learnfastaa.com

Flashlight

Flashlight:

Using the context of the different environments in mobile devices a flashlight is understood as the LED bulb on the rear side of the device which can be used to provide light. This feature is present on most of the developing mobile operating systems for smartphones and more recently for tablets with a rear camera.

The flashlight can be switched to bright mode, where light emitted by the orb will be focused giving it the appearance of a traditional flashlight.

Example:

                                    
// AndroidManifest.xml:
<uses-feature android:name="android.hardware.camera.flash" />

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:layout_gravity="center"
    android:gravity="center"
    android:padding="16dp">

    <TextView
        android:id="@+id/textFlashlight"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Flashlight OFF"
        android:textStyle="bold"
        android:textSize="28sp"
        android:textColor="#000000"
        android:padding="16dp"
        android:layout_marginBottom="20dp"
    />

    <ToggleButton
        android:layout_below="@id/textFlashlight"
        android:id="@+id/flashlightButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Flashlight"
        android:textSize="16sp"
        android:textColor="#FFFFFF"
        android:padding="16dp"
        android:background="@color/colorPrimaryDark"
    />

</RelativeLayout>

                                    
                                        import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraManager;
import android.os.Build;
import android.os.Bundle;
import android.widget.CompoundButton;
import android.widget.TextView;
import android.widget.ToggleButton;

import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private TextView textFlashlight;
    private ToggleButton toggleButton;
    private CameraManager mCameraManager;
    private String mCameraId;

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

        toggleButton = findViewById(R.id.flashlightButton);
        textFlashlight = findViewById(R.id.textFlashlight);

        textFlashlight.setText("FLASHLIGHT OFF");

        boolean isFlashAvailable = getApplicationContext().getPackageManager()
                .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);

        if (!isFlashAvailable) {
            flashNotFoundError();
        }

        mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
            mCameraId = mCameraManager.getCameraIdList()[0];
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }

        toggleButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @RequiresApi(api = Build.VERSION_CODES.M)
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                switchFlashLight(isChecked);
            }
        });
    }

    @RequiresApi(api = Build.VERSION_CODES.M)
    public void switchFlashLight(boolean status) {

        try {
            if (status) {
                textFlashlight.setText("FLASHLIGHT ON");
            } else {
                textFlashlight.setText("FLASHLIGHT OFF");
            }

            mCameraManager.setTorchMode(mCameraId, status);

        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    public void flashNotFoundError() {
        AlertDialog alert = new AlertDialog.Builder(this)
                .create();
        alert.setTitle("Oops!");
        alert.setMessage("Flash is not available in this device.");
        alert.setButton(DialogInterface.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                finish();
            }
        });
        alert.show();
    }
}

                                      
                                        import android.content.Context
import android.content.DialogInterface
import android.content.pm.PackageManager
import android.hardware.camera2.CameraAccessException
import android.hardware.camera2.CameraManager
import android.os.Build
import android.os.Bundle
import android.widget.CompoundButton
import android.widget.TextView
import android.widget.ToggleButton
import androidx.annotation.RequiresApi
import androidx.appcompat.app.AlertDialog
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    private lateinit var textFlashlight: TextView
    private lateinit var toggleButton: ToggleButton
    private lateinit var mCameraManager: CameraManager
    private var mCameraId: String? = null

    @RequiresApi(Build.VERSION_CODES.M)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        toggleButton = findViewById(R.id.flashlightButton)
        textFlashlight = findViewById(R.id.textFlashlight)

        textFlashlight.text = "FLASHLIGHT OFF"

        val isFlashAvailable =
            applicationContext.packageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)

        if (!isFlashAvailable) {
            flashNotFoundError()
        }

        mCameraManager = getSystemService(Context.CAMERA_SERVICE) as CameraManager
        try {
            mCameraId = mCameraManager.cameraIdList[0]
        } catch (e: CameraAccessException) {
            e.printStackTrace()
        }

        toggleButton.setOnCheckedChangeListener { buttonView, isChecked ->
            switchFlashLight(isChecked)
        }
    }

    @RequiresApi(Build.VERSION_CODES.M)
    private fun switchFlashLight(status: Boolean) {
        try {
            if (status) {
                textFlashlight.text = "FLASHLIGHT ON"
            } else {
                textFlashlight.text = "FLASHLIGHT OFF"
            }

            mCameraManager.setTorchMode(mCameraId!!, status)

        } catch (e: CameraAccessException) {
            e.printStackTrace()
        }
    }

    private fun flashNotFoundError() {
        val alert: AlertDialog = AlertDialog.Builder(this).create()
        alert.setTitle("Oops!")
        alert.setMessage("Flash is not available in this device.")
        alert.setButton(DialogInterface.BUTTON_POSITIVE, "OK") { dialog, which -> finish() }
        alert.show()
    }
}