camera/EmulatedCameraFactory.h

/*
 * Copyright (C) 2011 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.
 */

#ifndef HW_EMULATOR_CAMERA_EMULATED_CAMERA_FACTORY_H
#define HW_EMULATOR_CAMERA_EMULATED_CAMERA_FACTORY_H

#include <utils/RefBase.h>
#include "EmulatedBaseCamera.h"
#include "QemuClient.h"

namespace android {

struct EmulatedCameraHotplugThread;

/*
 * Contains declaration of a class EmulatedCameraFactory that manages cameras
 * available for the emulation. A global instance of this class is statically
 * instantiated and initialized when camera emulation HAL is loaded.
 */

/* Class EmulatedCameraFactoryManages cameras available for the emulation.
 *
 * When the global static instance of this class is created on the module load,
 * it enumerates cameras available for the emulation by connecting to the
 * emulator's 'camera' service. For every camera found out there it creates an
 * instance of an appropriate class, and stores it an in array of emulated
 * cameras. In addition to the cameras reported by the emulator, a fake camera
 * emulator is always created, so there is always at least one camera that is
 * available.
 *
 * Instance of this class is also used as the entry point for the camera HAL API,
 * including:
 *  - hw_module_methods_t::open entry point
 *  - camera_module_t::get_number_of_cameras entry point
 *  - camera_module_t::get_camera_info entry point
 *
 */
class EmulatedCameraFactory {
public:
    /* Constructs EmulatedCameraFactory instance.
     * In this constructor the factory will create and initialize a list of
     * emulated cameras. All errors that occur on this constructor are reported
     * via mConstructedOK data member of this class.
     */
    EmulatedCameraFactory();

    /* Destructs EmulatedCameraFactory instance. */
    ~EmulatedCameraFactory();

    /****************************************************************************
     * Camera HAL API handlers.
     ***************************************************************************/

public:
    /* Opens (connects to) a camera device.
     * This method is called in response to hw_module_methods_t::open callback.
     */
    int cameraDeviceOpen(int camera_id, hw_device_t** device);

    /* Gets emulated camera information.
     * This method is called in response to camera_module_t::get_camera_info callback.
     */
    int getCameraInfo(int camera_id, struct camera_info *info);

    /* Sets emulated camera callbacks.
     * This method is called in response to camera_module_t::set_callbacks callback.
     */
    int setCallbacks(const camera_module_callbacks_t *callbacks);

    /****************************************************************************
     * Camera HAL API callbacks.
     ***************************************************************************/

public:
    /* camera_module_t::get_number_of_cameras callback entry point. */
    static int get_number_of_cameras(void);

    /* camera_module_t::get_camera_info callback entry point. */
    static int get_camera_info(int camera_id, struct camera_info *info);

    /* camera_module_t::set_callbacks callback entry point. */
    static int set_callbacks(const camera_module_callbacks_t *callbacks);

private:
    /* hw_module_methods_t::open callback entry point. */
    static int device_open(const hw_module_t* module,
                           const char* name,
                           hw_device_t** device);

    /****************************************************************************
     * Public API.
     ***************************************************************************/

public:

    /* Gets fake camera orientation. */
    int getFakeCameraOrientation() {
        /* TODO: Have a boot property that controls that. */
        return 90;
    }

    /* Gets qemu camera orientation. */
    int getQemuCameraOrientation() {
        /* TODO: Have a boot property that controls that. */
        return 270;
    }

    /* Gets number of emulated cameras.
     */
    int getEmulatedCameraNum() const {
        return mEmulatedCameraNum;
    }

    /* Checks whether or not the constructor has succeeded.
     */
    bool isConstructedOK() const {
        return mConstructedOK;
    }

    void onStatusChanged(int cameraId, int newStatus);

    /****************************************************************************
     * Private API
     ***************************************************************************/

private:
    /* Populates emulated cameras array with cameras that are available via
     * 'camera' service in the emulator. For each such camera and instance of
     * the EmulatedCameraQemud will be created and added to the mEmulatedCameras
     * array.
     */
    void createQemuCameras();

    /* Checks if fake camera emulation is on for the camera facing back. */
    bool isBackFakeCameraEmulationOn();

    /* Gets camera device version number to use for back camera emulation */
    int getBackCameraHalVersion();

    /* Checks if fake camera emulation is on for the camera facing front. */
    bool isFrontFakeCameraEmulationOn();

    /* Gets camera device version number to use for front camera emulation */
    int getFrontCameraHalVersion();

    /****************************************************************************
     * Data members.
     ***************************************************************************/

private:
    /* Connection to the camera service in the emulator. */
    FactoryQemuClient   mQemuClient;

    /* Array of cameras available for the emulation. */
    EmulatedBaseCamera**    mEmulatedCameras;

    /* Number of emulated cameras (including the fake ones). */
    int                 mEmulatedCameraNum;

    /* Number of emulated fake cameras. */
    int                 mFakeCameraNum;

    /* Flags whether or not constructor has succeeded. */
    bool                mConstructedOK;

    /* Camera callbacks (for status changing) */
    const camera_module_callbacks_t* mCallbacks;

    /* Hotplug thread (to call onStatusChanged) */
    sp<EmulatedCameraHotplugThread> mHotplugThread;

public:
    /* Contains device open entry point, as required by HAL API. */
    static struct hw_module_methods_t   mCameraModuleMethods;
};

}; /* namespace android */

/* References the global EmulatedCameraFactory instance. */
extern android::EmulatedCameraFactory   gEmulatedCameraFactory;

#endif  /* HW_EMULATOR_CAMERA_EMULATED_CAMERA_FACTORY_H */