Harden new game screen against bad scenarios (#13826)

* Refactor and lint ScenarioSelectTable

* Catch and display scenario file parsing errors

android/assets/jsons/translations/template.properties

@@ -379,6 +379,7 @@ Custom =
 Map Generation Type = 
 Enabled Map Generation Types = 
 Example map = 
+Scenario file [name] is invalid. = 
 
 # Map types
 Default = 

core/src/com/unciv/ui/screens/newgamescreen/MapOptionsTable.kt

@@ -1,67 +1,11 @@
 package com.unciv.ui.screens.newgamescreen
 
-import com.badlogic.gdx.files.FileHandle
 import com.badlogic.gdx.scenes.scene2d.ui.Table
-import com.unciv.Constants
-import com.unciv.logic.GameInfoPreview
 import com.unciv.logic.map.MapGeneratedMainType
-import com.unciv.models.ruleset.Ruleset
 import com.unciv.ui.components.extensions.toLabel
 import com.unciv.ui.components.input.onChange
 import com.unciv.ui.components.widgets.TranslatedSelectBox
 import com.unciv.ui.screens.basescreen.BaseScreen
-import com.unciv.utils.Concurrency
-
-class ScenarioSelectTable(val newGameScreen: NewGameScreen) : Table() {
-    
-    data class ScenarioData(val name:String, val file: FileHandle){
-        var preview: GameInfoPreview? = null
-    }
-    
-    val scenarios = HashMap<String, ScenarioData>()
-    lateinit var selectedScenario: ScenarioData
-    var scenarioSelectBox: TranslatedSelectBox? = null
-    
-    init {
-        // Only the first so it's fast
-        val firstScenarioFile = newGameScreen.game.files.getScenarioFiles().firstOrNull()
-        if (firstScenarioFile != null) {
-            createScenarioSelectBox(listOf(firstScenarioFile))
-            Concurrency.run {
-                val scenarioFiles = newGameScreen.game.files.getScenarioFiles().toList()
-                Concurrency.runOnGLThread {
-                    createScenarioSelectBox(scenarioFiles)
-                }
-            }
-        }
-    }
-
-    private fun createScenarioSelectBox(scenarioFiles: List<Pair<FileHandle, Ruleset>>) {
-        for ((file, _) in scenarioFiles)
-            scenarios[file.name()] = ScenarioData(file.name(), file)
-
-        scenarioSelectBox = TranslatedSelectBox(scenarios.keys.sorted(), scenarios.keys.first())
-        scenarioSelectBox!!.onChange { selectScenario() }
-        clear()
-        add(scenarioSelectBox)
-    }
-
-    fun selectScenario(){
-        val scenario = scenarios[scenarioSelectBox!!.selected.value]!!
-        val preload = if (scenario.preview != null) scenario.preview!! else {
-            val preview = newGameScreen.game.files.loadGamePreviewFromFile(scenario.file)
-            scenario.preview = preview
-            preview
-        }
-        newGameScreen.gameSetupInfo.gameParameters.players = preload.gameParameters.players
-            .apply { removeAll { it.chosenCiv == Constants.spectator } }
-        newGameScreen.gameSetupInfo.gameParameters.baseRuleset = preload.gameParameters.baseRuleset
-        newGameScreen.gameSetupInfo.gameParameters.mods = preload.gameParameters.mods
-        newGameScreen.tryUpdateRuleset(true)
-        newGameScreen.playerPickerTable.update()
-        selectedScenario = scenario
-    }
-}
 
 class MapOptionsTable(private val newGameScreen: NewGameScreen) : Table() {
 
@@ -126,8 +70,8 @@ class MapOptionsTable(private val newGameScreen: NewGameScreen) : Table() {
         add(mapTypeSelectWrapper).pad(10f).fillX().row()
         add(mapTypeSpecificTable).row()
     }
-    
+
-    fun getSelectedScenario(): ScenarioSelectTable.ScenarioData? {
+    internal fun getSelectedScenario(): ScenarioSelectTable.ScenarioData? {
         if (mapTypeSelectBox.selected.value != MapGeneratedMainType.scenario) return null
         return scenarioOptionsTable.selectedScenario
     }

core/src/com/unciv/ui/screens/newgamescreen/ScenarioSelectTable.kt

@@ -0,0 +1,71 @@
+package com.unciv.ui.screens.newgamescreen
+
+import com.badlogic.gdx.files.FileHandle
+import com.badlogic.gdx.scenes.scene2d.ui.Table
+import com.badlogic.gdx.utils.SerializationException
+import com.unciv.Constants
+import com.unciv.logic.GameInfoPreview
+import com.unciv.logic.files.UncivFiles
+import com.unciv.models.ruleset.Ruleset
+import com.unciv.ui.components.input.onChange
+import com.unciv.ui.components.widgets.TranslatedSelectBox
+import com.unciv.ui.popups.ToastPopup
+import com.unciv.utils.Concurrency
+
+internal class ScenarioSelectTable(private val newGameScreen: NewGameScreen) : Table() {
+
+    data class ScenarioData(val name:String, val file: FileHandle) {
+        var preview: GameInfoPreview? = null
+    }
+
+    val scenarios = HashMap<String, ScenarioData>()
+    var selectedScenario: ScenarioData? = null
+    private var scenarioSelectBox: TranslatedSelectBox? = null
+
+    init {
+        // Only the first so it's fast
+        val firstScenarioFile = newGameScreen.game.files.getScenarioFiles().firstOrNull()
+        if (firstScenarioFile != null) {
+            createScenarioSelectBox(listOf(firstScenarioFile))
+            Concurrency.run {
+                val scenarioFiles = newGameScreen.game.files.getScenarioFiles().toList()
+                Concurrency.runOnGLThread {
+                    createScenarioSelectBox(scenarioFiles)
+                }
+            }
+        }
+    }
+
+    private fun createScenarioSelectBox(scenarioFiles: List<Pair<FileHandle, Ruleset>>) {
+        for ((file, _) in scenarioFiles)
+            scenarios[file.name()] = ScenarioData(file.name(), file)
+
+        scenarioSelectBox = TranslatedSelectBox(scenarios.keys.sorted(), scenarios.keys.first())
+        scenarioSelectBox!!.onChange { selectScenario() }
+        clear()
+        add(scenarioSelectBox)
+    }
+
+    fun selectScenario() {
+        val scenario = scenarios[scenarioSelectBox!!.selected.value]!!
+        val preload = scenario.getCachedPreview() ?: return
+        newGameScreen.gameSetupInfo.gameParameters.players = preload.gameParameters.players
+            .apply { removeAll { it.chosenCiv == Constants.spectator } }
+        newGameScreen.gameSetupInfo.gameParameters.baseRuleset = preload.gameParameters.baseRuleset
+        newGameScreen.gameSetupInfo.gameParameters.mods = preload.gameParameters.mods
+        newGameScreen.tryUpdateRuleset(true)
+        newGameScreen.playerPickerTable.update()
+        selectedScenario = scenario
+    }
+
+    private fun ScenarioData.getCachedPreview(): GameInfoPreview? {
+        if (preview == null) {
+            try {
+                preview = newGameScreen.game.files.loadGamePreviewFromFile(file)
+            } catch (_: SerializationException) {
+                ToastPopup("Scenario file [${file.name()}] is invalid.", newGameScreen)
+            }
+        }
+        return preview
+    }
+}