Fix shipyard layout preview/button not showing until re-selection

Selecting a ship schematic in the shipyard left the layout preview and
Configure Layout button hidden until the building was deselected and
re-selected.

The recipe change is applied via a queued command that only drains on a
later frame, so the immediate rebuild() in onSelectRecipeClicked() still
saw the old (empty) recipe and hid both widgets. The per-tick
refreshBuffers() path then updated the preview's data but never set its
visibility -- that was only ever done in buildSingle() -- so the widgets
stayed hidden until a re-selection re-ran buildSingle().

Extract the shipyard preview/button show-hide-and-populate logic into
updateShipyardLayoutWidgets() and call it from both buildSingle() and
refreshBuffers(), so the per-tick refresh becomes authoritative for
visibility and the widgets appear on the first tick after the command
drains.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DyCu8vwChKMbLJQ3xosYEN

src/ui/SelectedBuildingPanel.cpp

@@ -294,38 +294,12 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
         }
         m_recipeSelectButton->show();
 
-        if (type == BuildingType::Shipyard && !recipeId.empty())
+        updateShipyardLayoutWidgets(type, recipeId, shipLayout);
-        {
-            const ShipDef* sDef = findShipDef(recipeId);
-            if (sDef && !sDef->layout.empty())
-            {
-                ShipLayoutConfig layout;
-                if (shipLayout.has_value())
-                {
-                    layout = *shipLayout;
-                }
-                m_layoutPreview->setShipAndLayout(
-                    sDef->layout, layout, &m_config->modules.modules);
-                m_layoutPreview->show();
-                m_configureLayoutBtn->show();
-            }
-            else
-            {
-                m_layoutPreview->hide();
-                m_configureLayoutBtn->hide();
-            }
-        }
-        else
-        {
-            m_layoutPreview->hide();
-            m_configureLayoutBtn->hide();
-        }
     }
     else
     {
         m_recipeSelectButton->hide();
-        m_layoutPreview->hide();
+        updateShipyardLayoutWidgets(type, recipeId, shipLayout);
-        m_configureLayoutBtn->hide();
     }
 
     // Belt "Clear" removes items from a live belt tile; a construction site has
@@ -530,15 +504,38 @@ void SelectedBuildingPanel::refreshBuffers(const Building* b)
 
     m_buffersLabel->setText(bufText);
 
-    if (b->type == BuildingType::Shipyard && shipDef && !shipDef->layout.empty())
+    // The recipe/schematic is applied via a queued command that only drains on a
+    // later frame, so the per-tick refresh must own the shipyard preview and the
+    // Configure Layout button's visibility; otherwise they stay hidden until the
+    // building is re-selected (which re-runs buildSingle).
+    updateShipyardLayoutWidgets(b->type, b->recipeId, b->shipLayout);
+}
+
+void SelectedBuildingPanel::updateShipyardLayoutWidgets(
+    BuildingType type,
+    const std::string& recipeId,
+    const std::optional<ShipLayoutConfig>& shipLayout)
+{
+    const ShipDef* shipDef = (type == BuildingType::Shipyard)
+        ? findShipDef(recipeId)
+        : nullptr;
+
+    if (shipDef && !shipDef->layout.empty())
     {
         ShipLayoutConfig layout;
-        if (b->shipLayout.has_value())
+        if (shipLayout.has_value())
         {
-            layout = *b->shipLayout;
+            layout = *shipLayout;
         }
         m_layoutPreview->setShipAndLayout(
             shipDef->layout, layout, &m_config->modules.modules);
+        m_layoutPreview->show();
+        m_configureLayoutBtn->show();
+    }
+    else
+    {
+        m_layoutPreview->hide();
+        m_configureLayoutBtn->hide();
     }
 }
 
@@ -647,9 +644,11 @@ void SelectedBuildingPanel::onSelectRecipeClicked()
         return;
     }
     // The emit is synchronous: MainWindow pauses the game, runs the modal
-    // selection dialog, applies the chosen recipe/schematic, and restores the
+    // selection dialog, and restores the speed before this returns. The chosen
-    // speed before this returns. rebuild() then refreshes the button caption,
+    // recipe/schematic is only *enqueued* as a command, though, and drains on a
-    // tooltip, preview, and buffers for the new selection.
+    // later frame -- so this rebuild() still sees the old recipe. The per-tick
+    // refreshBuffers() path picks up the new schematic (and shows the layout
+    // preview + Configure Layout button) once the command has been applied.
     EventManager::getInstance()->sendEventImmediately(
         std::make_shared<RecipeSelectionRequestedEvent>(m_singleBuildingId));
     rebuild();

src/ui/SelectedBuildingPanel.h

@@ -64,6 +64,9 @@ private:
     void buildSingle(BuildingId id);
     void buildMulti(const std::vector<BuildingId>& ids);
     void refreshBuffers(const Building* b);
+    void updateShipyardLayoutWidgets(BuildingType type,
+                                     const std::string& recipeId,
+                                     const std::optional<ShipLayoutConfig>& shipLayout);
     void buildSplitterFilters(const std::optional<BeltSystem::SplitterInfo>& info);
     const RecipeDef* findRecipe(const Building* b) const;
     const ShipDef*   findShipDef(const std::string& id) const;