Added ability to raze cities

core/src/com/unciv/logic/city/CityInfo.kt

@@ -27,7 +27,7 @@ class CityInfo {
 
     var tiles = HashSet<Vector2>()
     var workedTiles = HashSet<Vector2>()
-
+    var isBeingRazed = false
 
     internal val tileMap: TileMap
         get() = civInfo.gameInfo.tileMap
@@ -132,6 +132,14 @@ class CityInfo {
         population.nextTurn(stats.food)
         cityConstructions.nextTurn(stats)
         expansion.nextTurn(stats.culture)
+        if(isBeingRazed){
+            population.population--
+            population.unassignExtraPopulation()
+            if(population.population==0){
+                civInfo.addNotification("$name has been razed to the ground!",location, Color.RED)
+                civInfo.cities.remove(this)
+            }
+        }
 
         val maxHealth =getMaxHealth()
         health = min(health+maxHealth/10, maxHealth)

core/src/com/unciv/logic/city/PopulationManager.kt

@@ -46,12 +46,7 @@ class PopulationManager {
         // starvation!
         {
             population--
-            if(cityInfo.workedTiles.size>population) {
+            unassignExtraPopulation()
-                val lowestRankedWorkedTile = cityInfo.workedTiles
-                        .map { cityInfo.tileMap[it] }
-                        .minBy { Automation().rankTile(it, cityInfo.civInfo) }!!
-                cityInfo.workedTiles.remove(lowestRankedWorkedTile.position)
-            }
             foodStored = 0
             cityInfo.civInfo.addNotification(cityInfo.name + " is starving!", cityInfo.location, Color.RED)
         }
@@ -74,4 +69,13 @@ class PopulationManager {
             cityInfo.workedTiles.add(toWork.position)
     }
 
+    fun unassignExtraPopulation() {
+        while (cityInfo.workedTiles.size > population) {
+            val lowestRankedWorkedTile = cityInfo.workedTiles
+                    .map { cityInfo.tileMap[it] }
+                    .minBy { Automation().rankTile(it, cityInfo.civInfo) }!!
+            cityInfo.workedTiles.remove(lowestRankedWorkedTile.position)
+        }
+    }
+
 }

core/src/com/unciv/logic/civilization/CivilizationInfo.kt

@@ -140,7 +140,7 @@ class CivilizationInfo {
 
         if (cities.size > 0) tech.nextTurn(nextTurnStats.science.toInt())
 
-        for (city in cities) {
+        for (city in cities.toList()) { // a city can be removed while iterating (if it's being razed) so we need to iterate over a copy
             city.endTurn()
             greatPeople.addGreatPersonPoints(city.getGreatPersonPoints())
         }

core/src/com/unciv/ui/cityscreen/CityScreen.kt

@@ -123,7 +123,7 @@ class CityScreen(internal val city: CityInfo) : CameraStageBaseScreen() {
             cityPickerTable.add(prevCityButton)
         }
 
-        val currentCityLabel = Label(city.name, CameraStageBaseScreen.skin)
+        val currentCityLabel = Label(city.name+" ("+city.population.population+")", CameraStageBaseScreen.skin)
         currentCityLabel.setFontScale(2f)
         cityPickerTable.add(currentCityLabel)
 
@@ -137,6 +137,19 @@ class CityScreen(internal val city: CityInfo) : CameraStageBaseScreen() {
                 }
             cityPickerTable.add(nextCityButton)
         }
+        cityPickerTable.row()
+
+        if(!city.isBeingRazed) {
+            val razeCityButton = TextButton("Raze city", skin)
+            razeCityButton.addClickListener { city.isBeingRazed=true; update() }
+            cityPickerTable.add(razeCityButton)
+        }
+        else{
+            val stopRazingCityButton = TextButton("Stop razing city", skin)
+            stopRazingCityButton.addClickListener { city.isBeingRazed=false; update() }
+            cityPickerTable.add(stopRazingCityButton)
+        }
+
         cityPickerTable.pack()
         cityPickerTable.centerX(stage)
         stage.addActor(cityPickerTable)

core/src/com/unciv/ui/tilegroups/WorldTileGroup.kt

@@ -49,6 +49,11 @@ class WorldTileGroup(tileInfo: TileInfo) : TileGroup(tileInfo) {
     }
 
     private fun updateCityButton(city: CityInfo?) {
+        if(city==null && cityButton!=null)// there used to be a city here but it was razed
+        {
+            cityButton!!.remove()
+            cityButton=null
+        }
         if (city != null && tileInfo.isCityCenter()) {
             if (cityButton == null) {
                 cityButton = Table()