Merge pull request #1617 from deltachat/fix-relaunch2

fix launch if there is an ongoing process

res/values/strings.xml

@@ -482,6 +482,7 @@
     <string name="pref_background_default_color">Default color</string>
     <string name="pref_background_custom_image">Custom image</string>
     <string name="pref_background_custom_color">Custom color</string>
+    <string name="export_aborted">Export aborted.</string>
 
     <!-- automatically delete message -->
     <string name="delete_old_messages">Delete old messages</string>

src/org/thoughtcrime/securesms/DummyActivity.java

@@ -3,10 +3,8 @@ package org.thoughtcrime.securesms;
 import android.app.Activity;
 import android.os.Bundle;
 
-/**
- * Workaround for Android bug:
- * https://code.google.com/p/android/issues/detail?id=53313
- */
+// dummy activity that just pushes the app to foreground when fired.
+// can also be used to work around android bug https://code.google.com/p/android/issues/detail?id=53313
 public class DummyActivity extends Activity {
   @Override
   public void onCreate(Bundle bundle) {

src/org/thoughtcrime/securesms/PassphraseRequiredActionBarActivity.java

@@ -9,6 +9,7 @@ import androidx.fragment.app.Fragment;
 import android.util.Log;
 
 import org.thoughtcrime.securesms.connect.DcHelper;
+import org.thoughtcrime.securesms.service.GenericForegroundService;
 
 import java.util.Locale;
 
@@ -22,6 +23,15 @@ public abstract class PassphraseRequiredActionBarActivity extends BaseActionBarA
     Log.w(TAG, "onCreate(" + savedInstanceState + ")");
     onPreCreate();
 
+    if (GenericForegroundService.isForegroundTaskStarted()) {
+      // this does not prevent intent set by onNewIntent(),
+      // however, at least during onboarding,
+      // this catches a lot of situations with otherwise weird app states.
+      super.onCreate(savedInstanceState);
+      finish();
+      return;
+    }
+
     if (!DcHelper.isConfigured(getApplicationContext())) {
       Intent intent = new Intent(this, WelcomeActivity.class);
       startActivity(intent);

src/org/thoughtcrime/securesms/preferences/ListSummaryPreferenceFragment.java

@@ -3,6 +3,7 @@ package org.thoughtcrime.securesms.preferences;
 
 import android.content.DialogInterface;
 import android.os.Bundle;
+import android.widget.Toast;
 
 import androidx.appcompat.app.AlertDialog;
 import androidx.preference.ListPreference;
@@ -37,6 +38,28 @@ public abstract class ListSummaryPreferenceFragment extends CorrectedPreferenceF
   @Override
   public void onDestroy() {
     dcContext.eventCenter.removeObservers(this);
+
+    if (notificationController != null) {
+      // cancel backup when settings-activity is destroyed.
+      //
+      // where possible, we avoid the settings-activity from being destroyed,
+      // however, i did not find a simple way to cancel ConversationListActivity.onNewIntent() -
+      // which one is cleaning up "back stack" due to the singleTask flag.
+      // using a dummy activity and several workarounds all result even in worse side-effects
+      // than cancel-backup when the user relaunches the app.
+      // maybe we could bear the singleTask flag or could decouple
+      // backup completely from ui-flows -
+      // however, all this is some work and probably not maybe the effort just now.
+      //
+      // anyway, normally, the backup is fast enough and the users will just wait.
+      // btw, import does not have this issue (no singleTask in play there)
+      // and also for export, switching to other apps and tapping the notification will work.
+      // so, the current state is not that bad :)
+      notificationController.close();
+      dcContext.stopOngoingProcess();
+      Toast.makeText(getActivity(), R.string.export_aborted, Toast.LENGTH_LONG).show();
+    }
+
     super.onDestroy();
   }
 
@@ -83,6 +106,7 @@ public abstract class ListSummaryPreferenceFragment extends CorrectedPreferenceF
     progressDialog.setButton(DialogInterface.BUTTON_NEGATIVE, getActivity().getString(android.R.string.cancel), (dialog, which) -> {
       dcContext.stopOngoingProcess();
       notificationController.close();
+      notificationController = null;
     });
     progressDialog.show();
 
@@ -106,6 +130,7 @@ public abstract class ListSummaryPreferenceFragment extends CorrectedPreferenceF
                   .show();
         }
         notificationController.close();
+        notificationController = null;
       }
       else if (progress<1000/*progress in permille*/) {
         int percent = (int)progress / 10;
@@ -118,6 +143,7 @@ public abstract class ListSummaryPreferenceFragment extends CorrectedPreferenceF
         progressDialog.dismiss();
         progressDialog = null;
         notificationController.close();
+        notificationController = null;
         String msg = "";
         if (progressWhat==DcContext.DC_IMEX_EXPORT_BACKUP) {
           msg = getActivity().getString(R.string.pref_backup_written_to_x, imexDir);

src/org/thoughtcrime/securesms/service/GenericForegroundService.java

@@ -3,6 +3,7 @@ package org.thoughtcrime.securesms.service;
 import android.annotation.TargetApi;
 import android.app.NotificationChannel;
 import android.app.NotificationManager;
+import android.app.PendingIntent;
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
@@ -17,6 +18,7 @@ import androidx.annotation.Nullable;
 import androidx.core.app.NotificationCompat.Builder;
 import androidx.core.content.ContextCompat;
 
+import org.thoughtcrime.securesms.DummyActivity;
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.notifications.NotificationCenter;
 
@@ -47,6 +49,7 @@ public final class GenericForegroundService extends Service {
   private static final AtomicInteger NEXT_ID = new AtomicInteger();
   private static final AtomicBoolean CHANNEL_CREATED = new AtomicBoolean(false);
 
+  private static int startedCounter = 0;
 
   private final LinkedHashMap<Integer, Entry> allActiveMessages = new LinkedHashMap<>();
 
@@ -114,6 +117,7 @@ public final class GenericForegroundService extends Service {
                                                            .setTicker(active.contentText)
                                                            .setContentText(active.contentText)
                                                            .setProgress(active.progressMax, active.progress, active.indeterminate)
+                                                           .setContentIntent(PendingIntent.getActivity(this, 0, new Intent(this, DummyActivity.class), 0))
                                                            .build());
   }
 
@@ -124,6 +128,7 @@ public final class GenericForegroundService extends Service {
 
 
   public static NotificationController startForegroundTask(@NonNull Context context, @NonNull String task) {
+    startedCounter++;
     final int id = NEXT_ID.getAndIncrement();
 
     createFgNotificationChannel(context);
@@ -145,6 +150,11 @@ public final class GenericForegroundService extends Service {
     intent.putExtra(EXTRA_ID, id);
 
     ContextCompat.startForegroundService(context, intent);
+    startedCounter = Math.max(startedCounter-1, 0);
+  }
+
+  public static boolean isForegroundTaskStarted() {
+    return startedCounter > 0;
   }
 
   synchronized void replaceProgress(int id, int progressMax, int progress, boolean indeterminate, String message) {