Camera Controller

Introduction

The Camera Controller provides functionality for taking pictures and recording videos, separating these actions from UI state management. By using a controller, you can manage camera operations independently of the CameraPreview composable.

Usage example

val controller = remember { CameraController() }
val cameraSession = rememberCameraSession(controller)

CameraPreview(
    cameraSession = cameraSession,
)

Why Use a CameraController?

In earlier versions of Camposer, actions such as taking pictures or recording videos were handled directly in cameraSession. This approach limited camera operations to the UI layer, making it difficult to separate logic from presentation.

Starting from Camposer 1.0, the CameraController was introduced to decouple camera operations from UI logic, following clean architecture principles.

For example, you can instantiate the controller in a ViewModel and handle all camera actions there, keeping the UI layer focused solely on presentation.

ViewModel Example

class MyViewModel : ViewModel() {

    val cameraController = CameraController()

    fun takePicture() {
        cameraController.takePicture(
            // Provide configuration and callbacks here
        )
    }

    fun startRecording() {
        cameraController.startRecording(
            // Provide configuration and callbacks here
        )
    }

    fun stopRecording() {
        cameraController.stopRecording()
    }
}

View Example

@Composable
fun CameraScreen(viewModel: MyViewModel) {
    // You can also store the CameraController in your UI state, 
    // allowing it to persist across recompositions while keeping it 
    // separate from the composable UI.
    val cameraSession = rememberCameraSession(viewModel.cameraController)

    CameraPreview(cameraSession = cameraSession)

    Row {
        Button(onClick = viewModel::takePicture) {
            Text("Take Picture")
        }

        Button(onClick = viewModel::startRecording) {
            Text("Start Recording")
        }

        Button(onClick = viewModel::stopRecording) {
            Text("Stop Recording")
        }
    }
}