CameraProvider

open fun addCameraPresenceListener(
    executor: Executor,
    listener: CameraPresenceListener
): Unit

Adds a listener for changes in camera presence.

The listener will be notified when cameras are added to or removed from the set of devices that can be used by CameraX. This list of "usable" cameras has already been processed by any configured CameraSelector limiters and compatibility filters.

Important Note on Synchronization: To prevent race conditions, this method immediately invokes CameraPresenceListener.onCamerasAdded once on the provided executor with a Set containing all cameras that are currently available. This guarantees that the listener's state is synchronized with the provider's state at the moment of registration.

This listener reports on persistent hardware changes and does not fire for temporary, recoverable errors, such as when a camera is in use by another application.

open fun getCameraInfo(cameraSelector: CameraSelector): CameraInfo

Returns the CameraInfo instance of the camera resulted from the specified CameraSelector.

The returned CameraInfo corresponds to the camera that will be bound when calling bindToLifecycle with the specified CameraSelector.

open fun getCameraInfo(
    cameraSelector: CameraSelector,
    sessionConfig: SessionConfig
): CameraInfo

Returns the CameraInfo instance of the camera resulted from the specified CameraSelector and SessionConfig.

The returned CameraInfo corresponds to the camera that will be bound when calling bindToLifecycle with the specified CameraSelector and SessionConfig.

This method is used for the case when the input SessionConfig can affect the camera selection or the information provided by the obtained CameraInfo object. For example, the androidx.camera.extensions.ExtensionSessionConfig.

fun hasCamera(cameraSelector: CameraSelector): Boolean

Checks whether this provider supports at least one camera that meets the requirements from a CameraSelector.

If this method returns true, then the camera selector can be used to bind use cases and retrieve a Camera instance.

open fun removeCameraPresenceListener(listener: CameraPresenceListener): Unit

Removes a previously registered camera presence listener.

Once removed, the listener will no longer receive updates. If the listener was not previously registered, this method is a no-op.

val availableCameraInfos: List<CameraInfo>

The CameraInfo instances of the available cameras.

While iterating through all the available CameraInfo, if one of them meets some predefined requirements, a CameraSelector that uniquely identifies its camera can be retrieved using CameraInfo.getCameraSelector, which can then be used to bind use cases to that camera.