StatusBar - Change color with scrolling in a CollapsingToolbar

Currently I have an image on a profile screen and StatusBar is "transparent". Running right!

Problem:

The problem is with the scrolling of the screen, because in this case I have already been able to make the Color of the StatusBar in PrimaryDark color - when scrolling (up).

Code: I'm using this template

AppBarLayout appBarLayout = (AppBarLayout) findViewById(R.id.app_bar_layout_edit_profile);
        appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
            boolean isShow = false;
            int scrollRange = -1;

            @Override
            public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
                if (scrollRange == -1) {
                    scrollRange = appBarLayout.getTotalScrollRange();
                }
                if (scrollRange + verticalOffset == 0) {       
                      Window window = activity.getWindow();
                      window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);

                      window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
                      window.setStatusBarColor(activity.getResources().getColor(R.color.primary_color));


                    isShow = true;
                } else if (isShow) {
                    collapsingToolbarLayout.setTitle(" ");
                    isShow = false;
                    Window w = activity.this.getWindow(); 
                    w.setFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATU‌​S, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
                }
            }
        });

What does not work: When scrolling the screen (down) I have a Toolbar that is fixed. When it finishes loading the data of RecyclerView , then yes it returns to the original state. (with transparency)

But it has a certain transparency, in that roll back. (prints below)

I need to somehow identify when return rollout occurs and set the colorPrimaryDark.

Ex:

• Expanded:

• Collapsed: