♻️ Improve camera facing system

docs/dialogs/camera-picker.mdx

@@ -59,10 +59,12 @@ Video capture support is planned for a future release.
 ## Camera facing
 
 You can specify whether the front or rear facing camera is used, using the `cameraFacing` parameter:
+- `System` lets the camera app decide which camera to open (default)
 - `Front` opens the front facing camera (Selfie-Camera)
 - `Back` opens the rear facing camera
 
-By default, the rear facing camera is used.
+By default, the camera app decides which camera to use.
+On Android, FileKit only applies camera-facing intent extras when you explicitly request `Front` or `Back`.
 
 <CodeGroup>
 ```kotlin filekit-dialogs

filekit-dialogs-compose/src/mobileMain/kotlin/io/github/vinceglb/filekit/dialogs/compose/FileKitResultLauncher.mobile.kt

@@ -19,7 +19,7 @@ public class PhotoResultLauncher(
     @OptIn(ExperimentalUuidApi::class)
     public fun launch(
         type: FileKitCameraType = FileKitCameraType.Photo,
-        cameraFacing: FileKitCameraFacing = FileKitCameraFacing.Back,
+        cameraFacing: FileKitCameraFacing = FileKitCameraFacing.System,
         destinationFile: PlatformFile = FileKit.cacheDir / "${Uuid.random()}.jpg",
     ) {
         onLaunch(type, cameraFacing, destinationFile)

filekit-dialogs/src/androidMain/kotlin/io/github/vinceglb/filekit/dialogs/FileKit.android.kt

@@ -6,9 +6,7 @@ import android.content.Intent
 import android.content.Intent.ACTION_VIEW
 import android.content.Intent.FLAG_ACTIVITY_NEW_TASK
 import android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION
-import android.hardware.camera2.CameraCharacteristics
 import android.net.Uri
-import android.os.Build
 import android.webkit.MimeTypeMap
 import androidx.activity.ComponentActivity
 import androidx.activity.result.ActivityResultRegistry
@@ -112,7 +110,7 @@ public actual suspend fun FileKit.openDirectoryPicker(
  * Opens a camera picker dialog.
  *
  * @param type The type of media to capture (Image or Video).
- * @param cameraFacing The camera facing (Back or Front).
+ * @param cameraFacing The camera facing (System, Back or Front).
  * @param destinationFile The file where the captured media will be saved.
  * @param openCameraSettings Platform-specific settings for the camera.
  * @return The saved file as a [PlatformFile], or null if cancelled.
@@ -152,7 +150,7 @@ public actual suspend fun FileKit.openCameraPicker(
  * 2. With [setCameraFacing] for reusable contracts (e.g., with rememberLauncherForActivityResult)
  */
 public class TakePictureWithCameraFacing(
-    cameraFacing: FileKitCameraFacing = FileKitCameraFacing.Back,
+    cameraFacing: FileKitCameraFacing = FileKitCameraFacing.System,
 ) : ActivityResultContracts.TakePicture() {
     private var currentCameraFacing: FileKitCameraFacing = cameraFacing
 
@@ -165,28 +163,36 @@ public class TakePictureWithCameraFacing(
     }
 
     override fun createIntent(context: Context, input: Uri): Intent = super.createIntent(context, input).apply {
-        // Intent extras taken from the flutter codebase because they are known to work and battle-tested:
-        // https://github.com/flutter/packages/blob/27a2302a3d716e7ee3abbb08e57c5dfa729c9e2e/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerDelegate.java#L990
-        val cameraCharacteristic = when (currentCameraFacing) {
-            FileKitCameraFacing.Front -> CameraCharacteristics.LENS_FACING_FRONT
-            FileKitCameraFacing.Back -> CameraCharacteristics.LENS_FACING_BACK
+        if (currentCameraFacing == FileKitCameraFacing.System) {
+            return@apply
         }
-        putExtra("android.intent.extras.CAMERA_FACING", cameraCharacteristic)
+        applyCameraFacingExtras(currentCameraFacing)
+    }
 
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-            putExtra(
-                "android.intent.extras.USE_FRONT_CAMERA",
-                currentCameraFacing == FileKitCameraFacing.Front,
-            )
-        }
+    private fun Intent.applyCameraFacingExtras(cameraFacing: FileKitCameraFacing) {
+        val isFront = cameraFacing == FileKitCameraFacing.Front
 
-        // Required for Samsung according to https://stackoverflow.com/questions/64263476/android-camera-intent-open-front-camera-instead-of-back-camera
-        val facing = when (currentCameraFacing) {
-            FileKitCameraFacing.Front -> "front"
-            FileKitCameraFacing.Back -> "rear"
+        // Intent extras adapted from community implementations (expo-image-picker / Flutter).
+        // They are undocumented, so we apply them only when the caller explicitly requested a facing.
+        if (isFront) {
+            // https://github.com/expo/expo/blob/c54eb1e0cbc0f09af9e4308ff76ed9dca457d90e/packages/expo-image-picker/android/src/main/java/expo/modules/imagepicker/contracts/CameraContract.kt#L32
+            putExtra("android.intent.extras.LENS_FACING_FRONT", 1)
+            putExtra("android.intent.extras.CAMERA_FACING", 1)
+            putExtra("android.intent.extra.USE_FRONT_CAMERA", true)
+
+            // Required for Samsung according to https://stackoverflow.com/questions/64263476/android-camera-intent-open-front-camera-instead-of-back-camera
+            putExtra("camerafacing", "front")
+            putExtra("previous_mode", "front")
+        } else {
+            // https://github.com/expo/expo/blob/c54eb1e0cbc0f09af9e4308ff76ed9dca457d90e/packages/expo-image-picker/android/src/main/java/expo/modules/imagepicker/contracts/CameraContract.kt#L32
+            putExtra("android.intent.extras.LENS_FACING_BACK", 1)
+            putExtra("android.intent.extras.CAMERA_FACING", 0)
+            putExtra("android.intent.extra.USE_FRONT_CAMERA", false)
+
+            // Required for Samsung according to https://stackoverflow.com/questions/64263476/android-camera-intent-open-front-camera-instead-of-back-camera
+            putExtra("camerafacing", "rear")
+            putExtra("previous_mode", "rear")
         }
-        putExtra("camerafacing", facing)
-        putExtra("previous_mode", facing)
     }
 }
 

filekit-dialogs/src/iosMain/kotlin/io/github/vinceglb/filekit/dialogs/FileKit.ios.kt

@@ -208,7 +208,7 @@ public actual suspend fun FileKit.openFileSaver(
  * Opens a camera picker dialog.
  *
  * @param type The type of media to capture (Image or Video).
- * @param cameraFacing The camera facing (Back or Front).
+ * @param cameraFacing The camera facing (System, Back or Front).
  * @param destinationFile The file where the captured media will be saved.
  * @param openCameraSettings Platform-specific settings for the camera.
  * @return The saved file as a [PlatformFile], or null if cancelled.
@@ -248,9 +248,18 @@ public actual suspend fun FileKit.openCameraPicker(
             UIImagePickerControllerSourceType.UIImagePickerControllerSourceTypeCamera
         pickerController.delegate = cameraControllerDelegate
 
-        pickerController.cameraDevice = when (cameraFacing) {
-            FileKitCameraFacing.Front -> UIImagePickerControllerCameraDevice.UIImagePickerControllerCameraDeviceFront
-            FileKitCameraFacing.Back -> UIImagePickerControllerCameraDevice.UIImagePickerControllerCameraDeviceRear
+        when (cameraFacing) {
+            FileKitCameraFacing.Front -> {
+                pickerController.cameraDevice =
+                    UIImagePickerControllerCameraDevice.UIImagePickerControllerCameraDeviceFront
+            }
+
+            FileKitCameraFacing.Back -> {
+                pickerController.cameraDevice =
+                    UIImagePickerControllerCameraDevice.UIImagePickerControllerCameraDeviceRear
+            }
+
+            FileKitCameraFacing.System -> {}
         }
 
         UIApplication.sharedApplication.topMostViewController()?.presentViewController(

filekit-dialogs/src/mobileMain/kotlin/io/github/vinceglb/filekit/dialogs/FileKit.mobile.kt

@@ -8,14 +8,15 @@ import kotlin.uuid.ExperimentalUuidApi
 import kotlin.uuid.Uuid
 
 public enum class FileKitCameraFacing {
+    System,
     Front,
     Back,
 }
 
 @OptIn(ExperimentalUuidApi::class)
 public expect suspend fun FileKit.openCameraPicker(
     type: FileKitCameraType = FileKitCameraType.Photo,
-    cameraFacing: FileKitCameraFacing = FileKitCameraFacing.Back,
+    cameraFacing: FileKitCameraFacing = FileKitCameraFacing.System,
     destinationFile: PlatformFile = FileKit.cacheDir / "${Uuid.random()}.jpg",
     openCameraSettings: FileKitOpenCameraSettings = FileKitOpenCameraSettings.createDefault(),
 ): PlatformFile?

sample/shared/src/commonMain/kotlin/io/github/vinceglb/filekit/sample/shared/ui/screens/camerapicker/CameraPickerLauncher.kt

@@ -4,6 +4,7 @@ import androidx.compose.runtime.Composable
 import io.github.vinceglb.filekit.PlatformFile
 
 internal enum class CameraFacingOption {
+    System,
     Front,
     Back,
 }

sample/shared/src/commonMain/kotlin/io/github/vinceglb/filekit/sample/shared/ui/screens/camerapicker/CameraPickerScreen.kt

@@ -61,7 +61,7 @@ private fun CameraPickerScreen(
     onDisplayFileDetails: (file: PlatformFile) -> Unit,
 ) {
     var buttonState by remember { mutableStateOf(AppScreenHeaderButtonState.Enabled) }
-    var cameraFacing by remember { mutableStateOf(CameraFacingOption.Back) }
+    var cameraFacing by remember { mutableStateOf(CameraFacingOption.System) }
     var capturedFiles by remember { mutableStateOf(emptyList<PlatformFile>()) }
 
     val cameraLauncher = rememberCameraPickerLauncher { file ->
@@ -201,6 +201,11 @@ private fun CameraPickerSettingsCard(
 }
 
 private val facingOptions: List<AppDropdownItem.IconItem<CameraFacingOption>> = listOf(
+    AppDropdownItem.IconItem(
+        label = "System Default",
+        value = CameraFacingOption.System,
+        icon = LucideIcons.Camera,
+    ),
     AppDropdownItem.IconItem(
         label = "Rear Camera",
         value = CameraFacingOption.Back,

sample/shared/src/mobileMain/kotlin/io/github/vinceglb/filekit/sample/shared/ui/screens/camerapicker/CameraPickerLauncher.mobile.kt

@@ -19,6 +19,7 @@ internal actual fun rememberCameraPickerLauncher(
             override fun launch(cameraFacing: CameraFacingOption) {
                 launcher.launch(
                     cameraFacing = when (cameraFacing) {
+                        CameraFacingOption.System -> FileKitCameraFacing.System
                         CameraFacingOption.Front -> FileKitCameraFacing.Front
                         CameraFacingOption.Back -> FileKitCameraFacing.Back
                     },