For #12287: Show devices with no tabs in Synced Tabs list

app/src/main/java/org/mozilla/fenix/sync/ext/SyncedTabsAdapter.kt

@@ -7,16 +7,16 @@ package org.mozilla.fenix.sync.ext
 import mozilla.components.browser.storage.sync.SyncedDeviceTabs
 import org.mozilla.fenix.sync.SyncedTabsAdapter.AdapterItem
 
-fun List<SyncedDeviceTabs>.toAdapterList(
-): MutableList<AdapterItem> {
-    val allDeviceTabs = mutableListOf<AdapterItem>()
+/**
+ * Converts a list of [SyncedDeviceTabs] into a list of [AdapterItem].
+ */
+fun List<SyncedDeviceTabs>.toAdapterList() = asSequence().flatMap { (device, tabs) ->
 
-    forEach { (device, tabs) ->
-        if (tabs.isNotEmpty()) {
-            allDeviceTabs.add(AdapterItem.Device(device))
-            tabs.mapTo(allDeviceTabs) { AdapterItem.Tab(it) }
-        }
+    val deviceTabs = if (tabs.isEmpty()) {
+        sequenceOf(AdapterItem.NoTabs(device))
+    } else {
+        tabs.asSequence().map { AdapterItem.Tab(it) }
     }
 
-    return allDeviceTabs
-}
+    sequenceOf(AdapterItem.Device(device)) + deviceTabs
+}.toList()

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

@@ -8,6 +8,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
+    android:layout_marginBottom="8dp"
     android:background="?android:attr/selectableItemBackground">
 
     <TextView
@@ -42,16 +43,4 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/synced_tab_item_title" />
 
-    <View
-        android:id="@+id/synced_tab_item_separator"
-        android:layout_width="match_parent"
-        android:layout_height="1dp"
-        android:layout_marginTop="7dp"
-        android:background="?syncedTabsSeparator"
-        android:importantForAccessibility="no"
-        android:visibility="invisible"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/synced_tab_item_url" />
-
 </androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -4,6 +4,18 @@
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="wrap_content"
+    android:paddingBottom="24dp">
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="72dp"
+        android:layout_marginTop="16dp"
+        android:singleLine="true"
+        android:text="@string/synced_tabs_no_open_tabs"
+        android:textAlignment="viewStart"
+        android:textColor="?secondaryText"
+        android:textSize="12sp" />
 
 </FrameLayout>

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

@@ -1455,6 +1455,8 @@
     <string name="synced_tabs_sign_in_message">View a list of tabs from your other devices.</string>
     <!-- Text displayed on a button in the synced tabs screen to link users to sign in when a user is not signed in to Firefox Sync -->
     <string name="synced_tabs_sign_in_button">Sign in to sync</string>
+    <!-- The text displayed when a synced device has no tabs to show in the list of Synced Tabs. -->
+    <string name="synced_tabs_no_open_tabs">No open tabs</string>
 
     <!-- Top Sites -->
     <!-- Title text displayed in the dialog when top sites limit is reached. -->

app/src/test/java/org/mozilla/fenix/sync/ext/SyncedTabsAdapterKtTest.kt

@@ -87,6 +87,8 @@ class SyncedTabsAdapterKtTest {
         val syncedDeviceList = listOf(noTabDevice)
         val adapterData = syncedDeviceList.toAdapterList()
 
-        assertEquals(0, adapterData.count())
+        assertEquals(2, adapterData.count())
+        assertTrue(adapterData[0] is SyncedTabsAdapter.AdapterItem.Device)
+        assertTrue(adapterData[1] is SyncedTabsAdapter.AdapterItem.NoTabs)
     }
 }