FocusMeteringAction

public final class FocusMeteringAction
extends Object

A configuration used to trigger a focus and/or metering action.

To construct a FocusMeteringAction, apps have to create a FocusMeteringAction.Builder by FocusMeteringAction.Builder.from(MeteringPoint) or FocusMeteringAction.Builder.from(MeteringPoint, int). MeteringPoint is a point used to specify the focus/metering areas. Apps can use various MeteringPointFactory to create the points. When the FocusMeteringAction is built, pass it to CameraControl.startFocusAndMetering(FocusMeteringAction) to initiate the focus and metering action.

The default FocusMeteringAction.MeteringMode is FocusMeteringAction.MeteringMode.AF | FocusMeteringAction.MeteringMode.AE | FocusMeteringAction.MeteringMode.AWB which means the point is used for all AF/AE/AWB regions. Apps can set the proper FocusMeteringAction.MeteringMode to optionally exclude some 3A regions. Multiple regions for specific 3A type are also supported via FocusMeteringAction.Builder.addPoint(MeteringPoint) or FocusMeteringAction.Builder.addPoint(MeteringPoint, int). App can also this API to enable different region for AF and AE respectively.

If any AF points are specified, it will trigger autofocus to start a manual scan. When focus is locked and specified AF/AE/AWB regions are updated in capture result, the returned ListenableFuture in CameraControl.startFocusAndMetering(FocusMeteringAction) will completed with FocusMeteringResult.isFocusSuccessful() set to indicate if focus is done successfully or not. If AF point is not specified, it will not trigger autofocus and simply wait for specified AE/AWB regions being updated to complete the returned ListenableFuture. In the case of AF points not specified, FocusMeteringResult.isFocusSuccessful() will be set to false. If Af points are specified but current camera does not support auto focus, FocusMeteringResult.isFocusSuccessful() will be set to true .

App can set a auto-cancel duration to let CameraX call CameraControl.cancelFocusAndMetering() automatically in the specified duration. By default the auto-cancel duration is 5 seconds. Apps can call FocusMeteringAction.Builder.disableAutoCancel() to disable auto-cancel.

Summary

Public methods

public long getAutoCancelDurationInMillis ()

public List<MeteringPoint> getMeteringPointsAe ()

public List<MeteringPoint> getMeteringPointsAf ()

public List<MeteringPoint> getMeteringPointsAwb ()

public boolean isAutoCancelEnabled ()