Add: CommandCost supports an optional second error string

src/autoreplace_cmd.cpp

@@ -442,7 +442,7 @@ static CommandCost ReplaceFreeUnit(Vehicle **single_unit, DoCommandFlag flags, b
 	Train *old_v = Train::From(*single_unit);
 	assert(!old_v->IsArticulatedPart() && !old_v->IsRearDualheaded());
 
-	CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
+	CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, (Money)0);
 
 	/* Build and refit replacement vehicle */
 	Vehicle *new_v = nullptr;
@@ -494,7 +494,7 @@ static CommandCost ReplaceChain(Vehicle **chain, DoCommandFlag flags, bool wagon
 	Vehicle *old_head = *chain;
 	assert(old_head->IsPrimaryVehicle());
 
-	CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
+	CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, (Money)0);
 
 	if (old_head->type == VEH_TRAIN) {
 		/* Store the length of the old vehicle chain, rounded up to whole tiles */
@@ -753,7 +753,7 @@ CommandCost CmdAutoreplaceVehicle(DoCommandFlag flags, VehicleID veh_id)
 		w = (!free_wagon && w->type == VEH_TRAIN ? Train::From(w)->GetNextUnit() : nullptr);
 	}
 
-	CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, 0);
+	CommandCost cost = CommandCost(EXPENSES_NEW_VEHICLES, (Money)0);
 	bool nothing_to_do = true;
 
 	if (any_replacements) {

src/command.cpp

@@ -259,7 +259,7 @@ void CommandHelperBase::InternalPostResult(const CommandCost &res, TileIndex til
 	if (res.Failed()) {
 		/* Only show the error when it's for us. */
 		if (estimate_only || (IsLocalCompany() && err_message != 0 && my_cmd)) {
-			ShowErrorMessage(err_message, res.GetErrorMessage(), WL_INFO, x, y, res.GetTextRefStackGRF(), res.GetTextRefStackSize(), res.GetTextRefStack());
+			ShowErrorMessage(err_message, x, y, res);
 		}
 	} else if (estimate_only) {
 		ShowEstimatedCostOrIncome(res.GetCost(), x, y);

src/command_type.h

@@ -28,6 +28,7 @@ class CommandCost {
 	bool success;                               ///< Whether the command went fine up to this moment
 	const GRFFile *textref_stack_grffile;       ///< NewGRF providing the #TextRefStack content.
 	uint textref_stack_size;                    ///< Number of uint32 values to put on the #TextRefStack for the error message.
+	StringID extra_message = INVALID_STRING_ID; ///< Additional warning message for when success is unset
 
 	static uint32 textref_stack[16];
 
@@ -38,9 +39,9 @@ public:
 	CommandCost() : expense_type(INVALID_EXPENSES), cost(0), message(INVALID_STRING_ID), success(true), textref_stack_grffile(nullptr), textref_stack_size(0) {}
 
 	/**
-	 * Creates a command return value the is failed with the given message
+	 * Creates a command return value with one, or optionally two, error message strings.
 	 */
-	explicit CommandCost(StringID msg) : expense_type(INVALID_EXPENSES), cost(0), message(msg), success(false), textref_stack_grffile(nullptr), textref_stack_size(0) {}
+	explicit CommandCost(StringID msg, StringID extra_msg = INVALID_STRING_ID) : expense_type(INVALID_EXPENSES), cost(0), message(msg), success(false), textref_stack_grffile(nullptr), textref_stack_size(0), extra_message(extra_msg) {}
 
 	/**
 	 * Creates a command cost with given expense type and start cost of 0
@@ -98,11 +99,12 @@ public:
 	 * Makes this #CommandCost behave like an error command.
 	 * @param message The error message.
 	 */
-	void MakeError(StringID message)
+	void MakeError(StringID message, StringID extra_message = INVALID_STRING_ID)
 	{
 		assert(message != INVALID_STRING_ID);
 		this->success = false;
 		this->message = message;
+		this->extra_message = extra_message;
 	}
 
 	void UseTextRefStack(const GRFFile *grffile, uint num_registers);
@@ -144,6 +146,16 @@ public:
 		return this->message;
 	}
 
+	/**
+	 * Returns the extra error message of a command
+	 * @return the extra error message, if succeeded #INVALID_STRING_ID
+	 */
+	StringID GetExtraErrorMessage() const
+	{
+		if (this->success) return INVALID_STRING_ID;
+		return this->extra_message;
+	}
+
 	/**
 	 * Did this command succeed?
 	 * @return true if and only if it succeeded

src/error.h

@@ -13,6 +13,7 @@
 #include <list>
 #include "strings_type.h"
 #include "company_type.h"
+#include "command_type.h"
 #include "core/geometry_type.hpp"
 #include "guitimer_func.h"
 
@@ -37,13 +38,14 @@ protected:
 	uint32 textref_stack[16];       ///< Values to put on the #TextRefStack for the error message.
 	StringID summary_msg;           ///< General error message showed in first line. Must be valid.
 	StringID detailed_msg;          ///< Detailed error message showed in second line. Can be #INVALID_STRING_ID.
+	StringID extra_msg;             ///< Extra error message shown in third line. Can be #INVALID_STRING_ID.
 	Point position;                 ///< Position of the error message window.
 	CompanyID face;                 ///< Company belonging to the face being shown. #INVALID_COMPANY if no face present.
 
 public:
 	ErrorMessageData(const ErrorMessageData &data);
 	~ErrorMessageData();
-	ErrorMessageData(StringID summary_msg, StringID detailed_msg, uint duration = 0, int x = 0, int y = 0, const GRFFile *textref_stack_grffile = nullptr, uint textref_stack_size = 0, const uint32 *textref_stack = nullptr);
+	ErrorMessageData(StringID summary_msg, StringID detailed_msg, uint duration = 0, int x = 0, int y = 0, const GRFFile *textref_stack_grffile = nullptr, uint textref_stack_size = 0, const uint32 *textref_stack = nullptr, StringID extra_msg = INVALID_STRING_ID);
 
 	/* Remove the copy assignment, as the default implementation will not do the right thing. */
 	ErrorMessageData &operator=(ErrorMessageData &rhs) = delete;
@@ -64,7 +66,8 @@ typedef std::list<ErrorMessageData> ErrorList;
 void ScheduleErrorMessage(ErrorList &datas);
 void ScheduleErrorMessage(const ErrorMessageData &data);
 
-void ShowErrorMessage(StringID summary_msg, StringID detailed_msg, WarningLevel wl, int x = 0, int y = 0, const GRFFile *textref_stack_grffile = nullptr, uint textref_stack_size = 0, const uint32 *textref_stack = nullptr);
+void ShowErrorMessage(StringID summary_msg, int x, int y, CommandCost cc);
+void ShowErrorMessage(StringID summary_msg, StringID detailed_msg, WarningLevel wl, int x = 0, int y = 0, const GRFFile *textref_stack_grffile = nullptr, uint textref_stack_size = 0, const uint32 *textref_stack = nullptr, StringID extra_msg = INVALID_STRING_ID);
 bool HideActiveErrorMessage();
 
 void ClearErrorMessages();

src/error_gui.cpp

@@ -72,7 +72,7 @@ static WindowDesc _errmsg_face_desc(
  */
 ErrorMessageData::ErrorMessageData(const ErrorMessageData &data) :
 	display_timer(data.display_timer), textref_stack_grffile(data.textref_stack_grffile), textref_stack_size(data.textref_stack_size),
-	summary_msg(data.summary_msg), detailed_msg(data.detailed_msg), position(data.position), face(data.face)
+	summary_msg(data.summary_msg), detailed_msg(data.detailed_msg), extra_msg(data.extra_msg), position(data.position), face(data.face)
 {
 	memcpy(this->textref_stack, data.textref_stack, sizeof(this->textref_stack));
 	memcpy(this->decode_params, data.decode_params, sizeof(this->decode_params));
@@ -101,12 +101,14 @@ ErrorMessageData::~ErrorMessageData()
  * @param textref_stack_grffile NewGRF that provides the #TextRefStack for the error message.
  * @param textref_stack_size Number of uint32 values to put on the #TextRefStack for the error message; 0 if the #TextRefStack shall not be used.
  * @param textref_stack Values to put on the #TextRefStack.
+ * @param extra_msg    Extra error message showed in third line. Can be INVALID_STRING_ID.
  */
-ErrorMessageData::ErrorMessageData(StringID summary_msg, StringID detailed_msg, uint duration, int x, int y, const GRFFile *textref_stack_grffile, uint textref_stack_size, const uint32 *textref_stack) :
+ErrorMessageData::ErrorMessageData(StringID summary_msg, StringID detailed_msg, uint duration, int x, int y, const GRFFile *textref_stack_grffile, uint textref_stack_size, const uint32 *textref_stack, StringID extra_msg) :
 	textref_stack_grffile(textref_stack_grffile),
 	textref_stack_size(textref_stack_size),
 	summary_msg(summary_msg),
 	detailed_msg(detailed_msg),
+	extra_msg(extra_msg),
 	face(INVALID_COMPANY)
 {
 	this->position.x = x;
@@ -184,6 +186,7 @@ struct ErrmsgWindow : public Window, ErrorMessageData {
 private:
 	uint height_summary;            ///< Height of the #summary_msg string in pixels in the #WID_EM_MESSAGE widget.
 	uint height_detailed;           ///< Height of the #detailed_msg string in pixels in the #WID_EM_MESSAGE widget.
+	uint height_extra;              ///< Height of the #extra_msg string in pixels in the #WID_EM_MESSAGE widget.
 
 public:
 	ErrmsgWindow(const ErrorMessageData &data) : Window(data.HasFace() ? &_errmsg_face_desc : &_errmsg_desc), ErrorMessageData(data)
@@ -200,11 +203,13 @@ public:
 
 				this->height_summary = GetStringHeight(this->summary_msg, size->width);
 				this->height_detailed = (this->detailed_msg == INVALID_STRING_ID) ? 0 : GetStringHeight(this->detailed_msg, size->width);
+				this->height_extra = (this->extra_msg == INVALID_STRING_ID) ? 0 : GetStringHeight(this->extra_msg, size->width);
 
 				if (this->textref_stack_size > 0) StopTextRefStackUsage();
 
 				uint panel_height = this->height_summary;
 				if (this->detailed_msg != INVALID_STRING_ID) panel_height += this->height_detailed + WidgetDimensions::scaled.vsep_wide;
+				if (this->extra_msg != INVALID_STRING_ID) panel_height += this->height_extra + WidgetDimensions::scaled.vsep_wide;
 
 				size->height = std::max(size->height, panel_height);
 				break;
@@ -280,13 +285,24 @@ public:
 
 				if (this->detailed_msg == INVALID_STRING_ID) {
 					DrawStringMultiLine(r, this->summary_msg, TC_FROMSTRING, SA_CENTER);
-				} else {
+				} else if (this->extra_msg == INVALID_STRING_ID) {
 					/* Extra space when message is shorter than company face window */
 					int extra = (r.Height() - this->height_summary - this->height_detailed - WidgetDimensions::scaled.vsep_wide) / 2;
 
 					/* Note: NewGRF supplied error message often do not start with a colour code, so default to white. */
 					DrawStringMultiLine(r.WithHeight(this->height_summary + extra, false), this->summary_msg, TC_WHITE, SA_CENTER);
 					DrawStringMultiLine(r.WithHeight(this->height_detailed + extra, true), this->detailed_msg, TC_WHITE, SA_CENTER);
+				} else {
+					/* Extra space when message is shorter than company face window */
+					int extra = (r.Height() - this->height_summary - this->height_detailed - this->height_extra - (WidgetDimensions::scaled.vsep_wide * 2)) / 3;
+
+					/* Note: NewGRF supplied error message often do not start with a colour code, so default to white. */
+					Rect top_section = r.WithHeight(this->height_summary + extra, false);
+					Rect bottom_section = r.WithHeight(this->height_extra + extra, true);
+					Rect middle_section = { top_section.left, top_section.bottom, top_section.right, bottom_section.top };
+					DrawStringMultiLine(top_section, this->summary_msg, TC_WHITE, SA_CENTER);
+					DrawStringMultiLine(middle_section, this->detailed_msg, TC_WHITE, SA_CENTER);
+					DrawStringMultiLine(bottom_section, this->extra_msg, TC_WHITE, SA_CENTER);
 				}
 
 				if (this->textref_stack_size > 0) StopTextRefStackUsage();
@@ -361,6 +377,19 @@ void UnshowCriticalError()
 	}
 }
 
+/**
+ * Display an error message in a window.
+ * Note: CommandCost errors are always severity level WL_INFO.
+ * @param summary_msg  General error message showed in first line. Must be valid.
+ * @param x            World X position (TileVirtX) of the error location. Set both x and y to 0 to just center the message when there is no related error tile.
+ * @param y            World Y position (TileVirtY) of the error location. Set both x and y to 0 to just center the message when there is no related error tile.
+ * @param cc           CommandCost containing the optional detailed and extra error messages shown in the second and third lines (can be INVALID_STRING_ID) and TextRefStack info.
+ */
+void ShowErrorMessage(StringID summary_msg, int x, int y, CommandCost cc)
+{
+	ShowErrorMessage(summary_msg, cc.GetErrorMessage(), WL_INFO, x, y, cc.GetTextRefStackGRF(), cc.GetTextRefStackSize(), cc.GetTextRefStack(), cc.GetExtraErrorMessage());
+}
+
 /**
  * Display an error message in a window.
  * @param summary_msg  General error message showed in first line. Must be valid.
@@ -371,8 +400,9 @@ void UnshowCriticalError()
  * @param textref_stack_grffile NewGRF providing the #TextRefStack for the error message.
  * @param textref_stack_size Number of uint32 values to put on the #TextRefStack for the error message; 0 if the #TextRefStack shall not be used.
  * @param textref_stack Values to put on the #TextRefStack.
+ * @param extra_msg    Extra error message shown in third line. Can be INVALID_STRING_ID.
  */
-void ShowErrorMessage(StringID summary_msg, StringID detailed_msg, WarningLevel wl, int x, int y, const GRFFile *textref_stack_grffile, uint textref_stack_size, const uint32 *textref_stack)
+void ShowErrorMessage(StringID summary_msg, StringID detailed_msg, WarningLevel wl, int x, int y, const GRFFile *textref_stack_grffile, uint textref_stack_size, const uint32 *textref_stack, StringID extra_msg)
 {
 	assert(textref_stack_size == 0 || (textref_stack_grffile != nullptr && textref_stack != nullptr));
 	if (summary_msg == STR_NULL) summary_msg = STR_EMPTY;
@@ -388,6 +418,10 @@ void ShowErrorMessage(StringID summary_msg, StringID detailed_msg, WarningLevel
 			b += seprintf(b, lastof(buf), " ");
 			GetString(b, detailed_msg, lastof(buf));
 		}
+		if (extra_msg != INVALID_STRING_ID) {
+			b += seprintf(b, lastof(buf), " ");
+			GetString(b, extra_msg, lastof(buf));
+		}
 
 		if (textref_stack_size > 0) StopTextRefStackUsage();
 
@@ -399,7 +433,7 @@ void ShowErrorMessage(StringID summary_msg, StringID detailed_msg, WarningLevel
 	if (_game_mode == GM_BOOTSTRAP) return;
 	if (_settings_client.gui.errmsg_duration == 0 && !no_timeout) return;
 
-	ErrorMessageData data(summary_msg, detailed_msg, no_timeout ? 0 : _settings_client.gui.errmsg_duration, x, y, textref_stack_grffile, textref_stack_size, textref_stack);
+	ErrorMessageData data(summary_msg, detailed_msg, no_timeout ? 0 : _settings_client.gui.errmsg_duration, x, y, textref_stack_grffile, textref_stack_size, textref_stack, extra_msg);
 	data.CopyOutDParams();
 
 	ErrmsgWindow *w = (ErrmsgWindow*)FindWindowById(WC_ERRMSG, 0);

src/misc_cmd.cpp

@@ -222,6 +222,6 @@ CommandCost CmdChangeBankBalance(DoCommandFlag flags, TileIndex tile, Money delt
 	}
 
 	/* This command doesn't cost anything for deity. */
-	CommandCost zero_cost(expenses_type, 0);
+	CommandCost zero_cost(expenses_type, (Money)0);
 	return zero_cost;
 }