Element.optimalWidth

Element.optimalWidth.js

Element.implement({
    // if called with callback, the element is set to the optimalWidth and called back when ready
    // else the optimalWidth is calculated and returned
    optimalWidth : function(callback){
        var increment = 10;
        var fuse = 10; //how many unchanged iterations before we're done?
        var originalSize = this.getSize();
        var lastForwardChange;
        for(var lcv=0; lcv < fuse; lcv++){
            var currentSize = this.getSize();
            var newWidth = currentSize.x + increment;
            this.setStyle('width', newWidth);
            if(currentSize.y > this.getSize().y){ //smaller height
                lastForwardChange = newWidth;
                lcv = 0; //reset the loop if values are changing
            }
        }
        if(lastForwardChange){
            if(callback){
                this.setStyle('width', lastForwardChange);
                if(typeOf(callback) == 'function') callback();
            }else{
                this.setStyle('width', originalSize.x);
            }
            return lastForwardChange;
        }
        var lastBackwardUnchanged;
        for(var lcv=0; lcv < fuse; lcv++){
            var currentSize = this.getSize();
            var newWidth = currentSize.x - increment;
            this.setStyle('width', newWidth);
            if(currentSize.y == this.getSize().y){
                lastBackwardUnchanged = newWidth; //even height
                lcv = 0; //reset the loop if values are changing
            }else break;
        }
        if(lastBackwardUnchanged){
            if(callback){
                this.setStyle('width', lastBackwardUnchanged);
                if(typeOf(callback) == 'function') callback();
            }else{
                this.setStyle('width', originalSize.x);
            }
            return lastBackwardUnchanged;
        }
        return currentSize.x; //exception?
    }
});