public abstract class CameraController
extends Object


The abstract base camera controller class.

This a high level controller that provides most of the CameraX core features in a single class. It handles camera initialization, creates and configures UseCases. It also listens to device motion sensor and set the target rotation for the use cases.

The controller is required to be used with a PreviewView. PreviewView provides the UI elements to display camera preview. The layout of the PreviewView is used to set the crop rect so the output from other use cases matches the preview display in a WYSIWYG way. The controller also listens to PreviewView's touch events to handle tap-to-focus and pinch-to-zoom features.

This class provides features of 4 UseCases: Preview, ImageCapture, ImageAnalysis and an experimental video capture. Preview is required and always enabled. ImageCapture and ImageAnalysis are enabled by default. The video capture feature is experimental. It's disabled by default because it might conflict with other use cases, especially on lower end devices. It might be necessary to disable ImageCapture and/or ImageAnalysis before the video capture feature can be enabled. Disabling/enabling UseCases freezes the preview for a short period of time. To avoid the glitch, the UseCases need to be enabled/disabled before the controller is set on PreviewView.


Nested classes

class CameraController.OutputSize

Represents the output size of a UseCase



Bitmask option to enable ImageAnalysis.


Bitmask option to enable ImageCapture.


The previous tap-to-focus action was failed to complete.


No tap-to-focus action has been started by the end user.


A tap-to-focus action has started but not completed.


The previous tap-to-focus action was completed successfully and the camera is focused.


The previous tap-to-focus action was completed successfully but the camera is still unfocused.


Bitmask option to enable video capture use case.

Public methods

void clearImageAnalysisAnalyzer()

Removes a previously set analyzer.

ListenableFuture<Void> enableTorch(boolean torchEnabled)

Enable the torch or disable the torch.

CameraControl getCameraControl()

Gets the CameraControl of the currently attached camera.

CameraInfo getCameraInfo()

Gets the CameraInfo of the currently attached camera.

CameraSelector getCameraSelector()

Gets the CameraSelector.

Executor getImageAnalysisBackgroundExecutor()

Gets the default executor for ImageAnalysis background tasks.

int getImageAnalysisBackpressureStrategy()

Returns the mode with which images are acquired.

int getImageAnalysisImageQueueDepth()

Gets the image queue depth of ImageAnalysis.

CameraController.OutputSize getImageAnalysisTargetSize()

Returns the intended output size for ImageAnalysis set by setImageAnalysisTargetSize(OutputSize), or null if not set.

int getImageCaptureFlashMode()

Gets the flash mode for ImageCapture.

Executor getImageCaptureIoExecutor()

Gets the default executor for ImageCapture IO tasks.

int getImageCaptureMode()

Returns the image capture mode.

CameraController.OutputSize getImageCaptureTargetSize()

Returns the intended output size for ImageCapture set by setImageCaptureTargetSize(OutputSize), or null if not set.

ListenableFuture<Void> getInitializationFuture()

Gets a ListenableFuture that completes when camera initialization completes.

CameraController.OutputSize getPreviewTargetSize()

Returns the intended output size for Preview set by setPreviewTargetSize(OutputSize), or null if not set.

LiveData<Integer> getTapToFocusState()

Returns a LiveData with the latest tap-to-focus state.

LiveData<Integer> getTorchState()

Returns a LiveData of current TorchState.

CameraController.OutputSize getVideoCaptureTargetSize()

Returns the intended output size for VideoCapture set by setVideoCaptureTargetSize(OutputSize), or null if not set.

LiveData<ZoomState> getZoomState()

Returns a LiveData of ZoomState.

boolean hasCamera(CameraSelector cameraSelector)

Checks if the given CameraSelector can be resolved to a camera.

boolean isImageAnalysisEnabled()

Checks if ImageAnalysis is enabled.

boolean isImageCaptureEnabled()

Checks if ImageCapture is enabled.

boolean isPinchToZoomEnabled()

Returns whether pinch-to-zoom is enabled.

boolean isRecording()

Returns whether there is a in progress video recording.

boolean isTapToFocusEnabled()

Returns whether tap-to-focus is enabled.

boolean isVideoCaptureEnabled()

Checks if video capture is enabled.

void setCameraSelector(CameraSelector cameraSelector)

Sets the CameraSelector.

void setEnabledUseCases(int enabledUseCases)

Enables or disables use cases.

void setImageAnalysisAnalyzer(Executor executor, ImageAnalysis.Analyzer analyzer)

Sets an analyzer to receive and analyze images.

void setImageAnalysisBackgroundExecutor(Executor executor)

Sets the executor that will be used for ImageAnalysis background tasks.

void setImageAnalysisBackpressureStrategy(int strategy)

Sets the backpressure strategy to apply to the image producer to deal with scenarios where images may be produced faster than they can be analyzed.

void setImageAnalysisImageQueueDepth(int depth)

Sets the image queue depth of ImageAnalysis.

void setImageAnalysisTargetSize(CameraController.OutputSize targetSize)

Sets the intended output size for ImageAnalysis.

void setImageCaptureFlashMode(int flashMode)

Sets the flash mode for ImageCapture.

void setImageCaptureIoExecutor(Executor executor)

Sets the default executor that will be used for ImageCapture IO tasks.

void setImageCaptureMode(int captureMode)

Sets the image capture mode.

void setImageCaptureTargetSize(CameraController.OutputSize targetSize)

Sets the intended image size for ImageCapture.

ListenableFuture<Void> setLinearZoom(float linearZoom)

Sets current zoom by a linear zoom value ranging from 0f to 1.0f.

void setPinchToZoomEnabled(boolean enabled)

Enables/disables pinch-to-zoom.

void setPreviewTargetSize(CameraController.OutputSize targetSize)

Sets the intended output size for Preview.

void setTapToFocusEnabled(boolean enabled)

Enables/disables tap-to-focus.

void setVideoCaptureTargetSize(CameraController.OutputSize targetSize)

Sets the intended video size for VideoCapture.

ListenableFuture<Void> setZoomRatio(float zoomRatio)

Sets current zoom by ratio.

void startRecording(OutputFileOptions outputFileOptions, Executor executor, OnVideoSavedCallback callback)

Takes a video and calls the OnVideoSavedCallback when done.

void stopRecording()

Stops a in progress video recording.

void takePicture(ImageCapture.OutputFileOptions outputFileOptions, Executor executor, ImageCapture.OnImageSavedCallback imageSavedCallback)

Captures a new still image and saves to a file along with application specified metadata.

void takePicture(Executor executor, ImageCapture.OnImageCapturedCallback callback)

Captures a new still image for in memory access.

Inherited methods