Add auto-fill backup key support.

app/src/main/java/org/thoughtcrime/securesms/backup/v2/ui/subscription/MessageBackupsKeyVerifyScreen.kt

@@ -32,16 +32,17 @@ import androidx.compose.material3.TextButton
 import androidx.compose.material3.TextField
 import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
+import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.platform.LocalSoftwareKeyboardController
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.dimensionResource
@@ -63,6 +64,8 @@ import org.signal.core.ui.compose.SignalPreview
 import org.signal.core.ui.compose.horizontalGutters
 import org.thoughtcrime.securesms.R
 import org.thoughtcrime.securesms.registrationv3.ui.restore.BackupKeyVisualTransformation
+import org.thoughtcrime.securesms.registrationv3.ui.restore.attachBackupKeyAutoFillHelper
+import org.thoughtcrime.securesms.registrationv3.ui.restore.backupKeyAutoFillHelper
 import org.whispersystems.signalservice.api.AccountEntropyPool
 import kotlin.random.Random
 import kotlin.random.nextInt
@@ -71,7 +74,7 @@ import org.signal.core.ui.R as CoreUiR
 /**
  * Prompt user to re-enter backup key (AEP) to confirm they have it still.
  */
-@OptIn(ExperimentalMaterial3Api::class)
+@OptIn(ExperimentalMaterial3Api::class, ExperimentalComposeUiApi::class)
 @Composable
 fun MessageBackupsKeyVerifyScreen(
   backupKey: String,
@@ -119,12 +122,20 @@ fun MessageBackupsKeyVerifyScreen(
 
         Spacer(modifier = Modifier.height(48.dp))
 
+        val updateEnteredBackupKey = { input: String ->
+          enteredBackupKey = AccountEntropyPool.removeIllegalCharacters(input).uppercase()
+          isBackupKeyValid = enteredBackupKey == backupKey
+          showError = !isBackupKeyValid && enteredBackupKey.length >= backupKey.length
+        }
+
+        var requestFocus: Boolean by remember { mutableStateOf(true) }
+        val autoFillHelper = backupKeyAutoFillHelper { updateEnteredBackupKey(it) }
+
         TextField(
           value = enteredBackupKey,
           onValueChange = {
-            enteredBackupKey = AccountEntropyPool.removeIllegalCharacters(it).uppercase()
-            isBackupKeyValid = enteredBackupKey == backupKey
-            showError = !isBackupKeyValid && enteredBackupKey.length >= backupKey.length
+            updateEnteredBackupKey(it)
+            autoFillHelper.onValueChanged(it)
           },
           label = {
             Text(text = stringResource(id = R.string.MessageBackupsKeyVerifyScreen__backup_key))
@@ -154,13 +165,16 @@ fun MessageBackupsKeyVerifyScreen(
           modifier = Modifier
             .fillMaxWidth()
             .focusRequester(focusRequester)
+            .attachBackupKeyAutoFillHelper(autoFillHelper)
+            .onGloballyPositioned {
+              if (requestFocus) {
+                focusRequester.requestFocus()
+                requestFocus = false
+              }
+            }
         )
       }
 
-      LaunchedEffect(Unit) {
-        focusRequester.requestFocus()
-      }
-
       Surface(
         shadowElevation = if (scrollState.canScrollForward) 8.dp else 0.dp,
         modifier = Modifier.fillMaxWidth()

app/src/main/java/org/thoughtcrime/securesms/registrationv3/ui/restore/BackupKeyAutoFill.kt

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.registrationv3.ui.restore
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.os.Build
+import android.view.autofill.AutofillManager
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.ExperimentalComposeUiApi
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.autofill.Autofill
+import androidx.compose.ui.autofill.AutofillNode
+import androidx.compose.ui.autofill.AutofillType
+import androidx.compose.ui.focus.onFocusChanged
+import androidx.compose.ui.layout.boundsInWindow
+import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.platform.LocalAutofill
+import androidx.compose.ui.platform.LocalAutofillTree
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalView
+import androidx.core.content.ContextCompat
+import kotlin.math.roundToInt
+import android.graphics.Rect as ViewRect
+import androidx.compose.ui.geometry.Rect as ComposeRect
+
+/**
+ * Provide a compose friendly way to autofill the backup key from a password manager.
+ */
+@OptIn(ExperimentalComposeUiApi::class)
+@SuppressLint("NewApi")
+@Composable
+fun backupKeyAutoFillHelper(
+  onFill: (String) -> Unit
+): BackupKeyAutoFillHelper {
+  val view = LocalView.current
+  val context = LocalContext.current
+  val autofill: Autofill? = LocalAutofill.current
+
+  val node = remember { AutofillNode(autofillTypes = listOf(AutofillType.Password), onFill = onFill) }
+  LocalAutofillTree.current += node
+
+  return remember {
+    object : BackupKeyAutoFillHelper(context) {
+      override fun request() {
+        if (node.boundingBox != null) {
+          autofill?.requestAutofillForNode(node)
+        }
+      }
+
+      override fun cancel() {
+        autofill?.cancelAutofillForNode(node)
+      }
+
+      /**
+       * Call when need to manually prompt auto-fill options when text field is empty. For some reason calling
+       * [request] like we do for on focus changes is not enough.
+       */
+      override fun requestDirectly() {
+        val bounds = node.boundingBox?.let { ViewRect(it.left.roundToInt(), it.top.roundToInt(), it.right.roundToInt(), it.bottom.roundToInt()) }
+        if (bounds != null) {
+          autoFillManager?.requestAutofill(view, node.id, bounds)
+        }
+      }
+
+      override fun updateNodeBounds(boundsInWindow: ComposeRect) {
+        node.boundingBox = boundsInWindow
+      }
+    }
+  }
+}
+
+/**
+ * Attach a [BackupKeyAutoFillHelper] return from [backupKeyAutoFillHelper] to setup the default
+ * callbacks needed to make requests on the view's behalf.
+ */
+fun Modifier.attachBackupKeyAutoFillHelper(helper: BackupKeyAutoFillHelper): Modifier {
+  return this.then(
+    Modifier
+      .onFocusChanged {
+        if (it.isFocused) {
+          helper.request()
+        } else {
+          helper.cancel()
+        }
+      }
+      .onGloballyPositioned {
+        helper.updateNodeBounds(it.boundsInWindow())
+      }
+  )
+}
+
+/**
+ * Weird compose-interop abstract class to let us return something to the caller of [backupKeyAutoFillHelper]
+ * and capture inner compose data to implement the methods that need various compose provided things.
+ */
+abstract class BackupKeyAutoFillHelper(context: Context) {
+  protected val autoFillManager: AutofillManager? = if (Build.VERSION.SDK_INT >= 26) {
+    ContextCompat.getSystemService(context, AutofillManager::class.java)
+  } else {
+    null
+  }
+
+  fun onValueChanged(value: String) {
+    if (value.isEmpty()) {
+      requestDirectly()
+    }
+  }
+
+  abstract fun request()
+  abstract fun cancel()
+  abstract fun requestDirectly()
+  abstract fun updateNodeBounds(boundsInWindow: ComposeRect)
+}

app/src/main/java/org/thoughtcrime/securesms/registrationv3/ui/restore/EnterBackupKeyScreen.kt

@@ -30,13 +30,16 @@ import androidx.compose.material3.TextButton
 import androidx.compose.material3.TextField
 import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.platform.LocalSoftwareKeyboardController
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
@@ -124,12 +127,18 @@ fun EnterBackupKeyScreen(
     }
   ) {
     val focusRequester = remember { FocusRequester() }
+    var requestFocus: Boolean by remember { mutableStateOf(true) }
     val visualTransform = remember(chunkLength) { BackupKeyVisualTransformation(chunkSize = chunkLength) }
     val keyboardController = LocalSoftwareKeyboardController.current
 
+    val autoFillHelper = backupKeyAutoFillHelper { onBackupKeyChanged(it) }
+
     TextField(
       value = backupKey,
-      onValueChange = onBackupKeyChanged,
+      onValueChange = {
+        onBackupKeyChanged(it)
+        autoFillHelper.onValueChanged(it)
+      },
       label = {
         Text(text = stringResource(id = R.string.EnterBackupKey_backup_key))
       },
@@ -158,12 +167,15 @@ fun EnterBackupKeyScreen(
       modifier = Modifier
         .fillMaxWidth()
         .focusRequester(focusRequester)
+        .attachBackupKeyAutoFillHelper(autoFillHelper)
+        .onGloballyPositioned {
+          if (requestFocus) {
+            focusRequester.requestFocus()
+            requestFocus = false
+          }
+        }
     )
 
-    LaunchedEffect(Unit) {
-      focusRequester.requestFocus()
-    }
-
     if (sheetState.isVisible) {
       ModalBottomSheet(
         dragHandle = null,