Add split pane UI for add group members screen.

app/src/main/java/org/thoughtcrime/securesms/calls/new/NewCallActivity.kt

@@ -116,7 +116,6 @@ private interface UiCallbacks :
   RecipientPickerCallbacks.NewCall {
 
   override suspend fun shouldAllowSelection(selection: RecipientSelection): Boolean = true
-  override fun onPendingRecipientSelectionsConsumed() = Unit
   fun onUserMessageDismissed(userMessage: UserMessage)
   fun onBackPressed()
 

app/src/main/java/org/thoughtcrime/securesms/components/settings/conversation/ConversationSettingsEvent.kt

@@ -1,6 +1,7 @@
 package org.thoughtcrime.securesms.components.settings.conversation
 
 import org.thoughtcrime.securesms.groups.GroupId
+import org.thoughtcrime.securesms.groups.SelectionLimits
 import org.thoughtcrime.securesms.groups.ui.GroupChangeFailureReason
 import org.thoughtcrime.securesms.recipients.Recipient
 import org.thoughtcrime.securesms.recipients.RecipientId
@@ -13,9 +14,7 @@ sealed class ConversationSettingsEvent {
 
   class AddMembersToGroup(
     val groupId: GroupId,
-    val selectionWarning: Int,
-    val selectionLimit: Int,
-    val isAnnouncementGroup: Boolean,
+    val selectionLimits: SelectionLimits,
     val groupMembersWithoutSelf: List<RecipientId>
   ) : ConversationSettingsEvent()
 

app/src/main/java/org/thoughtcrime/securesms/components/settings/conversation/ConversationSettingsFragment.kt

@@ -955,9 +955,8 @@ class ConversationSettingsFragment : DSLSettingsFragment(
         requireContext(),
         addMembersToGroup.groupId,
         ContactSelectionDisplayMode.FLAG_PUSH,
-        addMembersToGroup.selectionWarning,
-        addMembersToGroup.selectionLimit,
-        addMembersToGroup.isAnnouncementGroup,
+        addMembersToGroup.selectionLimits.recommendedLimit,
+        addMembersToGroup.selectionLimits.hardLimit,
         addMembersToGroup.groupMembersWithoutSelf
       ),
       REQUEST_CODE_ADD_MEMBERS_TO_GROUP

app/src/main/java/org/thoughtcrime/securesms/components/settings/conversation/ConversationSettingsViewModel.kt

@@ -30,6 +30,7 @@ import org.thoughtcrime.securesms.database.model.StoryViewState
 import org.thoughtcrime.securesms.dependencies.AppDependencies
 import org.thoughtcrime.securesms.groups.GroupId
 import org.thoughtcrime.securesms.groups.LiveGroup
+import org.thoughtcrime.securesms.groups.SelectionLimits
 import org.thoughtcrime.securesms.groups.ui.GroupChangeFailureReason
 import org.thoughtcrime.securesms.groups.v2.GroupAddMembersResult
 import org.thoughtcrime.securesms.keyvalue.SignalStore
@@ -435,9 +436,7 @@ sealed class ConversationSettingsViewModel(
           internalEvents.onNext(
             ConversationSettingsEvent.AddMembersToGroup(
               groupId,
-              capacityResult.getSelectionWarning(),
-              capacityResult.getSelectionLimit(),
-              capacityResult.isAnnouncementGroup,
+              SelectionLimits(capacityResult.getSelectionWarning(), capacityResult.getSelectionLimit()),
               capacityResult.getMembersWithoutSelf()
             )
           )

app/src/main/java/org/thoughtcrime/securesms/conversation/NewConversationActivity.kt

@@ -275,7 +275,6 @@ private interface UiCallbacks :
   fun onRemoveConfirmed(recipient: Recipient)
   fun onBlockConfirmed(recipient: Recipient)
   fun onUserMessageDismissed(userMessage: UserMessage)
-  override fun onPendingRecipientSelectionsConsumed() = Unit
   fun onBackPressed()
 
   object Empty : UiCallbacks {
@@ -285,7 +284,6 @@ private interface UiCallbacks :
     override fun onFindByPhoneNumber() = Unit
     override suspend fun shouldAllowSelection(selection: RecipientSelection): Boolean = true
     override fun onRecipientSelected(selection: RecipientSelection) = Unit
-    override fun onPendingRecipientSelectionsConsumed() = Unit
     override fun onMessage(id: RecipientId) = Unit
     override fun onVoiceCall(recipient: Recipient) = Unit
     override fun onVideoCall(recipient: Recipient) = Unit

app/src/main/java/org/thoughtcrime/securesms/groups/ui/addmembers/AddMembersActivity.java

@@ -39,7 +39,6 @@ import java.util.function.Consumer;
 public class AddMembersActivity extends PushContactSelectionActivity implements ContactSelectionListFragment.FindByCallback {
 
   public static final String GROUP_ID           = "group_id";
-  public static final String ANNOUNCEMENT_GROUP = "announcement_group";
 
   private View                               done;
   private AddMembersViewModel                viewModel;
@@ -50,12 +49,9 @@ public class AddMembersActivity extends PushContactSelectionActivity implements
                                              int displayModeFlags,
                                              int selectionWarning,
                                              int selectionLimit,
-                                             boolean isAnnouncementGroup,
                                              @NonNull List<RecipientId> membersWithoutSelf)  {
     Intent intent = new Intent(context, AddMembersActivity.class);
-
     intent.putExtra(GROUP_ID, groupId.toString());
-    intent.putExtra(ANNOUNCEMENT_GROUP, isAnnouncementGroup);
     intent.putExtra(ContactSelectionArguments.DISPLAY_MODE, displayModeFlags);
     intent.putExtra(ContactSelectionArguments.SELECTION_LIMITS, new SelectionLimits(selectionWarning, selectionLimit));
     intent.putParcelableArrayListExtra(ContactSelectionArguments.CURRENT_SELECTION, new ArrayList<>(membersWithoutSelf));
@@ -184,10 +180,6 @@ public class AddMembersActivity extends PushContactSelectionActivity implements
     return GroupId.parseOrThrow(getIntent().getStringExtra(GROUP_ID));
   }
 
-  private boolean isAnnouncementGroup() {
-    return getIntent().getBooleanExtra(ANNOUNCEMENT_GROUP, false);
-  }
-
   private void displayAlertMessage(@NonNull AddMembersViewModel.AddMemberDialogMessageState state) {
     Recipient recipient = Util.firstNonNull(state.getRecipient(), Recipient.UNKNOWN);
 

app/src/main/java/org/thoughtcrime/securesms/groups/ui/addmembers/AddMembersActivityV2.kt

@@ -0,0 +1,339 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.groups.ui.addmembers
+
+import android.app.Activity.RESULT_CANCELED
+import android.app.Activity.RESULT_OK
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import android.widget.Toast
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
+import androidx.activity.result.ActivityResult
+import androidx.activity.result.ActivityResultLauncher
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.Text
+import androidx.compose.material3.adaptive.ExperimentalMaterial3AdaptiveApi
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
+import org.signal.core.ui.compose.AllDevicePreviews
+import org.signal.core.ui.compose.Buttons
+import org.signal.core.ui.compose.Dialogs
+import org.signal.core.ui.compose.Previews
+import org.signal.core.util.getParcelableArrayListExtraCompat
+import org.signal.core.util.getParcelableExtraCompat
+import org.signal.core.util.nullIfBlank
+import org.thoughtcrime.securesms.PassphraseRequiredActivity
+import org.thoughtcrime.securesms.PushContactSelectionActivity
+import org.thoughtcrime.securesms.R
+import org.thoughtcrime.securesms.components.settings.conversation.ConversationSettingsEvent
+import org.thoughtcrime.securesms.compose.SignalTheme
+import org.thoughtcrime.securesms.contacts.SelectedContact
+import org.thoughtcrime.securesms.database.model.GroupRecord
+import org.thoughtcrime.securesms.groups.GroupId
+import org.thoughtcrime.securesms.groups.SelectionLimits
+import org.thoughtcrime.securesms.groups.ui.addmembers.AddMembersUiState.UserMessage
+import org.thoughtcrime.securesms.recipients.RecipientId
+import org.thoughtcrime.securesms.recipients.ui.RecipientLookupFailureMessage
+import org.thoughtcrime.securesms.recipients.ui.RecipientPicker
+import org.thoughtcrime.securesms.recipients.ui.RecipientPickerCallbacks
+import org.thoughtcrime.securesms.recipients.ui.RecipientPickerScaffold
+import org.thoughtcrime.securesms.recipients.ui.RecipientSelection
+import org.thoughtcrime.securesms.recipients.ui.findby.FindByActivity
+import org.thoughtcrime.securesms.recipients.ui.findby.FindByMode
+import java.text.NumberFormat
+
+/**
+ * Allows members to be added to an existing Signal group by selecting from a list of recipients.
+ */
+class AddMembersActivityV2 : PassphraseRequiredActivity() {
+  companion object {
+    private const val EXTRA_GROUP_ID = "group_id"
+    private const val EXTRA_SELECTION_LIMITS = "selection_limits"
+    private const val EXTRA_PRESELECTED_RECIPIENTS = "preselected_recipients"
+
+    fun createIntent(
+      context: Context,
+      event: ConversationSettingsEvent.AddMembersToGroup
+    ): Intent {
+      return Intent(context, AddMembersActivityV2::class.java).apply {
+        putExtra(EXTRA_GROUP_ID, event.groupId)
+        putExtra(EXTRA_SELECTION_LIMITS, event.selectionLimits)
+        putParcelableArrayListExtra(EXTRA_PRESELECTED_RECIPIENTS, ArrayList(event.groupMembersWithoutSelf))
+      }
+    }
+  }
+
+  override fun onCreate(savedInstanceState: Bundle?, ready: Boolean) {
+    enableEdgeToEdge()
+    super.onCreate(savedInstanceState, ready)
+
+    setContent {
+      SignalTheme {
+        AddMembersScreen(
+          viewModel = viewModel {
+            AddMembersViewModelV2(
+              groupId = intent.getParcelableExtraCompat(EXTRA_GROUP_ID, GroupId::class.java)!!,
+              existingMembersMinusSelf = intent.getParcelableArrayListExtraCompat(EXTRA_PRESELECTED_RECIPIENTS, RecipientId::class.java)!!.toSet(),
+              selectionLimits = intent.getParcelableExtraCompat(EXTRA_SELECTION_LIMITS, SelectionLimits::class.java)!!
+            )
+          },
+          activityIntent = intent,
+          closeScreen = { result ->
+            setResult(result.resultCode, result.data)
+            onBackPressedDispatcher.onBackPressed()
+          }
+        )
+      }
+    }
+  }
+}
+
+@Composable
+private fun AddMembersScreen(
+  viewModel: AddMembersViewModelV2,
+  activityIntent: Intent,
+  closeScreen: (result: ActivityResult) -> Unit
+) {
+  val findByLauncher: ActivityResultLauncher<FindByMode> = rememberLauncherForActivityResult(
+    contract = FindByActivity.Contract(),
+    onResult = { id -> id?.let(viewModel::selectRecipient) }
+  )
+
+  val callbacks = remember {
+    object : UiCallbacks {
+      override fun onSearchQueryChanged(query: String) = viewModel.onSearchQueryChanged(query)
+      override fun onFindByUsername() = findByLauncher.launch(FindByMode.USERNAME)
+      override fun onFindByPhoneNumber() = findByLauncher.launch(FindByMode.PHONE_NUMBER)
+      override suspend fun shouldAllowSelection(selection: RecipientSelection): Boolean = viewModel.shouldAllowSelection(selection)
+      override fun onSelectionChanged(newSelections: List<SelectedContact>, totalMembersCount: Int) = viewModel.onSelectionChanged(newSelections)
+      override fun onPendingRecipientSelectionsConsumed() = viewModel.clearPendingRecipientSelections()
+      override fun onDoneClicked() = viewModel.addSelectedMembers()
+      override fun onAddConfirmed(recipientIds: Set<RecipientId>) {
+        val resultIntent = activityIntent.apply {
+          putParcelableArrayListExtra(
+            PushContactSelectionActivity.KEY_SELECTED_RECIPIENTS,
+            ArrayList(recipientIds.toList())
+          )
+        }
+        closeScreen(ActivityResult(RESULT_OK, resultIntent))
+      }
+
+      override fun onUserMessageDismissed(userMessage: UserMessage) = viewModel.clearUserMessage()
+      override fun onBackPressed() = closeScreen(ActivityResult(RESULT_CANCELED, null))
+    }
+  }
+
+  val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+
+  AddMembersScreenUi(
+    uiState = uiState,
+    callbacks = callbacks
+  )
+}
+
+@OptIn(ExperimentalMaterial3Api::class, ExperimentalMaterial3AdaptiveApi::class)
+@Composable
+private fun AddMembersScreenUi(
+  uiState: AddMembersUiState,
+  callbacks: UiCallbacks
+) {
+  val title = if (uiState.totalMembersCount > 0) {
+    pluralStringResource(
+      id = R.plurals.CreateGroupActivity__s_members,
+      count = uiState.totalMembersCount,
+      NumberFormat.getInstance().format(uiState.totalMembersCount)
+    )
+  } else {
+    stringResource(R.string.AddMembersActivity__add_members)
+  }
+
+  RecipientPickerScaffold(
+    title = title,
+    forceSplitPane = uiState.forceSplitPane,
+    onNavigateUpClick = callbacks::onBackPressed,
+    topAppBarActions = {},
+    snackbarHostState = remember { SnackbarHostState() },
+    primaryContent = {
+      AddMembersRecipientPicker(
+        uiState = uiState,
+        callbacks = callbacks
+      )
+
+      UserMessagesHost(
+        userMessage = uiState.userMessage,
+        onAddConfirmed = callbacks::onAddConfirmed,
+        onDismiss = callbacks::onUserMessageDismissed
+      )
+
+      if (uiState.isLookingUpRecipient) {
+        Dialogs.IndeterminateProgressDialog()
+      }
+    }
+  )
+}
+
+@Composable
+private fun AddMembersRecipientPicker(
+  uiState: AddMembersUiState,
+  callbacks: UiCallbacks,
+  modifier: Modifier = Modifier
+) {
+  Box(modifier = modifier) {
+    RecipientPicker(
+      searchQuery = uiState.searchQuery,
+      displayModes = setOf(RecipientPicker.DisplayMode.PUSH),
+      selectionLimits = uiState.selectionLimits,
+      preselectedRecipients = uiState.existingMembersMinusSelf,
+      pendingRecipientSelections = uiState.pendingRecipientSelections,
+      isRefreshing = false,
+      listBottomPadding = 64.dp,
+      clipListToPadding = false,
+      callbacks = RecipientPickerCallbacks(
+        listActions = callbacks,
+        findByUsername = callbacks,
+        findByPhoneNumber = callbacks
+      ),
+      modifier = modifier.fillMaxSize()
+    )
+
+    Box(
+      modifier = Modifier
+        .align(Alignment.BottomEnd)
+        .padding(start = 16.dp, end = 16.dp, bottom = 16.dp)
+    ) {
+      Buttons.MediumTonal(
+        enabled = uiState.newSelections.isNotEmpty(),
+        onClick = callbacks::onDoneClicked
+      ) {
+        Text(text = stringResource(R.string.AddMembersActivity__done))
+      }
+    }
+  }
+}
+
+private interface UiCallbacks :
+  RecipientPickerCallbacks.ListActions,
+  RecipientPickerCallbacks.FindByUsername,
+  RecipientPickerCallbacks.FindByPhoneNumber {
+
+  override fun onRecipientSelected(selection: RecipientSelection) = Unit
+  fun onDoneClicked()
+  fun onAddConfirmed(recipientIds: Set<RecipientId>)
+  fun onUserMessageDismissed(userMessage: UserMessage)
+  fun onBackPressed()
+
+  object Empty : UiCallbacks {
+    override fun onSearchQueryChanged(query: String) = Unit
+    override fun onFindByUsername() = Unit
+    override fun onFindByPhoneNumber() = Unit
+    override suspend fun shouldAllowSelection(selection: RecipientSelection): Boolean = true
+    override fun onDoneClicked() = Unit
+    override fun onAddConfirmed(recipientIds: Set<RecipientId>) = Unit
+    override fun onUserMessageDismissed(userMessage: UserMessage) = Unit
+    override fun onBackPressed() = Unit
+  }
+}
+
+@Composable
+private fun UserMessagesHost(
+  userMessage: UserMessage?,
+  onAddConfirmed: (Set<RecipientId>) -> Unit,
+  onDismiss: (UserMessage) -> Unit
+) {
+  when (userMessage) {
+    null -> {}
+
+    is UserMessage.RecipientLookupFailed -> {
+      RecipientLookupFailureMessage(
+        failure = userMessage.failure,
+        onDismissed = { onDismiss(userMessage) }
+      )
+    }
+
+    is UserMessage.CantAddRecipientToLegacyGroup -> {
+      Toast.makeText(LocalContext.current, R.string.AddMembersActivity__this_person_cant_be_added_to_legacy_groups, Toast.LENGTH_SHORT).show()
+      onDismiss(userMessage)
+    }
+
+    is UserMessage.GroupAddConfirmation -> {
+      GroupAddConfirmationDialog(
+        message = userMessage,
+        onAddConfirmed = onAddConfirmed,
+        onDismiss = onDismiss
+      )
+    }
+  }
+}
+
+@Composable
+private fun GroupAddConfirmationDialog(
+  message: UserMessage.GroupAddConfirmation,
+  onAddConfirmed: (Set<RecipientId>) -> Unit,
+  onDismiss: (UserMessage) -> Unit
+) {
+  val context: Context = LocalContext.current
+  val bodyText: String = when (message) {
+    is UserMessage.ConfirmAddMember -> {
+      stringResource(
+        id = R.string.AddMembersActivityV2__add_member_to_s,
+        message.recipient.getDisplayName(context),
+        message.group.getDisplayTitle(context)
+      )
+    }
+
+    is UserMessage.ConfirmAddMembers -> {
+      pluralStringResource(
+        id = R.plurals.AddMembersActivityV2__add_d_members_to_s,
+        message.recipientIds.size,
+        message.recipientIds.size,
+        message.group.getDisplayTitle(context)
+      )
+    }
+  }
+
+  Dialogs.SimpleAlertDialog(
+    title = "",
+    body = bodyText,
+    confirm = stringResource(R.string.AddMembersActivity__add),
+    dismiss = stringResource(android.R.string.cancel),
+    onConfirm = { onAddConfirmed(message.recipientIds) },
+    onDismiss = { onDismiss(message) }
+  )
+}
+
+private fun GroupRecord.getDisplayTitle(context: Context): String {
+  return this.title.nullIfBlank() ?: context.getString(R.string.Recipient_unknown)
+}
+
+@AllDevicePreviews
+@Composable
+private fun AddMembersScreenPreview() {
+  Previews.Preview {
+    AddMembersScreenUi(
+      uiState = AddMembersUiState(
+        forceSplitPane = false,
+        selectionLimits = SelectionLimits.NO_LIMITS
+      ),
+      callbacks = UiCallbacks.Empty
+    )
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/groups/ui/addmembers/AddMembersViewModelV2.kt

@@ -0,0 +1,170 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.groups.ui.addmembers
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import org.thoughtcrime.securesms.contacts.SelectedContact
+import org.thoughtcrime.securesms.database.SignalDatabase
+import org.thoughtcrime.securesms.database.model.GroupRecord
+import org.thoughtcrime.securesms.groups.GroupId
+import org.thoughtcrime.securesms.groups.SelectionLimits
+import org.thoughtcrime.securesms.groups.ui.addmembers.AddMembersUiState.UserMessage
+import org.thoughtcrime.securesms.keyvalue.SignalStore
+import org.thoughtcrime.securesms.recipients.PhoneNumber
+import org.thoughtcrime.securesms.recipients.Recipient
+import org.thoughtcrime.securesms.recipients.RecipientId
+import org.thoughtcrime.securesms.recipients.RecipientRepository
+import org.thoughtcrime.securesms.recipients.ui.RecipientSelection
+import kotlin.collections.plus
+
+class AddMembersViewModelV2(
+  private val groupId: GroupId,
+  existingMembersMinusSelf: Set<RecipientId>,
+  selectionLimits: SelectionLimits
+) : ViewModel() {
+
+  private val group: GroupRecord = SignalDatabase.groups.requireGroup(groupId)
+
+  private val internalUiState = MutableStateFlow(
+    AddMembersUiState(
+      existingMembersMinusSelf = existingMembersMinusSelf,
+      selectionLimits = selectionLimits
+    )
+  )
+  val uiState: StateFlow<AddMembersUiState> = internalUiState.asStateFlow()
+
+  fun onSearchQueryChanged(query: String) {
+    internalUiState.update { it.copy(searchQuery = query) }
+  }
+
+  suspend fun shouldAllowSelection(selection: RecipientSelection): Boolean {
+    val recipientHasE164 = selection is RecipientSelection.HasId &&
+      withContext(Dispatchers.IO) { Recipient.resolved(selection.id) }.hasE164
+
+    return when {
+      groupId.isV1 && !recipientHasE164 -> {
+        internalUiState.update {
+          it.copy(userMessage = UserMessage.CantAddRecipientToLegacyGroup)
+        }
+        false
+      }
+
+      selection is RecipientSelection.HasId -> true
+      selection is RecipientSelection.HasPhone -> recipientExists(selection.phone)
+      else -> false
+    }
+  }
+
+  private suspend fun recipientExists(phone: PhoneNumber): Boolean {
+    internalUiState.update { it.copy(isLookingUpRecipient = true) }
+
+    return when (val lookupResult = RecipientRepository.lookup(phone)) {
+      is RecipientRepository.LookupResult.Success -> {
+        internalUiState.update { it.copy(isLookingUpRecipient = false) }
+        true
+      }
+
+      is RecipientRepository.LookupResult.Failure -> {
+        internalUiState.update {
+          it.copy(
+            isLookingUpRecipient = false,
+            userMessage = UserMessage.RecipientLookupFailed(failure = lookupResult)
+          )
+        }
+        false
+      }
+    }
+  }
+
+  fun onSelectionChanged(newSelections: List<SelectedContact>) {
+    internalUiState.update {
+      it.copy(
+        searchQuery = "",
+        newSelections = newSelections
+      )
+    }
+  }
+
+  fun addSelectedMembers() {
+    viewModelScope.launch {
+      val confirmAddMessage = if (uiState.value.newSelections.size == 1) {
+        UserMessage.ConfirmAddMember(
+          group = group,
+          recipient = withContext(Dispatchers.IO) {
+            Recipient.resolved(uiState.value.newSelections.single().orCreateRecipientId)
+          }
+        )
+      } else {
+        UserMessage.ConfirmAddMembers(
+          group = group,
+          recipientIds = uiState.value.newSelections.map { it.orCreateRecipientId }.toSet()
+        )
+      }
+
+      internalUiState.update { it.copy(userMessage = confirmAddMessage) }
+    }
+  }
+
+  fun selectRecipient(id: RecipientId) {
+    internalUiState.update {
+      it.copy(pendingRecipientSelections = it.pendingRecipientSelections + id)
+    }
+  }
+
+  fun clearPendingRecipientSelections() {
+    internalUiState.update {
+      it.copy(pendingRecipientSelections = emptySet())
+    }
+  }
+
+  fun clearUserMessage() {
+    internalUiState.update { it.copy(userMessage = null) }
+  }
+}
+
+data class AddMembersUiState(
+  val forceSplitPane: Boolean = SignalStore.internal.forceSplitPane,
+  val searchQuery: String = "",
+  val existingMembersMinusSelf: Set<RecipientId> = emptySet(),
+  val selectionLimits: SelectionLimits,
+  val newSelections: List<SelectedContact> = emptyList(),
+  val isLookingUpRecipient: Boolean = false,
+  val pendingRecipientSelections: Set<RecipientId> = emptySet(),
+  val userMessage: UserMessage? = null
+) {
+  val totalMembersCount: Int
+    get() = existingMembersMinusSelf.size + newSelections.size + 1
+
+  sealed interface UserMessage {
+    data class RecipientLookupFailed(val failure: RecipientRepository.LookupResult.Failure) : UserMessage
+    data object CantAddRecipientToLegacyGroup : UserMessage
+
+    sealed interface GroupAddConfirmation : UserMessage {
+      val group: GroupRecord
+      val recipientIds: Set<RecipientId>
+    }
+
+    data class ConfirmAddMember(
+      override val group: GroupRecord,
+      val recipient: Recipient
+    ) : GroupAddConfirmation {
+      override val recipientIds: Set<RecipientId> = setOf(recipient.id)
+    }
+
+    data class ConfirmAddMembers(
+      override val group: GroupRecord,
+      override val recipientIds: Set<RecipientId>
+    ) : GroupAddConfirmation
+  }
+}

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

@@ -37,8 +37,8 @@ class CreateGroupViewModel : ViewModel() {
   }
 
   suspend fun shouldAllowSelection(selection: RecipientSelection): Boolean = when (selection) {
-    is RecipientSelection.WithId, is RecipientSelection.WithIdAndPhone -> true
-    is RecipientSelection.WithPhone -> recipientExists(selection.phone)
+    is RecipientSelection.HasId -> true
+    is RecipientSelection.HasPhone -> recipientExists(selection.phone)
   }
 
   private suspend fun recipientExists(phone: PhoneNumber): Boolean {

app/src/main/java/org/thoughtcrime/securesms/recipients/ui/RecipientPicker.kt

@@ -70,6 +70,7 @@ fun RecipientPicker(
   selectionLimits: SelectionLimits? = ContactSelectionArguments.Defaults.SELECTION_LIMITS,
   isRefreshing: Boolean,
   focusAndShowKeyboard: Boolean = LocalConfiguration.current.screenHeightDp.dp > 600.dp,
+  preselectedRecipients: Set<RecipientId> = emptySet(),
   pendingRecipientSelections: Set<RecipientId> = emptySet(),
   shouldResetContactsList: Boolean = false,
   listBottomPadding: Dp? = null,
@@ -109,6 +110,7 @@ fun RecipientPicker(
       selectionLimits = selectionLimits,
       searchQuery = searchQuery,
       isRefreshing = isRefreshing,
+      preselectedRecipients = preselectedRecipients,
       pendingRecipientSelections = pendingRecipientSelections,
       shouldResetContactsList = shouldResetContactsList,
       bottomPadding = listBottomPadding,
@@ -127,6 +129,7 @@ private fun RecipientSearchResultsList(
   displayModes: Set<RecipientPicker.DisplayMode>,
   searchQuery: String,
   isRefreshing: Boolean,
+  preselectedRecipients: Set<RecipientId>,
   pendingRecipientSelections: Set<RecipientId>,
   shouldResetContactsList: Boolean,
   selectionLimits: SelectionLimits? = ContactSelectionArguments.Defaults.SELECTION_LIMITS,
@@ -142,6 +145,7 @@ private fun RecipientSearchResultsList(
     enableFindByUsername = callbacks.findByUsername != null,
     enableFindByPhoneNumber = callbacks.findByPhoneNumber != null,
     showCallButtons = callbacks.newCall != null,
+    currentSelection = preselectedRecipients,
     selectionLimits = selectionLimits,
     recyclerPadBottom = with(LocalDensity.current) { bottomPadding?.toPx()?.toInt() ?: ContactSelectionArguments.Defaults.RECYCLER_PADDING_BOTTOM },
     recyclerChildClipping = clipListToPadding
@@ -396,7 +400,7 @@ class RecipientPickerCallbacks(
     suspend fun shouldAllowSelection(selection: RecipientSelection): Boolean
     fun onRecipientSelected(selection: RecipientSelection)
     fun onSelectionChanged(newSelections: List<SelectedContact>, totalMembersCount: Int) = Unit
-    fun onPendingRecipientSelectionsConsumed()
+    fun onPendingRecipientSelectionsConsumed() = Unit
     fun onContactsListReset() = Unit
 
     object Empty : ListActions {

app/src/main/java/org/thoughtcrime/securesms/recipients/ui/RecipientSelection.kt

@@ -9,7 +9,15 @@ import org.thoughtcrime.securesms.recipients.PhoneNumber
 import org.thoughtcrime.securesms.recipients.RecipientId
 
 sealed interface RecipientSelection {
-  data class WithId(val id: RecipientId) : RecipientSelection
-  data class WithPhone(val phone: PhoneNumber) : RecipientSelection
-  data class WithIdAndPhone(val id: RecipientId, val phone: PhoneNumber) : RecipientSelection
+  sealed interface HasId : RecipientSelection {
+    val id: RecipientId
+  }
+
+  sealed interface HasPhone : RecipientSelection {
+    val phone: PhoneNumber
+  }
+
+  data class WithId(override val id: RecipientId) : HasId
+  data class WithPhone(override val phone: PhoneNumber) : HasPhone
+  data class WithIdAndPhone(override val id: RecipientId, override val phone: PhoneNumber) : HasId, HasPhone
 }

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

@@ -1396,11 +1396,22 @@
     <!-- AddMembersActivity -->
     <string name="AddMembersActivity__done">Done</string>
     <string name="AddMembersActivity__this_person_cant_be_added_to_legacy_groups">This person can\'t be added to legacy groups.</string>
+
     <!-- Confirmation text when adding a member to a group. If one person is added, %1$s is their name. If multiple people are added, the total number is %3$d. %2$s is the name of the group -->
     <plurals name="AddMembersActivity__add_d_members_to_s">
         <item quantity="one">Add \"%1$s\" to \"%2$s\"?</item>
         <item quantity="other">Add %3$d members to \"%2$s\"?</item>
     </plurals>
+
+    <!-- Confirmation text when adding one member to a group. %1$s is the member's name, %2$s is the group name. -->
+    <string name="AddMembersActivityV2__add_member_to_s">Add \"%1$s\" to \"%2$s\"?</string>
+
+    <!-- Confirmation text when adding members to a group. %1$d is the number of members added. %2$s is the name of the group. -->
+    <plurals name="AddMembersActivityV2__add_d_members_to_s">
+        <item quantity="one">Add %1$d member to \"%2$s\"?</item>
+        <item quantity="other">Add %1$d members to \"%2$s\"?</item>
+    </plurals>
+
     <string name="AddMembersActivity__add">Add</string>
     <string name="AddMembersActivity__add_members">Add members</string>