CameraView

Kotlin |Java

class CameraView : ViewGroup

kotlin.Any
↳	android.view.View
	↳	android.view.ViewGroup
		↳	androidx.camera.view.CameraView

A View that displays a preview of the camera with methods , takePicture(File, Executor, OnImageSavedListener), startRecording(File, Executor, OnVideoSavedListener) and stopRecording().

Because the Camera is a limited resource and consumes a high amount of power, CameraView must be opened/closed. CameraView will handle opening/closing automatically through use of a . Use bindToLifecycle(LifecycleOwner) to start the camera.

Summary

Nested classes
	CaptureMode The capture mode used by CameraView.
	ScaleType Options for scaling the bounds of the view finder to the bounds of this view.

Public constructors
<init>(context: Context!)
<init>(context: Context!, attrs: AttributeSet!)
<init>(context: Context!, attrs: AttributeSet!, defStyle: Int)
<init>(context: Context!, attrs: AttributeSet!, defStyleAttr: Int, defStyleRes: Int)

Public methods
Unit	bindToLifecycle(lifecycleOwner: LifecycleOwner!) Binds control of the camera used by this view to the given lifecycle.
Unit	enableTorch(torch: Boolean) Turns on/off torch.
CameraX.LensFacing?	getCameraLensFacing() Returns the currently selected LensFacing.
CameraView.CaptureMode!	getCaptureMode() Returns the scale type used to scale the preview.
FlashMode!	getFlash() Gets the active flash strategy.
Float	getMaxZoomLevel() Returns the maximum zoom level.
Float	getMinZoomLevel() Returns the minimum zoom level.
CameraView.ScaleType!	getScaleType() Returns the scale type used to scale the preview.
Float	getZoomLevel() Returns the current zoom level.
Boolean	hasCameraWithLensFacing(lensFacing: CameraX.LensFacing!) Queries whether the current device has a camera with the specified direction.
Boolean	isPinchToZoomEnabled() Returns whether the view allows pinch-to-zoom.
Boolean	isRecording()
Boolean	isTorchOn() Returns current torch status.
Boolean	isZoomSupported() Returns whether the bound camera supports zooming.
Boolean	onTouchEvent(@NonNull event: MotionEvent)
Boolean	performClick() Focus the position of the touch event, or focus the center of the preview for accessibility events
Unit	setCameraLensFacing(@Nullable lensFacing: CameraX.LensFacing?) Sets the desired camera by specifying desired lensFacing.
Unit	setCaptureMode(captureMode: CameraView.CaptureMode!) Sets the CameraView capture mode
Unit	setFlash(@NonNull flashMode: FlashMode) Sets the active flash strategy.
Unit	setPinchToZoomEnabled(enabled: Boolean) Sets whether the view should allow pinch-to-zoom.
Unit	setScaleType(scaleType: CameraView.ScaleType!) Sets the view finder scale type.
Unit	setZoomLevel(zoomLevel: Float) Sets the current zoom level.
Unit	startRecording(@NonNull file: File, @NonNull executor: Executor, @NonNull listener: OnVideoSavedListener) Takes a video and calls the OnVideoSavedListener when done.
Unit	stopRecording() Stops an in progress video.
Unit	takePicture(@NonNull executor: Executor, @NonNull listener: ImageCapture.OnImageCapturedListener) Takes a picture, and calls OnImageCapturedListener#onCaptureSuccess(ImageProxy, int) once when done.
Unit	takePicture(@NonNull file: File, @NonNull executor: Executor, @NonNull listener: ImageCapture.OnImageSavedListener) Takes a picture and calls OnImageSavedListener#onImageSaved(File) when done.
Unit	toggleCamera() Toggles between the primary front facing camera and the primary back facing camera.

Protected methods
LayoutParams!	generateDefaultLayoutParams()
Unit	onAttachedToWindow()
Unit	onDetachedFromWindow()
Unit	onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int)
Unit	onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int)
Unit	onRestoreInstanceState(savedState: Parcelable!)
Parcelable!	onSaveInstanceState()

Public constructors

<init>

CameraView(context: Context!)

<init>

CameraView(context: Context!, attrs: AttributeSet!)

<init>

CameraView(context: Context!, attrs: AttributeSet!, defStyle: Int)

<init>

CameraView(context: Context!, attrs: AttributeSet!, defStyleAttr: Int, defStyleRes: Int)

Public methods

bindToLifecycle

fun bindToLifecycle(lifecycleOwner: LifecycleOwner!): Unit

Binds control of the camera used by this view to the given lifecycle.

This links opening/closing the camera to the given lifecycle. The camera will not operate unless this method is called with a valid LifecycleOwner that is not in the state. Call this method only once camera permissions have been obtained.

Once the provided lifecycle has transitioned to a state, CameraView must be bound to a new lifecycle through this method in order to operate the camera.

Parameters
lifecycleOwner	LifecycleOwner!: The lifecycle that will control this view's camera

Exceptions
IllegalArgumentException	if provided lifecycle is in a state.
IllegalStateException	if camera permissions are not granted.

enableTorch

fun enableTorch(torch: Boolean): Unit

Turns on/off torch.

Parameters
torch	Boolean: True to turn on torch, false to turn off torch.

getCameraLensFacing

@Nullable fun getCameraLensFacing(): CameraX.LensFacing?

Returns the currently selected LensFacing.

getCaptureMode

fun getCaptureMode(): CameraView.CaptureMode!

Returns the scale type used to scale the preview.

Return
CameraView.CaptureMode!: The current CaptureMode.

getFlash

fun getFlash(): FlashMode!

Gets the active flash strategy.

getMaxZoomLevel

fun getMaxZoomLevel(): Float

Returns the maximum zoom level.

The zoom level corresponds to the ratio between both the widths and heights of a non-zoomed image and a maximally zoomed image for the selected camera.

Return
Float: The maximum zoom level.

getMinZoomLevel

fun getMinZoomLevel(): Float

Returns the minimum zoom level.

For most cameras this should return a zoom level of 1. A zoom level of 1 corresponds to a non-zoomed image.

Return
Float: The minimum zoom level.

getScaleType

fun getScaleType(): CameraView.ScaleType!

Returns the scale type used to scale the preview.

Return
CameraView.ScaleType!: The current ScaleType.

getZoomLevel

fun getZoomLevel(): Float

Returns the current zoom level.

Return
Float: The current zoom level.

hasCameraWithLensFacing

fun hasCameraWithLensFacing(lensFacing: CameraX.LensFacing!): Boolean

Queries whether the current device has a camera with the specified direction.

Return
Boolean: True if the device supports the direction.

Exceptions
IllegalStateException	if the CAMERA permission is not currently granted.

isPinchToZoomEnabled

fun isPinchToZoomEnabled(): Boolean

Returns whether the view allows pinch-to-zoom.

Return
Boolean: True if pinch to zoom is enabled.

isRecording

fun isRecording(): Boolean

Return
Boolean: True if currently recording.

isTorchOn

fun isTorchOn(): Boolean

Returns current torch status.

Return
Boolean: true if torch is on , otherwise false

isZoomSupported

fun isZoomSupported(): Boolean

Returns whether the bound camera supports zooming.

Return
Boolean: True if the camera supports zooming.

onTouchEvent

fun onTouchEvent(@NonNull event: MotionEvent): Boolean

performClick

fun performClick(): Boolean

Focus the position of the touch event, or focus the center of the preview for accessibility events

setCameraLensFacing

fun setCameraLensFacing(@Nullable lensFacing: CameraX.LensFacing?): Unit

Sets the desired camera by specifying desired lensFacing.

This will choose the primary camera with the specified camera lensFacing.

If called before bindToLifecycle(LifecycleOwner), this will set the camera to be used when first bound to the lifecycle. If the specified lensFacing is not supported by the device, as determined by hasCameraWithLensFacing(LensFacing), the first supported lensFacing will be chosen when bindToLifecycle(LifecycleOwner) is called.

If called with null AFTER binding to the lifecycle, the behavior would be equivalent to unbind the use cases without the lifecycle having to be destroyed.

Parameters
lensFacing	CameraX.LensFacing?: The desired camera lensFacing.

setCaptureMode

fun setCaptureMode(captureMode: CameraView.CaptureMode!): Unit

Sets the CameraView capture mode

This controls only image or video capture function is enabled or both are enabled.

Parameters
captureMode	CameraView.CaptureMode!: The desired CaptureMode.

setFlash

fun setFlash(@NonNull flashMode: FlashMode): Unit

Sets the active flash strategy.

setPinchToZoomEnabled

fun setPinchToZoomEnabled(enabled: Boolean): Unit

Sets whether the view should allow pinch-to-zoom.

When enabled, the user can pinch the camera to zoom in/out. This only has an effect if the bound camera supports zoom.

Parameters
enabled	Boolean: True to enable pinch-to-zoom.

setScaleType

fun setScaleType(scaleType: CameraView.ScaleType!): Unit

Sets the view finder scale type.

This controls how the view finder should be scaled and positioned within the view.

Parameters
scaleType	CameraView.ScaleType!: The desired ScaleType.

setZoomLevel

fun setZoomLevel(zoomLevel: Float): Unit

Sets the current zoom level.

Valid zoom values range from 1 to getMaxZoomLevel().

Parameters
zoomLevel	Float: The requested zoom level.

startRecording

fun startRecording(@NonNull file: File, @NonNull executor: Executor, @NonNull listener: OnVideoSavedListener): Unit

Takes a video and calls the OnVideoSavedListener when done.

Parameters
file	File: The destination.
executor	File: The executor in which the listener callback methods will be run.
listener	File: Listener which will receive success or failure callbacks.

stopRecording

fun stopRecording(): Unit

Stops an in progress video.

takePicture

fun takePicture(@NonNull executor: Executor, @NonNull listener: ImageCapture.OnImageCapturedListener): Unit

Takes a picture, and calls OnImageCapturedListener#onCaptureSuccess(ImageProxy, int) once when done.

Parameters
executor	Executor: The executor in which the listener callback methods will be run.
listener	Executor: Listener which will receive success or failure callbacks.

takePicture

fun takePicture(@NonNull file: File, @NonNull executor: Executor, @NonNull listener: ImageCapture.OnImageSavedListener): Unit

Takes a picture and calls OnImageSavedListener#onImageSaved(File) when done.

Parameters
file	File: The destination.
executor	File: The executor in which the listener callback methods will be run.
listener	File: Listener which will receive success or failure callbacks.

toggleCamera

fun toggleCamera(): Unit

Toggles between the primary front facing camera and the primary back facing camera.

This will have no effect if not already bound to a lifecycle via .

Protected methods

generateDefaultLayoutParams

protected fun generateDefaultLayoutParams(): LayoutParams!

onAttachedToWindow

protected fun onAttachedToWindow(): Unit

onDetachedFromWindow

protected fun onDetachedFromWindow(): Unit

onLayout

protected fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int): Unit

onMeasure

protected fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int): Unit

onRestoreInstanceState

protected fun onRestoreInstanceState(savedState: Parcelable!): Unit

onSaveInstanceState

protected fun onSaveInstanceState(): Parcelable!