// 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();
};