// DHTMLapi3.js custom API for cross-platform
// object positioning by Danny Goodman (http://www.dannyg.com).
// Release 3.0. Supports NN4, IE, and W3C DOMs.
// --
// Extended by Lutz Issler / Systemantics, Bureau for Informatics.
// http://www.systemantics.net/
var DHTMLAPI = {
	browserClass : new Object( ),
	init : function ( ) {
		this.browserClass.isCSS = ((document.body && document.body.style) ? true : false);
		this.browserClass.isW3C = ((this.browserClass.isCSS && document.getElementById) ? true : false),
		this.browserClass.isIE4 = ((this.browserClass.isCSS && document.all) ? true : false),
		this.browserClass.isNN4 = ((document.layers) ? true : false),
		this.browserClass.isIECSSCompat = ((document.compatMode && document.compatMode.indexOf("CSS1") >= 0) ? true : false)
	},
	// Seek nested NN4 layer from string name
	seekLayer : function (doc, name) {
		var elem;
		for (var i = 0; i < doc.layers.length; i++) {
			if (doc.layers[i].name == name) {
				elem = doc.layers[i];
				break;
			}
			// dive into nested layers if necessary
			if (doc.layers[i].document.layers.length > 0) {
				elem = this.seekLayer(doc.layers[i].document, name);
				if (elem) {break;}
			}
		}
		return elem;
	},
	// Convert element name string or object reference
	// into a valid element object reference
	getRawObject : function (elemRef) {
		var elem;
		if (typeof elemRef == "string") {
			if (this.browserClass.isW3C) {
				elem = document.getElementById(elemRef);
			} else if (this.browserClass.isIE4) {
				elem = document.all(elemRef);
			} else if (this.browserClass.isNN4) {
				elem = this.seekLayer(document, elemRef);
			}
		} else {
			// pass through object reference
			elem = elemRef;
		}
		return elem;
	},
	// Convert element name string or object reference
	// into a valid style (or NN4 layer) object reference
	getStyleObject : function (elemRef) {
		var elem = this.getRawObject(elemRef);
		if (elem && this.browserClass.isCSS) {
			elem = elem.style;
		}
		return elem;
	},
	// Position an element at a specific pixel coordinate
	moveTo : function (elemRef, x, y) {
		var elem = this.getStyleObject(elemRef);
		if (elem) {
			if (this.browserClass.isCSS) {
				// equalize incorrect numeric value type
				var units = (typeof elem.left == "string") ? "px" : 0;
				elem.left = x + units;
				elem.top = y + units;
			} else if (this.browserClass.isNN4) {
				elem.moveTo(x,y);
			}
		}
	},
	// Move an element by x and/or y pixels
	moveBy : function (elemRef, deltaX, deltaY) {
		var elem = this.getStyleObject(elemRef);
		if (elem) {
			if (this.browserClass.isCSS) {
				// equalize incorrect numeric value type
				var units = (typeof elem.left == "string") ? "px" : 0;
				elem.left = this.getElementLeft(elemRef) + deltaX + units;
				elem.top = this.getElementTop(elemRef) + deltaY + units;
			} else if (this.browserClass.isNN4) {
				elem.moveBy(deltaX, deltaY);
			}
		}
	},
	// Set the z-order of an object
	setZIndex : function (obj, zOrder) {
		var elem = this.getStyleObject(obj);
		if (elem) {
			elem.zIndex = zOrder;
		}
	},
	// Set the background color of an object
	setBGColor : function (obj, color) {
		var elem = this.getStyleObject(obj);
		if (elem) {
			if (this.browserClass.isCSS) {
				elem.backgroundColor = color;
			} else if (this.browserClass.isNN4) {
				elem.bgColor = color;
			}
		}
	},
	// Set the visibility of an object to visible
	show : function (obj) {
		var elem = this.getStyleObject(obj);
		if (elem) {
			elem.visibility = "visible";
		}
	},
	// Set the visibility of an object to hidden
	hide : function (obj) {
		var elem = this.getStyleObject(obj);
		if (elem) {
			elem.visibility = "hidden";
		}
	},
	// Set the visibility of an object to hidden
	setDisplayMode : function (obj, displayMode) {
		var elem = this.getStyleObject(obj);
		if (elem) {
			elem.display = displayMode;
		}
	},
	// return computed value for an element's style property
	getComputedStyle : function (elemRef, CSSStyleProp) {
		var elem = this.getRawObject(elemRef);
		var styleValue, camel;
		if (elem) {
			if (document.defaultView) {
				// W3C DOM version
				var compStyle = document.defaultView.getComputedStyle(elem, "");
				styleValue = compStyle.getPropertyValue(CSSStyleProp);
			} else if (elem.currentStyle) {
				// make IE style property camelCase name from CSS version
				var IEStyleProp = CSSStyleProp;
				var re = /-\D/;
				while (re.test(IEStyleProp)) {
				camel = IEStyleProp.match(re)[0].charAt(1).toUpperCase( );
				IEStyleProp = IEStyleProp.replace(re, camel);
			}
				styleValue = elem.currentStyle[IEStyleProp];
			}
		}
		return (styleValue) ? styleValue : null;
	},
	// Retrieve the x coordinate of a positionable object
	getElementLeft : function (elemRef) {
		var elem = this.getRawObject(elemRef);
		var result = null;
		if (this.browserClass.isCSS || this.browserClass.isW3C) {
			result = parseInt(this.getComputedStyle(elem, "left"));
		} else if (this.browserClass.isNN4) {
			result = elem.left;
		}
		return result;
	},
	// Retrieve the y coordinate of a positionable object
	getElementTop : function (elemRef) {
		var elem = this.getRawObject(elemRef);
		var result = null;
		if (this.browserClass.isCSS || this.browserClass.isW3C) {
			result = parseInt(this.getComputedStyle(elem, "top"));
		} else if (this.browserClass.isNN4) {
			result = elem.top;
		}
		return result;
	},
	// Retrieve the rendered width of an element
	getElementWidth : function (elemRef) {
		var result = null;
		var elem = this.getRawObject(elemRef);
		if (elem) {
			// W3C DOM supporters
			result = parseInt(this.getComputedStyle(elemRef, "width"));
			// others, including "auto" results
			if (result == null || isNaN(parseInt(result))) {
				if (elem.offsetWidth) {
					if (elem.scrollWidth && (elem.offsetWidth != elem.scrollWidth)) {
						result = elem.scrollWidth;
					} else {
						result = elem.offsetWidth;
					}
				} else if (elem.clip && elem.clip.width) {
					// Netscape 4 positioned elements
					result = elem.clip.width;
				}
			}
		}
		return result;
	},
	// Sets the width of an element
	setElementWidth : function (elemRef, width) {
		var elem = this.getStyleObject(elemRef);
		if (elem) {
			elem.width = width+"px";
		}
	},
	// Sets the height of an element
	setElementHeight : function (elemRef, height) {
		var elem = this.getStyleObject(elemRef);
		if (elem) {
			elem.height = height+"px";
		}
	},
	// Retrieve the rendered height of an element
	getElementHeight : function (elemRef) {
		var result = null;
		var elem = this.getRawObject(elemRef);
		if (elem) {
			// W3C DOM supporters
			result = parseInt(this.getComputedStyle(elemRef, "height"));
			// others, including "auto" results
			if (result == null || isNaN(parseInt(result))) {
				if (elem.offsetHeight) {
					result = elem.offsetHeight;
				} else if (elem.clip && elem.clip.height) {
					result = elem.clip.height;
				}
				return parseInt(result);
			}
		}
		return result;
	},
	// Return the available content width space in browser window
	getInsideWindowWidth : function ( ) {
		if (window.innerWidth) {
			return window.innerWidth;
		} else if (this.browserClass.isIECSSCompat) {
			// measure the html element's clientWidth
			return document.body.parentElement.clientWidth;
		} else if (document.body && document.body.clientWidth) {
			return document.body.clientWidth;
		}
		return null;
	},
	// Return the available content height space in browser window
	getInsideWindowHeight : function ( ) {
		if (window.innerHeight) {
			return window.innerHeight;
		} else if (this.browserClass.isIECSSCompat) {
			// measure the html element's clientHeight
			return document.body.parentElement.clientHeight;
		} else if (document.body && document.body.clientHeight) {
			return document.body.clientHeight;
		}
		return null;
	},
	// Retrieve the z-order of an object
	getZIndex : function (obj) {
		var elem = this.getStyleObject(obj);
		if (elem) {
			return elem.zIndex;
		}
		return null;
	}
}