Question

So i’m making a custom View that displays some graphs (plots), and in some ocasions i want to rotate the canvas 90 degrees.
All i can guess is that there’s a bug in my device (HTC Desire, with android 2.3), i haven’t test it yet in another device.

@Override
public void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    canvas.save();
    canvas.rotate((float) 90.0);
    canvas.drawPoint(10, 10, pointPaint); /* Sorry about missing that these
            * coordinates will fall out after being rotated... it's just an
            * example. put 10, -10 and it should work, but it doesn't */
    canvas.restore();
}

This won’t draw the point, but if we change that 90.0 for a 90.014 (i found that this was the minimum, 90.013 doesn’t work either) then the point will show up.

So… is it something i’m doing wrong, or it’s just Android’s bug? I googled a lot, but couldn’t find nothing….

-Victor –

edit: Additional info: Only points doesn’t work. Rects, lines and circles work perfect.
edit: screenshot of my app, you can see how the red line has dots on the 90.014 degree version, and the 90.0 doesn’t.:

(As you can see, the 90.014 it looks like a little bit flipped (you can see how the Y axis is ‘broken’)

Answer 1

Setting the Paint of the dots to use a ROUND stroke cap resolves the problem, even though it doesn’t yet explain the strange behavior you are experiencing. e.g.:

paint.setStrokeCap(Paint.Cap.ROUND)