Add: "Many random towns" button in scenario editor now prompts for the number of towns, with defaults based on new game settings (#14158)

src/town.h

@@ -231,7 +231,8 @@ void ChangeTownRating(Town *t, int add, int max, DoCommandFlags flags);
 HouseZone GetTownRadiusGroup(const Town *t, TileIndex tile);
 void SetTownRatingTestMode(bool mode);
 TownActions GetMaskOfTownActions(CompanyID cid, const Town *t);
-bool GenerateTowns(TownLayout layout);
+uint GetDefaultTownsForMapSize();
+bool GenerateTowns(TownLayout layout, std::optional<uint> number = std::nullopt);
 const CargoSpec *FindFirstCargoWithTownAcceptanceEffect(TownAcceptanceEffect effect);
 CargoArray GetAcceptedCargoOfHouse(const HouseSpec *hs);
 

src/town_cmd.cpp

@@ -2372,19 +2372,39 @@ static Town *CreateRandomTown(uint attempts, uint32_t townnameparts, TownSize si
 	return nullptr;
 }
 
-static const uint8_t _num_initial_towns[4] = {5, 11, 23, 46};  // very low, low, normal, high
+/**
+ * Calculate the number of towns which should be on the map according to the current "town density" newgame setting and the map size.
+ * If the number of towns is set to "custom", the function will always return that value instead.
+ * @return The number of towns.
+ */
+uint GetDefaultTownsForMapSize()
+{
+	static const uint8_t num_initial_towns[4] = {5, 11, 23, 46};  // very low, low, normal, high
+	if (_settings_game.difficulty.number_towns == static_cast<uint>(CUSTOM_TOWN_NUMBER_DIFFICULTY)) {
+		return _settings_newgame.game_creation.custom_town_number;
+	}
+	return Map::ScaleBySize(num_initial_towns[_settings_game.difficulty.number_towns]);
+}
 
 /**
  * Generate a number of towns with a given layout.
  * This function is used by the Random Towns button in Scenario Editor as well as in world generation.
  * @param layout The road layout to build.
+ * @param number The number of towns to create. std::nullopt means to use the game settings.
  * @return true if towns have been successfully created.
  */
-bool GenerateTowns(TownLayout layout)
+bool GenerateTowns(TownLayout layout, std::optional<uint> number)
 {
 	uint current_number = 0;
-	uint difficulty = (_game_mode != GM_EDITOR) ? _settings_game.difficulty.number_towns : 0;
+	uint total;
-	uint total = (difficulty == (uint)CUSTOM_TOWN_NUMBER_DIFFICULTY) ? _settings_game.game_creation.custom_town_number : Map::ScaleBySize(_num_initial_towns[difficulty] + (Random() & 7));
+	if (number.has_value()) {
+		total = number.value();
+	} else if (_settings_game.difficulty.number_towns == static_cast<uint>(CUSTOM_TOWN_NUMBER_DIFFICULTY)) {
+		total = GetDefaultTownsForMapSize();
+	} else {
+		total = GetDefaultTownsForMapSize() + (Random() & 7);
+	}
+
 	total = std::min<uint>(TownPool::MAX_SIZE, total);
 	uint32_t townnameparts;
 	TownNames town_names;

src/town_gui.cpp

@@ -34,6 +34,7 @@
 #include "townname_func.h"
 #include "core/backup_type.hpp"
 #include "core/geometry_func.hpp"
+#include "core/string_consumer.hpp"
 #include "genworld.h"
 #include "fios.h"
 #include "stringfilter_type.h"
@@ -1249,16 +1250,10 @@ public:
 				break;
 
 			case WID_TF_MANY_RANDOM_TOWNS: {
-				Backup<bool> old_generating_world(_generating_world, true);
+				std::string default_town_number = fmt::format("{}", GetDefaultTownsForMapSize());
-				UpdateNearestTownForRoadTiles(true);
+				ShowQueryString(default_town_number, STR_MAPGEN_NUMBER_OF_TOWNS, 5, this, CS_NUMERAL, {QueryStringFlag::AcceptUnchanged});
-				if (!GenerateTowns(this->town_layout)) {
-					ShowErrorMessage(GetEncodedString(STR_ERROR_CAN_T_GENERATE_TOWN), GetEncodedString(STR_ERROR_NO_SPACE_FOR_TOWN), WL_INFO);
-				}
-				UpdateNearestTownForRoadTiles(false);
-				old_generating_world.Restore();
 				break;
 			}
-
 			case WID_TF_LOAD_FROM_FILE:
 				ShowSaveLoadDialog(FT_TOWN_DATA, SLO_LOAD);
 				break;
@@ -1293,6 +1288,23 @@ public:
 		}
 	}
 
+	void OnQueryTextFinished(std::optional<std::string> str) override
+	{
+		/* Was 'cancel' pressed? */
+		if (!str.has_value()) return;
+
+		auto value = ParseInteger(*str);
+		if (!value.has_value()) return;
+
+		Backup<bool> old_generating_world(_generating_world, true);
+		UpdateNearestTownForRoadTiles(true);
+		if (!GenerateTowns(this->town_layout, value)) {
+			ShowErrorMessage(GetEncodedString(STR_ERROR_CAN_T_GENERATE_TOWN), GetEncodedString(STR_ERROR_NO_SPACE_FOR_TOWN), WL_INFO);
+		}
+		UpdateNearestTownForRoadTiles(false);
+		old_generating_world.Restore();
+	}
+
 	void OnPlaceObject([[maybe_unused]] Point pt, TileIndex tile) override
 	{
 		this->ExecuteFoundTownCommand(tile, false, STR_ERROR_CAN_T_FOUND_TOWN_HERE, CcFoundTown);