Merge "Add an auto-exposure lock feature to the Camera API."

const char CameraParameters::KEY_MAX_EXPOSURE_COMPENSATION[] = "max-exposure-compensation";

const char CameraParameters::KEY_MIN_EXPOSURE_COMPENSATION[] = "min-exposure-compensation";

const char CameraParameters::KEY_EXPOSURE_COMPENSATION_STEP[] = "exposure-compensation-step";

const char CameraParameters::KEY_AUTO_EXPOSURE_LOCK[] = "auto-exposure-lock";

const char CameraParameters::KEY_AUTO_EXPOSURE_LOCK_SUPPORTED[] = "auto-exposure-lock-supported";

const char CameraParameters::KEY_MAX_NUM_METERING_AREAS[] = "max-num-metering-areas";

const char CameraParameters::KEY_METERING_AREAS[] = "metering-areas";

const char CameraParameters::KEY_ZOOM[] = "zoom";

const char CameraParameters::KEY_PREFERRED_PREVIEW_SIZE_FOR_VIDEO[] = "preferred-preview-size-for-video";

const char CameraParameters::TRUE[] = "true";

const char CameraParameters::FALSE[] = "false";

const char CameraParameters::FOCUS_DISTANCE_INFINITY[] = "Infinity";

// Values for white balance settings.

    // 0.3333, EV is -2.

    // Example value: "0.333333333" or "0.5". Read only.

    static const char KEY_EXPOSURE_COMPENSATION_STEP[];

    // The state of the auto-exposure lock. "true" means that auto-exposure is

    // locked to its current value and will not change. "false" means the

    // auto-exposure routine is free to change exposure settings. Changing

    // exposure compensation settings will still affect the exposure settings

    // while auto-exposure is locked. Stopping preview or taking a still image

    // will release the lock. However, the lock can be re-enabled prior to

    // preview being re-started, to keep the exposure values from the previous

    // lock. In conjunction with exposure compensation, this allows for

    // capturing multi-exposure brackets with known relative exposure

    // values. Locking auto-exposure after open but before the first cal to

    // startPreview may result in severly over- or under-exposed images.  The

    // driver may independently enable the AE lock after auto-focus

    // completes. If it does so, this key must have its value updated to reflect

    // the lock's existence. Applications are free to release such a lock, to

    // re-enable AE without restarting preview.

    static const char KEY_AUTO_EXPOSURE_LOCK[];

    // Whether locking the auto-exposure is supported. "true" means it is, and

    // "false" or this key not existing means it is not supported.

    static const char KEY_AUTO_EXPOSURE_LOCK_SUPPORTED[];

    // The maximum number of metering areas supported. This is the maximum

    // length of KEY_METERING_AREAS.

    // Example value: "0" or "2". Read only.

    // Value for KEY_ZOOM_SUPPORTED or KEY_SMOOTH_ZOOM_SUPPORTED.

    static const char TRUE[];

    static const char FALSE[];

    // Value for KEY_FOCUS_DISTANCES.

    static const char FOCUS_DISTANCE_INFINITY[];