// SprySlidingPanels.js - version 0.4 - Spry Pre-Release 1.5

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";

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


if (!this.currentPanel)
this.currentPanel = this.getContentPanels()[1];

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.returnResult = 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)
{

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 = 5000;
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();
};