EasyPermission Library

In this tutorial,we will learn, how to use the EasyPermissions library to request a dangerous permission at run time, which is necessary since Android Marshmallow (API level 23). This library provides an easy way to request multiple permissions at once, handle the results (granted or denied), show a rationale when the user previously denied a permission with an explanation of why this permission is needed and it even provides an easy way to create an AlertDialog that sends the user directly to the settings of the phone to manually grant a permission if he previously checked the “don’t ask again” box.

In MainActivity.java class file add these lies of codes:-

package com.deftskill.easypermissionexample;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.util.List;

import pub.devrel.easypermissions.AfterPermissionGranted;
import pub.devrel.easypermissions.AppSettingsDialog;
import pub.devrel.easypermissions.EasyPermissions;

public class MainActivity extends AppCompatActivity implements EasyPermissions.PermissionCallbacks {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button buttonOpenCamera = findViewById(R.id.button_open_camera);
        buttonOpenCamera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openCamera();
            }
        });
    }
    @AfterPermissionGranted(123)
    private void openCamera() {
        String[] perms = {Manifest.permission.CAMERA, Manifest.permission.READ_EXTERNAL_STORAGE};
        if (EasyPermissions.hasPermissions(this, perms)) {
            Toast.makeText(this, "Opening camera", Toast.LENGTH_SHORT).show();
        } else {
            EasyPermissions.requestPermissions(this, "We need permissions because this and that",
                    123, perms);
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
    }
    @Override
    public void onPermissionsGranted(int requestCode, @NonNull List<String> perms) {
    }
    @Override
    public void onPermissionsDenied(int requestCode, @NonNull List<String> perms) {
        if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) {
            new AppSettingsDialog.Builder(this).build().show();
        }
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == AppSettingsDialog.DEFAULT_SETTINGS_REQ_CODE) {
        }
    }
}

In activity_main.xml add these lines of codes:-

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

    <Button
        android:id="@+id/button_open_camera"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Open camera"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

In AndroidManifest.xml add these lines of codes:-
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.deftskill.easypermissionexample">
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <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>
    </application>

</manifest>

After adding these lines of codes run this application.