Effect.ScaleAndMove = Class.create(Effect.Base, {
	initialize: function(element, percentX, percentY) {
		this.element = $(element);
		if(!this.element) throw(Effect._elementDoesNotExistError);
		var options = Object.extend({
			scaleX: true,
			scaleY: true,
			moveX: true,
			moveY: true,
			scaleMode: 'box',        // 'box' or 'contents' or { } with provided values
			scaleFromX: 100.0,
			scaleToX:   percentX,
			scaleFromY: 100.0,
			scaleToY:   percentY,
			moveToX:    null,
			moveToY:    null
		}, arguments[3] || { });
		this.start(options);
	},
	setup: function() {
		this.restoreAfterFinish = this.options.restoreAfterFinish || false;
		this.elementPositioning = this.element.getStyle('position');

		this.originalStyle = { };
		['top','left','width','height'].each(function(k) {
			this.originalStyle[k] = this.element.style[k];
		}.bind(this));

		this.originalTop  = this.element.offsetTop;
		this.originalLeft = this.element.offsetLeft;

		this.scaleFactorX = (this.options.scaleToX - this.options.scaleFromX) / 100;
		this.scaleFactorY = (this.options.scaleToY - this.options.scaleFromY) / 100;

		this.moveFactorX  = this.options.moveToX - this.originalLeft;
		this.moveFactorY  = this.options.moveToY - this.originalTop;

		this.dims = null;
		if(this.options.scaleMode=='box') {
			this.dims = [this.element.offsetHeight, this.element.offsetWidth];
		} else if(/^content/.test(this.options.scaleMode)) {
			this.dims = [this.element.scrollHeight, this.element.scrollWidth];
		} else {
			this.dims = [this.options.scaleMode.originalHeight, this.options.scaleMode.originalWidth];
		}
	},
	update: function(position) {
		var currentScaleX = (this.options.scaleFromX / 100.0) + (this.scaleFactorX * position);
		var currentScaleY = (this.options.scaleFromY / 100.0) + (this.scaleFactorY * position);

		var currentMoveX  = this.moveFactorX * position;
		var currentMoveY  = this.moveFactorY * position;

		this.setDimensionsAndPosition(
			this.dims[0] * currentScaleY,
			this.dims[1] * currentScaleX,
			this.originalTop  + currentMoveY,
			this.originalLeft + currentMoveX
		);
	},
	finish: function(position) {
		if(this.restoreAfterFinish) this.element.setStyle(this.originalStyle);
	},
	setDimensionsAndPosition: function(height, width, top, left) {
		var d = { };
		if(this.options.scaleX) d.width  = width.round()  + 'px';
		if(this.options.scaleY) d.height = height.round() + 'px';
		if(this.options.moveX)  d.left   = left.round()   + 'px';
		if(this.options.moveY)  d.top    = top.round()    + 'px';
		this.element.setStyle(d);
	}
});