How to draw RelativeLayout to canvas?

Question

I want to draw a RelativeLayout with all it's children to Canvas.

This is what I been trying to do:

    // from View constructor
    container = (RelativeLayout) LayoutInflater.from(context).inflate(R.layout.containerLayout, null);

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        container.layout(0,0, w, h);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawRGB(0, 0, 0);
        container.draw(canvas);
    }

I debug and saw that onSizeChanged is called with good values. Also this code works for ImageView, so how is RelativeLayout different?

My problem is that it doesn't draw on screen, I don't seen any of its children. How to solve this?

Answer 1

Adding RelativeLAyout.mesure() solves the problem.

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    container.measure(w, h);
    container.layout(0,0, w, h);
}