Wsrtjtyk

I want to detect if a particular gesture was made in some other screen (Not when the app's UI is open).

I have seen it in some phones, you make a 'C' kind of gesture and the camera will open. Is there something like this in Android Studio?

You can do that using Service that is running on background.

As you know, there is some applications which are using this skill such as Facebook messenger.

You can handle touch event in setOnTouchListener callback implementation of FloatingService.kt.

Please refer my source code.

[FloatingService.kt]

package com.antasis9.android.playground



import android.app.Service

import android.content.Context

import android.content.Intent

import android.graphics.PixelFormat

import android.os.IBinder

import android.util.Log

import android.view.LayoutInflater

import android.view.ViewGroup

import android.view.WindowManager

import android.widget.Button



class FloatingService : Service() {

        override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {

                Log.d("FloatingService", "FloatingService.onStartCommand()");



                val layout = LayoutInflater.from(this).inflate(R.layout.activity_floating, null)

                layout.setOnTouchListener { v, event ->



                        // HANDLE TOUCH EVENT HERE!



                        Log.d("FloatingService", "v: $v, event: $event")

                        false

                }



                val layoutParams = WindowManager.LayoutParams(

                                WindowManager.LayoutParams.MATCH_PARENT,

                                WindowManager.LayoutParams.MATCH_PARENT,

                                WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY,

                                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,

                                PixelFormat.TRANSLUCENT

                )



                (getSystemService(Context.WINDOW_SERVICE) as WindowManager).addView(layout, layoutParams)



                return super.onStartCommand(intent, flags, startId)

        }



        override fun onBind(intent: Intent): IBinder? {

                return null

        }

}

[activity_floating.xml]

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:background="@android:color/transparent">

</android.support.constraint.ConstraintLayout>

[MainActivity.java]

I used activity to start FloatingService but you can start this service with other ways.

package com.antasis9.android.playground;



import android.content.Intent;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;



public class MainActivity extends AppCompatActivity {



        @Override

        protected void onCreate(Bundle savedInstanceState) {

                super.onCreate(savedInstanceState);

                setContentView(R.layout.activity_main);



                findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {

                        @Override

                        public void onClick(View v) {

                                Intent intent = new Intent(getApplicationContext(), FloatingService.class);

                                startService(intent);

                        }

                });



                findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() {

                        @Override

                        public void onClick(View v) {

                                Intent intent = new Intent(getApplicationContext(), FloatingService.class);

                                stopService(intent);

                        }

                });

        }

}

[AndroidManifest.xml]

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

        package="com.antasis9.android.playground">



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



        <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">

                        <intent-filter>

                                <action android:name="android.intent.action.MAIN" />



                                <category android:name="android.intent.category.LAUNCHER" />

                        </intent-filter>

                </activity>



                <service

                        android:name=".FloatingService"

                        android:enabled="true"

                        android:exported="false"></service>

        </application>

</manifest>

[This is last step]

You should turn on 'display over other apps' option.

You can find this option 'Settings' -> 'Apps' -> Select {your app name}