Convert Tabs to use database

app/src/main/java/org/wikipedia/WikipediaApp.kt

@@ -29,7 +29,6 @@ import org.wikipedia.language.AcceptLanguageUtil
 import org.wikipedia.language.AppLanguageState
 import org.wikipedia.notifications.NotificationCategory
 import org.wikipedia.notifications.NotificationPollBroadcastReceiver
-import org.wikipedia.page.tabs.Tab
 import org.wikipedia.push.WikipediaFirebaseMessagingService
 import org.wikipedia.settings.Prefs
 import org.wikipedia.theme.Theme
@@ -66,7 +65,6 @@ class WikipediaApp : Application() {
     private var defaultWikiSite: WikiSite? = null
 
     val connectionStateMonitor = ConnectionStateMonitor()
-    val tabList = mutableListOf<Tab>()
 
     var currentTheme = Theme.fallback
         set(value) {
@@ -112,10 +110,6 @@ class WikipediaApp : Application() {
             return defaultWikiSite!!
         }
 
-    // handle the case where we have a single tab with an empty backstack, which shouldn't count as a valid tab:
-    val tabCount
-        get() = if (tabList.size > 1) tabList.size else if (tabList.isEmpty()) 0 else if (tabList[0].backStack.isEmpty()) 0 else tabList.size
-
     val isOnline
         get() = connectionStateMonitor.isOnline()
 
@@ -149,7 +143,6 @@ class WikipediaApp : Application() {
 
         currentTheme = unmarshalTheme(Prefs.currentThemeId)
 
-        initTabs()
         enableWebViewDebugging()
         registerActivityLifecycleCallbacks(activityLifecycleHandler)
         registerComponentCallbacks(activityLifecycleHandler)
@@ -211,15 +204,6 @@ class WikipediaApp : Application() {
         // TODO: send exception to custom crash reporting system
     }
 
-    fun commitTabState() {
-        if (tabList.isEmpty()) {
-            Prefs.clearTabs()
-            initTabs()
-        } else {
-            Prefs.tabs = tabList
-        }
-    }
-
     /**
      * Gets the current size of the app's font. This is given as a device-specific size (not "sp"),
      * and can be passed directly to setTextSize() functions.
@@ -280,15 +264,6 @@ class WikipediaApp : Application() {
         return result
     }
 
-    private fun initTabs() {
-        if (Prefs.hasTabs) {
-            tabList.addAll(Prefs.tabs)
-        }
-        if (tabList.isEmpty()) {
-            tabList.add(Tab())
-        }
-    }
-
     companion object {
         lateinit var instance: WikipediaApp
             private set

app/src/main/java/org/wikipedia/database/AppDatabase.kt

@@ -20,6 +20,10 @@ import org.wikipedia.notifications.db.Notification
 import org.wikipedia.notifications.db.NotificationDao
 import org.wikipedia.offline.db.OfflineObject
 import org.wikipedia.offline.db.OfflineObjectDao
+import org.wikipedia.page.tabs.PageBackStackItem
+import org.wikipedia.page.tabs.PageBackStackItemDao
+import org.wikipedia.page.tabs.Tab
+import org.wikipedia.page.tabs.TabDao
 import org.wikipedia.pageimages.db.PageImage
 import org.wikipedia.pageimages.db.PageImageDao
 import org.wikipedia.readinglist.database.ReadingList
@@ -30,6 +34,7 @@ import org.wikipedia.readinglist.db.ReadingListPageDao
 import org.wikipedia.readinglist.db.RecommendedPageDao
 import org.wikipedia.search.db.RecentSearch
 import org.wikipedia.search.db.RecentSearchDao
+import org.wikipedia.settings.Prefs
 import org.wikipedia.staticdata.MainPageNameData
 import org.wikipedia.talk.db.TalkPageSeen
 import org.wikipedia.talk.db.TalkPageSeenDao
@@ -38,7 +43,7 @@ import org.wikipedia.talk.db.TalkTemplateDao
 import java.time.LocalDate
 
 const val DATABASE_NAME = "wikipedia.db"
-const val DATABASE_VERSION = 31
+const val DATABASE_VERSION = 32
 
 @Database(
     entities = [
@@ -54,7 +59,9 @@ const val DATABASE_VERSION = 31
         TalkTemplate::class,
         Category::class,
         DailyGameHistory::class,
-        RecommendedPage::class
+        RecommendedPage::class,
+        Tab::class,
+        PageBackStackItem::class
     ],
     version = DATABASE_VERSION
 )
@@ -80,6 +87,8 @@ abstract class AppDatabase : RoomDatabase() {
     abstract fun categoryDao(): CategoryDao
     abstract fun dailyGameHistoryDao(): DailyGameHistoryDao
     abstract fun recommendedPageDao(): RecommendedPageDao
+    abstract fun tabDao(): TabDao
+    abstract fun pageBackStackItemDao(): PageBackStackItemDao
 
     companion object {
         val MIGRATION_19_20 = object : Migration(19, 20) {
@@ -347,13 +356,65 @@ abstract class AppDatabase : RoomDatabase() {
                 db.execSQL("ALTER TABLE Category_temp RENAME TO Category")
             }
         }
+        val MIGRATION_31_32 = object : Migration(31, 32) {
+            override fun migrate(db: SupportSQLiteDatabase) {
+                db.execSQL("CREATE TABLE IF NOT EXISTS `Tab` (" +
+                        "  `id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL," +
+                        "  `order` INTEGER NOT NULL," +
+                        "  `backStackIds` TEXT NOT NULL," +
+                        "  `backStackPosition` INTEGER NOT NULL" +
+                        ")")
+                db.execSQL("CREATE TABLE IF NOT EXISTS `PageBackStackItem` (" +
+                        "  `id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL," +
+                        "  `apiTitle` TEXT NOT NULL," +
+                        "  `displayTitle` TEXT NOT NULL," +
+                        "  `langCode` TEXT NOT NULL," +
+                        "  `namespace` TEXT NOT NULL," +
+                        "  `timestamp` INTEGER NOT NULL," +
+                        "  `scrollY` INTEGER NOT NULL," +
+                        "  `source` INTEGER NOT NULL," +
+                        "  `thumbUrl` TEXT," +
+                        "  `description` TEXT," +
+                        "  `extract` TEXT" +
+                        ")")
+
+                // Migrating from Pres.tabs to database
+                var pageBackStackItemIndex = 1
+                Prefs.tabs.forEachIndexed { index, tab ->
+                    // Insert back stack items to PageBackStackItem and get the IDs
+                    var backStackIds = mutableListOf<Int>()
+                    // TODO: make sure the order is correct
+                    tab.backStack.forEach { backStackItem ->
+                        db.execSQL("INSERT INTO PageBackStackItem " +
+                                "(apiTitle, displayTitle, langCode, namespace, timestamp, scrollY, source, thumbUrl, description, extract) " +
+                                "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+                            arrayOf<Any?>(
+                                backStackItem.apiTitle,
+                                backStackItem.displayTitle,
+                                backStackItem.langCode,
+                                backStackItem.namespace,
+                                backStackItem.timestamp,
+                                backStackItem.scrollY,
+                                backStackItem.source,
+                                backStackItem.thumbUrl,
+                                backStackItem.description,
+                                backStackItem.extract
+                            ))
+                        backStackIds.add(pageBackStackItemIndex++)
+                    }
+                    // Insert the tab into the Tab table
+                    db.execSQL("INSERT INTO Tab (`order`, backStackIds, backStackPosition) VALUES (?, ?, ?)",
+                        arrayOf<Any?>(index, backStackIds.joinToString(","), tab.backStackPosition))
+                }
+            }
+        }
 
         val instance: AppDatabase by lazy(LazyThreadSafetyMode.SYNCHRONIZED) {
             Room.databaseBuilder(WikipediaApp.instance, AppDatabase::class.java, DATABASE_NAME)
                 .addMigrations(MIGRATION_19_20, MIGRATION_20_21, MIGRATION_21_22, MIGRATION_22_23,
                     MIGRATION_23_24, MIGRATION_24_25, MIGRATION_25_26, MIGRATION_26_27,
                     MIGRATION_26_28, MIGRATION_27_28, MIGRATION_28_29, MIGRATION_29_30,
-                    MIGRATION_30_31)
+                    MIGRATION_30_31, MIGRATION_31_32)
                 .fallbackToDestructiveMigration(false)
                 .build()
         }

app/src/main/java/org/wikipedia/feed/news/NewsFragment.kt

@@ -12,6 +12,7 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.core.os.bundleOf
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
+import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.LinearLayoutManager
 import com.google.android.material.appbar.AppBarLayout
 import org.wikipedia.Constants
@@ -24,14 +25,14 @@ import org.wikipedia.feed.model.Card
 import org.wikipedia.feed.view.ListCardItemView
 import org.wikipedia.history.HistoryEntry
 import org.wikipedia.page.PageActivity
+import org.wikipedia.page.tabs.TabHelper
 import org.wikipedia.readinglist.ReadingListBehaviorsUtil
 import org.wikipedia.richtext.RichTextUtil
 import org.wikipedia.util.DeviceUtil
 import org.wikipedia.util.DimenUtil
 import org.wikipedia.util.FeedbackUtil
 import org.wikipedia.util.GradientUtil
 import org.wikipedia.util.ResourceUtil
-import org.wikipedia.util.TabUtil
 import org.wikipedia.views.DefaultRecyclerAdapter
 import org.wikipedia.views.DefaultViewHolder
 import org.wikipedia.views.DrawableItemDecoration
@@ -109,7 +110,7 @@ class NewsFragment : Fragment() {
     private inner class Callback : ListCardItemView.Callback {
         override fun onSelectPage(card: Card, entry: HistoryEntry, openInNewBackgroundTab: Boolean) {
             if (openInNewBackgroundTab) {
-                TabUtil.openInNewBackgroundTab(entry)
+                TabHelper.openInNewBackgroundTab(viewLifecycleOwner.lifecycleScope, entry)
                 FeedbackUtil.showMessage(requireActivity(), R.string.article_opened_in_background_tab)
             } else {
                 startActivity(PageActivity.newIntentForNewTab(requireContext(), entry, entry.title))

app/src/main/java/org/wikipedia/feed/onthisday/OnThisDayPagesViewHolder.kt

@@ -6,21 +6,22 @@ import android.view.View
 import android.widget.FrameLayout
 import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.RecyclerView
 import org.wikipedia.Constants
 import org.wikipedia.R
 import org.wikipedia.dataclient.WikiSite
 import org.wikipedia.dataclient.page.PageSummary
 import org.wikipedia.history.HistoryEntry
 import org.wikipedia.page.PageActivity
+import org.wikipedia.page.tabs.TabHelper
 import org.wikipedia.readinglist.LongPressMenu
 import org.wikipedia.readinglist.ReadingListBehaviorsUtil
 import org.wikipedia.readinglist.database.ReadingListPage
 import org.wikipedia.util.DeviceUtil
 import org.wikipedia.util.DimenUtil
 import org.wikipedia.util.FeedbackUtil
 import org.wikipedia.util.StringUtil
-import org.wikipedia.util.TabUtil
 import org.wikipedia.util.TransitionUtil
 import org.wikipedia.views.FaceAndColorDetectImageView
 
@@ -92,7 +93,7 @@ class OnThisDayPagesViewHolder(
                 }
 
                 override fun onOpenInNewTab(entry: HistoryEntry) {
-                    TabUtil.openInNewBackgroundTab(entry)
+                    TabHelper.openInNewBackgroundTab(activity.lifecycleScope, entry)
                     FeedbackUtil.showMessage(activity, R.string.article_opened_in_background_tab)
                 }
 

app/src/main/java/org/wikipedia/feed/topread/TopReadFragment.kt

@@ -10,6 +10,7 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.core.os.bundleOf
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
+import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.LinearLayoutManager
 import org.wikipedia.Constants
 import org.wikipedia.Constants.InvokeSource
@@ -20,10 +21,10 @@ import org.wikipedia.feed.model.Card
 import org.wikipedia.feed.view.ListCardItemView
 import org.wikipedia.history.HistoryEntry
 import org.wikipedia.page.PageActivity
+import org.wikipedia.page.tabs.TabHelper
 import org.wikipedia.readinglist.ReadingListBehaviorsUtil
 import org.wikipedia.util.DimenUtil
 import org.wikipedia.util.FeedbackUtil
-import org.wikipedia.util.TabUtil
 import org.wikipedia.views.DefaultRecyclerAdapter
 import org.wikipedia.views.DefaultViewHolder
 import org.wikipedia.views.DrawableItemDecoration
@@ -77,7 +78,7 @@ class TopReadFragment : Fragment() {
     private inner class Callback : ListCardItemView.Callback {
         override fun onSelectPage(card: Card, entry: HistoryEntry, openInNewBackgroundTab: Boolean) {
             if (openInNewBackgroundTab) {
-                TabUtil.openInNewBackgroundTab(entry)
+                TabHelper.openInNewBackgroundTab(viewLifecycleOwner.lifecycleScope, entry)
                 FeedbackUtil.showMessage(requireActivity(), R.string.article_opened_in_background_tab)
             } else {
                 startActivity(PageActivity.newIntentForNewTab(requireContext(), entry, entry.title))

app/src/main/java/org/wikipedia/json/PageBackStackItemSerializer.kt

@@ -0,0 +1,45 @@
+package org.wikipedia.json
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.descriptors.buildClassSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.decodeFromJsonElement
+import kotlinx.serialization.json.jsonObject
+import org.wikipedia.history.HistoryEntry
+import org.wikipedia.page.PageTitle
+import org.wikipedia.page.tabs.PageBackStackItem
+
+// TODO: remove on 2026-07-01
+object PageBackStackItemSerializer : KSerializer<PageBackStackItem> {
+    override val descriptor = buildClassSerialDescriptor("PageBackStackItem")
+
+    override fun deserialize(decoder: Decoder): PageBackStackItem {
+        val input = decoder as JsonDecoder
+        val element = input.decodeJsonElement().jsonObject
+
+        // This is to handle the old format of PageBackStackItem which originally stored in the Prefs.tabs
+        return if (element.containsKey("title") && element.containsKey("historyEntry")) {
+            val oldFormat = Json.decodeFromJsonElement<OldPageBackStackItem>(element)
+            PageBackStackItem(oldFormat.title, oldFormat.historyEntry).also {
+                it.scrollY = oldFormat.scrollY
+            }
+        } else {
+            Json.decodeFromJsonElement<PageBackStackItem>(element)
+        }
+    }
+
+    override fun serialize(encoder: Encoder, value: PageBackStackItem) {
+        encoder.encodeSerializableValue(PageBackStackItem.serializer(), value)
+    }
+}
+
+@Serializable
+private data class OldPageBackStackItem(
+    val title: PageTitle,
+    val historyEntry: HistoryEntry,
+    val scrollY: Int = 0
+)

app/src/main/java/org/wikipedia/main/MainFragment.kt

@@ -65,6 +65,7 @@ import org.wikipedia.page.ExclusiveBottomSheetPresenter
 import org.wikipedia.page.PageActivity
 import org.wikipedia.page.PageTitle
 import org.wikipedia.page.tabs.TabActivity
+import org.wikipedia.page.tabs.TabHelper
 import org.wikipedia.places.PlacesActivity
 import org.wikipedia.random.RandomActivity
 import org.wikipedia.readinglist.ReadingListBehaviorsUtil
@@ -82,7 +83,6 @@ import org.wikipedia.usercontrib.UserContribListActivity
 import org.wikipedia.util.DimenUtil
 import org.wikipedia.util.FeedbackUtil
 import org.wikipedia.util.ShareUtil
-import org.wikipedia.util.TabUtil
 import org.wikipedia.views.NotificationButtonView
 import org.wikipedia.views.TabCountsView
 import org.wikipedia.views.imageservice.ImageService
@@ -216,7 +216,7 @@ class MainFragment : Fragment(), BackPressedHandler, MenuProvider, FeedFragment.
                 FeedbackUtil.showMessage(this, R.string.login_success_toast)
             }
         } else if (requestCode == Constants.ACTIVITY_REQUEST_BROWSE_TABS) {
-            if (WikipediaApp.instance.tabCount == 0) {
+            if (TabHelper.count == 0) {
                 // They browsed the tabs and cleared all of them, without wanting to open a new tab.
                 return
             }
@@ -275,14 +275,14 @@ class MainFragment : Fragment(), BackPressedHandler, MenuProvider, FeedFragment.
         menu.findItem(R.id.menu_overflow_button).isVisible = currentFragment is ReadingListsFragment
 
         val tabsItem = menu.findItem(R.id.menu_tabs)
-        if (WikipediaApp.instance.tabCount < 1 || currentFragment is SuggestedEditsTasksFragment) {
+        if (TabHelper.count < 1 || currentFragment is SuggestedEditsTasksFragment) {
             tabsItem.isVisible = false
             tabCountsView = null
         } else {
             tabsItem.isVisible = true
             tabCountsView = TabCountsView(requireActivity(), null)
             tabCountsView!!.setOnClickListener {
-                if (WikipediaApp.instance.tabCount == 1) {
+                if (TabHelper.count == 1) {
                     startActivity(PageActivity.newIntent(requireActivity()))
                 } else {
                     startActivityForResult(TabActivity.newIntent(requireActivity()), Constants.ACTIVITY_REQUEST_BROWSE_TABS)
@@ -333,7 +333,7 @@ class MainFragment : Fragment(), BackPressedHandler, MenuProvider, FeedFragment.
             goToTab(NavTab.of(intent.getIntExtra(Constants.INTENT_EXTRA_GO_TO_SE_TAB, NavTab.EDITS.code())))
         } else if (intent.hasExtra(Constants.INTENT_EXTRA_PREVIEW_SAVED_READING_LISTS)) {
             goToTab(NavTab.READING_LISTS)
-        } else if (lastPageViewedWithin(1) && !intent.hasExtra(Constants.INTENT_RETURN_TO_MAIN) && WikipediaApp.instance.tabCount > 0) {
+        } else if (lastPageViewedWithin(1) && !intent.hasExtra(Constants.INTENT_RETURN_TO_MAIN) && TabHelper.count > 0) {
             startActivity(PageActivity.newIntent(requireContext()))
         }
     }
@@ -354,9 +354,10 @@ class MainFragment : Fragment(), BackPressedHandler, MenuProvider, FeedFragment.
 
     override fun onFeedSelectPage(entry: HistoryEntry, openInNewBackgroundTab: Boolean) {
         if (openInNewBackgroundTab) {
-            TabUtil.openInNewBackgroundTab(entry)
-            showTabCountsAnimation = true
-            requireActivity().invalidateOptionsMenu()
+            TabHelper.openInNewBackgroundTab(viewLifecycleOwner.lifecycleScope, entry) {
+                showTabCountsAnimation = true
+                requireActivity().invalidateOptionsMenu()
+            }
         } else {
             startActivity(PageActivity.newIntentForNewTab(requireContext(), entry, entry.title))
         }