Photo start and stop

Camera 1

When can I start or stop photo capture ?

Photo capture can be started only when all of the the following conditions are met:

• camera is active: camera.isActive == true

• camera mode is photo: camera.mode().value == Camera.Mode.PHOTO

• photo state is stopped: camera.photoState().get() == CameraPhoto.State.FunctionState.STOPPED

Photo capture can be stopped when the following condition is true:

• photo state is started: camera.photoState().get() == CameraPhoto.State.FunctionState.STARTED

The Camera API provides helper methods telling whether photo capture can be started are stopped:

• camera.canStartPhotoCapture(): tells whether photo capture can be started

• camera.canStopPhotoCapture(): tells whether photo capture can be stopped

Sample code to monitor whether photo capture can be started or stopped :

/** Reference on MainCamera peripheral. */
private var cameraRef: Ref<MainCamera>? = null

/** Monitors and prints whether photo capture can be started or stopped. */
fun monitorCanStartStopPhotoCapture(drone: Drone) {
    cameraRef = drone.getPeripheral(MainCamera::class.java) { camera ->
        // called on main thread when the camera peripheral changes
        camera?.run {
            when {
                canStartPhotoCapture() ->
                    println("Photo capture can be started")

                canStopPhotoCapture() ->
                    println("Photo capture can be stopped")

                else ->
                    println("Photo capture can't be started or stopped")
            }
        }
    }
}

How to start or stop photo capture ?

Sample code to start and stop photo capture:

/** Starts or stops photo capture. */
fun toggleStartStopPhotoCapture(drone: Drone) {
    drone.getPeripheral(MainCamera::class.java)?.run {
        when {
            // photo capture can be started
            canStartPhotoCapture() -> startPhotoCapture()

            // photo capture can be stopped
            canStopPhotoCapture() -> stopPhotoCapture()

            // photo capture can't be started or stopped
            else -> println("Photo capture can't be started or stopped")
        }
    }
}

Camera 2

When can I start or stop photo capture ?

Photo capture can be started only when all of the following conditions are met:

• camera is active: camera.active == true

• camera mode is photo: camera.config[Camera.Config.MODE].value == Camera.Mode.PHOTO

• photo capture state is stopped: camera.component<Camera.PhotoCapture>()?.state is Camera.PhotoCapture.State.Stopped

Photo capture can be stopped when the following condition is true:

• photo capture state is started or starting:

  • camera.component<Camera.PhotoCapture>()?.state is Camera.PhotoCapture.State.Starting

  • OR camera.component<Camera.PhotoCapture>()?.state is Camera.PhotoCapture.State.Started

Sample code to monitor whether photo capture can be started or stopped :

/** Reference on MainCamera peripheral. */
private var cameraRef: Ref<MainCamera>? = null
/** `MainCamera` peripheral. This is used to know when peripheral appears. */
private var mainCamera: Camera? = null

/** Monitors and prints whether photo capture can be started or stopped. */
fun monitorCanStartStopPhotoCapture(drone: Drone) {
    cameraRef = drone.getPeripheral(MainCamera::class.java) { camera ->
        // called on main thread when the camera peripheral changes
        camera?.run {
            // register sub-component listener, only when camera peripheral appears
            if (mainCamera == null) {
                // get notified every time photo capture sub-component changes
                camera.component<Camera.PhotoCapture> { photoCapture ->
                    when (photoCapture?.state) {
                        Camera.PhotoCapture.State.Starting,
                        is Camera.PhotoCapture.State.Started ->
                            println("Photo capture can be stopped")

                        is Camera.PhotoCapture.State.Stopped ->
                            println("Photo capture can be started")

                        else ->
                            println("Photo capture can't be started or stopped")
                    }
                }
            }
        }
        mainCamera = camera
    }
}

How to start or stop photo capture ?

Sample code to start and stop photo capture:

/** Starts or stops photo capture. */
fun toggleStartStopPhotoCapture(drone: Drone) {
    drone.getPeripheral(MainCamera::class.java)?.run {
        component<Camera.PhotoCapture>()?.apply {
            when (state) {
                // photo capture can be stopped
                Camera.PhotoCapture.State.Starting,
                is Camera.PhotoCapture.State.Started -> start()

                // photo capture can be started
                is Camera.PhotoCapture.State.Stopped -> stop()

                // photo capture state don't allow to start or stop
                else -> println("Photo capture can't be started or stopped")
            }
        } ?: run {
            // photo capture component not available at present
            println("Photo capture not available")
        }
    }
}