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PreviewConfig.Builder

public static final class PreviewConfig.Builder
extends Object implements Config.ExtendableBuilder, Builder<PreviewConfig.Builder>

java.lang.Object
   ↳ androidx.camera.core.PreviewConfig.Builder

Builder for a PreviewConfig.

Summary

Public constructors

PreviewConfig.Builder()

Creates a new Builder object.

Public methods

PreviewConfig build()

Builds an immutable PreviewConfig from the current state.

static PreviewConfig.Builder fromConfig(PreviewConfig configuration)

Generates a Builder from another Config object

PreviewConfig.Builder setBackgroundExecutor(Executor executor)

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

PreviewConfig.Builder setCallbackHandler(Handler handler)

Sets the default handler that will be used for callbacks.

PreviewConfig.Builder setLensFacing(CameraX.LensFacing lensFacing)

Sets the primary camera to be configured based on the direction the lens is facing.

PreviewConfig.Builder setTargetAspectRatio(Rational aspectRatio)

Sets the aspect ratio of the intended target for images from this configuration.

PreviewConfig.Builder setTargetName(String targetName)

Sets the name of the target object being configured.

PreviewConfig.Builder setTargetResolution(Size resolution)

Sets the resolution of the intended target from this configuration.

PreviewConfig.Builder setTargetRotation(int rotation)

Sets the rotation of the intended target for images from this configuration.

Inherited methods

Public constructors

PreviewConfig.Builder

public PreviewConfig.Builder ()

Creates a new Builder object.

Public methods

build

public PreviewConfig build ()

Builds an immutable PreviewConfig from the current state.

Returns
PreviewConfig A PreviewConfig populated with the current state.

fromConfig

public static PreviewConfig.Builder fromConfig (PreviewConfig configuration)

Generates a Builder from another Config object

Parameters
configuration PreviewConfig: An immutable configuration to pre-populate this builder.
Returns
PreviewConfig.Builder The new Builder.

setBackgroundExecutor

public PreviewConfig.Builder setBackgroundExecutor (Executor executor)

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

Parameters
executor Executor: The executor which will be used for background tasks.
Returns
PreviewConfig.Builder the current Builder.

setCallbackHandler

public PreviewConfig.Builder setCallbackHandler (Handler handler)

Sets the default handler that will be used for callbacks.

Parameters
handler Handler: The handler which will be used to post callbacks.
Returns
PreviewConfig.Builder the current Builder.

setLensFacing

public PreviewConfig.Builder setLensFacing (CameraX.LensFacing lensFacing)

Sets the primary camera to be configured based on the direction the lens is facing.

If multiple cameras exist with equivalent lens facing direction, the first ("primary") camera for that direction will be chosen.

Parameters
lensFacing CameraX.LensFacing: The direction of the camera's lens.
Returns
PreviewConfig.Builder the current Builder.

setTargetAspectRatio

public PreviewConfig.Builder setTargetAspectRatio (Rational aspectRatio)

Sets the aspect ratio of the intended target for images from this configuration.

This is the ratio of the target's width to the image's height, where the numerator of the provided Rational corresponds to the width, and the denominator corresponds to the height.

The target aspect ratio is used as a hint when determining the resulting output aspect ratio which may differ from the request, possibly due to device constraints. Application code should check the resulting output's resolution.

For Preview, the output is the SurfaceTexture of the Preview.PreviewOutput.

Parameters
aspectRatio Rational: A Rational representing the ratio of the target's width and height.
Returns
PreviewConfig.Builder The current Builder.

setTargetName

public PreviewConfig.Builder setTargetName (String targetName)

Sets the name of the target object being configured.

The name should be a value that can uniquely identify an instance of the object being configured.

Parameters
targetName String: A unique string identifier for the instance of the class being configured.
Returns
PreviewConfig.Builder the current Builder.

setTargetResolution

public PreviewConfig.Builder setTargetResolution (Size resolution)

Sets the resolution of the intended target from this configuration.

The target resolution attempts to establish a minimum bound for the preview resolution. The actual preview resolution will be the closest available resolution in size that is not smaller than the target resolution, as determined by the Camera implementation. However, if no resolution exists that is equal to or larger than the target resolution, the nearest available resolution smaller than the target resolution will be chosen.

Parameters
resolution Size: The target resolution to choose from supported output sizes list.
Returns
PreviewConfig.Builder The current Builder.

setTargetRotation

public PreviewConfig.Builder setTargetRotation (int rotation)

Sets the rotation of the intended target for images from this configuration.

This is one of four valid values: Surface.ROTATION_0, Surface.ROTATION_90, Surface.ROTATION_180, Surface.ROTATION_270. Rotation values are relative to the "natural" rotation, Surface.ROTATION_0.

Parameters
rotation int: The rotation of the intended target.
Returns
PreviewConfig.Builder The current Builder.