/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @addtogroup Camera
* @{
*/
/**
* @file NdkCameraManager.h
*/
/*
* This file defines an NDK API.
* Do not remove methods.
* Do not change method signatures.
* Do not change the value of constants.
* Do not change the size of any of the classes defined in here.
* Do not reference types that are not part of the NDK.
* Do not #include files that aren't part of the NDK.
*/
#ifndef _NDK_CAMERA_MANAGER_H
#define _NDK_CAMERA_MANAGER_H
#include "NdkCameraError.h"
#include "NdkCameraMetadata.h"
#include "NdkCameraDevice.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* ACameraManager is opaque type that provides access to camera service.
*
* A pointer can be obtained using {@link ACameraManager_create} method.
*/
typedef struct ACameraManager ACameraManager;
/**
* Create ACameraManager instance.
*
* <p>The ACameraManager is responsible for
* detecting, characterizing, and connecting to {@link ACameraDevice}s.</p>
*
* <p>The caller must call {@link ACameraManager_delete} to free the resources once it is done
* using the ACameraManager instance.</p>
*
* @return a {@link ACameraManager} instance.
*
*/
ACameraManager* ACameraManager_create();
/**
* <p>Delete the {@link ACameraManager} instance and free its resources. </p>
*
* @param manager the {@link ACameraManager} instance to be deleted.
*/
void ACameraManager_delete(ACameraManager* manager);
/// Struct to hold list of camera devices
typedef struct ACameraIdList {
int numCameras; ///< Number of connected camera devices
const char** cameraIds; ///< list of identifier of connected camera devices
} ACameraIdList;
/**
* Create a list of currently connected camera devices, including
* cameras that may be in use by other camera API clients.
*
* <p>Non-removable cameras use integers starting at 0 for their
* identifiers, while removable cameras have a unique identifier for each
* individual device, even if they are the same model.</p>
*
* <p>ACameraManager_getCameraIdList will allocate and return an {@link ACameraIdList}.
* The caller must call {@link ACameraManager_deleteCameraIdList} to free the memory</p>
*
* @param manager the {@link ACameraManager} of interest
* @param cameraIdList the output {@link ACameraIdList} will be filled in here if the method call
* succeeds.
*
* @return <ul>
* <li>{@link ACAMERA_OK} if the method call succeeds.</li>
* <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager or cameraIdList is NULL.</li>
* <li>{@link ACAMERA_ERROR_CAMERA_DISCONNECTED} if connection to camera service fails.</li>
* <li>{@link ACAMERA_ERROR_NOT_ENOUGH_MEMORY} if allocating memory fails.</li></ul>
*/
camera_status_t ACameraManager_getCameraIdList(ACameraManager* manager,
/*out*/ACameraIdList** cameraIdList);
/**
* Delete a list of camera devices allocated via {@link ACameraManager_getCameraIdList}.
*
* @param cameraIdList the {@link ACameraIdList} to be deleted.
*/
void ACameraManager_deleteCameraIdList(ACameraIdList* cameraIdList);
/**
* Definition of camera availability callbacks.
*
* @param context The optional application context provided by user in
* {@link ACameraManager_AvailabilityCallbacks}.
* @param cameraId The ID of the camera device whose availability is changing. The memory of this
* argument is owned by camera framework and will become invalid immediately after
* this callback returns.
*/
typedef void (*ACameraManager_AvailabilityCallback)(void* context, const char* cameraId);
/**
* A listener for camera devices becoming available or unavailable to open.
*
* <p>Cameras become available when they are no longer in use, or when a new
* removable camera is connected. They become unavailable when some
* application or service starts using a camera, or when a removable camera
* is disconnected.</p>
*
* @see ACameraManager_registerAvailabilityCallback
*/
typedef struct ACameraManager_AvailabilityListener {
/// Optional application context.
void* context;
/// Called when a camera becomes available
ACameraManager_AvailabilityCallback onCameraAvailable;
/// Called when a camera becomes unavailable
ACameraManager_AvailabilityCallback onCameraUnavailable;
} ACameraManager_AvailabilityCallbacks;
/**
* Register camera availability callbacks.
*
* <p>onCameraUnavailable will be called whenever a camera device is opened by any camera API client.
* Other camera API clients may still be able to open such a camera device, evicting the existing
* client if they have higher priority than the existing client of a camera device.
* See {@link ACameraManager_openCamera} for more details.</p>
*
* <p>The callbacks will be called on a dedicated thread shared among all ACameraManager
* instances.</p>
*
* <p>Since this callback will be registered with the camera service, remember to unregister it
* once it is no longer needed; otherwise the callback will continue to receive events
* indefinitely and it may prevent other resources from being released. Specifically, the
* callbacks will be invoked independently of the general activity lifecycle and independently
* of the state of individual ACameraManager instances.</p>
*
* @param manager the {@link ACameraManager} of interest.
* @param callback the {@link ACameraManager_AvailabilityCallbacks} to be registered.
*
* @return <ul>
* <li>{@link ACAMERA_OK} if the method call succeeds.</li>
* <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager or callback is NULL, or
* {ACameraManager_AvailabilityCallbacks#onCameraAvailable} or
* {ACameraManager_AvailabilityCallbacks#onCameraUnavailable} is NULL.</li></ul>
*/
camera_status_t ACameraManager_registerAvailabilityCallback(
ACameraManager* manager, const ACameraManager_AvailabilityCallbacks* callback);
/**
* Unregister camera availability callbacks.
*
* <p>Removing a callback that isn't registered has no effect.</p>
*
* @param manager the {@link ACameraManager} of interest.
* @param callback the {@link ACameraManager_AvailabilityCallbacks} to be unregistered.
*
* @return <ul>
* <li>{@link ACAMERA_OK} if the method call succeeds.</li>
* <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if callback,
* {ACameraManager_AvailabilityCallbacks#onCameraAvailable} or
* {ACameraManager_AvailabilityCallbacks#onCameraUnavailable} is NULL.</li></ul>
*/
camera_status_t ACameraManager_unregisterAvailabilityCallback(
ACameraManager* manager, const ACameraManager_AvailabilityCallbacks* callback);
/**
* Query the capabilities of a camera device. These capabilities are
* immutable for a given camera.
*
* <p>See {@link ACameraMetadata} document and {@link NdkCameraMetadataTags.h} for more details.</p>
*
* <p>The caller must call {@link ACameraMetadata_free} to free the memory of the output
* characteristics.</p>
*
* @param manager the {@link ACameraManager} of interest.
* @param cameraId the ID string of the camera device of interest.
* @param characteristics the output {@link ACameraMetadata} will be filled here if the method call
* succeeeds.
*
* @return <ul>
* <li>{@link ACAMERA_OK} if the method call succeeds.</li>
* <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager, cameraId, or characteristics
* is NULL, or cameraId does not match any camera devices connected.</li>
* <li>{@link ACAMERA_ERROR_CAMERA_DISCONNECTED} if connection to camera service fails.</li>
* <li>{@link ACAMERA_ERROR_NOT_ENOUGH_MEMORY} if allocating memory fails.</li>
* <li>{@link ACAMERA_ERROR_UNKNOWN} if the method fails for some other reasons.</li></ul>
*/
camera_status_t ACameraManager_getCameraCharacteristics(
ACameraManager* manager, const char* cameraId,
/*out*/ACameraMetadata** characteristics);
/**
* Open a connection to a camera with the given ID. The opened camera device will be
* returned in the `device` parameter.
*
* <p>Use {@link ACameraManager_getCameraIdList} to get the list of available camera
* devices. Note that even if an id is listed, open may fail if the device
* is disconnected between the calls to {@link ACameraManager_getCameraIdList} and
* {@link ACameraManager_openCamera}, or if a higher-priority camera API client begins using the
* camera device.</p>
*
* <p>Devices for which the
* {@link ACameraManager_AvailabilityCallbacks#onCameraUnavailable} callback has been called due to
* the device being in use by a lower-priority, background camera API client can still potentially
* be opened by calling this method when the calling camera API client has a higher priority
* than the current camera API client using this device. In general, if the top, foreground
* activity is running within your application process, your process will be given the highest
* priority when accessing the camera, and this method will succeed even if the camera device is
* in use by another camera API client. Any lower-priority application that loses control of the
* camera in this way will receive an
* {@link ACameraDevice_stateCallbacks#onDisconnected} callback.</p>
*
* <p>Once the camera is successfully opened,the ACameraDevice can then be set up
* for operation by calling {@link ACameraDevice_createCaptureSession} and
* {@link ACameraDevice_createCaptureRequest}.</p>
*
* <p>If the camera becomes disconnected after this function call returns,
* {@link ACameraDevice_stateCallbacks#onDisconnected} with a
* ACameraDevice in the disconnected state will be called.</p>
*
* <p>If the camera runs into error after this function call returns,
* {@link ACameraDevice_stateCallbacks#onError} with a
* ACameraDevice in the error state will be called.</p>
*
* @param manager the {@link ACameraManager} of interest.
* @param cameraId the ID string of the camera device to be opened.
* @param callback the {@link ACameraDevice_StateCallbacks} associated with the opened camera device.
* @param device the opened {@link ACameraDevice} will be filled here if the method call succeeds.
*
* @return <ul>
* <li>{@link ACAMERA_OK} if the method call succeeds.</li>
* <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if manager, cameraId, callback, or device
* is NULL, or cameraId does not match any camera devices connected.</li>
* <li>{@link ACAMERA_ERROR_CAMERA_DISCONNECTED} if connection to camera service fails.</li>
* <li>{@link ACAMERA_ERROR_NOT_ENOUGH_MEMORY} if allocating memory fails.</li>
* <li>{@link ACAMERA_ERROR_CAMERA_IN_USE} if camera device is being used by a higher
* priority camera API client.</li>
* <li>{@link ACAMERA_ERROR_MAX_CAMERA_IN_USE} if the system-wide limit for number of open
* cameras or camera resources has been reached, and more camera devices cannot be
* opened until previous instances are closed.</li>
* <li>{@link ACAMERA_ERROR_CAMERA_DISABLED} if the camera is disabled due to a device
* policy, and cannot be opened.</li>
* <li>{@link ACAMERA_ERROR_PERMISSION_DENIED} if the application does not have permission
* to open camera.</li>
* <li>{@link ACAMERA_ERROR_UNKNOWN} if the method fails for some other reasons.</li></ul>
*/
camera_status_t ACameraManager_openCamera(
ACameraManager* manager, const char* cameraId,
ACameraDevice_StateCallbacks* callback,
/*out*/ACameraDevice** device);
#ifdef __cplusplus
} // extern "C"
#endif
#endif //_NDK_CAMERA_MANAGER_H
/** @} */