;
    if (!ele)
        return;

    if (this.enableKeyboardNavigation)
    {
        var focusEle = null;
        var tabIndexAttr = ele.attributes.getNamedItem("tabindex");
        if (tabIndexAttr || ele.nodeName.toLowerCase() == "a")
            focusEle = ele;
    
        if (focusEle)
        {
            var self = this;
            Spry.Widget.SlidingPanels.addEventListener(focusEle, "focus", function(e) { return self.onFocus(e || window.event); }, false);
            Spry.Widget.SlidingPanels.addEventListener(focusEle, "blur", function(e) { return self.onBlur(e || window.event); }, false);
            Spry.Widget.SlidingPanels.addEventListener(focusEle, "keydown", function(e) { return self.onKeyDown(e || window.event); }, false);
        }
    }

    if (this.currentPanel)
    {
        // Temporarily turn off animation when showing the
        // initial panel.

        var ea = this.enableAnimation;
        this.enableAnimation = false;
        this.showPanel(this.currentPanel);
        this.enableAnimation = ea;
    }
};

Spry.Widget.SlidingPanels.prototype.getElement = function(ele)
{
    if (ele && typeof ele == "string")
        return document.getElementById(ele);
    return ele;
};

Spry.Widget.SlidingPanels.prototype.addClassName = function(ele, className)
{
    if (!ele || !className || (ele.className && ele.className.search(new RegExp("\\b" + className + "\\b")) != -1))
        return;
    ele.className += (ele.className ? " " : "") + className;
};

Spry.Widget.SlidingPanels.prototype.removeClassName = function(ele, className)
{
    if (!ele || !className || (ele.className && ele.className.search(new RegExp("\\b" + className + "\\b")) == -1))
        return;
    ele.className = ele.className.replace(new RegExp("\\s*\\b" + className + "\\b", "g"), "");
};

Spry.Widget.SlidingPanels.setOptions = function(obj, optionsObj, ignoreUndefinedProps)
{
    if (!optionsObj)
        return;
    for (var optionName in optionsObj)
    {
        if (ignoreUndefinedProps && optionsObj[optionName] == undefined)
            continue;
        obj[optionName] = optionsObj[optionName];
    }
};

Spry.Widget.SlidingPanels.prototype.getElementChildren = function(element)
{
    var children = [];
    var child = element.firstChild;
    while (child)
    {
        if (child.nodeType == 1 /* Node.ELEMENT_NODE */)
            children.push(child);
        child = child.nextSibling;
    }
    return children;
};

Spry.Widget.SlidingPanels.prototype.getCurrentPanel = function()
{
    return this.currentPanel;
};

Spry.Widget.SlidingPanels.prototype.getContentGroup = function()
{
    return this.getElementChildren(this.element)[0];
};

Spry.Widget.SlidingPanels.prototype.getContentPanels = function()
{
    return this.getElementChildren(this.getContentGroup());
};

Spry.Widget.SlidingPanels.prototype.getContentPanelsCount = function()
{
    return this.getContentPanels().length;
};

Spry.Widget.SlidingPanels.onloadDidFire = false;
Spry.Widget.SlidingPanels.loadQueue = [];

Spry.Widget.SlidingPanels.addLoadListener = function(handler)
{
    if (typeof window.addEventListener != 'undefined')
        window.addEventListener('load', handler, false);
    else if (typeof document.addEventListener != 'undefined')
        document.addEventListener('load', handler, false);
    else if (typeof window.attachEvent != 'undefined')
        window.attachEvent('onload', handler);
};

Spry.Widget.SlidingPanels.processLoadQueue = function(handler)
{
    Spry.Widget.SlidingPanels.onloadDidFire = true;
    var q = Spry.Widget.SlidingPanels.loadQueue;
    var qlen = q.length;
    for (var i = 0; i < qlen; i++)
        q[i].attachBehaviors();
};

Spry.Widget.SlidingPanels.addLoadListener(Spry.Widget.SlidingPanels.processLoadQueue);

Spry.Widget.SlidingPanels.addEventListener = function(element, eventType, handler, capture)
{
    try
    {
        if (element.addEventListener)
            element.addEventListener(eventType, handler, capture);
        else if (element.attachEvent)
            element.attachEvent("on" + eventType, handler);
    }
    catch (e) {}
};

Spry.Widget.SlidingPanels.prototype.getContentPanelIndex = function(ele)
{
    if (ele)
    {
        ele = this.getElement(ele);
        var panels = this.getContentPanels();
        var numPanels = panels.length;
        for (var i = 0; i < numPanels; i++)
        {
            if (panels[i] == ele)
                return i;
        }
    }
    return -1;
};

Spry.Widget.SlidingPanels.prototype.showPanel = function(elementOrIndex)
{
    var pIndex = -1;
    
    if (typeof elementOrIndex == "number")
        pIndex = elementOrIndex;
    else // Must be the element for the content panel.
        pIndex = this.getContentPanelIndex(elementOrIndex);

    var numPanels = this.getContentPanelsCount();
    if (numPanels > 0)
        pIndex = (pIndex >= numPanels) ? numPanels - 1 : pIndex;
    else
        pIndex = 0;

    var panel = this.getContentPanels()[pIndex];
    var contentGroup = this.getContentGroup();

    if (panel && contentGroup)
    {
        if (this.currentPanel)
            this.removeClassName(this.currentPanel, this.currentPanelClass);
        this.currentPanel = panel;

        var nx = -panel.offsetLeft;
        var ny = -panel.offsetTop;

        if (this.enableAnimation)
        {
            if (this.animator)
                this.animator.stop();
            var cx = contentGroup.offsetLeft;
            var cy = contentGroup.offsetTop;
            if (cx != nx || cy != ny)
            {
                var self = this;
                this.addClassName(this.element, this.animatingClass);
                this.animator = new Spry.Widget.SlidingPanels.PanelAnimator(contentGroup, cx, cy, nx, ny, { duration: this.duration, fps: this.fps, transition: this.transition, finish: function()
                {
                    self.removeClassName(self.element, self.animatingClass);
                    self.addClassName(panel, self.currentPanelClass);
                } });
                this.animator.start();
            }
        }
        else
        {
            contentGroup.style.left = nx + "px";
            contentGroup.style.top = ny + "px";
            this.addClassName(panel, this.currentPanelClass);
        }
    }

    return panel;
};

Spry.Widget.SlidingPanels.prototype.showFirstPanel = function()
{
    return this.showPanel(0);
};

Spry.Widget.SlidingPanels.prototype.showLastPanel = function()
{
    return this.showPanel(this.getContentPanels().length - 1);
};

Spry.Widget.SlidingPanels.prototype.showPreviousPanel = function()
{
    return this.showPanel(this.getContentPanelIndex(this.currentPanel) - 1);
};

Spry.Widget.SlidingPanels.prototype.showNextPanel = function()
{
    return this.showPanel(this.getContentPanelIndex(this.currentPanel) + 1);
};

Spry.Widget.SlidingPanels.PanelAnimator = function(ele, curX, curY, dstX, dstY, opts)
{
    this.element = ele;

    this.curX = curX;
    this.curY = curY;
    this.dstX = dstX;
    this.dstY = dstY;
    this.fps = 60;
    this.duration = 500;
    this.transition = Spry.Widget.SlidingPanels.PanelAnimator.defaultTransition;
    this.startTime = 0;
    this.timerID = 0;
    this.finish = null;

    var self = this;
    this.intervalFunc = function() { self.step(); };
    
    Spry.Widget.SlidingPanels.setOptions(this, opts, true);

    this.interval = 1000/this.fps;
};

Spry.Widget.SlidingPanels.PanelAnimator.defaultTransition = function(time, begin, finish, duration) { time /= duration; return begin + ((2 - time) * time * finish); };

Spry.Widget.SlidingPanels.PanelAnimator.prototype.start = function()
{
    this.stop();
    this.startTime = (new Date()).getTime();
    this.timerID = setTimeout(this.intervalFunc, this.interval);
};

Spry.Widget.SlidingPanels.PanelAnimator.prototype.stop = function()
{
    if (this.timerID)
        clearTimeout(this.timerID);
    this.timerID = 0;
};

Spry.Widget.SlidingPanels.PanelAnimator.prototype.step = function()
{
    var elapsedTime = (new Date()).getTime() - this.startTime;
    var done = elapsedTime >= this.duration;
    var x, y;

    if (done)
    {
        x = this.curX = this.dstX;
        y = this.curY = this.dstY;
    }
    else
    {
        x = this.transition(elapsedTime, this.curX, this.dstX - this.curX, this.duration);
        y = this.transition(elapsedTime, this.curY, this.dstY - this.curY, this.duration);
    }

    this.element.style.left = x + "px";
    this.element.style.top = y + "px";

    if (!done)
        this.timerID = setTimeout(this.intervalFunc, this.interval);
    else if (this.finish)
        this.finish();
};