For mozilla-mobile#19916 - Add last viewed tab to home screen

Co-authored-by: Jonathan Almeida <jalmeida@mozilla.com>

app/src/main/java/org/mozilla/fenix/FeatureFlags.kt

@@ -33,4 +33,9 @@ object FeatureFlags {
      * Enables the Home button in the browser toolbar to navigate back to the home screen.
      */
     val showHomeButtonFeature = Config.channel.isNightlyOrDebug
+
+    /**
+     * Enables the "recent" tabs feature in the home screen.
+     */
+    val showRecentTabsFeature = Config.channel.isNightlyOrDebug
 }

app/src/main/java/org/mozilla/fenix/ext/BrowserState.kt

@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.ext
+
+import mozilla.components.browser.state.selector.selectedTab
+import mozilla.components.browser.state.state.BrowserState
+import mozilla.components.browser.state.state.TabSessionState
+
+/**
+ * Returns the currently selected tab if there's one as a list.
+ *
+ * @return A list of the currently selected tab or an empty list.
+ */
+fun BrowserState.asRecentTabs(): List<TabSessionState> =
+    if (selectedTab != null) {
+        listOfNotNull(selectedTab)
+    } else {
+        emptyList()
+    }

app/src/main/java/org/mozilla/fenix/home/HomeFragment.kt

@@ -85,6 +85,7 @@ import mozilla.components.support.ktx.kotlinx.coroutines.flow.ifChanged
 import mozilla.components.ui.tabcounter.TabCounterMenu
 import org.mozilla.fenix.BrowserDirection
 import org.mozilla.fenix.Config
+import org.mozilla.fenix.FeatureFlags
 import org.mozilla.fenix.GleanMetrics.PerfStartup
 import org.mozilla.fenix.HomeActivity
 import org.mozilla.fenix.R
@@ -101,6 +102,7 @@ import org.mozilla.fenix.components.tips.Tip
 import org.mozilla.fenix.components.tips.providers.MasterPasswordTipProvider
 import org.mozilla.fenix.components.toolbar.FenixTabCounterMenu
 import org.mozilla.fenix.components.toolbar.ToolbarPosition
+import org.mozilla.fenix.ext.asRecentTabs
 import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.hideToolbar
 import org.mozilla.fenix.ext.navigateBlockingForAsyncNavGraph
@@ -112,6 +114,7 @@ import org.mozilla.fenix.ext.runIfFragmentIsAttached
 import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.home.mozonline.showPrivacyPopWindow
 import org.mozilla.fenix.home.sessioncontrol.DefaultSessionControlController
+import org.mozilla.fenix.home.sessioncontrol.RecentTabsListFeature
 import org.mozilla.fenix.home.sessioncontrol.SessionControlInteractor
 import org.mozilla.fenix.home.sessioncontrol.SessionControlView
 import org.mozilla.fenix.home.sessioncontrol.viewholders.CollectionViewHolder
@@ -171,6 +174,7 @@ class HomeFragment : Fragment() {
     private lateinit var currentMode: CurrentMode
 
     private val topSitesFeature = ViewBoundFeatureWrapper<TopSitesFeature>()
+    private val recentTabsListFeature = ViewBoundFeatureWrapper<RecentTabsListFeature>()
 
     @VisibleForTesting
     internal var getMenuButton: () -> MenuButton? = { menuButton }
@@ -243,6 +247,17 @@ class HomeFragment : Fragment() {
             view = view
         )
 
+        if (FeatureFlags.showRecentTabsFeature) {
+            recentTabsListFeature.set(
+                feature = RecentTabsListFeature(
+                    browserStore = components.core.store,
+                    homeStore = homeFragmentStore
+                ),
+                owner = viewLifecycleOwner,
+                view = view
+            )
+        }
+
         _sessionControlInteractor = SessionControlInteractor(
             DefaultSessionControlController(
                 activity = activity,
@@ -578,7 +593,8 @@ class HomeFragment : Fragment() {
                         )
                     ).getTip()
                 },
-                showCollectionPlaceholder = components.settings.showCollectionsPlaceholderOnHome
+                showCollectionPlaceholder = components.settings.showCollectionsPlaceholderOnHome,
+                recentTabs = components.core.store.state.asRecentTabs()
             )
         )
 

app/src/main/java/org/mozilla/fenix/home/HomeFragmentStore.kt

@@ -5,6 +5,7 @@
 package org.mozilla.fenix.home
 
 import android.graphics.Bitmap
+import mozilla.components.browser.state.state.TabSessionState
 import mozilla.components.feature.tab.collections.TabCollection
 import mozilla.components.feature.top.sites.TopSite
 import mozilla.components.lib.state.Action
@@ -16,7 +17,7 @@ import org.mozilla.fenix.components.tips.Tip
  * The [Store] for holding the [HomeFragmentState] and applying [HomeFragmentAction]s.
  */
 class HomeFragmentStore(
-    initialState: HomeFragmentState
+    initialState: HomeFragmentState = HomeFragmentState()
 ) : Store<HomeFragmentState, HomeFragmentAction>(
     initialState, ::homeFragmentStateReducer
 )
@@ -41,15 +42,17 @@ data class Tab(
  * @property topSites The list of [TopSite] in the [HomeFragment].
  * @property tip The current [Tip] to show on the [HomeFragment].
  * @property showCollectionPlaceholder If true, shows a placeholder when there are no collections.
+ * @property recentTabs The list of recent [TabSessionState] in the [HomeFragment].
  */
 data class HomeFragmentState(
-    val collections: List<TabCollection>,
-    val expandedCollections: Set<Long>,
-    val mode: Mode,
-    val topSites: List<TopSite>,
+    val collections: List<TabCollection> = emptyList(),
+    val expandedCollections: Set<Long> = emptySet(),
+    val mode: Mode = Mode.Normal,
+    val topSites: List<TopSite> = emptyList(),
     val tip: Tip? = null,
-    val showCollectionPlaceholder: Boolean,
-    val showSetAsDefaultBrowserCard: Boolean
+    val showCollectionPlaceholder: Boolean = false,
+    val showSetAsDefaultBrowserCard: Boolean = false,
+    val recentTabs: List<TabSessionState> = emptyList()
 ) : State
 
 sealed class HomeFragmentAction : Action {
@@ -58,7 +61,8 @@ sealed class HomeFragmentAction : Action {
         val mode: Mode,
         val collections: List<TabCollection>,
         val tip: Tip? = null,
-        val showCollectionPlaceholder: Boolean
+        val showCollectionPlaceholder: Boolean,
+        val recentTabs: List<TabSessionState>
     ) :
         HomeFragmentAction()
 
@@ -69,6 +73,7 @@ sealed class HomeFragmentAction : Action {
     data class ModeChange(val mode: Mode) : HomeFragmentAction()
     data class TopSitesChange(val topSites: List<TopSite>) : HomeFragmentAction()
     data class RemoveTip(val tip: Tip) : HomeFragmentAction()
+    data class RecentTabsChange(val recentTabs: List<TabSessionState>) : HomeFragmentAction()
     object RemoveCollectionsPlaceholder : HomeFragmentAction()
     object RemoveSetDefaultBrowserCard : HomeFragmentAction()
 }
@@ -82,7 +87,8 @@ private fun homeFragmentStateReducer(
             collections = action.collections,
             mode = action.mode,
             topSites = action.topSites,
-            tip = action.tip
+            tip = action.tip,
+            recentTabs = action.recentTabs
         )
         is HomeFragmentAction.CollectionExpanded -> {
             val newExpandedCollection = state.expandedCollections.toMutableSet()
@@ -105,5 +111,6 @@ private fun homeFragmentStateReducer(
             state.copy(showCollectionPlaceholder = false)
         }
         is HomeFragmentAction.RemoveSetDefaultBrowserCard -> state.copy(showSetAsDefaultBrowserCard = false)
+        is HomeFragmentAction.RecentTabsChange -> state.copy(recentTabs = action.recentTabs)
     }
 }

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/RecentTabsListFeature.kt

@@ -0,0 +1,42 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.home.sessioncontrol
+
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.map
+import mozilla.components.browser.state.selector.selectedTab
+import mozilla.components.browser.state.state.BrowserState
+import mozilla.components.browser.state.store.BrowserStore
+import mozilla.components.lib.state.helpers.AbstractBinding
+import mozilla.components.support.ktx.kotlinx.coroutines.flow.ifChanged
+import org.mozilla.fenix.home.HomeFragmentAction
+import org.mozilla.fenix.home.HomeFragmentStore
+
+/**
+ * View-bound feature that dispatches recent tab changes to the [HomeFragmentStore] when the
+ * [BrowserStore] is updated.
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+class RecentTabsListFeature(
+    browserStore: BrowserStore,
+    private val homeStore: HomeFragmentStore,
+) : AbstractBinding<BrowserState>(browserStore) {
+
+    override suspend fun onState(flow: Flow<BrowserState>) {
+        flow.map { it.selectedTab }
+            .ifChanged()
+            .collect { selectedTab ->
+                val recentTabsList = if (selectedTab != null) {
+                    listOf(selectedTab)
+                } else {
+                    emptyList()
+                }
+
+                homeStore.dispatch(HomeFragmentAction.RecentTabsChange(recentTabsList))
+            }
+    }
+}

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/SessionControlAdapter.kt

@@ -12,6 +12,7 @@ import androidx.lifecycle.LifecycleOwner
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ListAdapter
 import androidx.recyclerview.widget.RecyclerView
+import mozilla.components.browser.state.state.TabSessionState
 import mozilla.components.feature.tab.collections.TabCollection
 import mozilla.components.feature.top.sites.TopSite
 import mozilla.components.ui.widgets.WidgetSiteItemView
@@ -36,6 +37,8 @@ import org.mozilla.fenix.home.sessioncontrol.viewholders.onboarding.OnboardingTh
 import org.mozilla.fenix.home.sessioncontrol.viewholders.onboarding.OnboardingToolbarPositionPickerViewHolder
 import org.mozilla.fenix.home.sessioncontrol.viewholders.onboarding.OnboardingTrackingProtectionViewHolder
 import org.mozilla.fenix.home.sessioncontrol.viewholders.onboarding.OnboardingWhatsNewViewHolder
+import org.mozilla.fenix.home.sessioncontrol.viewholders.recenttabs.RecentTabViewHolder
+import org.mozilla.fenix.home.sessioncontrol.viewholders.recenttabs.RecentTabsHeaderViewHolder
 import org.mozilla.fenix.home.tips.ButtonTipViewHolder
 import mozilla.components.feature.tab.collections.Tab as ComponentTab
 
@@ -131,6 +134,11 @@ sealed class AdapterItem(@LayoutRes val viewType: Int) {
 
     object OnboardingWhatsNew : AdapterItem(OnboardingWhatsNewViewHolder.LAYOUT_ID)
 
+    object RecentTabsHeader : AdapterItem(RecentTabsHeaderViewHolder.LAYOUT_ID)
+    data class RecentTabItem(val tab: TabSessionState) : AdapterItem(RecentTabViewHolder.LAYOUT_ID) {
+        override fun sameAs(other: AdapterItem) = other is RecentTabItem && tab.id == other.tab.id
+    }
+
     /**
      * True if this item represents the same value as other. Used by [AdapterItemDiffCallback].
      */
@@ -211,7 +219,8 @@ class SessionControlAdapter(
                 view
             )
             ExperimentDefaultBrowserCardViewHolder.LAYOUT_ID -> ExperimentDefaultBrowserCardViewHolder(view, interactor)
-
+            RecentTabsHeaderViewHolder.LAYOUT_ID -> RecentTabsHeaderViewHolder(view, interactor)
+            RecentTabViewHolder.LAYOUT_ID -> RecentTabViewHolder(view, interactor)
             else -> throw IllegalStateException()
         }
     }
@@ -263,6 +272,9 @@ class SessionControlAdapter(
             is OnboardingAutomaticSignInViewHolder -> holder.bind(
                 (item as AdapterItem.OnboardingAutomaticSignIn).state.withAccount
             )
+            is RecentTabViewHolder -> {
+                holder.bindTab((item as AdapterItem.RecentTabItem).tab)
+            }
         }
     }
 }

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/SessionControlController.kt

@@ -39,6 +39,7 @@ import org.mozilla.fenix.components.tips.Tip
 import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.metrics
 import org.mozilla.fenix.ext.nav
+import org.mozilla.fenix.ext.navigateBlockingForAsyncNavGraph
 import org.mozilla.fenix.ext.openSetDefaultBrowserOption
 import org.mozilla.fenix.home.HomeFragment
 import org.mozilla.fenix.home.HomeFragmentAction
@@ -178,6 +179,16 @@ interface SessionControlController {
      * @see [ExperimentCardInteractor.onCloseExperimentCardClicked]
      */
     fun handleCloseExperimentCard()
+
+    /**
+     * @see [RecentTabInteractor.onRecentTabClicked]
+     */
+    fun handleRecentTabClicked(tabId: String)
+
+    /**
+     * @see [RecentTabInteractor.onRecentTabShowAllClicked]
+     */
+    fun handleRecentTabShowAllClicked()
 }
 
 @Suppress("TooManyFunctions", "LargeClass")
@@ -576,4 +587,16 @@ class DefaultSessionControlController(
         metrics.track(Event.CloseExperimentCardClicked)
         fragmentStore.dispatch(HomeFragmentAction.RemoveSetDefaultBrowserCard)
     }
+
+    override fun handleRecentTabClicked(tabId: String) {
+        selectTabUseCase.invoke(tabId)
+        navController.navigateBlockingForAsyncNavGraph(R.id.browserFragment)
+    }
+
+    override fun handleRecentTabShowAllClicked() {
+        navController.nav(
+            R.id.homeFragment,
+            HomeFragmentDirections.actionGlobalTabsTrayFragment()
+        )
+    }
 }

app/src/main/java/org/mozilla/fenix/home/sessioncontrol/SessionControlInteractor.kt

@@ -202,6 +202,24 @@ interface ExperimentCardInteractor {
     fun onCloseExperimentCardClicked()
 }
 
+/**
+ * Interface for recent tab related actions in the [SessionControlInteractor].
+ */
+interface RecentTabInteractor {
+    /**
+     * Opens the given tab. Called when a user clicks on a recent tab.
+     *
+     * @param tabId The ID of the tab to open.
+     */
+    fun onRecentTabClicked(tabId: String)
+
+    /**
+     * Show the tabs tray. Called when a user clicks on the "Show all" button besides the recent
+     * tabs.
+     */
+    fun onRecentTabShowAllClicked()
+}
+
 /**
  * Interactor for the Home screen.
  * Provides implementations for the CollectionInteractor, OnboardingInteractor,
@@ -211,7 +229,7 @@ interface ExperimentCardInteractor {
 class SessionControlInteractor(
     private val controller: SessionControlController
 ) : CollectionInteractor, OnboardingInteractor, TopSiteInteractor, TipInteractor,
-    TabSessionInteractor, ToolbarInteractor, ExperimentCardInteractor {
+    TabSessionInteractor, ToolbarInteractor, ExperimentCardInteractor, RecentTabInteractor {
     override fun onCollectionAddTabTapped(collection: TabCollection) {
         controller.handleCollectionAddTabTapped(collection)
     }
@@ -315,4 +333,12 @@ class SessionControlInteractor(
     override fun onCloseExperimentCardClicked() {
         controller.handleCloseExperimentCard()
     }
+
+    override fun onRecentTabClicked(tabId: String) {
+        controller.handleRecentTabClicked(tabId)
+    }
+
+    override fun onRecentTabShowAllClicked() {
+        controller.handleRecentTabShowAllClicked()
+    }
 }