Signal-Android/app/src/main/java/org/thoughtcrime/securesms/devicetransfer/newdevice/NewDeviceTransferFragment.java

package org.thoughtcrime.securesms.devicetransfer.newdevice;

import android.os.Bundle;
import android.view.View;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.navigation.fragment.NavHostFragment;

import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.greenrobot.eventbus.ThreadMode;
import org.signal.devicetransfer.DeviceToDeviceTransferService;
import org.thoughtcrime.securesms.R;
import org.thoughtcrime.securesms.devicetransfer.DeviceTransferFragment;

/**
 * Shows transfer progress on the new device. Most logic is in {@link DeviceTransferFragment}
 * and it delegates to this class for strings, navigation, and updating progress.
 */
public final class NewDeviceTransferFragment extends DeviceTransferFragment {

  private final ServerTaskListener serverTaskListener = new ServerTaskListener();

  @Override
  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    EventBus.getDefault().register(serverTaskListener);
  }

  @Override
  public void onDestroyView() {
    EventBus.getDefault().unregister(serverTaskListener);
    super.onDestroyView();
  }

  @Override
  protected void navigateToRestartTransfer() {
    NavHostFragment.findNavController(this).navigate(R.id.action_newDeviceTransfer_to_newDeviceTransferInstructions);
  }

  @Override
  protected void navigateAwayFromTransfer() {
    EventBus.getDefault().unregister(serverTaskListener);
    NavHostFragment.findNavController(this)
                   .navigate(R.id.action_restart_to_welcomeFragment);
  }

  @Override
  protected void navigateToTransferComplete() {
    NavHostFragment.findNavController(this).navigate(R.id.action_newDeviceTransfer_to_newDeviceTransferComplete);
  }

  private class ServerTaskListener {
    @Subscribe(threadMode = ThreadMode.MAIN)
    public void onEventMainThread(@NonNull NewDeviceServerTask.Status event) {
      status.setText(getString(R.string.DeviceTransfer__d_messages_so_far, event.getMessageCount()));
      switch (event.getState()) {
        case IN_PROGRESS:
          break;
        case SUCCESS:
          transferFinished = true;
          DeviceToDeviceTransferService.stop(requireContext());
          navigateToTransferComplete();
          break;
        case FAILURE_VERSION_DOWNGRADE:
          abort(R.string.NewDeviceTransfer__cannot_transfer_from_a_newer_version_of_signal);
          break;
        case FAILURE_UNKNOWN:
          abort();
          break;
      }
    }
  }
}