CameraControl

abstract @NonNull ListenableFuture<Void> cancelFocusAndMetering()

Cancels current FocusMeteringAction and clears AF/AE/AWB regions.

Clear the AF/AE/AWB regions and update current AF mode to continuous AF (if supported). If current FocusMeteringAction has not completed, the returned ListenableFuture in startFocusAndMetering will fail with OperationCanceledException.

abstract @NonNull ListenableFuture<Void> enableTorch(boolean torch)

Enable the torch or disable the torch.

getTorchState can be used to query the torch state. If the camera doesn't have a flash unit (see hasFlashUnit), then the call will do nothing, the returned ListenableFuture will complete immediately with a failed result and the torch state will be OFF.

When the torch is enabled, the torch will remain enabled during photo capture regardless of the flashMode setting. When the torch is disabled, flash will function as the flash mode set by either setFlashMode or setFlashMode.

abstract @NonNull ListenableFuture<Integer> setExposureCompensationIndex(int value)

Set the exposure compensation value for the camera.

Only one setExposureCompensationIndex is allowed to run at the same time. If multiple setExposureCompensationIndex are executed in a row, only the latest one setting will be kept in the camera. The other actions will be cancelled and the ListenableFuture will fail with the OperationCanceledException. After all the previous actions is cancelled, the camera device will adjust the brightness according to the latest setting.

abstract @NonNull ListenableFuture<Void> setLinearZoom(@FloatRange(from = 0.0, to = 1.0) float linearZoom)

Sets current zoom by a linear zoom value ranging from 0f to 1.0f. LinearZoom 0f represents the minimum zoom while linearZoom 1.0f represents the maximum zoom. The advantage of linearZoom is that it ensures the field of view (FOV) varies linearly with the linearZoom value, for use with slider UI elements (while setZoomRatio works well for pinch-zoom gestures).

It modifies both current zoomRatio and linearZoom so if apps are observing zoomRatio or linearZoom, they will get the update as well. If the linearZoom is not in the range [0..1], the returned ListenableFuture will fail with IllegalArgumentException and it won't modify current linearZoom and zoomRatio. It is application's duty to clamp the linearZoom within [0..1].

abstract @NonNull ListenableFuture<Void> setZoomRatio(float ratio)

Sets current zoom by ratio.

It modifies both current zoomRatio and linearZoom so if apps are observing zoomRatio or linearZoom, they will get the update as well. If the ratio is smaller than getMinZoomRatio or larger than getMaxZoomRatio, the returned ListenableFuture will fail with IllegalArgumentException and it won't modify current zoom ratio. It is the applications' duty to clamp the ratio.

abstract @NonNull ListenableFuture<FocusMeteringResult> startFocusAndMetering(@NonNull FocusMeteringAction action)

Starts a focus and metering action configured by the FocusMeteringAction.

It will trigger an auto focus action and enable AF/AE/AWB metering regions. The action is configured by a FocusMeteringAction which contains the configuration of multiple AF/AE/AWB MeteringPoints and an auto-cancel duration. See FocusMeteringAction for more details.

Only one FocusMeteringAction is allowed to run at a time. If multiple FocusMeteringAction are executed in a row, only the latest one will work and other actions will be cancelled.

If the FocusMeteringAction specifies more AF/AE/AWB points than what is supported on the current device, only the first point and then in order up to the number of points supported by the device will be enabled.

If none of the points with either AF/AE/AWB can be supported on the device or none of the points generates valid metering rectangles, the returned ListenableFuture in startFocusAndMetering will fail immediately.