Allow EmpireOverview persistence across game launches (#11725)

* Remove blank space between header and list in ResourceOverviewTab vertical mode

* Allow EmpireOverview persistence across game launches

core/src/com/unciv/models/metadata/GameSettings.kt

@@ -98,7 +98,10 @@ class GameSettings {
     var autoPlay = GameSettingsAutoPlay()
 
     // This is a string not an enum so if tabs change it won't screw up the json serialization
+    //TODO remove line in a future update
     var lastOverviewPage = EmpireOverviewCategories.Cities.name
+    /** Holds EmpireOverviewScreen per-page persistable states */
+    val overview = OverviewPersistableData()
 
     /** Orientation for mobile platforms */
     var displayOrientation = ScreenOrientation.Landscape

core/src/com/unciv/models/metadata/OverviewPersistableData.kt

@@ -0,0 +1,61 @@
+package com.unciv.models.metadata
+
+import com.badlogic.gdx.utils.Json
+import com.badlogic.gdx.utils.JsonValue
+import com.badlogic.gdx.utils.SerializationException
+import com.unciv.ui.screens.overviewscreen.EmpireOverviewCategories
+import com.unciv.ui.screens.overviewscreen.EmpireOverviewTab
+
+class OverviewPersistableData(
+    private val map: LinkedHashMap<EmpireOverviewCategories, EmpireOverviewTab.EmpireOverviewTabPersistableData> = linkedMapOf()
+) : Json.Serializable,
+    Map<EmpireOverviewCategories, EmpireOverviewTab.EmpireOverviewTabPersistableData> by map
+{
+    //todo so far this is saved but not used, should replace [GameSettings.lastOverviewPage] in a future update.
+    var last: EmpireOverviewCategories = EmpireOverviewCategories.Cities
+
+    fun update(pageObjects: Map<EmpireOverviewCategories, EmpireOverviewTab>) {
+        for ((category, page) in pageObjects)
+            map[category] = page.persistableData
+    }
+
+    /**
+     *  Gdx Serialize
+     *  - Intended format: `"overview":{"Cities":{"sortedBy":"Population","direction":"Descending"},...,"Resources":{"vertical":true}}`
+     *  - Outer field name and Object markers are already cared for, so we can begin directly with our fields
+     */
+    override fun write(json: Json) {
+        if (last != EmpireOverviewCategories.Cities)
+            json.writeValue("last", last.name, String::class.java)
+        for ((category, data) in map) {
+            val clazz = category.getPersistDataClass() ?: continue
+            if (data.isEmpty()) continue
+            json.writeValue(category.name, data, clazz)
+        }
+    }
+
+    /**
+     *  Gdx Deserialize (format see [write])
+     *  - Gdx architecture means this operates on a default instance Gdx just created using the zero-args constructor
+     *  - Should be tolerant against Enum values that do not exist in current code
+     */
+    override fun read(json: Json, jsonData: JsonValue) {
+        val lastName = jsonData.get("last")?.asString() // Nullable, benign if field missing - getString() is not.
+        EmpireOverviewCategories.values().firstOrNull { it.name == lastName }?.let { last = it }
+        if (jsonData.isObject && jsonData.notEmpty())
+            for (element in jsonData) readEntry(json, element)
+    }
+
+    private fun readEntry(json: Json, element: JsonValue) {
+        val name = element.name()
+        val category = EmpireOverviewCategories.values().firstOrNull { it.name == name }
+            ?: return // Guards against downgrading to an Unciv missing a category, but also skips "last" here
+        val clazz = category.getPersistDataClass()
+        try {
+            val data = json.readValue(clazz, element)
+            map[category] = data
+        } catch (ex: SerializationException) {
+            // Unknown Enum values inside an EmpireOverviewTabPersistableData subclass end up here
+        }
+    }
+}

core/src/com/unciv/ui/screens/overviewscreen/CityOverviewTab.kt

@@ -16,12 +16,10 @@ class CityOverviewTab(
     overviewScreen: EmpireOverviewScreen,
     persistedData: EmpireOverviewTabPersistableData? = null
 ) : EmpireOverviewTab(viewingPlayer, overviewScreen) {
-    class CityTabPersistableData(
-        override var sortedBy: CityOverviewTabColumn = CityOverviewTabColumn.CityColumn,
-
-    ) : EmpireOverviewTabPersistableData(), SortableGrid.ISortState<CityOverviewTabColumn> {
-        override fun isEmpty() = sortedBy == CityOverviewTabColumn.CityColumn
-        override var direction = SortableGrid.SortDirection.None
+    class CityTabPersistableData : EmpireOverviewTabPersistableData(), SortableGrid.ISortState<CityOverviewTabColumn> {
+        override var sortedBy: CityOverviewTabColumn = CityOverviewTabColumn.CityColumn
+        override var direction: SortableGrid.SortDirection = SortableGrid.SortDirection.None
+        override fun isEmpty() = sortedBy == CityOverviewTabColumn.CityColumn && direction != SortableGrid.SortDirection.Descending
     }
 
     override val persistableData = (persistedData as? CityTabPersistableData) ?: CityTabPersistableData()

core/src/com/unciv/ui/screens/overviewscreen/EmpireOverviewCategories.kt

@@ -23,6 +23,7 @@ enum class EmpireOverviewCategories(
         override fun createTab(viewingPlayer: Civilization, overviewScreen: EmpireOverviewScreen, persistedData: EmpireOverviewTabPersistableData?) =
                 CityOverviewTab(viewingPlayer, overviewScreen, persistedData)
         override fun showDisabled(viewingPlayer: Civilization) = viewingPlayer.cities.isEmpty()
+        override fun getPersistDataClass() = CityOverviewTab.CityTabPersistableData::class.java
     },
     Stats("StatIcons/Gold", 'S', Align.top) {
         override fun createTab(viewingPlayer: Civilization, overviewScreen: EmpireOverviewScreen, persistedData: EmpireOverviewTabPersistableData?) =
@@ -42,16 +43,19 @@ enum class EmpireOverviewCategories(
         override fun createTab(viewingPlayer: Civilization, overviewScreen: EmpireOverviewScreen, persistedData: EmpireOverviewTabPersistableData?) =
                 UnitOverviewTab(viewingPlayer, overviewScreen, persistedData)
         override fun showDisabled(viewingPlayer: Civilization) = viewingPlayer.units.getCivUnits().none()
+        override fun getPersistDataClass() = UnitOverviewTab.UnitTabPersistableData::class.java
     },
     Politics("OtherIcons/Politics", 'P', Align.top) {
         override fun createTab(viewingPlayer: Civilization, overviewScreen: EmpireOverviewScreen, persistedData: EmpireOverviewTabPersistableData?) =
                 GlobalPoliticsOverviewTable(viewingPlayer, overviewScreen, persistedData)
         override fun showDisabled(viewingPlayer: Civilization) = viewingPlayer.diplomacy.isEmpty()
+        override fun getPersistDataClass() = GlobalPoliticsOverviewTable.DiplomacyTabPersistableData::class.java
     },
     Resources("StatIcons/Happiness", 'R', Align.topLeft) {
         override fun createTab(viewingPlayer: Civilization, overviewScreen: EmpireOverviewScreen, persistedData: EmpireOverviewTabPersistableData?) =
                 ResourcesOverviewTab(viewingPlayer, overviewScreen, persistedData)
         override fun showDisabled(viewingPlayer: Civilization) = viewingPlayer.detailedCivResources.none { it.resource.resourceType != ResourceType.Bonus }
+        override fun getPersistDataClass() = ResourcesOverviewTab.ResourcesTabPersistableData::class.java
     },
     Religion("StatIcons/Faith", 'F', Align.top) {
         override fun createTab(viewingPlayer: Civilization, overviewScreen: EmpireOverviewScreen, persistedData: EmpireOverviewTabPersistableData?) =
@@ -85,4 +89,9 @@ enum class EmpireOverviewCategories(
     open fun testState(viewingPlayer: Civilization) =
             if (showDisabled(viewingPlayer)) EmpireOverviewTabState.Disabled
             else EmpireOverviewTabState.Normal
+
+    /** Get Java class of persistable data for Json serialization
+     *  - only needed if the data should actually be saved to GameSettings.json: Leaving it at `null` means any specific state persists only through one game run
+     */
+    open fun getPersistDataClass(): Class<out EmpireOverviewTabPersistableData>? = null
 }

core/src/com/unciv/ui/screens/overviewscreen/EmpireOverviewScreen.kt

@@ -11,7 +11,6 @@ import com.unciv.ui.images.ImageGetter
 import com.unciv.ui.screens.basescreen.BaseScreen
 import com.unciv.ui.screens.basescreen.RecreateOnResize
 import com.unciv.ui.screens.overviewscreen.EmpireOverviewCategories.EmpireOverviewTabState
-import com.unciv.ui.screens.overviewscreen.EmpireOverviewTab.EmpireOverviewTabPersistableData
 
 class EmpireOverviewScreen(
     private var viewingPlayer: Civilization,
@@ -25,25 +24,19 @@ class EmpireOverviewScreen(
     private val tabbedPager: TabbedPager
     private val pageObjects = HashMap<EmpireOverviewCategories, EmpireOverviewTab>()
 
-    companion object {
-        // This is what keeps per-tab states between overview invocations
-        var persistState: Map<EmpireOverviewCategories, EmpireOverviewTabPersistableData>? = null
-
-        private fun updatePersistState(pageObjects: HashMap<EmpireOverviewCategories, EmpireOverviewTab>) {
-            persistState = pageObjects.mapValues { it.value.persistableData }.filterNot { it.value.isEmpty() }
-        }
-    }
+    internal val persistState by game.settings::overview
 
     override fun dispose() {
         tabbedPager.selectPage(-1)
-        updatePersistState(pageObjects)
         super.dispose()
     }
 
     override fun getCivilopediaRuleset() = viewingPlayer.gameInfo.ruleset
 
     init {
-        val selectCategory = defaultCategory ?: EmpireOverviewCategories.values().firstOrNull { it.name == game.settings.lastOverviewPage }
+        val selectCategory = defaultCategory
+            //TODO replace with `?: persistState.last` in a future update
+            ?: EmpireOverviewCategories.values().firstOrNull { it.name == game.settings.lastOverviewPage }
         val iconSize = Constants.defaultFontSize.toFloat()
 
         tabbedPager = TabbedPager(
@@ -56,7 +49,7 @@ class EmpireOverviewScreen(
             val tabState = category.testState(viewingPlayer)
             if (tabState == EmpireOverviewTabState.Hidden) continue
             val icon = if (category.iconName.isEmpty()) null else ImageGetter.getImage(category.iconName)
-            val pageObject = category.createTab(viewingPlayer, this, persistState?.get(category))
+            val pageObject = category.createTab(viewingPlayer, this, persistState[category])
             pageObject.pad(10f, 0f, 10f, 0f)
             pageObjects[category] = pageObject
             val index = tabbedPager.addPage(
@@ -72,21 +65,19 @@ class EmpireOverviewScreen(
                 select(pageObject, selection)
             }
         }
+        persistState.update(pageObjects)
 
         val closeButton = getCloseButton { game.popScreen() }
         tabbedPager.decorateHeader(closeButton)
 
         tabbedPager.setFillParent(true)
         stage.addActor(tabbedPager)
-
-//         closeButton.setPosition(stage.width - 10f, stage.height - 10f, Align.topRight)
-//         stage.addActor(closeButton)
    }
 
     override fun recreate(): BaseScreen {
         tabbedPager.selectPage(-1)  // trigger deselect on _old_ instance so the tabs can persist their stuff
-        updatePersistState(pageObjects)
         return EmpireOverviewScreen(viewingPlayer,
+            //TODO replace with `persistState.last)` in a future update
             EmpireOverviewCategories.values().firstOrNull { it.name == game.settings.lastOverviewPage })
     }
 

core/src/com/unciv/ui/screens/overviewscreen/EmpireOverviewTab.kt

@@ -10,14 +10,22 @@ abstract class EmpireOverviewTab (
     val overviewScreen: EmpireOverviewScreen,
     persistedData: EmpireOverviewTabPersistableData? = null
 ) : Table(BaseScreen.skin), TabbedPager.IPageExtensions {
+    /** Abstract container for persistable data
+     *  - default class does nothing
+     *  - If persistence should end when quitting the game - do not override [isEmpty] and [EmpireOverviewCategories.getPersistDataClass].
+     *  - For persistence in GameSettings.json, override **both**.
+     */
     open class EmpireOverviewTabPersistableData {
+        /** Used by serialization to detect when a default state can be omitted */
         open fun isEmpty() = true
     }
     open val persistableData = persistedData ?: EmpireOverviewTabPersistableData()
 
     override fun activated(index: Int, caption: String, pager: TabbedPager) {
-        if (caption.isEmpty()) return
+        if (caption.isEmpty()) return // called from EmpireOverviewScreen.resume()
+        //TODO remove line in a future update
         overviewScreen.game.settings.lastOverviewPage = caption
+        overviewScreen.persistState.last = EmpireOverviewCategories.values()[index]  // Change this if categories are ever reordered or filtered
     }
 
     /** Override if the tab can _select_ something specific.

core/src/com/unciv/ui/screens/overviewscreen/NotificationsOverviewTable.kt

@@ -19,10 +19,8 @@ class NotificationsOverviewTable(
     persistedData: EmpireOverviewTabPersistableData? = null
 ) : EmpireOverviewTab(viewingPlayer, overviewScreen) {
     class NotificationsTabPersistableData(
-            var scrollY: Float? = null
-    ) : EmpireOverviewTabPersistableData() {
-        override fun isEmpty() = scrollY == null
-    }
+        var scrollY: Float? = null
+    ) : EmpireOverviewTabPersistableData()
     override val persistableData = (persistedData as? NotificationsTabPersistableData) ?: NotificationsTabPersistableData()
     override fun activated(index: Int, caption: String, pager: TabbedPager) {
         if (persistableData.scrollY != null)

core/src/com/unciv/ui/screens/overviewscreen/ReligionOverviewTab.kt

@@ -29,9 +29,7 @@ class ReligionOverviewTab(
 ) : EmpireOverviewTab(viewingPlayer, overviewScreen) {
     class ReligionTabPersistableData(
         var selectedReligion: String? = null
-    ) : EmpireOverviewTabPersistableData() {
-        override fun isEmpty() = selectedReligion == null
-    }
+    ) : EmpireOverviewTabPersistableData()
     override val persistableData = (persistedData as? ReligionTabPersistableData) ?: ReligionTabPersistableData()
 
     private val civStatsTable = Table()

core/src/com/unciv/ui/screens/overviewscreen/ResourcesOverviewTab.kt

@@ -129,6 +129,7 @@ class ResourcesOverviewTab(
 
     init {
         defaults().pad(defaultPad)
+        top()
         fixedContent.defaults().pad(defaultPad)
 
         turnImageH.onClick {

core/src/com/unciv/ui/screens/overviewscreen/UnitOverviewTab.kt

@@ -20,10 +20,12 @@ class UnitOverviewTab(
     persistedData: EmpireOverviewTabPersistableData? = null
 ) : EmpireOverviewTab(viewingPlayer, overviewScreen) {
     class UnitTabPersistableData : EmpireOverviewTabPersistableData(), SortableGrid.ISortState<UnitOverviewTabColumn> {
+        @Transient
         var scrollY: Float? = null
+
         override var sortedBy: UnitOverviewTabColumn = UnitOverviewTabColumn.Name
         override var direction = SortableGrid.SortDirection.None
-        override fun isEmpty() = scrollY == null && sortedBy == UnitOverviewTabColumn.Name && direction != SortableGrid.SortDirection.Descending
+        override fun isEmpty() = sortedBy == UnitOverviewTabColumn.Name && direction != SortableGrid.SortDirection.Descending
     }
     override val persistableData = (persistedData as? UnitTabPersistableData) ?: UnitTabPersistableData()