android - getWidth() and getHeight() always returning 0. Custom view

Question

In a Fragment, I am inflating a Layout with multiple child View. I need to get the dimensions (width and height) of one of them which is a custom view.

Inside the custom view class I can do it easily. But if I try to do it from the fragment I always get 0 as dimensions.

 public void onViewCreated(View view, Bundle savedInstanceState) {

    super.onViewCreated(view, savedInstanceState);
    View culoide = view.findViewWithTag(DRAW_AREA_TAG);
    Log.d("event", "culoide is: "+culoide.getWidth()); // always 0
}

I figure that onViewCreated should be the right place to get it, but well this happens. I tried before super.onViewCreated, in debug it looks like 'findViewWithTag' finds the right view, tried with api 7 v4 support only.

Any help?

Answer 1

You must wait until after the first measure and layout in order to get nonzero values for getWidth() and getHeight(). You can do this with a ViewTreeObserver.OnGlobalLayouListener

public void onViewCreated(final View view, Bundle saved) {
    super.onViewCreated(view, saved);
    view.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
        public void onGlobalLayout() {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
              view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
            } else {
              view.getViewTreeObserver().removeGlobalOnLayoutListener(this);
            }

            // get width and height of the view
        }
    });
}