Enforce a local GV2 capacity limit driven by a feature flag.

app/src/main/java/org/thoughtcrime/securesms/ContactSelectionListFragment.java

@@ -29,6 +29,7 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.WindowManager;
+import android.view.animation.CycleInterpolator;
 import android.widget.Button;
 import android.widget.HorizontalScrollView;
 import android.widget.TextView;
@@ -67,7 +68,6 @@ import org.thoughtcrime.securesms.permissions.Permissions;
 import org.thoughtcrime.securesms.recipients.LiveRecipient;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientId;
-import org.thoughtcrime.securesms.util.Debouncer;
 import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.thoughtcrime.securesms.util.StickyHeaderDecoration;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
@@ -81,6 +81,7 @@ import org.whispersystems.libsignal.util.guava.Optional;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
+import java.util.Locale;
 
 /**
  * Fragment for selecting a one or more contacts from a list.
@@ -94,13 +95,16 @@ public final class ContactSelectionListFragment extends    Fragment
   @SuppressWarnings("unused")
   private static final String TAG = Log.tag(ContactSelectionListFragment.class);
 
-  private static final int CHIP_GROUP_EMPTY_COUNT        = 1;
+  private static final int CHIP_GROUP_EMPTY_CHILD_COUNT  = 1;
   private static final int CHIP_GROUP_REVEAL_DURATION_MS = 150;
 
-  public static final String DISPLAY_MODE = "display_mode";
+  public static final int NO_LIMIT = Integer.MAX_VALUE;
-  public static final String MULTI_SELECT = "multi_select";
+
-  public static final String REFRESHABLE  = "refreshable";
+  public static final String DISPLAY_MODE    = "display_mode";
-  public static final String RECENTS      = "recents";
+  public static final String MULTI_SELECT    = "multi_select";
+  public static final String REFRESHABLE     = "refreshable";
+  public static final String RECENTS         = "recents";
+  public static final String SELECTION_LIMIT = "selection_limit";
 
   private ConstraintLayout            constraintLayout;
   private TextView                    emptyText;
@@ -116,12 +120,14 @@ public final class ContactSelectionListFragment extends    Fragment
   private ContactSelectionListAdapter cursorRecyclerViewAdapter;
   private ChipGroup                   chipGroup;
   private HorizontalScrollView        chipGroupScrollContainer;
+  private TextView                    groupLimit;
 
   @Nullable private FixedViewsAdapter headerAdapter;
   @Nullable private FixedViewsAdapter footerAdapter;
   @Nullable private ListCallback      listCallback;
   @Nullable private ScrollCallback    scrollCallback;
             private GlideRequests     glideRequests;
+            private int               selectionLimit;
 
   @Override
   public void onAttach(@NonNull Context context) {
@@ -185,15 +191,29 @@ public final class ContactSelectionListFragment extends    Fragment
     showContactsProgress     = view.findViewById(R.id.progress);
     chipGroup                = view.findViewById(R.id.chipGroup);
     chipGroupScrollContainer = view.findViewById(R.id.chipGroupScrollContainer);
+    groupLimit               = view.findViewById(R.id.group_limit);
     constraintLayout         = view.findViewById(R.id.container);
 
     recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
 
     swipeRefresh.setEnabled(requireActivity().getIntent().getBooleanExtra(REFRESHABLE, true));
 
+    selectionLimit = requireActivity().getIntent().getIntExtra(SELECTION_LIMIT, NO_LIMIT);
+
+    updateGroupLimit(getChipCount());
+
     return view;
   }
 
+  private void updateGroupLimit(int childCount) {
+    if (selectionLimit != NO_LIMIT) {
+      groupLimit.setText(String.format(Locale.getDefault(), "%d/%d", childCount, selectionLimit));
+      groupLimit.setVisibility(View.VISIBLE);
+    } else {
+      groupLimit.setVisibility(View.GONE);
+    }
+  }
+
   @Override
   public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
     Permissions.onRequestPermissionsResult(this, requestCode, permissions, grantResults);
@@ -408,6 +428,12 @@ public final class ContactSelectionListFragment extends    Fragment
                                                                  : SelectedContact.forPhone(contact.getRecipientId().orNull(), contact.getNumber());
 
       if (!isMulti() || !cursorRecyclerViewAdapter.isSelectedContact(selectedContact)) {
+        if (selectionLimitReached()) {
+          Toast.makeText(requireContext(), R.string.ContactSelectionListFragment_the_group_is_full, Toast.LENGTH_SHORT).show();
+          groupLimit.animate().scaleX(1.3f).scaleY(1.3f).setInterpolator(new CycleInterpolator(0.5f)).start();
+          return;
+        }
+
         if (contact.isUsernameType()) {
           AlertDialog loadingDialog = SimpleProgressDialog.show(requireContext());
 
@@ -447,6 +473,10 @@ public final class ContactSelectionListFragment extends    Fragment
       }}
   }
 
+  private boolean selectionLimitReached() {
+    return getChipCount() >= selectionLimit;
+  }
+
   private void markContactSelected(@NonNull SelectedContact selectedContact, @NonNull ContactSelectionListItem listItem) {
     cursorRecyclerViewAdapter.addSelectedContact(selectedContact);
     listItem.setChecked(true);
@@ -469,7 +499,9 @@ public final class ContactSelectionListFragment extends    Fragment
       }
     }
 
-    if (chipGroup.getChildCount() == CHIP_GROUP_EMPTY_COUNT) {
+    updateGroupLimit(getChipCount());
+
+    if (getChipCount() == 0) {
       setChipGroupVisibility(ConstraintSet.GONE);
     }
   }
@@ -477,7 +509,7 @@ public final class ContactSelectionListFragment extends    Fragment
   private void addChipForContact(@NonNull ContactSelectionListItem contact, @NonNull SelectedContact selectedContact) {
     final ContactChip chip = new ContactChip(requireContext());
 
-    if (chipGroup.getChildCount() == CHIP_GROUP_EMPTY_COUNT) {
+    if (getChipCount() == 0) {
       setChipGroupVisibility(ConstraintSet.VISIBLE);
     }
 
@@ -503,12 +535,23 @@ public final class ContactSelectionListFragment extends    Fragment
 
     LiveRecipient recipient = contact.getRecipient();
     if (recipient != null) {
-      chip.setAvatar(glideRequests, recipient.get(), () -> chipGroup.addView(chip));
+      chip.setAvatar(glideRequests, recipient.get(), () -> addChip(chip));
     } else {
-      chipGroup.addView(chip);
+      addChip(chip);
     }
   }
 
+  private void addChip(@NonNull ContactChip chip) {
+    chipGroup.addView(chip);
+    updateGroupLimit(getChipCount());
+  }
+
+  private int getChipCount() {
+    int count = chipGroup.getChildCount() - CHIP_GROUP_EMPTY_CHILD_COUNT;
+    if (count < 0) throw new AssertionError();
+    return count;
+  }
+
   private void registerChipRecipientObserver(@NonNull ContactChip chip, @Nullable LiveRecipient recipient) {
     if (recipient != null) {
       recipient.observe(getViewLifecycleOwner(), resolved -> {

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

@@ -44,6 +44,7 @@ public class CreateGroupActivity extends ContactSelectionActivity {
                                                                   : ContactsCursorLoader.DisplayMode.FLAG_PUSH;
 
     intent.putExtra(ContactSelectionListFragment.DISPLAY_MODE, displayMode);
+    intent.putExtra(ContactSelectionListFragment.SELECTION_LIMIT, FeatureFlags.gv2GroupCapacity() - 1);
 
     return intent;
   }

app/src/main/java/org/thoughtcrime/securesms/groups/ui/managegroup/ManageGroupFragment.java

@@ -23,14 +23,12 @@ import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.ViewModelProviders;
 
 import org.thoughtcrime.securesms.AvatarPreviewActivity;
-import org.thoughtcrime.securesms.ContactSelectionListFragment;
 import org.thoughtcrime.securesms.MediaPreviewActivity;
 import org.thoughtcrime.securesms.MuteDialog;
 import org.thoughtcrime.securesms.PushContactSelectionActivity;
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.components.AvatarImageView;
 import org.thoughtcrime.securesms.components.ThreadPhotoRailView;
-import org.thoughtcrime.securesms.contacts.ContactsCursorLoader;
 import org.thoughtcrime.securesms.contacts.avatars.FallbackContactPhoto;
 import org.thoughtcrime.securesms.contacts.avatars.ResourceContactPhoto;
 import org.thoughtcrime.securesms.groups.GroupId;
@@ -225,11 +223,7 @@ public class ManageGroupFragment extends Fragment {
     disappearingMessagesRow.setOnClickListener(v -> viewModel.handleExpirationSelection());
     blockGroup.setOnClickListener(v -> viewModel.blockAndLeave(requireActivity()));
 
-    addMembers.setOnClickListener(v -> {
+    addMembers.setOnClickListener(v -> viewModel.onAddMembersClick(this, PICK_CONTACT));
-      Intent intent = new Intent(requireActivity(), PushContactSelectionActivity.class);
-      intent.putExtra(ContactSelectionListFragment.DISPLAY_MODE, ContactsCursorLoader.DisplayMode.FLAG_PUSH);
-      startActivityForResult(intent, PICK_CONTACT);
-    });
 
     viewModel.getMembershipRights().observe(getViewLifecycleOwner(), r -> {
         if (r != null) {

app/src/main/java/org/thoughtcrime/securesms/groups/ui/managegroup/ManageGroupRepository.java

@@ -6,7 +6,10 @@ import androidx.annotation.NonNull;
 import androidx.annotation.WorkerThread;
 import androidx.core.util.Consumer;
 
+import org.signal.storageservice.protos.groups.local.DecryptedGroup;
+import org.thoughtcrime.securesms.ContactSelectionListFragment;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.database.GroupDatabase;
 import org.thoughtcrime.securesms.database.ThreadDatabase;
 import org.thoughtcrime.securesms.groups.GroupAccessControl;
 import org.thoughtcrime.securesms.groups.GroupChangeBusyException;
@@ -21,6 +24,7 @@ import org.thoughtcrime.securesms.groups.ui.GroupChangeFailureReason;
 import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientId;
+import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.thoughtcrime.securesms.util.concurrent.SignalExecutors;
 import org.thoughtcrime.securesms.util.concurrent.SimpleTask;
 
@@ -47,6 +51,18 @@ final class ManageGroupRepository {
     SignalExecutors.BOUNDED.execute(() -> onGroupStateLoaded.accept(getGroupState()));
   }
 
+  void getGroupCapacity(@NonNull Consumer<GroupCapacityResult> onGroupCapacityLoaded) {
+    SimpleTask.run(SignalExecutors.BOUNDED, () -> {
+      GroupDatabase.GroupRecord groupRecord = DatabaseFactory.getGroupDatabase(context).getGroup(groupId).get();
+      if (groupRecord.isV2Group()) {
+        DecryptedGroup decryptedGroup = groupRecord.requireV2GroupProperties().getDecryptedGroup();
+        return new GroupCapacityResult(decryptedGroup.getMembersCount(), decryptedGroup.getPendingMembersCount(), FeatureFlags.gv2GroupCapacity());
+      } else {
+        return new GroupCapacityResult(groupRecord.getMembers().size(), 0, ContactSelectionListFragment.NO_LIMIT);
+      }
+    }, onGroupCapacityLoaded::accept);
+  }
+
   @WorkerThread
   private GroupStateResult getGroupState() {
     ThreadDatabase threadDatabase = DatabaseFactory.getThreadDatabase(context);
@@ -152,4 +168,20 @@ final class ManageGroupRepository {
     }
   }
 
+  static final class GroupCapacityResult {
+    private final int fullMembers;
+    private final int pendingMembers;
+    private final int totalCapacity;
+
+    GroupCapacityResult(int fullMembers, int pendingMembers, int totalCapacity) {
+      this.fullMembers    = fullMembers;
+      this.pendingMembers = pendingMembers;
+      this.totalCapacity  = totalCapacity;
+    }
+
+    public int getRemainingCapacity() {
+      return totalCapacity - fullMembers - pendingMembers;
+    }
+  }
+
 }

app/src/main/java/org/thoughtcrime/securesms/groups/ui/managegroup/ManageGroupViewModel.java

@@ -1,11 +1,13 @@
 package org.thoughtcrime.securesms.groups.ui.managegroup;
 
 import android.content.Context;
+import android.content.Intent;
 import android.database.Cursor;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.WorkerThread;
+import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
@@ -14,7 +16,11 @@ import androidx.lifecycle.ViewModel;
 import androidx.lifecycle.ViewModelProvider;
 
 import org.thoughtcrime.securesms.BlockUnblockDialog;
+import org.thoughtcrime.securesms.ContactSelectionListFragment;
 import org.thoughtcrime.securesms.ExpirationDialog;
+import org.thoughtcrime.securesms.PushContactSelectionActivity;
+import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.contacts.ContactsCursorLoader;
 import org.thoughtcrime.securesms.database.MediaDatabase;
 import org.thoughtcrime.securesms.database.loaders.MediaLoader;
 import org.thoughtcrime.securesms.database.loaders.ThreadMediaLoader;
@@ -211,6 +217,20 @@ public class ManageGroupViewModel extends ViewModel {
     Util.runOnMain(() -> Toast.makeText(context, GroupErrors.getUserDisplayMessage(e), Toast.LENGTH_LONG).show());
   }
 
+  public void onAddMembersClick(@NonNull Fragment fragment, int resultCode) {
+    manageGroupRepository.getGroupCapacity(capacity -> {
+      int remainingCapacity = capacity.getRemainingCapacity();
+      if (remainingCapacity <= 0) {
+        Toast.makeText(fragment.requireContext(), R.string.ContactSelectionListFragment_the_group_is_full, Toast.LENGTH_SHORT).show();
+      } else {
+        Intent intent = new Intent(fragment.requireActivity(), PushContactSelectionActivity.class);
+        intent.putExtra(ContactSelectionListFragment.DISPLAY_MODE, ContactsCursorLoader.DisplayMode.FLAG_PUSH);
+        intent.putExtra(ContactSelectionListFragment.SELECTION_LIMIT, remainingCapacity);
+        fragment.startActivityForResult(intent, resultCode);
+      }
+    });
+  }
+
   static final class GroupViewState {
              private final long          threadId;
     @NonNull private final Recipient     groupRecipient;

app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java

@@ -65,6 +65,7 @@ public final class FeatureFlags {
   private static final String VERSIONED_PROFILES         = "android.versionedProfiles";
   private static final String GROUPS_V2                  = "android.groupsv2";
   private static final String GROUPS_V2_CREATE           = "android.groupsv2.create";
+  private static final String GROUPS_V2_CAPACITY         = "android.groupsv2.capacity";
 
   /**
    * We will only store remote values for flags in this set. If you want a flag to be controllable
@@ -87,6 +88,7 @@ public final class FeatureFlags {
       VERSIONED_PROFILES,
       GROUPS_V2,
       GROUPS_V2_CREATE,
+      GROUPS_V2_CAPACITY,
       NEW_GROUP_UI
   );
 
@@ -283,6 +285,13 @@ public final class FeatureFlags {
     return groupsV2() && getBoolean(GROUPS_V2_CREATE, false);
   }
 
+  /**
+   * Maximum number of members allowed in a group.
+   */
+  public static int gv2GroupCapacity() {
+    return getInteger(GROUPS_V2_CAPACITY, 100);
+  }
+
   /** Only for rendering debug info. */
   public static synchronized @NonNull Map<String, Object> getMemoryValues() {
     return new TreeMap<>(REMOTE_VALUES);

app/src/main/res/layout/contact_selection_list_fragment.xml

@@ -110,6 +110,17 @@
 
     </LinearLayout>
 
+    <TextView
+        android:id="@+id/group_limit"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textAppearance="@style/TextAppearance.Signal.Body2"
+        android:visibility="gone"
+        app:layout_constraintEnd_toEndOf="@+id/chipGroupScrollContainer"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:text="999/999"
+        tools:visibility="visible" />
+
     <HorizontalScrollView
         android:id="@+id/chipGroupScrollContainer"
         android:layout_width="match_parent"
@@ -122,7 +133,7 @@
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintHorizontal_bias="0.5"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/group_limit"
         tools:visibility="visible">
 
         <com.google.android.material.chip.ChipGroup

app/src/main/res/values/strings.xml

@@ -1372,6 +1372,7 @@
     <string name="ContactSelectionListFragment_username_not_found">Username not found</string>
     <string name="ContactSelectionListFragment_s_is_not_a_signal_user">"%1$s" is not a Signal user. Please check the username and try again.</string>
     <string name="ContactSelectionListFragment_okay">Okay</string>
+    <string name="ContactSelectionListFragment_the_group_is_full">The group is full</string>
 
     <!-- blocked_contacts_fragment -->
     <string name="blocked_contacts_fragment__no_blocked_contacts">No blocked contacts</string>