Camera permission in android kotlin

Question

I am currently working on an Android app that involves camera object detection. However, I have encountered some issues that need to be addressed:

The app displays a black screen after granting camera permission, requiring one or two app restarts to open the camera successfully. I also made an alert dialog to prompt the user if camera permission is not granted. However, the alert dialog has some bugs:
If the user clicks "OK" in the alert dialog and denies camera permission, the app enters into a loop and repeatedly displays the alert dialog.
If the user denies camera permission initially, and then grants it by clicking "OK" in the alert dialog, the app closes unexpectedly.

onCreate function:

if (ContextCompat.checkSelfPermission(
               this,
               android.Manifest.permission.CAMERA
           ) != PackageManager.PERMISSION_GRANTED
       )
           requestPermissions(arrayOf(android.Manifest.permission.CAMERA), 101)
       else
           detectObject()

Permission functions:

    fun getPermission() {
        if (ContextCompat.checkSelfPermission(
                this,
                android.Manifest.permission.CAMERA
            ) != PackageManager.PERMISSION_GRANTED
        )
        {
            requestPermissions(arrayOf(android.Manifest.permission.CAMERA), 101)
        }
        else
        {
            detectObject()
        }
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<out String>,
        grantResults: IntArray)
        {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        if (requestCode == 101 && grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED)
        {
            detectObject()
        }
        else
        {
            val alert = PermissionDialog()
            alert.show(supportFragmentManager, null)
        }
    }

Alert dialog class:

   import android.app.AlertDialog
   import android.app.Dialog
   import android.media.MediaPlayer
   import android.os.Bundle
   import android.widget.Toast
   import androidx.fragment.app.DialogFragment
   import com.example.sightfulkotlin.MainActivity
   import com.example.sightfulkotlin.R
   
   class PermissionDialog : DialogFragment() {
   
       private lateinit var mediaPlayer: MediaPlayer
   
       override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
           val builder = AlertDialog.Builder(activity)
           builder
               .setTitle("Camera Permission")
               .setIcon(android.R.drawable.ic_menu_camera)
               .setMessage("Camera permission denied")
               .setPositiveButton("Ok") { _, _ -> (activity as MainActivity).getPermission()}
               .setNegativeButton("Cancel") { _, _ ->
                   Toast.makeText(context, "Sorry, we can't make the app work without the camera permission.", Toast.LENGTH_LONG).show()
               }
               .setCancelable(false)
           return builder.create()
       }

in your third point. how exactly you making user to grant on click on alert dialogue — Dilshad, Apr 14 '23 at 13:46
forcing user to Protection level: dangerous permissions like camera is not a good idea. — Dilshad, Apr 14 '23 at 13:51
You seem to be asking three separate questions. It's best if you create three separate posts that can get 3 specific answers to the specific problem. — dominicoder, Apr 14 '23 at 14:50
I think this is what you are looking for https://stackoverflow.com/a/50540517/21647161 — Hoàng Trương Văn, Apr 15 '23 at 02:28

Hoàng Trương Văn · Answer 1 · 2023-04-15T02:32:02.943

Below I have written a code for granting a runtime permissions for Camera, There is an Array of String in which you can give multiple requests granting as which is needed at runtime.

public class MainActivity extends AppCompatActivity {
    private static final int PERMISSION_REQUEST_CODE = 200;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (checkPermission()) {
        //main logic or main code

       // . write your main code to execute, It will execute if the permission is already given.

        } else {
            requestPermission();
        }
    }

    private boolean checkPermission() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                != PackageManager.PERMISSION_GRANTED) {
            // Permission is not granted
            return false;
        }
        return true;
    }

    private void requestPermission() {

        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.CAMERA},
                PERMISSION_REQUEST_CODE);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case PERMISSION_REQUEST_CODE:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    Toast.makeText(getApplicationContext(), "Permission Granted", Toast.LENGTH_SHORT).show();

                    // main logic
                } else {
                    Toast.makeText(getApplicationContext(), "Permission Denied", Toast.LENGTH_SHORT).show();
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                                != PackageManager.PERMISSION_GRANTED) {
                            showMessageOKCancel("You need to allow access permissions",
                                    new DialogInterface.OnClickListener() {
                                        @Override
                                        public void onClick(DialogInterface dialog, int which) {
                                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                                                requestPermission();
                                            }
                                        }
                                    });
                        }
                    }
                }
                break;
        }
    }

    private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
        new AlertDialog.Builder(MainActivity.this)
                .setMessage(message)
                .setPositiveButton("OK", okListener)
                .setNegativeButton("Cancel", null)
                .create()
                .show();
    }
}

Camera permission in android kotlin

1 Answers1