Incorrect bounds in flash / actionscript

Question

I have a simple UIComponent that overrides measure and updateDisplayList to draw a vertical line. I've calculated the beginning and end of the line by taking into account the stroke width. The code is below. I am expecting the bounds to be printed as (x:0 y:0 w:1 h:300) but it prints (x:0 y:0 w:1 h:299) i.e. the height is 299 instead of 300. What am I missing?

override protected function measure():void
{
    super.measure();
    measuredWidth = measuredMinWidth = 300;
    measuredHeight = measuredMinHeight = 300;
}

override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void
{
    super.updateDisplayList(unscaledWidth, unscaledHeight);
    var stroke:SolidColorStroke = new SolidColorStroke(0xd8d8d8, 1, 1);

    var g:Graphics = graphics;
    g.clear();

    var bX:Number;
    var bY:Number;
    var tX:Number;
    var tY:Number;
    var bW:Number;
    var bH:Number;

    bX = stroke.weight * 0.5;
    bY = stroke.weight * 0.5;
    tX = stroke.weight * 0.5;
    tY = unscaledHeight - 1 - stroke.weight * 0.5;
    bW = unscaledWidth - stroke.weight;
    bH = unscaledHeight - stroke.weight;
    trace ("From (", bX, ",", bY, ") To (", tX, ",", tY, ")");

    stroke.apply(g, null, null);
    g.moveTo(bX, bY);
    g.lineTo(tX, tY);
    trace ("Bounds:", getBounds(this));
 }

Answer 1

Why do you use magical number → -1? You have all as a parameters already. Change calculation for tY:

tY = unscaledHeight - stroke.weight * 0.5;