CameraController API

Low-level camera operations. Available when camera state is Ready.

Accessing Controller

val cameraState by stateHolder.cameraState.collectAsStateWithLifecycle()

when (cameraState) {
    is CameraKState.Ready -> {
        val controller = (cameraState as CameraKState.Ready).controller
        // Use controller here
    }
}

Image Capture

takePictureToFile()

Recommended — Captures image directly to file.

suspend fun takePictureToFile(): ImageCaptureResult

Returns: - ImageCaptureResult.SuccessWithFile(filePath: String) - ImageCaptureResult.Error(exception: Exception)

Example:

scope.launch {
    when (val result = controller.takePictureToFile()) {
        is ImageCaptureResult.SuccessWithFile -> {
            println("Saved: ${result.filePath}")
        }
        is ImageCaptureResult.Error -> {
            println("Error: ${result.exception.message}")
        }
    }
}

Benefits: - 2-3 seconds faster than takePicture() - No ByteArray conversion - Lower memory usage

takePicture()

Deprecated — Returns image as ByteArray.

@Deprecated("Use takePictureToFile()")
suspend fun takePicture(): ImageCaptureResult

Returns: - ImageCaptureResult.Success(byteArray: ByteArray) - ImageCaptureResult.Error(exception: Exception)

Zoom Control

setZoom()

fun setZoom(zoomRatio: Float)

Sets zoom level between 1.0 and maxZoom.

Parameters: - zoomRatio — Zoom level (1.0 = no zoom)

Example:

controller.setZoom(2.5f)  // 2.5x zoom

getZoom()

fun getZoom(): Float

Returns current zoom level.

Example:

val currentZoom = controller.getZoom()  // e.g., 2.5

getMaxZoom()

fun getMaxZoom(): Float

Returns maximum supported zoom.

Example:

val maxZoom = controller.getMaxZoom()  // e.g., 10.0

Flash Control

setFlashMode()

fun setFlashMode(mode: FlashMode)

Sets flash mode.

Parameters: - FlashMode.ON — Always fire flash - FlashMode.OFF — Flash disabled - FlashMode.AUTO — Flash in low light

Example:

controller.setFlashMode(FlashMode.ON)

getFlashMode()

fun getFlashMode(): FlashMode?

Returns current flash mode or null if not available.

Example:

val flashMode = controller.getFlashMode()
when (flashMode) {
    FlashMode.ON -> println("Flash enabled")
    FlashMode.OFF -> println("Flash disabled")
    FlashMode.AUTO -> println("Flash automatic")
    null -> println("Flash not available")
}

toggleFlashMode()

fun toggleFlashMode()

Cycles through: OFF → ON → AUTO → OFF

Example:

IconButton(onClick = { controller.toggleFlashMode() }) {
    Icon(Icons.Default.FlashOn, "Toggle Flash")
}

Torch Control

setTorchMode()

fun setTorchMode(mode: TorchMode)

Sets torch (flashlight) mode.

Parameters: - TorchMode.ON — Torch enabled - TorchMode.OFF — Torch disabled

Example:

controller.setTorchMode(TorchMode.ON)

getTorchMode()

fun getTorchMode(): TorchMode?

Returns current torch mode or null if not available.

toggleTorchMode()

fun toggleTorchMode()

Toggles torch ON ↔ OFF.

Example:

IconButton(onClick = { controller.toggleTorchMode() }) {
    val isOn = controller.getTorchMode() == TorchMode.ON
    Icon(
        if (isOn) Icons.Default.FlashlightOn else Icons.Default.FlashlightOff,
        "Toggle Torch"
    )
}

Camera Lens

setCameraLens()

fun setCameraLens(lens: CameraLens)

Sets camera to front or back.

Parameters: - CameraLens.FRONT — Front camera - CameraLens.BACK — Back camera

Example:

controller.setCameraLens(CameraLens.FRONT)

getCameraLens()

fun getCameraLens(): CameraLens?

Returns current camera lens.

toggleCameraLens()

fun toggleCameraLens()

Switches between front and back.

Example:

IconButton(onClick = { controller.toggleCameraLens() }) {
    Icon(Icons.Default.Cameraswitch, "Switch Camera")
}

Configuration Getters

getImageFormat()

fun getImageFormat(): ImageFormat

Returns configured image format (JPEG or PNG).

getQualityPrioritization()

fun getQualityPrioritization(): QualityPrioritization

Returns quality prioritization setting.

getPreferredCameraDeviceType()

fun getPreferredCameraDeviceType(): CameraDeviceType

Returns iOS camera device type (ULTRA_WIDE, TELEPHOTO, etc.)

Session Management

startSession()

fun startSession()

Starts camera session. Called automatically.

stopSession()

fun stopSession()

Stops camera session.

Example:

DisposableEffect(Unit) {
    onDispose {
        controller.stopSession()
    }
}

Listeners

addImageCaptureListener()

fun addImageCaptureListener(listener: (ByteArray) -> Unit)

Adds listener for captured images. Used by plugins.

Example:

controller.addImageCaptureListener { imageData ->
    processImage(imageData)
}

removeImageCaptureListener()

fun removeImageCaptureListener(listener: (ByteArray) -> Unit)

Removes image capture listener.

Cleanup

cleanup()

fun cleanup()

Releases all resources. Called automatically on dispose.

Example:

DisposableEffect(Unit) {
    onDispose {
        controller.cleanup()
    }
}

Complete Example

@Composable
fun CompleteControllerExample() {
    val permissions = providePermissions()
    val scope = rememberCoroutineScope()
    val stateHolder = rememberCameraKState(permissions = permissions)
    val cameraState by stateHolder.cameraState.collectAsStateWithLifecycle()

    Box(modifier = Modifier.fillMaxSize()) {
        when (cameraState) {
            is CameraKState.Ready -> {
                val controller = (cameraState as CameraKState.Ready).controller
                val maxZoom = remember { controller.getMaxZoom() }
                var currentZoom by remember { mutableStateOf(1.0f) }

                CameraPreviewComposable(
                    controller = controller,
                    modifier = Modifier
                        .fillMaxSize()
                        .pointerInput(Unit) {
                            detectTransformGestures { _, _, zoom, _ ->
                                currentZoom = (currentZoom * zoom).coerceIn(1f, maxZoom)
                                controller.setZoom(currentZoom)
                            }
                        }
                )

                // Top controls
                Row(
                    modifier = Modifier
                        .align(Alignment.TopEnd)
                        .padding(16.dp),
                    horizontalArrangement = Arrangement.spacedBy(8.dp)
                ) {
                    // Flash toggle
                    IconButton(onClick = { controller.toggleFlashMode() }) {
                        Icon(
                            when (controller.getFlashMode()) {
                                FlashMode.ON -> Icons.Default.FlashOn
                                FlashMode.OFF -> Icons.Default.FlashOff
                                FlashMode.AUTO -> Icons.Default.FlashAuto
                                else -> Icons.Default.FlashOff
                            },
                            "Flash"
                        )
                    }

                    // Camera switch
                    IconButton(onClick = { controller.toggleCameraLens() }) {
                        Icon(Icons.Default.Cameraswitch, "Switch")
                    }

                    // Torch toggle
                    IconButton(onClick = { controller.toggleTorchMode() }) {
                        Icon(
                            if (controller.getTorchMode() == TorchMode.ON)
                                Icons.Default.FlashlightOn
                            else Icons.Default.FlashlightOff,
                            "Torch"
                        )
                    }
                }

                // Zoom indicator
                Text(
                    text = "${String.format("%.1f", currentZoom)}x",
                    modifier = Modifier
                        .align(Alignment.TopCenter)
                        .padding(16.dp),
                    color = Color.White
                )

                // Capture button
                FloatingActionButton(
                    onClick = {
                        scope.launch {
                            when (val result = controller.takePictureToFile()) {
                                is ImageCaptureResult.SuccessWithFile -> {
                                    println("Saved: ${result.filePath}")
                                }
                                is ImageCaptureResult.Error -> {
                                    println("Error: ${result.exception.message}")
                                }
                            }
                        }
                    },
                    modifier = Modifier
                        .align(Alignment.BottomCenter)
                        .padding(32.dp)
                ) {
                    Icon(Icons.Default.CameraAlt, "Capture")
                }
            }

            is CameraKState.Error -> Text("Error")
            CameraKState.Initializing -> CircularProgressIndicator()
        }
    }
}

Platform Availability

Method	Android	iOS	Desktop
takePictureToFile()	✅	✅	✅
setZoom()	✅	✅	Limited
setFlashMode()	✅ (rear)	✅ (rear)	❌
setTorchMode()	✅ (rear)	✅ (rear)	❌
toggleCameraLens()	✅	✅	Limited

See Also

• CameraKStateHolder — State management
• Configuration — Initial configuration
• Camera Capture Guide — Capture examples