Prototype ¬ Detail

author: kk [+], Submitted: 03.19.05 7a • Last Edit: 03.19.05 7a

//////////////////////////////////
//       .grin! wuz here        //
//////////////////////////////////
// 1.3:                         //
// changes: added  acceleration //
////////////////////////////////// 
MovieClip.prototype.changePropTo = function(prop, final, step, speedUp){
	var doIf = (this[prop] != final) && (typeof this[prop] == typeof final);
	if(doIf){
		if(!speedUp) speedUp = 0;
		var rel = this[prop]<final;
		var n = "$$chProp$$"+prop;
		var inc = (final - this[prop])/Math.abs(this[prop] - final);
		step = inc*Math.abs(step);
		this.createEmptyMovieClip(n, this.getNextHighestDepth());
		this[n].onEnterFrame = function (){
			step += speedUp;
			this = this._parent;
			if((this[prop]<final) == rel){
				this[prop] += step;
			} else {
				this[prop] = final;
				this[n].removeMovieClip()
				this.onOverChangeProp(prop, final)
			}
		}
	}
}

usage

mc.onOverChangeProp = function(prop, val){
	trace("Property "+mc+"."+prop+" is now "+val+".");
}
mc._y = mc._x = 0;
mc.changePropTo("_y", 300, 1, 1.5);
mc.changePropTo("_x", 300, 15);