Key event delegate to navigate through the carousel using TalkBack

CarouselKeyEventDelegate.kt

class CarouselKeyEventDelegate : BaseKeyEventDelegate() {

    init {
        keyEventActionMap.let {
            it.put(
                createKey(
                    R.id.carousel_container,
                    KEYCODE_DPAD_DOWN
                ),
                this::consumeDownKeyOnCarouselContainer
            )
            it.put(
                createKey(
                    R.id.carousel_container,
                    KEYCODE_DPAD_UP
                ),
                this::consumeUpKeyOnCarouselContainer
            )
            it.put(
                createKey(
                    R.id.carousel_container,
                    KEYCODE_ENTER
                ),
                this::consumeEnterKeyOnCarouselContainer
            )
            it.put(
                createKey(
                    R.id.carousel_element_item,
                    KEYCODE_DPAD_DOWN
                ),
                this::consumeDownKeyOnCarousel
            )
            it.put(
                createKey(
                    R.id.carousel_element_item,
                    KEYCODE_DPAD_UP
                ),
                this::consumeUpKeyOnCarousel
            )
            it.put(
                createKey(
                    R.id.carousel_element_item,
                    KEYCODE_DPAD_LEFT
                ),
                this::consumeLeftKeyOnCarousel
            )
            it.put(
                createKey(
                    R.id.carousel_element_item,
                    KEYCODE_DPAD_RIGHT
                ),
                this::consumeRightKeyOnCarousel
            )
        }
    }

    private fun consumeDownKeyOnCarouselContainer(currentFocus: View): Boolean {
        currentFocus.nextFocusDownId = R.id.button_turn_on
        return false
    }

    private fun consumeUpKeyOnCarouselContainer(currentFocus: View): Boolean {
        currentFocus.rootView.findViewById<RecyclerView>(R.id.gridRV)?.sendFocusToLastElement()
        return true
    }

    private fun consumeEnterKeyOnCarouselContainer(currentFocus: View): Boolean {
        currentFocus.findViewById<RecyclerView>(R.id.carouselRV)?.sendFocusToFirstElement()
        return false
    }

    private fun consumeDownKeyOnCarousel(currentFocus: View): Boolean = with(currentFocus) {
        getNextElementPosition().let { nextElementPosition ->
            if (isPositionInbound(nextElementPosition)) {
                sendFocusToListItem(nextElementPosition)
            } else {
                rootView.findViewById<View>(R.id.carousel_container)?.sendAccessibilityFocus()
            }
        }
        return true
    }

    private fun consumeUpKeyOnCarousel(currentFocus: View): Boolean = with(currentFocus) {
        getPreviousElementPosition().let { previousElementPosition ->
            if (isPositionInbound(previousElementPosition)) {
                sendFocusToListItem(previousElementPosition)
            } else {
                rootView.findViewById<View>(R.id.carousel_container)?.sendAccessibilityFocus()
            }
        }
        return true
    }

    private fun consumeLeftKeyOnCarousel(currentFocus: View): Boolean {
        currentFocus.rootView.findViewById<View>(R.id.carousel_container)?.sendAccessibilityFocus()
        return true
    }

    private fun consumeRightKeyOnCarousel(currentFocus: View): Boolean {
        currentFocus.rootView.findViewById<View>(R.id.carousel_container)?.sendAccessibilityFocus()
        return true
    }
}