Android screen overlay example. Draws a button over other apps.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Overlay example"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.design.widget.CoordinatorLayout>

MainActivity.java

package io.sjf.overlay;

import android.annotation.TargetApi;
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;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "Overlay";

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

    private static int REQUEST_CODE = 1;
    private boolean checkDrawOverlayPermission() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            /** check if we already  have permission to draw over other apps */
            if (!Settings.canDrawOverlays(this)) {
                Log.d(TAG, "canDrawOverlays NOK");
                /** if not construct intent to request permission */
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
                        Uri.parse("package:" + getPackageName()));
                /** request permission via start activity for result */
                startActivityForResult(intent, REQUEST_CODE);
                return false;
            } else {
                Log.d(TAG, "canDrawOverlays OK");
            }
        }
        return true;
    }

    @Override
    @TargetApi(Build.VERSION_CODES.M)
    protected void onActivityResult(int requestCode, int resultCode,  Intent data) {
        /** check if received result code
          is equal our requested code for draw permission  */
        if (requestCode == REQUEST_CODE) {
            if (Settings.canDrawOverlays(this)) {
                startOverlayService();
            }
        }
    }

    private void startOverlayService() {
        Intent intent = new Intent(this, OverlayService.class);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            startForegroundService(intent);
        } else {
            startService(intent);
        }
    }
}

manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="io.sjf.overlay">
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service
            android:name=".OverlayService"
            android:exported="false"/>
    </application>
</manifest>

OverlayService.java

package io.sjf.overlay;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.PixelFormat;
import android.os.Build;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.support.v4.app.NotificationCompat;
import android.util.Log;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.view.WindowManager;
import android.widget.Button;

public class OverlayService extends Service implements OnTouchListener, OnClickListener {
    private static String TAG = "OverlayService";
    private WindowManager wm;
    private Button button;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        super.onCreate();
        if (Build.VERSION.SDK_INT >= 26) {
            String CHANNEL_ID = "channel1";
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID,
                    "Overlay notification",
                    NotificationManager.IMPORTANCE_LOW);

            ((NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE))
                    .createNotificationChannel(channel);

            Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                    .setContentTitle("adsf")
                    .setContentText("asdf1")
                    .setSmallIcon(R.drawable.ic_launcher_foreground)
                    .build();

            startForeground(1, notification);
        }

        wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);

        button = new Button(this);
        button.setBackgroundResource(R.drawable.ic_button1);
        button.setText("Button");
        button.setAlpha(1);
        button.setBackgroundColor(Color.BLUE);
        button.setOnClickListener(this);

        int type = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O
                ? WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY
                : WindowManager.LayoutParams.TYPE_PHONE;

        WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                type,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL,
                PixelFormat.TRANSLUCENT);
        params.gravity = Gravity.START | Gravity.TOP;
        params.x = 0;
        params.y = 0;
        wm.addView(button, params);

        return START_NOT_STICKY;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        Log.d(TAG, " ++++ On touch");
        return false;
    }

    @Override
    public void onClick(View v) {
        Log.d(TAG, " ++++ On click");
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (button != null) {
            wm.removeView(button);
            button = null;
        }
    }
    
    @Override
    @Nullable
    public IBinder onBind(Intent intent) {
        return null;
    }

}

When you start the app, if it doesn't have permission to draw over other apps, it will prompt you to enable it. It should look like this when it is running.

This is awesome. Thank you!!!!

Can it move able?

@prokash447 you can control the positioning with the params.x/y passed to wm.addView here (Line 70)

when i open the setting app(system setting) the overlay does not work. why? have any solution?

Hello,

I see a blank activity that blocks touch events to home screen/ apps underneath. Are we missing any other configurations?