/**
 * Clip given window to round.
 *
 * This method should be called before window is show.
 *
 * @param window window needs to be clipped.
 * @return If clip succeed.
 */
public static boolean clipToScreenShape(final Window window) {
    if (window == null || window.getDecorView() == null) {
        return false;
    }

    // Record original drawable & set window to transparent to avoid window has solid color.
    final Drawable original = window.getDecorView().getBackground();
    window.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));

    window.getDecorView().setOnApplyWindowInsetsListener(new OnApplyWindowInsetsListener() {
        @Override
        public WindowInsets onApplyWindowInsets(View v, WindowInsets insets) {
            // Delay setting window background when shape is defined.
            Drawable background = getBackgroundDrawable(original, insets.isRound());
            window.setBackgroundDrawable(background);
            if (insets.isRound()) {
                clipToRound(v);
            }
            return insets;
        }
    });
    window.getDecorView().requestApplyInsets();

    return true;
}
 

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final Resources res = getResources();
    final GridViewPager pager = (GridViewPager) findViewById(R.id.pager);
    pager.setOnApplyWindowInsetsListener(new OnApplyWindowInsetsListener() {
        @Override
        public WindowInsets onApplyWindowInsets(View v, WindowInsets insets) {
            // Adjust page margins:
            //   A little extra horizontal spacing between pages looks a bit
            //   less crowded on a round display.
            final boolean round = insets.isRound();
            int rowMargin = res.getDimensionPixelOffset(R.dimen.page_row_margin);
            int colMargin = res.getDimensionPixelOffset(round ?
                    R.dimen.page_column_margin_round : R.dimen.page_column_margin);
            pager.setPageMargins(rowMargin, colMargin);
            return insets;
        }
    });
    pager.setAdapter(new SampleGridPagerAdapter(this, getFragmentManager()));
}
 

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final Resources res = getResources();
    final GridViewPager pager = (GridViewPager) findViewById(R.id.pager);
    pager.setOnApplyWindowInsetsListener(new OnApplyWindowInsetsListener() {
        @Override
        public WindowInsets onApplyWindowInsets(View v, WindowInsets insets) {
            // Adjust page margins:
            //   A little extra horizontal spacing between pages looks a bit
            //   less crowded on a round display.
            final boolean round = insets.isRound();
            int rowMargin = res.getDimensionPixelOffset(R.dimen.page_row_margin);
            int colMargin = res.getDimensionPixelOffset(round ?
                    R.dimen.page_column_margin_round : R.dimen.page_column_margin);
            pager.setPageMargins(rowMargin, colMargin);

            // GridViewPager relies on insets to properly handle
            // layout for round displays. They must be explicitly
            // applied since this listener has taken them over.
            pager.onApplyWindowInsets(insets);
            return insets;
        }
    });
    pager.setAdapter(new SampleGridPagerAdapter(this, getFragmentManager()));
    DotsPageIndicator dotsPageIndicator = (DotsPageIndicator) findViewById(R.id.page_indicator);
    dotsPageIndicator.setPager(pager);
}