Add reusable scaffold for recipient picker screens.

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

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.recipients.ui
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.widthIn
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.Text
+import androidx.compose.material3.adaptive.ExperimentalMaterial3AdaptiveApi
+import androidx.compose.material3.adaptive.currentWindowAdaptiveInfo
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.res.vectorResource
+import org.signal.core.ui.compose.AllDevicePreviews
+import org.signal.core.ui.compose.Previews
+import org.signal.core.ui.compose.Scaffolds
+import org.thoughtcrime.securesms.R
+import org.thoughtcrime.securesms.components.compose.ScreenTitlePane
+import org.thoughtcrime.securesms.window.AppScaffold
+import org.thoughtcrime.securesms.window.detailPaneMaxContentWidth
+import org.thoughtcrime.securesms.window.isSplitPane
+import org.thoughtcrime.securesms.window.rememberAppScaffoldNavigator
+
+/**
+ * Provides the common adaptive layout structure for recipient picker screens.
+ */
+@OptIn(ExperimentalMaterial3Api::class, ExperimentalMaterial3AdaptiveApi::class)
+@Composable
+fun RecipientPickerScaffold(
+  title: String,
+  forceSplitPane: Boolean,
+  onNavigateUpClick: () -> Unit,
+  topAppBarActions: @Composable () -> Unit,
+  snackbarHostState: SnackbarHostState,
+  primaryContent: @Composable () -> Unit
+) {
+  val windowSizeClass = currentWindowAdaptiveInfo().windowSizeClass
+  val isSplitPane = windowSizeClass.isSplitPane(forceSplitPane = forceSplitPane)
+
+  AppScaffold(
+    topBarContent = {
+      Scaffolds.DefaultTopAppBar(
+        title = if (!isSplitPane) title else "",
+        titleContent = { _, titleText -> Text(text = titleText, style = MaterialTheme.typography.titleLarge) },
+        navigationIcon = ImageVector.vectorResource(R.drawable.symbol_arrow_start_24),
+        navigationContentDescription = stringResource(R.string.DefaultTopAppBar__navigate_up_content_description),
+        onNavigationClick = onNavigateUpClick,
+        actions = { topAppBarActions() }
+      )
+    },
+
+    secondaryContent = {
+      if (isSplitPane) {
+        ScreenTitlePane(
+          title = title,
+          modifier = Modifier.fillMaxSize()
+        )
+      } else {
+        primaryContent()
+      }
+    },
+
+    primaryContent = {
+      Box(
+        contentAlignment = Alignment.Center,
+        modifier = Modifier.fillMaxSize()
+      ) {
+        Box(modifier = Modifier.widthIn(max = windowSizeClass.detailPaneMaxContentWidth)) {
+          primaryContent()
+        }
+      }
+    },
+
+    snackbarHost = {
+      SnackbarHost(snackbarHostState)
+    },
+
+    navigator = rememberAppScaffoldNavigator(
+      isSplitPane = isSplitPane
+    )
+  )
+}
+
+@AllDevicePreviews
+@Composable
+private fun RecipientPickerScaffoldPreview() {
+  Previews.Preview {
+    RecipientPickerScaffold(
+      title = "Screen Title",
+      forceSplitPane = false,
+      onNavigateUpClick = {},
+      topAppBarActions = {},
+      snackbarHostState = SnackbarHostState(),
+      primaryContent = {
+        Box(
+          modifier = Modifier
+            .fillMaxSize()
+            .background(color = Color.Gray),
+          contentAlignment = Alignment.Center
+        ) {
+          Text(text = "primaryContent")
+        }
+      }
+    )
+  }
+}

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

@@ -0,0 +1,15 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.recipients.ui
+
+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
+}