/* Copyright (c) 2005 Tim Taylor Consulting (see LICENSE.txt) */

/* FIXME: assumes position styles are specified in 'px' */

ToolMan._coordinatesFactory = {

	create : function(x, y) {
		// FIXME: Safari won't parse 'throw' and aborts trying to do anything with this file
		//if (isNaN(x) || isNaN(y)) throw "invalid x,y: " + x + "," + y
		return new _ToolManCoordinate(this, x, y)
	},

	origin : function() {
		return this.create(0, 0)
	},

	/*
	 * FIXME: Safari 1.2, returns (0,0) on absolutely positioned elements
	 */
	topLeftPosition : function(element) {
		var left = parseInt(ToolMan.css().readStyle(element, "left"))
		var left = isNaN(left) ? 0 : left
		var top = parseInt(ToolMan.css().readStyle(element, "top"))
		var top = isNaN(top) ? 0 : top

		return this.create(left, top)
	},

	bottomRightPosition : function(element) {
		return this.topLeftPosition(element).plus(this._size(element))
	},

	topLeftOffset : function(element) {
		var offset = this._offset(element) 

		var parent = element.offsetParent
		while (parent) {
			offset = offset.plus(this._offset(parent))
			parent = parent.offsetParent
		}
		return offset
	},

	bottomRightOffset : function(element) {
		return this.topLeftOffset(element).plus(
				this.create(element.offsetWidth, element.offsetHeight))
	},

	scrollOffset : function() {
		if (window.pageXOffset) {
			return this.create(window.pageXOffset, window.pageYOffset)
		} else if (document.documentElement) {
			return this.create(
					document.body.scrollLeft + document.documentElement.scrollLeft, 
					document.body.scrollTop + document.documentElement.scrollTop)
		} else if (document.body.scrollLeft >= 0) {
			return this.create(document.body.scrollLeft, document.body.scrollTop)
		} else {
			return this.create(0, 0)
		}
	},

	clientSize : function() {
		
		if (window.innerHeight >= 0) {
			return this.create(window.innerWidth, window.innerHeight)
		} 
		else if (document.body.clientHeight >= 0) {
			return this.create(document.body.clientWidth,
					document.body.clientHeight)
		}
		else if (document.documentElement) {
			return this.create(document.documentElement.clientWidth,
					document.documentElement.clientHeight)
		}  else {
			return this.create(0, 0)
		}
	},

	/**
	 * mouse coordinate relative to the window (technically the
	 * browser client area) i.e. the part showing your page
	 *
	 * NOTE: in Safari the coordinate is relative to the document
	 */
	mousePosition : function(event) {
		event = ToolMan.events().fix(event)
		return this.create(event.clientX, event.clientY)
	},
	mousePosition2 : function (event ) {
		
		event = ToolMan.events().fix(event)
		var posx = 0;
		var posy = 0;
		
		if (event.pageX || event.pageY)
		{
			posx = event.pageX;
			posy = event.pageY;
		}
		else if (event.clientX || event.clientY)
		{
			posx = event.clientX + document.body.scrollLeft;
			posy = event.clientY + document.body.scrollTop;
		}
		return this.create( posx  ,  posy )
		
	},
	
	alertCoord: function (e) {
		  if( !e ) {
			if( window.event ) {
			  //Internet Explorer
			  e = window.event;
			} else {
			  //total failure, we have no way of referencing the event
			  alert( "no way...")
			  return;
			}
		  }
		  if( typeof( e.pageX ) == 'number' ) {
			//most browsers
			var xcoord = e.pageX;
			var ycoord = e.pageY;
		  } else if( typeof( e.clientX ) == 'number' ) {
			//Internet Explorer and older browsers
			//other browsers provide this, but follow the pageX/Y branch
			var xcoord = e.clientX;
			var ycoord = e.clientY;
			var badOldBrowser = ( window.navigator.userAgent.indexOf( 'Opera' ) + 1 ) ||
			 ( window.ScriptEngine && ScriptEngine().indexOf( 'InScript' ) + 1 ) ||
			 ( navigator.vendor == 'KDE' )
			if( !badOldBrowser ) {
			  if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) {
				//IE 4, 5 & 6 (in non-standards compliant mode)
				xcoord += document.body.scrollLeft;
				ycoord += document.body.scrollTop;
			  } else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
				//IE 6 (in standards compliant mode)
				xcoord += document.documentElement.scrollLeft;
				ycoord += document.documentElement.scrollTop;
			  }
			}
		  } else {
			//total failure, we have no way of obtaining the mouse coordinates
			return;
		  }
		  window.alert('Mouse coordinates are ('+xcoord+','+ycoord+')');
	} ,

	/**
	 * mouse coordinate relative to the document
	 */
	mouseOffset : function(event) {
		event = ToolMan.events().fix(event)
		if (event.pageX >= 0 || event.pageX < 0) {
			return this.create(event.pageX, event.pageY)
		} else if (event.clientX >= 0 || event.clientX < 0) {
			return this.mousePosition(event).plus(this.scrollOffset())
		}
	},

	_size : function(element) {
	/* TODO: move to a Dimension class */
		return this.create(element.offsetWidth, element.offsetHeight)
	},

	_offset : function(element) {
		return this.create(element.offsetLeft, element.offsetTop)
	}
}

function _ToolManCoordinate(factory, x, y) {
	this.factory = factory
	this.x = isNaN(x) ? 0 : x
	this.y = isNaN(y) ? 0 : y
}

_ToolManCoordinate.prototype = {
	toString : function() {
		return "(" + this.x + "," + this.y + ")"
	},

	plus : function(that) {
		return this.factory.create(this.x + that.x, this.y + that.y)
	},

	minus : function(that) {
		return this.factory.create(this.x - that.x, this.y - that.y)
	},

	min : function(that) {
		return this.factory.create(
				Math.min(this.x , that.x), Math.min(this.y , that.y))
	},

	max : function(that) {
		return this.factory.create(
				Math.max(this.x , that.x), Math.max(this.y , that.y))
	},

	constrainTo : function (one, two) {
		var min = one.min(two)
		var max = one.max(two)

		return this.max(min).min(max)
	},

	distance : function (that) {
		return Math.sqrt(Math.pow(this.x - that.x, 2) + Math.pow(this.y - that.y, 2))
	},

	reposition : function(element) {
		element.style["top"] = this.y + "px"
		element.style["left"] = this.x + "px"
	}
}