How to Have a Transparent Status Bar but Leave Navigation Bar Opaque?

To independently control the transluscency of the status and navigation bars on KitKat, you can simply use the window manager flags FLAG_TRANSLUSCENT_STATUS and FLAG_TRANSLUSCENT_NAVIGATION in the onCreate() method of your activity. However, on KitKat the system may draw a semi-opaque gradient scrim drawable over the status bar. This appears to be device-specific: on my KitKat device it's fully transparent, but on Android Studio emulator it shows a scrim.

On Lolliop or later you can instead set the status bar colour using the Window#setStatusBarColor(int) method together with the FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS window manager flag. Note that you clear the FLAG_TRANSLUSCENT_STATUS flag in this case. If you want the colour to be transparent, that implies that your application supports full screen mode and sets the system UI visibility, so it's down to your app to manage the status bar background colour.

Putting it all together would look something like this:

@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    Window window = getWindow();    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {        window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);        window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);        window.setStatusBarColor(0x00000000);  // transparent    } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {        int flags = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;        window.addFlags(flags);    }    setContentView(R.layout.main);    window.getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);    setSupportActionBar(toolbar);}

Example of layout used:

<?xml version="1.0" encoding="utf-8"?><RelativeLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#ff00ff00"    android:fitsSystemWindows="false"    tools:context=".MainActivity">    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_centerInParent="true"        android:text="Hello World!"/>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:fitsSystemWindows="true"        android:orientation="vertical">        <android.support.v7.widget.Toolbar            android:id="@+id/toolbar"            android:layout_width="match_parent"            android:layout_height="?attr/actionBarSize"            android:background="?attr/colorPrimary"            app:popupTheme="@style/AppTheme.PopupOverlay"/>    </LinearLayout></RelativeLayout>

Example screenshots.

Lollipop:

KitKat:

Starting from API level 30, most of window flags are deprecated,

Using WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS Will make the activity overlaps with the navigation bar, also makes it transparent.

So, instead to make this work on API level 30, you can use setDecorFitsSystemWindows():

if (Build.VERSION.SDK_INT in 21..29) {     window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS)    window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS)    window.decorView.systemUiVisibility =        SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or SYSTEM_UI_FLAG_LAYOUT_STABLE    window.statusBarColor = Color.TRANSPARENT}if (Build.VERSION.SDK_INT >= 30) {    // Setting status bar color as not working with XML attribute    window.statusBarColor = Color.TRANSPARENT    // Making status bar overlaps with the activity    WindowCompat.setDecorFitsSystemWindows(window, false)}

And keep the below in the styles.xml:

<item name="android:windowTranslucentStatus" tools:targetApi="kitkat">true</item>

I figured it out :D

private void setTransparentStatusBarOnly(Activity activity) {    activity.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);    activity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);    activity.getWindow().setStatusBarColor(Color.TRANSPARENT);    // this lines ensure only the status-bar to become transparent without affecting the nav-bar    getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);}