折りたたみ式ディスプレイ モードをサポートする

dependencies {
    // Define window_version in your project's build configuration.
    implementation("androidx.window:window:$window_version")
}

dependencies {
    // TODO: Define window_version in your project's build configuration.
    implementation "androidx.window:window:$window_version"
}

private lateinit var windowAreaController: WindowAreaController
private lateinit var displayExecutor: Executor
private var windowAreaSession: WindowAreaSession? = null
private var windowAreaInfo: WindowAreaInfo? = null
private var capabilityStatus: WindowAreaCapability.Status =
    WindowAreaCapability.Status.WINDOW_AREA_STATUS_UNSUPPORTED

private val dualScreenOperation = WindowAreaCapability.Operation.OPERATION_PRESENT_ON_AREA
private val rearDisplayOperation = WindowAreaCapability.Operation.OPERATION_TRANSFER_ACTIVITY_TO_AREA
SupportFoldableDisplayModes.kt

private WindowAreaControllerCallbackAdapter windowAreaController = null;
private Executor displayExecutor = null;
private WindowAreaSessionPresenter windowAreaSession = null;
private WindowAreaInfo windowAreaInfo = null;
private WindowAreaCapability.Status capabilityStatus  =
        WindowAreaCapability.Status.WINDOW_AREA_STATUS_UNSUPPORTED;

private WindowAreaCapability.Operation dualScreenOperation =
        WindowAreaCapability.Operation.OPERATION_PRESENT_ON_AREA;
private WindowAreaCapability.Operation rearDisplayOperation =
        WindowAreaCapability.Operation.OPERATION_TRANSFER_ACTIVITY_TO_AREA;

displayExecutor = ContextCompat.getMainExecutor(this)
windowAreaController = WindowAreaController.getOrCreate()

lifecycleScope.launch(Dispatchers.Main) {
    lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
        windowAreaController.windowAreaInfos
            .map { info -> info.firstOrNull { it.type == WindowAreaInfo.Type.TYPE_REAR_FACING } }
            .onEach { info -> windowAreaInfo = info }
            .map { it?.getCapability(operation)?.status ?: WindowAreaCapability.Status.WINDOW_AREA_STATUS_UNSUPPORTED }
            .distinctUntilChanged()
            .collect {
                capabilityStatus = it
            }
    }
}
SupportFoldableDisplayModes.kt

displayExecutor = ContextCompat.getMainExecutor(this);
windowAreaController = new WindowAreaControllerCallbackAdapter(WindowAreaController.getOrCreate());
windowAreaController.addWindowAreaInfoListListener(displayExecutor, this);

windowAreaController.addWindowAreaInfoListListener(displayExecutor,
  windowAreaInfos -> {
    for(WindowAreaInfo newInfo : windowAreaInfos){
        if(newInfo.getType().equals(WindowAreaInfo.Type.TYPE_REAR_FACING)){
            windowAreaInfo = newInfo;
            capabilityStatus = newInfo.getCapability(presentOperation).getStatus();
            break;
        }
    }
});

when (capabilityStatus) {
    WindowAreaCapability.Status.WINDOW_AREA_STATUS_UNSUPPORTED -> {
      // The selected display mode is not supported on this device.
    }
    WindowAreaCapability.Status.WINDOW_AREA_STATUS_UNAVAILABLE -> {
      // The selected display mode is not available.
    }
    WindowAreaCapability.Status.WINDOW_AREA_STATUS_AVAILABLE -> {
      // The selected display mode is available and can be enabled.
    }
    WindowAreaCapability.Status.WINDOW_AREA_STATUS_ACTIVE -> {
      // The selected display mode is already active.
    }
    else -> {
      // The selected display mode status is unknown.
    }
}
SupportFoldableDisplayModes.kt

if (capabilityStatus.equals(WindowAreaCapability.Status.WINDOW_AREA_STATUS_UNSUPPORTED)) {
  // The selected display mode is not supported on this device.
}
else if (capabilityStatus.equals(WindowAreaCapability.Status.WINDOW_AREA_STATUS_UNAVAILABLE)) {
  // The selected display mode is not available.
}
else if (capabilityStatus.equals(WindowAreaCapability.Status.WINDOW_AREA_STATUS_AVAILABLE)) {
  // The selected display mode is available and can be enabled.
}
else if (capabilityStatus.equals(WindowAreaCapability.Status.WINDOW_AREA_STATUS_ACTIVE)) {
  // The selected display mode is already active.
}
else {
  // The selected display mode status is unknown.
}

fun toggleDualScreenMode() {
    if (windowAreaSession != null) {
        windowAreaSession?.close()
    }
    else {
        windowAreaInfo?.token?.let { token ->
            windowAreaController.presentContentOnWindowArea(
                token = token,
                activity = this,
                executor = displayExecutor,
                windowAreaPresentationSessionCallback = this
            )
        }
    }
}
SupportFoldableDisplayModes.kt

private void toggleDualScreenMode() {
    if(windowAreaSession != null) {
        windowAreaSession.close();
    }
    else {
        Binder token = windowAreaInfo.getToken();
        windowAreaController.presentContentOnWindowArea( token, this, displayExecutor, this);
    }
}

class ExampleActivity : ComponentActivity(), WindowAreaPresentationSessionCallback {
SupportFoldableDisplayModes.kt

public class MainActivity extends AppCompatActivity implements WindowAreaPresentationSessionCallback

override fun onSessionStarted(session: WindowAreaSessionPresenter) {
    windowAreaSession = session
    session.setContentView(ComposeView(session.context).apply {
        setContent {
            MyScreen()
        }
    })
}

override fun onSessionEnded(t: Throwable?) {
    if (t != null) {
        Log.e(logTag, "Something was broken: ${t.message}")
    }
}

override fun onContainerVisibilityChanged(isVisible: Boolean) {
     Log.d(logTag, "onContainerVisibilityChanged. isVisible = $isVisible")
}
SupportFoldableDisplayModes.kt

@Override
public void onSessionStarted(@NonNull WindowAreaSessionPresenter session) {
    windowAreaSession = session;
    TextView view = new TextView(session.getContext());
    view.setText("Hello world, from the other screen!");
    session.setContentView(view);
}

@Override public void onSessionEnded(@Nullable Throwable t) {
    if(t != null) {
        Log.e(logTag, "Something was broken: ${t.message}");
    }
}

@Override public void onContainerVisibilityChanged(boolean isVisible) {
    Log.d(logTag, "onContainerVisibilityChanged. isVisible = " + isVisible);
}

fun toggleRearDisplayMode() {
    if(capabilityStatus == WindowAreaCapability.Status.WINDOW_AREA_STATUS_ACTIVE) {
        if(windowAreaSession == null) {
            windowAreaSession = windowAreaInfo?.getActiveSession(
                operation
            )
        }
        windowAreaSession?.close()
    } else {
        windowAreaInfo?.token?.let { token ->
            windowAreaController.transferActivityToWindowArea(
                token = token,
                activity = this,
                executor = displayExecutor,
                windowAreaSessionCallback = this
            )
        }
    }
}
SupportFoldableDisplayModes.kt

void toggleRearDisplayMode() {
    if(capabilityStatus == WindowAreaCapability.Status.WINDOW_AREA_STATUS_ACTIVE) {
        if(windowAreaSession == null) {
            windowAreaSession = windowAreaInfo.getActiveSession(
                operation
            )
        }
        windowAreaSession.close();
    }
    else {
        Binder token = windowAreaInfo.getToken();
        windowAreaController.transferActivityToWindowArea(token, this, displayExecutor, this);
    }
}

override fun onSessionStarted(session: WindowAreaSession) {
     Log.d(logTag, "onSessionStarted")
}

override fun onSessionEnded(t: Throwable?) {
    if (t != null) {
        Log.e(logTag, "Something was broken: ${t.message}")
    }
}
SupportFoldableDisplayModes.kt

@Override public void onSessionStarted(){
    Log.d(logTag, "onSessionStarted");
}

@Override public void onSessionEnded(@Nullable Throwable t) {
    if(t != null) {
        Log.e(logTag, "Something was broken: ${t.message}");
    }
}