Change: Hide all variants from UI when (display) parent is hidden. (#10708)

src/autoreplace_gui.cpp

@@ -148,7 +148,7 @@ class ReplaceVehicleWindow : public Window {
 		GUIEngineList list;
 
 		for (const Engine *e : Engine::IterateType(type)) {
-			if (!draw_left && !this->show_hidden_engines && e->IsHidden(_local_company)) continue;
+			if (!draw_left && !this->show_hidden_engines && e->IsVariantHidden(_local_company)) continue;
 			EngineID eid = e->index;
 			switch (type) {
 				case VEH_TRAIN:

src/build_vehicle_gui.cpp

@@ -1349,7 +1349,7 @@ struct BuildVehicleWindow : Window {
 		 * and if not, reset selection to INVALID_ENGINE. This could be the case
 		 * when engines become obsolete and are removed */
 		for (const Engine *e : Engine::IterateType(VEH_TRAIN)) {
-			if (!this->show_hidden_engines && e->IsHidden(_local_company)) continue;
+			if (!this->show_hidden_engines && e->IsVariantHidden(_local_company)) continue;
 			EngineID eid = e->index;
 			const RailVehicleInfo *rvi = &e->u.rail;
 
@@ -1400,7 +1400,7 @@ struct BuildVehicleWindow : Window {
 		this->eng_list.clear();
 
 		for (const Engine *e : Engine::IterateType(VEH_ROAD)) {
-			if (!this->show_hidden_engines && e->IsHidden(_local_company)) continue;
+			if (!this->show_hidden_engines && e->IsVariantHidden(_local_company)) continue;
 			EngineID eid = e->index;
 			if (!IsEngineBuildable(eid, VEH_ROAD, _local_company)) continue;
 			if (this->filter.roadtype != INVALID_ROADTYPE && !HasPowerOnRoad(e->u.road.roadtype, this->filter.roadtype)) continue;
@@ -1419,7 +1419,7 @@ struct BuildVehicleWindow : Window {
 		this->eng_list.clear();
 
 		for (const Engine *e : Engine::IterateType(VEH_SHIP)) {
-			if (!this->show_hidden_engines && e->IsHidden(_local_company)) continue;
+			if (!this->show_hidden_engines && e->IsVariantHidden(_local_company)) continue;
 			EngineID eid = e->index;
 			if (!IsEngineBuildable(eid, VEH_SHIP, _local_company)) continue;
 			this->eng_list.emplace_back(eid, e->info.variant_id, e->display_flags, 0);
@@ -1443,7 +1443,7 @@ struct BuildVehicleWindow : Window {
 		 * and if not, reset selection to INVALID_ENGINE. This could be the case
 		 * when planes become obsolete and are removed */
 		for (const Engine *e : Engine::IterateType(VEH_AIRCRAFT)) {
-			if (!this->show_hidden_engines && e->IsHidden(_local_company)) continue;
+			if (!this->show_hidden_engines && e->IsVariantHidden(_local_company)) continue;
 			EngineID eid = e->index;
 			if (!IsEngineBuildable(eid, VEH_AIRCRAFT, _local_company)) continue;
 			/* First VEH_END window_numbers are fake to allow a window open for all different types at once */

src/engine.cpp

@@ -475,6 +475,30 @@ StringID Engine::GetAircraftTypeText() const
 	}
 }
 
+/**
+ * Check whether the engine variant chain is hidden in the GUI for the given company.
+ * @param c Company to check.
+ * @return \c true iff the engine variant chain is hidden in the GUI for the given company.
+ */
+bool Engine::IsVariantHidden(CompanyID c) const
+{
+	/* In case company is spectator. */
+	if (c >= MAX_COMPANIES) return false;
+
+	/* Shortcut if this engine is explicitly hidden. */
+	if (this->IsHidden(c)) return true;
+
+	/* Check for hidden parent variants. This is a bit convoluted as we must check hidden status of
+	 * the last display variant rather than the actual parent variant. */
+	const Engine *re = this;
+	const Engine *ve = re->GetDisplayVariant();
+	while (!(ve->IsHidden(c)) && re->info.variant_id != INVALID_ENGINE && re->info.variant_id != re->index) {
+		re = Engine::Get(re->info.variant_id);
+		ve = re->GetDisplayVariant();
+	}
+	return ve->IsHidden(c);
+}
+
 /**
  * Initializes the #EngineOverrideManager with the default engines.
  */

src/engine_base.h

@@ -137,6 +137,18 @@ struct Engine : EnginePool::PoolItem<&_engine_pool> {
 		return c < MAX_COMPANIES && HasBit(this->company_hidden, c);
 	}
 
+	/**
+	 * Get the last display variant for an engine.
+	 * @return Engine's last display variant or engine itself if no last display variant is set.
+	 */
+	const Engine *GetDisplayVariant() const
+	{
+		if (this->display_last_variant == this->index || this->display_last_variant == INVALID_ENGINE) return this;
+		return Engine::Get(this->display_last_variant);
+	}
+
+	bool IsVariantHidden(CompanyID c) const;
+
 	/**
 	 * Check if the engine is a ground vehicle.
 	 * @return True iff the engine is a train or a road vehicle.