How Create a Accessibility Service in Android

Hello friends, In this Tutorial. In this post, I will show you how to use Accessibility Service for Android. Before that, we need to know What is Accessibility Service.

Accessibility Service

Here, I am taking an example for creating Virtual Service Button instead of Default Back Button.

Project Structure:

Create a new Project in Android Studio with the required Specifications.

Codes:

AndroidManifest.xml
Don't forget to add the following permission in your manifest file.

<uses-permission android:name="android.permission.BIND_ACCESSIBILITY_SERVICE"/>
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>

Don't forget to add the following Lines in your manifest file to create service for your application.

<service
    android:name=".MyService"
    android:label="@string/app_name"
    android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
       <intent-filter>
          <action android:name="android.accessibilityservice.AccessibilityService" />
       </intent-filter>
 </service>

MainActivity.java
Open MainActivity.java and replace it with the following code

package example.backbutton;

import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.Settings;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Permission for Manifest.permission.SYSTEM_ALERT_WINDOW in Android M
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (!Settings.canDrawOverlays(getApplicationContext())) {
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
                        Uri.parse("package:" + getPackageName()));
                startActivityForResult(intent, 1);
            }
        }

  // Code to start the Service
        startService(new Intent(getApplication(), MyService.class));
    }
}

MyService.java
Open MyService.java and replace it with the following code

package example.backbutton;

import android.accessibilityservice.AccessibilityService;
import android.annotation.SuppressLint;
import android.graphics.PixelFormat;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.WindowManager;
import android.view.accessibility.AccessibilityEvent;
import android.widget.ImageView;

public class MyService extends AccessibilityService {

    WindowManager windowManager;
    ImageView back,home,notification,minimize;
    WindowManager.LayoutParams params;
    AccessibilityService service;

    @SuppressLint("RtlHardcoded")
    @Override
    public void onCreate() {
        super.onCreate();

        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);

        back = new ImageView(this);
        home = new ImageView(this);
        minimize = new ImageView(this);
        notification = new ImageView(this);

        back.setImageResource(R.mipmap.ic_back);
        home.setImageResource(R.mipmap.ic_home);
        minimize.setImageResource(R.mipmap.ic_min);
        notification.setImageResource(R.mipmap.ic_notification);

  params= new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);

        params.gravity = Gravity.CENTER_VERTICAL|Gravity.RIGHT;
        params.x = 10;
        params.y = 50;

        windowManager.addView(home, params);

        params= new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);

        params.gravity = Gravity.CENTER_VERTICAL|Gravity.RIGHT;
        params.x = 10;
        params.y = 100;

        windowManager.addView(minimize, params);

        params= new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);

        params.gravity = Gravity.CENTER_VERTICAL|Gravity.RIGHT;
        params.x = 10;
        params.y = 150;

        windowManager.addView(notification, params);

        back.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    performGlobalAction(AccessibilityService.GLOBAL_ACTION_BACK);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

        home.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    performGlobalAction(AccessibilityService.GLOBAL_ACTION_HOME);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

        notification.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    performGlobalAction(AccessibilityService.GLOBAL_ACTION_NOTIFICATIONS);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

        minimize.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    performGlobalAction(AccessibilityService.GLOBAL_ACTION_RECENTS);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

    }

    @Override
    public void onAccessibilityEvent(AccessibilityEvent event) {

    }

    @Override
    public void onInterrupt() {

    }

    @Override
    protected void onServiceConnected() {
        super.onServiceConnected();
        Log.d("TAG", "onServiceConnected");
    }

}

Important Note

Finally go to Settings --> Accessibility --> Your Application --> Turn ON