Allow empty group creation.

app/src/main/java/org/thoughtcrime/securesms/groups/ui/creategroup/CreateGroupActivity.java

@@ -3,6 +3,7 @@ package org.thoughtcrime.securesms.groups.ui.creategroup;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
+import android.util.Pair;
 import android.view.MenuItem;
 import android.view.View;
 
@@ -40,7 +41,6 @@ public class CreateGroupActivity extends ContactSelectionActivity {
 
   private static final String TAG = Log.tag(CreateGroupActivity.class);
 
-  private static final int   MINIMUM_GROUP_SIZE       = 1;
   private static final short REQUEST_CODE_ADD_DETAILS = 17275;
 
   private View next;
@@ -68,7 +68,6 @@ public class CreateGroupActivity extends ContactSelectionActivity {
 
     next = findViewById(R.id.next);
 
-    disableNext();
     next.setOnClickListener(v -> handleNextPressed());
   }
 
@@ -107,10 +106,6 @@ public class CreateGroupActivity extends ContactSelectionActivity {
     if (contactsFragment.hasQueryFilter()) {
       getToolbar().clear();
     }
-
-    if (contactsFragment.getSelectedContactsCount() < MINIMUM_GROUP_SIZE) {
-      disableNext();
-    }
   }
 
   private void enableNext() {
@@ -167,28 +162,33 @@ public class CreateGroupActivity extends ContactSelectionActivity {
 
       resolved = Recipient.resolvedList(ids);
 
+      Pair<Boolean, List<RecipientId>> result;
+
       boolean gv2 = Stream.of(recipientsAndSelf).allMatch(r -> r.getGroupsV2Capability() == Recipient.Capability.SUPPORTED);
       if (!gv2 && Stream.of(resolved).anyMatch(r -> !r.hasE164()))
       {
         Log.w(TAG, "Invalid GV1 group...");
         ids = Collections.emptyList();
+        result = Pair.create(false, ids);
+      } else {
+        result = Pair.create(true, ids);
       }
 
       stopwatch.split("gv1-check");
 
-      return ids;
+      return result;
-    }, ids -> {
+    }, result -> {
       dismissibleDialog.dismiss();
 
       stopwatch.stop(TAG);
 
-      if (ids.isEmpty()) {
+      if (result.first) {
+        startActivityForResult(AddGroupDetailsActivity.newIntent(this, result.second), REQUEST_CODE_ADD_DETAILS);
+      } else {
         new AlertDialog.Builder(this)
                        .setMessage(R.string.CreateGroupActivity_some_contacts_cannot_be_in_legacy_groups)
                        .setPositiveButton(android.R.string.ok, (d, w) -> d.dismiss())
                        .show();
-      } else {
-        startActivityForResult(AddGroupDetailsActivity.newIntent(this, ids), REQUEST_CODE_ADD_DETAILS);
       }
     });
   }

app/src/main/java/org/thoughtcrime/securesms/groups/ui/creategroup/details/AddGroupDetailsFragment.java

@@ -106,13 +106,7 @@ public class AddGroupDetailsFragment extends LoggingFragment {
     name.addTextChangedListener(new AfterTextChanged(editable -> viewModel.setName(editable.toString())));
     toolbar.setNavigationOnClickListener(unused -> callback.onNavigationButtonPressed());
     create.setOnClickListener(v -> handleCreateClicked());
-    viewModel.getMembers().observe(getViewLifecycleOwner(), recipients -> {
+    viewModel.getMembers().observe(getViewLifecycleOwner(), members::setMembers);
-      members.setMembers(recipients);
-      if (recipients.isEmpty()) {
-        toast(R.string.AddGroupDetailsFragment__groups_require_at_least_two_members);
-        callback.onNavigationButtonPressed();
-      }
-    });
     viewModel.getCanSubmitForm().observe(getViewLifecycleOwner(), isFormValid -> setCreateEnabled(isFormValid, true));
     viewModel.getIsMms().observe(getViewLifecycleOwner(), isMms -> {
       mmsWarning.setVisibility(isMms ? View.VISIBLE : View.GONE);
@@ -230,10 +224,6 @@ public class AddGroupDetailsFragment extends LoggingFragment {
       case ERROR_INVALID_NAME:
         name.setError(getString(R.string.AddGroupDetailsFragment__this_field_is_required));
         break;
-      case ERROR_INVALID_MEMBER_COUNT:
-        toast(R.string.AddGroupDetailsFragment__groups_require_at_least_two_members);
-        callback.onNavigationButtonPressed();
-        break;
       default:
         throw new IllegalStateException("Unexpected error: " + error.getErrorType().name());
     }

app/src/main/java/org/thoughtcrime/securesms/groups/ui/creategroup/details/AddGroupDetailsViewModel.java

@@ -124,11 +124,6 @@ public final class AddGroupDetailsViewModel extends ViewModel {
       return;
     }
 
-    if (memberIds.isEmpty()) {
-      groupCreateResult.postValue(GroupCreateResult.error(GroupCreateResult.Error.Type.ERROR_INVALID_MEMBER_COUNT));
-      return;
-    }
-
     repository.createGroup(memberIds,
                            avatarBytes,
                            groupName,

app/src/main/java/org/thoughtcrime/securesms/groups/ui/creategroup/details/GroupCreateResult.java

@@ -86,8 +86,7 @@ abstract class GroupCreateResult {
       ERROR_IO,
       ERROR_BUSY,
       ERROR_FAILED,
-      ERROR_INVALID_NAME,
+      ERROR_INVALID_NAME
-      ERROR_INVALID_MEMBER_COUNT
     }
   }