Set status bar color from DialogFragment

Question

I'm creating an app which changes status bar color dynamically.

My method in main Activity class works fine when called from any fragment. Fragments are placed in Activity pager:

public void setStatusBarColorIfPossible(int color) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        getWindow().setStatusBarColor(color);
    }
}

However, in DialogFragment which is created in any fragment and made fullscreen, calling my method has no effect. Status bar is instantly black (as set in styles.xml) and I can't change it.

public class AddOrEditWeekPlanDialog extends DialogFragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setStyle(DialogFragment.STYLE_NORMAL, R.style.MyDialog);
    }

    @Override
    public void onStart() {
        super.onStart();
        Dialog d = getDialog();
        if (d!=null){
            int width = ViewGroup.LayoutParams.MATCH_PARENT;
            int height = ViewGroup.LayoutParams.MATCH_PARENT;
            d.getWindow().setLayout(width, height);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View root = inflater.inflate(R.layout.fragment_dialog, container, false);
        Button button = (Button)root.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ((ThermostatActivity) getActivity()).setStatusBarColorIfPossible(0xFF0D47A1);
            }
        });

        return root;
    }

    @Override
    public void onResume() {
        super.onResume();

    }
}

styles.xml:

// Set in manifest for main activity
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
</style>

// Set in dialog class
<style name="MyDialog" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="android:windowIsFloating">false</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
</style>

resources.xml:

<resources>
    <color name="colorPrimary">#FFB72020</color>
    <color name="colorPrimaryDark">#000</color>
    <color name="textColor">#fff</color>
    <color name="tabsScrollColor">#fff</color>
</resources>

Anyone can explain me why?

Answer 1

In order to setStatusBarColor you need to set the flag: FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS

"Flag indicating that this Window is responsible for drawing the background for the system bars." (Google API level 21)

Try this code:

public void setStatusBarColorIfPossible(int color) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
       getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
       getWindow().setStatusBarColor(color);
    }
}