// -----------------------------------------------------------------------------
// DHTML API Library, dhtmlapi.js
// JavaScript & DHTML Cookbook
// Danny Goodman
// O'Reilly, ISBN 0-596-00467-2
// -----------------------------------------------------------------------------
// 29.08.2005 by MJS - execution now breaks out of the search loop if the seeked
// layer is found nested inside another layer
// -----------------------------------------------------------------------------

// Global Variables
var isCSS, isW3C, isIE4, isNN4, isIE6CSS;

// Initialise upon load to let all browsers establish content objects
function initDHTMLAPI() {
	if (document.images) {
		isCSS = (document.body && document.body.style) ? true : false;
		isW3C = (isCSS && document.getElementById) ? true : false;
		isIE4 = (isCSS && document.all) ? true : false;
		isNN4 = (document.layers) ? true : false;
		isIE6CSS = (document.compatMode && document.compatMode.indexOf("CSS1") >= 0) ? true : false;
	}
}

// Set event handler to initialise API, note the library
// will self initialise if the onload event handler is not
// specified anywhere else in the page, otherwise the
// initDHTMLAPI method must be called before using the library
// functions
window.onload = initDHTMLAPI;

// Seek nested NN4 layer from string name
function seekLayer(doc, name) {
	var theObj;
	for (var i = 0; i < doc.layers.length; i++) {
		if (doc.layers[i].name == name) {
			theObj = doc.layers[i];
			break;
		}
		// dive into nested layers if necessary
		if (doc.layers[i].document.layers.length > 0) {
			theObj = seekLayer(document.layers[i].document, name);
			if (theObj != "undefined")
				break;
		}
	}
	return theObj;
}

// Convert object name string or object reference
// into a valid element object reference
function getRawObject(obj) {
	var theObj;
	if (typeof obj == "string") {
		if (isW3C) {
			theObj = document.getElementById(obj);
		} else if (isIE4) {
			theObj = document.all(obj);
		} else if (isNN4) {
			theObj = seekLayer(document, obj);
		}
	} else {
		// pass through object reference
		theObj = obj;
	}
	return theObj;
}

// Convert object name string or object reference
// into a valid style (or NN4 layer) reference
function getObject(obj) {
	var theObj = getRawObject(obj);
	if (theObj && isCSS) {
		theObj = theObj.style;
	}
	return theObj;
}

// Position an object at a specific pixel coordinate
function shiftTo(obj, x, y) {
	var theObj = getObject(obj);
	if (theObj) {
		if (isCSS) {
			// equalise incorrect numeric value type
			var units = (typeof theObj.left == "string") ? "px" : 0;
			theObj.left = x + units;
			theObj.top = y + units;
		} else if (isNN4) {
			theObj.moveTo(x, y);
		}
	}
}

// Position an object by x and/or y pixels
function shiftBy(obj, deltaX, deltaY) {
	var theObj = getObject(obj);
	if (theObj) {
		if (isCSS) {
			// equalise incorrect numeric value type
			var units = (typeof theObj.left == "string") ? "px" : 0;
			theObj.left = getObjectLeft(obj) + deltaX + units;
			theObj.top = getObjectTop(obj) + deltaY + units;
		} else if (isNN4) {
			theObj.moveBy(deltaX, deltaY);
		}
	}
}

// Set the z-order of an object
function setZIndex(obj, zOrder) {
	var theObj = getObject(obj);
	if (theObj) {
		theObj.zIndex = zOrder;
	}
}

// Set the background colour of an object
function setBGColor(obj, color) {
	var theObj = getObject(obj);
	if (theObj) {
		if (isNN4) {
			theObj.bgColor = color;
		} else if (isCSS) {
			theObj.backgroundColor = color;
		}
	}
}

// Set the visibility of an object to visible
function show(obj) {
	var theObj = getObject(obj);
	if (theObj) {
		theObj.visibility = "visible";
	}
}

// Set the visibility of an object to hidden
function hide(obj) {
	var theObj = getObject(obj);
	if (theObj) {
		theObj.visibility = "hidden";
	}
}

// Retrieve the x coordinate of a positionable object
function getObjectLeft(obj) {
	var elem = getRawObject(obj);
	var result = 0;
	if (document.defaultView) {
		var style = document.defaultView;
		var cssDec1 = style.getComputedStyle(elem, "");
		result = cssDec1.getPropertyValue("left");
	} else if (elem.currentStyle) {
		result = elem.currentStyle.left;
	} else if (elem.style) {
		result = elem.style.left;
	} else if (isNN4) {
		result = elem.left;
	}
	return parseInt(result);
}

// Retrieve the y coordinate of a positionable object
function getObjectTop(obj) {
	var elem = getRawObject(obj);
	var result = 0;
	if (document.defaultView) {
		var style = document.defaultView;
		var cssDec1 = style.getComputedStyle(elem, "");
		result = cssDec1.getPropertyValue("top");
	} else if (elem.currentStyle) {
		result = elem.currentStyle.top;
	} else if (elem.style) {
		result = elem.style.top;
	} else if (isNN4) {
		result = elem.top;
	}
	return parseInt(result);
}

// Retrieve the rendered width of an element
function getObjectWidth(obj) {
	var elem = getRawObject(obj);
	var result = 0;
	if (elem.offsetWidth) {
		result = elem.offsetWidth;
	} else if (elem.clip && elem.clip.width) {
		result = elem.clip.width;
	} else if (elem.style && elem.style.pixelWidth) {
		result = elem.style.pixelWidth;
	}
	return parseInt(result);
}

// Retrieve the rendered height of an element
function getObjectHeight(obj) {
	var elem = getRawObject(obj);
	var result = 0;
	if (elem.offsetHeight) {
		result = elem.offsetHeight;
	} else if (elem.clip && elem.clip.height) {
		result = elem.clip.height;
	} else if (elem.style && elem.style.pixelHeight) {
		result = elem.style.pixelHeight;
	}
	return parseInt(result);
}

// Return the available content width of the browser window
function getInsideWindowWidth() {
	if (window.innerWidth) {
		return window.innerWidth;
	} else if (isIE6CSS) {
		// measure the html element's clientWidth
		return document.body.parentElement.clientWidth;
	} else if (document.body && document.body.clientWidth) {
		return document.body.clientWidth;
	}
	return 0;
}

// Return the available content height of the browser window
function getInsideWindowHeight() {
	if (window.innerHeight) {
		return window.innerHeight;
	} else if (isIE6CSS) {
		// measure the html element's clientHeight
		return document.body.parentElement.clientHeight;
	} else if (document.body && document.body.clientHeight) {
		return document.body.clientHeight;
	}
	return 0;
}

// Return the horizontal scroll offset
function getScrollLeft() {
	var scrLeft = 0;
	if (document.body && typeof document.body.scrollLeft != 'undefined') {
		scrLeft += document.body.scrollLeft;
		if (document.body.parentNode && typeof document.body.parentNode.scrollLeft != 'undefined')
			scrLeft += document.body.parentNode.scrollLeft;
	} else if (window.pageXOffset)
		scrLeft += window.pageXOffset;
	return parseInt(scrLeft);
}

// Return the vertical scroll offset
function getScrollTop() {
	var scrTop = 0;
	if (document.body && document.body.scrollTop) {
		scrTop += document.body.scrollTop;
		if (document.body.parentNode && document.body.parentNode.scrollTop)
			scrTop += document.body.parentNode.scrollTop;
	} else if (window.pageYOffset)
		scrTop += window.pageYOffset;
	return parseInt(scrTop);
}

// -----------------------------------------------------------------------------
// End of Library
// -----------------------------------------------------------------------------