Update linked devices screen.

2026-02-27 05:03:28 +00:00 · 2024-06-05 17:17:03 -07:00
parent 5c181e774f
commit ac52b5b992
21 changed files with 911 additions and 11 deletions
--- a/app/src/main/java/org/thoughtcrime/securesms/components/settings/app/AppSettingsFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/components/settings/app/AppSettingsFragment.kt
@@ -160,7 +160,11 @@ class AppSettingsFragment : DSLSettingsFragment(
        title = DSLSettingsText.from(R.string.preferences__linked_devices),
        icon = DSLSettingsIcon.from(R.drawable.symbol_devices_24),
        onClick = {
-          findNavController().safeNavigate(R.id.action_appSettingsFragment_to_deviceActivity)
+          if (FeatureFlags.linkedDevicesV2()) {
+            findNavController().safeNavigate(R.id.action_appSettingsFragment_to_linkDeviceFragment)
+          } else {
+            findNavController().safeNavigate(R.id.action_appSettingsFragment_to_deviceActivity)
+          }
        },
        isEnabled = state.isRegisteredAndUpToDate()
      )
--- a/app/src/main/java/org/thoughtcrime/securesms/linkdevice/Device.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/linkdevice/Device.kt
@@ -0,0 +1,6 @@
+package org.thoughtcrime.securesms.linkdevice
+
+/**
+ * Class that represents a linked device
+ */
+data class Device(val id: Long, val name: String, val createdMillis: Long, val lastSeenMillis: Long)
--- a/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceFragment.kt
@@ -0,0 +1,242 @@
+package org.thoughtcrime.securesms.linkdevice
+
+import android.widget.Toast
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.text.ClickableText
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.ColorFilter
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.fragment.app.viewModels
+import androidx.navigation.fragment.findNavController
+import org.signal.core.ui.Buttons
+import org.signal.core.ui.Dialogs
+import org.signal.core.ui.Dividers
+import org.signal.core.ui.Previews
+import org.signal.core.ui.Scaffolds
+import org.signal.core.ui.SignalPreview
+import org.thoughtcrime.securesms.DeviceActivity
+import org.thoughtcrime.securesms.R
+import org.thoughtcrime.securesms.compose.ComposeFragment
+import org.thoughtcrime.securesms.util.BottomSheetUtil
+import org.thoughtcrime.securesms.util.DateUtils
+import java.util.Locale
+
+/**
+ * Fragment that shows current linked devices
+ */
+class LinkDeviceFragment : ComposeFragment() {
+
+  private val viewModel: LinkDeviceViewModel by viewModels()
+
+  @Composable
+  override fun FragmentContent() {
+    val state by viewModel.state
+
+    LaunchedEffect(state.toastDialog) {
+      if (state.toastDialog.isNotEmpty()) {
+        Toast.makeText(requireContext(), state.toastDialog, Toast.LENGTH_LONG).show()
+      }
+    }
+
+    Scaffolds.Settings(
+      title = stringResource(id = R.string.preferences__linked_devices),
+      onNavigationClick = { findNavController().popBackStack() },
+      navigationIconPainter = painterResource(id = R.drawable.ic_arrow_left_24),
+      navigationContentDescription = stringResource(id = R.string.Material3SearchToolbar__close)
+    ) { contentPadding: PaddingValues ->
+      DeviceDescriptionScreen(
+        state = state,
+        modifier = Modifier.padding(contentPadding),
+        onLearnMore = this::openLearnMore,
+        onLinkDevice = this::openLinkNewDevice,
+        setDeviceToRemove = this::setDeviceToRemove,
+        onRemoveDevice = this::onRemoveDevice
+      )
+    }
+  }
+
+  override fun onResume() {
+    super.onResume()
+    viewModel.loadDevices(requireContext())
+  }
+
+  private fun openLearnMore() {
+    LinkDeviceLearnMoreBottomSheetFragment().show(childFragmentManager, BottomSheetUtil.STANDARD_BOTTOM_SHEET_FRAGMENT_TAG)
+  }
+
+  private fun openLinkNewDevice() {
+    // TODO(Michelle): Use linkDeviceAddFragment
+    startActivity(DeviceActivity.getIntentForScanner(requireContext()))
+    // findNavController().safeNavigate(R.id.action_linkDeviceFragment_to_linkDeviceAddFragment)
+  }
+
+  private fun setDeviceToRemove(device: Device?) {
+    viewModel.setDeviceToRemove(device)
+  }
+
+  private fun onRemoveDevice(device: Device) {
+    viewModel.removeDevice(requireContext(), device)
+  }
+}
+
+@Composable
+fun DeviceDescriptionScreen(
+  state: LinkDeviceSettingsState,
+  modifier: Modifier = Modifier,
+  onLearnMore: () -> Unit = {},
+  onLinkDevice: () -> Unit = {},
+  setDeviceToRemove: (Device?) -> Unit = {},
+  onRemoveDevice: (Device) -> Unit = {}
+) {
+  if (state.progressDialogMessage != -1) {
+    Dialogs.IndeterminateProgressDialog(stringResource(id = state.progressDialogMessage))
+  }
+  if (state.deviceToRemove != null) {
+    val device: Device = state.deviceToRemove
+    Dialogs.SimpleAlertDialog(
+      title = stringResource(id = R.string.DeviceListActivity_unlink_s, device.name),
+      body = stringResource(id = R.string.DeviceListActivity_by_unlinking_this_device_it_will_no_longer_be_able_to_send_or_receive),
+      confirm = stringResource(R.string.LinkDeviceFragment__unlink),
+      dismiss = stringResource(android.R.string.cancel),
+      onConfirm = { onRemoveDevice(device) },
+      onDismiss = { setDeviceToRemove(null) }
+    )
+  }
+
+  Column(horizontalAlignment = Alignment.CenterHorizontally, modifier = modifier.verticalScroll(rememberScrollState())) {
+    Icon(
+      painter = painterResource(R.drawable.ic_devices_intro),
+      contentDescription = stringResource(R.string.preferences__linked_devices),
+      tint = Color.Unspecified
+    )
+    Text(
+      text = stringResource(id = R.string.LinkDeviceFragment__use_signal_on_desktop_ipad),
+      textAlign = TextAlign.Center,
+      modifier = Modifier.padding(start = 20.dp, end = 20.dp, top = 12.dp, bottom = 4.dp)
+    )
+    ClickableText(
+      text = AnnotatedString(stringResource(id = R.string.LearnMoreTextView_learn_more)),
+      style = TextStyle(color = MaterialTheme.colorScheme.primary)
+    ) {
+      onLearnMore()
+    }
+
+    Spacer(modifier = Modifier.size(20.dp))
+
+    Buttons.LargeTonal(
+      onClick = onLinkDevice,
+      modifier = Modifier.width(300.dp)
+    ) {
+      Text(stringResource(id = R.string.LinkDeviceFragment__link_a_new_device))
+    }
+
+    if (state.devices.isNotEmpty()) {
+      Dividers.Default()
+
+      Column {
+        Text(
+          text = stringResource(R.string.LinkDeviceFragment__my_linked_devices),
+          style = MaterialTheme.typography.titleMedium,
+          modifier = Modifier.padding(start = 24.dp, top = 12.dp, bottom = 24.dp)
+        )
+        state.devices.forEach { device ->
+          DeviceRow(device, setDeviceToRemove)
+        }
+      }
+    }
+
+    Row(
+      modifier = Modifier.padding(horizontal = 40.dp, vertical = 12.dp),
+      verticalAlignment = Alignment.CenterVertically
+    ) {
+      Spacer(modifier = Modifier.size(12.dp))
+      Icon(
+        painter = painterResource(R.drawable.symbol_lock_24),
+        contentDescription = null
+      )
+      Text(
+        style = MaterialTheme.typography.bodySmall,
+        textAlign = TextAlign.Center,
+        text = stringResource(id = R.string.LinkDeviceFragment__messages_and_chat_info_are_protected)
+      )
+    }
+  }
+}
+
+@Composable
+fun DeviceRow(device: Device, setDeviceToRemove: (Device) -> Unit) {
+  val titleString = device.name.ifEmpty { stringResource(R.string.DeviceListItem_unnamed_device) }
+  val linkedDate = DateUtils.getDayPrecisionTimeSpanString(LocalContext.current, Locale.getDefault(), device.createdMillis)
+  val lastActive = DateUtils.getDayPrecisionTimeSpanString(LocalContext.current, Locale.getDefault(), device.lastSeenMillis)
+
+  Row(
+    modifier = Modifier
+      .fillMaxWidth()
+      .clickable { setDeviceToRemove(device) },
+    verticalAlignment = Alignment.CenterVertically
+  ) {
+    Image(
+      painter = painterResource(id = R.drawable.symbol_devices_24),
+      contentDescription = null,
+      colorFilter = ColorFilter.tint(MaterialTheme.colorScheme.onSurface),
+      contentScale = ContentScale.Inside,
+      modifier = Modifier
+        .padding(start = 24.dp)
+        .size(40.dp)
+        .background(
+          color = MaterialTheme.colorScheme.surfaceVariant,
+          shape = CircleShape
+        )
+    )
+    Spacer(modifier = Modifier.size(20.dp))
+    Column {
+      Text(text = titleString, style = MaterialTheme.typography.bodyLarge)
+      Spacer(modifier = Modifier.size(4.dp))
+      Text(stringResource(R.string.DeviceListItem_linked_s, linkedDate), style = MaterialTheme.typography.bodyMedium)
+      Text(stringResource(R.string.DeviceListItem_last_active_s, lastActive), style = MaterialTheme.typography.bodyMedium)
+    }
+  }
+  Spacer(modifier = Modifier.size(16.dp))
+}
+
+@SignalPreview
+@Composable
+private fun DeviceScreenPreview() {
+  val previewDevices = listOf(
+    Device(1, "Sam's Macbook Pro", 1715793982000, 1716053182000),
+    Device(1, "Sam's iPad", 1715793182000, 1716053122000)
+  )
+  val previewState = LinkDeviceSettingsState(devices = previewDevices)
+
+  Previews.Preview {
+    DeviceDescriptionScreen(previewState)
+  }
+}
--- a/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceLearnMoreBottomSheetFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceLearnMoreBottomSheetFragment.kt
@@ -0,0 +1,122 @@
+package org.thoughtcrime.securesms.linkdevice
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.wrapContentSize
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+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.painter.Painter
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import org.signal.core.ui.BottomSheets
+import org.signal.core.ui.Previews
+import org.signal.core.ui.SignalPreview
+import org.signal.core.ui.Texts
+import org.thoughtcrime.securesms.R
+import org.thoughtcrime.securesms.compose.ComposeBottomSheetDialogFragment
+import org.thoughtcrime.securesms.util.CommunicationActions
+import org.thoughtcrime.securesms.util.SpanUtil
+
+/**
+ *  Bottom sheet dialog displayed when users click 'Learn more' when linking a device
+ */
+class LinkDeviceLearnMoreBottomSheetFragment : ComposeBottomSheetDialogFragment() {
+
+  override val peekHeightPercentage: Float = 0.8f
+
+  companion object {
+    const val SIGNAL_DOWNLOAD_URL = "https://signal.org/download"
+  }
+
+  @Composable
+  override fun SheetContent() {
+    LearnMoreSheet()
+  }
+}
+
+@Composable
+fun LearnMoreSheet() {
+  val context = LocalContext.current
+  val downloadUrl = stringResource(id = R.string.LinkDeviceFragment__signal_download_url)
+  val fullString = stringResource(id = R.string.LinkDeviceFragment__on_other_device_visit_signal, downloadUrl)
+  val spanned = SpanUtil.urlSubsequence(fullString, downloadUrl, LinkDeviceLearnMoreBottomSheetFragment.SIGNAL_DOWNLOAD_URL)
+
+  return Column(
+    horizontalAlignment = Alignment.CenterHorizontally,
+    modifier = Modifier
+      .fillMaxWidth()
+      .wrapContentSize(Alignment.Center)
+      .padding(bottom = 48.dp)
+  ) {
+    BottomSheets.Handle()
+    Icon(
+      painter = painterResource(R.drawable.ic_all_devices),
+      contentDescription = null,
+      tint = Color.Unspecified,
+      modifier = Modifier.size(110.dp)
+    )
+    Text(
+      style = MaterialTheme.typography.titleLarge,
+      text = stringResource(R.string.LinkDeviceFragment__signal_on_desktop_ipad),
+      modifier = Modifier.padding(horizontal = 32.dp, vertical = 8.dp)
+    )
+    LinkedDeviceInformationRow(
+      painterResource(R.drawable.symbol_lock_24),
+      stringResource(R.string.LinkDeviceFragment__all_messaging_is_private)
+    )
+    LinkedDeviceInformationRow(
+      painterResource(R.drawable.ic_replies_outline_20),
+      stringResource(R.string.LinkDeviceFragment__signal_messages_are_synchronized)
+    )
+    Row(modifier = Modifier.fillMaxWidth().padding(bottom = 12.dp, start = 40.dp, end = 32.dp)) {
+      Icon(
+        painter = painterResource(R.drawable.symbol_save_android_24),
+        contentDescription = stringResource(R.string.preferences__linked_devices),
+        modifier = Modifier.size(24.dp).padding(top = 4.dp)
+      )
+      Texts.LinkifiedText(
+        textWithUrlSpans = spanned,
+        onUrlClick = { CommunicationActions.openBrowserLink(context, it) },
+        style = MaterialTheme.typography.bodyLarge.copy(color = MaterialTheme.colorScheme.onSurface),
+        modifier = Modifier.padding(start = 20.dp)
+      )
+    }
+  }
+}
+
+@Composable
+private fun LinkedDeviceInformationRow(
+  iconPainter: Painter,
+  text: String
+) {
+  Row(modifier = Modifier.fillMaxWidth().padding(bottom = 12.dp, start = 40.dp, end = 32.dp)) {
+    Icon(
+      painter = iconPainter,
+      contentDescription = null,
+      modifier = Modifier.size(24.dp).padding(top = 4.dp)
+    )
+    Text(
+      style = MaterialTheme.typography.bodyLarge,
+      text = text,
+      modifier = Modifier.padding(start = 20.dp)
+    )
+  }
+}
+
+@SignalPreview
+@Composable
+fun LearnMorePreview() {
+  Previews.BottomSheetPreview {
+    LearnMoreSheet()
+  }
+}
--- a/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceRepository.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceRepository.kt
@@ -0,0 +1,74 @@
+package org.thoughtcrime.securesms.linkdevice
+
+import org.signal.core.util.Base64.decode
+import org.signal.core.util.logging.Log
+import org.thoughtcrime.securesms.dependencies.AppDependencies
+import org.thoughtcrime.securesms.devicelist.protos.DeviceName
+import org.thoughtcrime.securesms.jobs.LinkedDeviceInactiveCheckJob
+import org.thoughtcrime.securesms.keyvalue.SignalStore
+import org.thoughtcrime.securesms.registration.secondary.DeviceNameCipher
+import org.whispersystems.signalservice.api.messages.multidevice.DeviceInfo
+import org.whispersystems.signalservice.api.push.SignalServiceAddress
+import java.io.IOException
+
+/**
+ * Repository for linked devices and its various actions (linking, unlinking, listing).
+ */
+object LinkDeviceRepository {
+
+  private val TAG = Log.tag(LinkDeviceRepository::class)
+
+  fun removeDevice(deviceId: Long): Boolean {
+    return try {
+      val accountManager = AppDependencies.signalServiceAccountManager
+      accountManager.removeDevice(deviceId)
+      LinkedDeviceInactiveCheckJob.enqueue()
+      true
+    } catch (e: IOException) {
+      Log.w(TAG, e)
+      false
+    }
+  }
+
+  fun loadDevices(): List<Device>? {
+    val accountManager = AppDependencies.signalServiceAccountManager
+    return try {
+      val devices: List<Device> = accountManager.getDevices()
+        .filter { d: DeviceInfo -> d.getId() != SignalServiceAddress.DEFAULT_DEVICE_ID }
+        .map { deviceInfo: DeviceInfo -> deviceInfo.toDevice() }
+        .sortedBy { it.createdMillis }
+        .toList()
+      devices
+    } catch (e: IOException) {
+      Log.w(TAG, e)
+      null
+    }
+  }
+
+  private fun DeviceInfo.toDevice(): Device {
+    val defaultDevice = Device(getId().toLong(), getName(), getCreated(), getLastSeen())
+    try {
+      if (getName().isNullOrEmpty() || getName().length < 4) {
+        Log.w(TAG, "Invalid DeviceInfo name.")
+        return defaultDevice
+      }
+
+      val deviceName = DeviceName.ADAPTER.decode(decode(getName()))
+      if (deviceName.ciphertext == null || deviceName.ephemeralPublic == null || deviceName.syntheticIv == null) {
+        Log.w(TAG, "Got a DeviceName that wasn't properly populated.")
+        return defaultDevice
+      }
+
+      val plaintext = DeviceNameCipher.decryptDeviceName(deviceName, SignalStore.account().aciIdentityKey)
+      if (plaintext == null) {
+        Log.w(TAG, "Failed to decrypt device name.")
+        return defaultDevice
+      }
+
+      return Device(getId().toLong(), String(plaintext), getCreated(), getLastSeen())
+    } catch (e: Exception) {
+      Log.w(TAG, "Failed while reading the protobuf.", e)
+    }
+    return defaultDevice
+  }
+}
--- a/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceSettingsState.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceSettingsState.kt
@@ -0,0 +1,13 @@
+package org.thoughtcrime.securesms.linkdevice
+
+import androidx.annotation.StringRes
+
+/**
+ * Information about linked devices. Used in [LinkDeviceViewModel].
+ */
+data class LinkDeviceSettingsState(
+  val devices: List<Device> = emptyList(),
+  val deviceToRemove: Device? = null,
+  @StringRes val progressDialogMessage: Int = -1,
+  val toastDialog: String = ""
+)
--- a/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceViewModel.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/linkdevice/LinkDeviceViewModel.kt
@@ -0,0 +1,64 @@
+package org.thoughtcrime.securesms.linkdevice
+
+import android.content.Context
+import androidx.compose.runtime.State
+import androidx.compose.runtime.mutableStateOf
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import org.thoughtcrime.securesms.R
+
+/**
+ * Maintains the state of the [LinkDeviceFragment]
+ */
+class LinkDeviceViewModel : ViewModel() {
+
+  private val _state = mutableStateOf(LinkDeviceSettingsState())
+  val state: State<LinkDeviceSettingsState> = _state
+
+  fun onResume() {
+    _state.value = _state.value.copy()
+  }
+
+  fun setDeviceToRemove(device: Device?) {
+    _state.value = _state.value.copy(deviceToRemove = device)
+  }
+
+  fun removeDevice(context: Context, device: Device) {
+    viewModelScope.launch(Dispatchers.IO) {
+      _state.value = _state.value.copy(
+        progressDialogMessage = R.string.DeviceListActivity_unlinking_device
+      )
+      val success = LinkDeviceRepository.removeDevice(device.id)
+      if (success) {
+        loadDevices(context)
+        _state.value = _state.value.copy(
+          toastDialog = context.getString(R.string.LinkDeviceFragment__s_unlinked, device.name),
+          progressDialogMessage = -1
+        )
+      } else {
+        _state.value = _state.value.copy(
+          progressDialogMessage = -1
+        )
+      }
+    }
+  }
+
+  fun loadDevices(context: Context) {
+    viewModelScope.launch(Dispatchers.IO) {
+      val devices = LinkDeviceRepository.loadDevices()
+      if (devices == null) {
+        _state.value = _state.value.copy(
+          toastDialog = context.getString(R.string.DeviceListActivity_network_failed),
+          progressDialogMessage = -1
+        )
+      } else {
+        _state.value = _state.value.copy(
+          devices = devices,
+          progressDialogMessage = -1
+        )
+      }
+    }
+  }
+}
--- a/app/src/main/java/org/thoughtcrime/securesms/util/DateUtils.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/util/DateUtils.kt
@@ -210,13 +210,7 @@ object DateUtils : android.text.format.DateUtils() {
    return if (isSameDay(System.currentTimeMillis(), timestamp)) {
      context.getString(R.string.DeviceListItem_today)
    } else {
-      val format: String = when {
-        timestamp.isWithin(6.days) -> "EEE "
-        timestamp.isWithin(365.days) -> "MMM d"
-        else -> "MMM d, yyy"
-      }
-
-      timestamp.toDateString(format, locale)
+      timestamp.toDateString("dd/MM/yy", locale)
    }
  }

--- a/app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java
@@ -129,6 +129,7 @@ public final class FeatureFlags {
  private static final String RESTORE_POST_REGISTRATION         = "android.registration.restorePostRegistration";
  private static final String LIBSIGNAL_WEB_SOCKET_SHADOW_PCT   = "android.libsignalWebSocketShadowingPercentage";
  private static final String DELETE_SYNC_SEND_RECEIVE          = "android.deleteSyncSendReceive";
+  private static final String LINKED_DEVICES_V2                 = "android.linkedDevices.v2";

  /**
   * We will only store remote values for flags in this set. If you want a flag to be controllable
@@ -211,7 +212,7 @@ public final class FeatureFlags {
  );

  @VisibleForTesting
-  static final Set<String> NOT_REMOTE_CAPABLE = SetUtil.newHashSet(MESSAGE_BACKUPS, REGISTRATION_V2, RESTORE_POST_REGISTRATION);
+  static final Set<String> NOT_REMOTE_CAPABLE = SetUtil.newHashSet(MESSAGE_BACKUPS, REGISTRATION_V2, RESTORE_POST_REGISTRATION, LINKED_DEVICES_V2);

  /**
   * Values in this map will take precedence over any value. This should only be used for local
@@ -750,6 +751,11 @@ public final class FeatureFlags {
    return getBoolean(DELETE_SYNC_SEND_RECEIVE, false);
  }

+  /** Whether or not to use V2 of linked devices. */
+  public static boolean linkedDevicesV2() {
+    return getBoolean(LINKED_DEVICES_V2, false);
+  }
+
  /** Only for rendering debug info. */
  public static synchronized @NonNull Map<String, Object> getMemoryValues() {
    return new TreeMap<>(REMOTE_VALUES);