Status Bar Scroll Surface - Material You

StatusBarScrollSurface.java

/**
 * @author Giorgio Cantoni - giorgio.canto98@gmail.com
 */

public class StatusBarScrollSurface {

    /**
     * Make the color of the status bar the same as the surface color of the toolbar when scrolling
     * @param context The current context
     * @param appBarLayout The current appBarLayout
     * @param toolbar The current toolbar
     * @param window The current window
     */
    public static void enableStatusBarScrollSurface(Context context, AppBarLayout appBarLayout, androidx.appcompat.widget.Toolbar toolbar, Window window) {

        final int[] scrollRange = {-1};

        appBarLayout.addOnOffsetChangedListener((appBarLayout1, verticalOffset) -> {

            // initialize the size of the scroll
            if (scrollRange[0] == -1) {
                scrollRange[0] = appBarLayout.getTotalScrollRange();
            }

            // check if the view is collapsed
            if (scrollRange[0] + verticalOffset == 0) {

                toolbar.setBackgroundColor(ContextCompat.getColor(context, R.color.colorPrimarySurface));
                window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
                window.setStatusBarColor(ContextCompat.getColor(context, R.color.colorPrimarySurface));

            } else {

                toolbar.setBackgroundColor(ContextCompat.getColor(context, android.R.color.transparent));
                window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
                window.setStatusBarColor(ContextCompat.getColor(context, android.R.color.transparent));

            }
        });
    }
}