In this tutorial, we will learn about Creating a Flashlight app using the kotlin language. This application is designed to turn flashlight on or off of the device with a simple click. Please note that this application is only available for mobile devices. I don’t know what it looks like on a tablet. equipment.

Content:

1. Preview
2. File: AndroidMenifest.xml
3. File: MainActivity.kt
4. File: activity_main.xml

Preview: Simple Flashlight app in Android

File: AndroidManifest.xml

^{Learn Java Programming & get Certificate}

In the manifest file, add permissions.
To use the Camera and FlashLight, you must add Permissions to the Android Manifest.xml file. To do so, open your AndroidManifest.xml file and paste the code given below to your AndroidManifest.xml file.

 <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" />

–>The code given below is the AndroidManifest.xml file code.

 <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.flashlightapp">
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" />


    <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/Theme.FlashlightApp">
        <activity android:name=".MainActivity"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

File: MainActivity.kt

–> In MainActivity.kt file, we will implement the backend of the flashlight application in the kotlin language, implement functions to get access to the camera service.

package com.example.flashlightapp

import android.content.Context

import android.hardware.camera2.CameraManager
import android.os.Build
import android.os.Bundle
import android.view.View
import android.widget.ImageButton
import androidx.annotation.RequiresApi
import androidx.appcompat.app.AppCompatActivity


@Suppress("DEPRECATION")
class MainActivity : AppCompatActivity() {
    private lateinit var cameraM: CameraManager
    private lateinit var powerBtn: ImageButton

    var isFlash = false

    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        powerBtn = findViewById(R.id.on)

        cameraM = getSystemService(Context.CAMERA_SERVICE) as CameraManager
        powerBtn.setOnClickListener {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                flashLightOnRoOff(it)
            }
        }
    }

    @RequiresApi(Build.VERSION_CODES.M)
    private fun flashLightOnRoOff(v: View?) {
        /**set flash code*/
        if (!isFlash) {
            val cameraListId = cameraM.cameraIdList[0]
            cameraM.setTorchMode(cameraListId, true)
            isFlash = true
            powerBtn.setImageResource(R.drawable.on)


        } else {
            val cameraListId = cameraM.cameraIdList[0]
            cameraM.setTorchMode(cameraListId, false)

            isFlash = false
            powerBtn.setImageResource(R.drawable.off)

        }


    }
}

File: activity_main.xml

–> activity_main.xml file contains two textview and an Imagebutton which has on or off functionality.

<?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"
    android:background="@drawable/bg"
    tools:context=".MainActivity">


    <TextView
        android:id="@+id/flashlight"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="199dp"
        android:layout_marginBottom="62dp"
        android:fontFamily="sans-serif-smallcaps"
        android:text="@string/flashlight"
        android:textColor="@color/teal_200"
        android:textSize="30sp"
        android:textStyle="bold"
        app:layout_constraintBottom_toTopOf="@+id/on"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.496"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0" />

    <ImageButton
        android:id="@+id/on"
        android:layout_width="130dp"
        android:layout_height="130dp"
        android:background="@null"
        android:scaleType="centerCrop"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.648"
        app:srcCompat="@drawable/on" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="14dp"
        android:text=" DEVELOPED BY - STAR COMMUNITY"
        android:textColor="#a4a4a4"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

• We hope that this guide will assist you in quickly creating a flashlight Application for Android. If you have any problems, please post them in the comments section and we will gladly assist you.

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