TreeObserver example

sample.java

        mView.getViewTreeObserver().addOnGlobalLayoutListener(
                new ViewTreeObserver.OnGlobalLayoutListener() {
                    public void onGlobalLayout() {
                        
                        int width = mView.getWidth();
                        int height =  mView.getHeight();

                        if (mView.getViewTreeObserver().isAlive()) {
                            // remove this layout listener
                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                                mView.getViewTreeObserver()
                                        .removeOnGlobalLayoutListener(this);
                            } else {
                                mView.getViewTreeObserver()
                                        .removeGlobalOnLayoutListener(this);
                            }
                        }
                    }
                }
        );