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Hide the Navigation Bar in Android

Hide the Navigation Bar

To hide the navigation bar in Android 4.0 (API level 14) and later versions, you can use the SYSTEM_UI_FLAG_HIDE_NAVIGATION flag. This approach allows you to hide both the navigation bar and the status bar. However, you should also ensure that your app handles the status bar visibility appropriately, as detailed below.

Sample Code

View decorView = getWindow().getDecorView();
// Hide both the navigation bar and the status bar
int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
    | View.SYSTEM_UI_FLAG_FULLSCREEN;
decorView.setSystemUiVisibility(uiOptions);

Important Notes

Make Content Appear Behind the Navigation Bar

Starting from Android 4.1 (API level 16), you can set your app's content to appear behind the navigation bar. This ensures that the content does not resize when the navigation bar is hidden or shown. Use the SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION flag for this purpose, along with SYSTEM_UI_FLAG_LAYOUT_STABLE to maintain a stable layout.

Example

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
    View decorView = getWindow().getDecorView();
    int uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
        | View.SYSTEM_UI_FLAG_LAYOUT_STABLE;
    decorView.setSystemUiVisibility(uiOptions);
}

Key Considerations

• Layout Stability: Use SYSTEM_UI_FLAG_LAYOUT_STABLE to ensure your app's layout remains consistent even when system bars are hidden or shown.
• Content Visibility: Ensure that critical UI elements are positioned correctly so that they do not get covered by the system bars.

Development Environment

• IDE: Android Studio 4.1.1
• Virtual Devices: Pixel 2 API 28
• Minimum SDK: API 16 (Android 4.1)

Project Setup

• Effect: The app demonstrates hiding the navigation bar and showing content behind it.
• Project Creation: Start with an Empty Activity, setting the Minimum SDK to API 16.
• Layout File: Modify src/main/res/layout/activity_main.xml to include a Toolbar and a Button.

Layout Configuration

Activity Code

package com.mk;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
                    View decorView = getWindow().getDecorView();
                    int uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                            | View.SYSTEM_UI_FLAG_LAYOUT_STABLE;
                    decorView.setSystemUiVisibility(uiOptions);
                }
            }
        });
    }
    @Override
    protected void onResume() {
        super.onResume();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
            View decorView = getWindow().getDecorView();
            int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_FULLSCREEN;
            decorView.setSystemUiVisibility(uiOptions);
        }
    }
}

Summary

This guide provides a comprehensive overview of hiding the navigation bar in Android applications. By using the appropriate system UI flags and understanding the nuances of UI visibility, you can create a more immersive user experience while ensuring your app behaves correctly when interacting with system bars.