get xadvance() {

		const padding = this._uiElement._padding._value;
		const width = this._uiElement._width;
		if( width._relative ) {
			return width._value * this._uiElement._fontSize.getInheritedInput( this._uiElement );
		}

		return padding.w + padding.y + width.value ;
	}
Rely on the parent for size computation
@override
@returns {number}