# Manage Camera Permissions ## In this learning path - [Introduction](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/) - [Set up the Development Environment](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/2-app-scaffolding/) - [Manage Camera Permissions](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/3-camera-permission/) - [Integrate MediaPipe solutions](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/4-introduce-mediapipe/) - [Manage UI state with ViewModel](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/5-view-model-setup/) - [Use SharedFlow to View Events](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/6-flow-data-to-view-1/) - [Use StateFlow to View Controller States](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/7-flow-data-to-view-2/) - [Mediate flows to trigger photo capture](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/8-mediate-flows/) - [Avoid duplicate photo capture requests](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/9-avoid-redundant-requests/) - [Next Steps](https://learn.arm.com/learning-paths/mobile-graphics-and-gaming/build-android-selfie-app-using-mediapipe-multimodality/_next-steps/) ## Connect your device to your machine with a USB data cable If this is your first time running and debugging Android apps, follow the guidance on the Android Developer website. See [Set up a device for development](https://developer.android.com/studio/run/device#setting-up), and check that you have completed these steps: 1. You have followed the instructions [Enable USB debugging on your device](https://developer.android.com/studio/debug/dev-options#Enable-debugging). 2. You have confirmed that you have enabled USB debugging by tapping **OK** on your device when the **Allow USB debugging** dialog appears, and that you have checked **Always allow from this computer**. See Figure 6. ![Figure 6: Allow USB Debugging.](https://ftc-docs.firstinspires.org/en/latest/_images/AllowUSBDebugging.jpg) 3. Make sure that your device model name and SDK version correctly show up in the top-right toolbar. Click the **Run** button to build and run the app. 4. After a while, you should see a notification of a successful build in Android Studio and the new app will be displayed on your Android device. 5. However, you will also see that the app shows a black screen while printing error messages in your [Logcat](https://developer.android.com/tools/logcat), which looks like this: ``` 2024-11-20 11:15:00.398 18782-18818 Camera2CameraImpl com.example.holisticselfiedemo E Camera reopening attempted for 10000ms without success. 2024-11-20 11:30:13.560 667-707 BufferQueueProducer pid-667 E [SurfaceView - com.example.holisticselfiedemo/com.example.holisticselfiedemo.MainActivity#0](id:29b00000283,api:4,p:2657,c:667) queueBuffer: BufferQueue has been abandoned 2024-11-20 11:36:13.100 20487-20499 isticselfiedem com.example.holisticselfiedemo E Failed to read message from agent control socket! Retrying: Bad file descriptor 2024-11-20 11:43:03.408 2709-3807 PackageManager pid-2709 E Permission android.permission.CAMERA isn't requested by package com.example.holisticselfiedemo ``` This is the expected behavior from having not yet correctly configured the app’s permissions. See [Permissions](https://developer.android.com/guide/topics/permissions/overview) on the Android Developer website. Android OS restricts the app’s access to camera features due to privacy constraints. ## Request camera permission at runtime 1. Navigate to `manifest.xml` in your `app` sub-project’s `src/main` path. Declare the camera hardware, and set the permissions by inserting the following lines into the `` element, ensuring that it is declared outside and above the `` element: ```xml ``` 2. Navigate to `strings.xml` in your `app` sub-project’s `src/main/res/values` path. Insert the following lines of text resources, which you will use at a later stage: ```xml Camera permission is required to recognize face and hands To grant Camera permission to this app, please go to system settings ``` 3. Navigate to `MainActivity.kt` and add the following permission-related values to companion object: ```kotlin // Permissions private val PERMISSIONS_REQUIRED = arrayOf(Manifest.permission.CAMERA) private const val REQUEST_CODE_CAMERA_PERMISSION = 233 ``` 4. Add a new method named `hasPermissions()` to check on runtime whether the camera permission has been granted: ```kotlin private fun hasPermissions(context: Context) = PERMISSIONS_REQUIRED.all { ContextCompat.checkSelfPermission(context, it) == PackageManager.PERMISSION_GRANTED } ``` 5. Add a condition check in on the `onCreate()` wrapping `setupCamera()` method, to request camera permission on runtime: ```kotlin if (!hasPermissions(baseContext)) { requestPermissions( arrayOf(Manifest.permission.CAMERA), REQUEST_CODE_CAMERA_PERMISSION ) } else { setupCamera() } ``` 6. Override the `onRequestPermissionsResult` method to handle permission request results: ```kotlin override fun onRequestPermissionsResult( requestCode: Int, permissions: Array, grantResults: IntArray ) { when (requestCode) { REQUEST_CODE_CAMERA_PERMISSION -> { if (PackageManager.PERMISSION_GRANTED == grantResults.getOrNull(0)) { setupCamera() } else { val messageResId = if (shouldShowRequestPermissionRationale(Manifest.permission.CAMERA)) R.string.permission_request_camera_rationale else R.string.permission_request_camera_message Toast.makeText(baseContext, getString(messageResId), Toast.LENGTH_LONG).show() } } else -> super.onRequestPermissionsResult(requestCode, permissions, grantResults) } } ``` ## Verify camera permission 1. Rebuild and run the app. Now you should see a dialog pop up requesting camera permissions. 2. Depending on your Android OS version, tap **Allow** or **While using the app**. You should then see your own face in the camera preview. Good job! **Tip**: You might need to restart the app to ensure that the permission change takes effect. In the next section, you will learn how to integrate MediaPipe vision solutions.