keep an auto-recipe building's summary between its cycles

src/ui/selection/AutoProductionContent.cpp

@@ -41,13 +41,22 @@ BufferedBuildingContent::CycleInfo AutoProductionContent::getCycleInfo(
         }
     }
 
-    if (!target.building || !target.building->production.has_value())
+    // Which recipe describes the cycle: the one running, or -- between cycles -- the one
+    // that ran last. Dropping it while idle would take the summary row and the chips'
+    // per-cycle amounts away and bring them back with every cycle, resizing the card in
+    // step with the building's status (REQ-UI-RECIPE-SUMMARY). Only a building that has
+    // never run has nothing to describe.
+    if (target.building && target.building->production.has_value())
+    {
+        m_lastRecipeId = target.building->production->recipeId;
+    }
+    if (!target.building || m_lastRecipeId.empty())
     {
         return info;
     }
 
-    const RecipeDef* recipe = getContext().config->recipes.findRecipeDef(
-        target.building->production->recipeId, target.type);
+    const RecipeDef* recipe =
+        getContext().config->recipes.findRecipeDef(m_lastRecipeId, target.type);
     if (!recipe)
     {
         return info;

src/ui/selection/AutoProductionContent.h

@@ -1,12 +1,14 @@
 #pragma once
 
+#include <string>
+
 #include "BufferedBuildingContent.h"
 #include "SelectionContentFactory.h"
 
 // The card for a Smelter or a Reprocessing Plant (REQ-UI-SELECTION-CONTENT). Both
 // auto-process whatever they receive and have no player-facing recipe selection
 // (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING), so the card has no configuration group at
-// all; its cycle is whichever recipe is currently in production.
+// all; its cycle is whichever recipe is in production, or the last one that was.
 class AutoProductionContent : public BufferedBuildingContent
 {
     Q_OBJECT
@@ -17,4 +19,11 @@ public:
 
 protected:
     CycleInfo getCycleInfo(const BuildingTarget& target) const override;
+
+private:
+    // The recipe last seen in production, which keeps describing the cycle while the
+    // building sits between cycles (REQ-UI-RECIPE-SUMMARY). Mutable because it is a
+    // record of what getCycleInfo() has observed rather than state of its own: the card
+    // shows the same thing whether or not it has been asked before.
+    mutable std::string m_lastRecipeId;
 };

src/ui/selection/BufferedBuildingContent.h

@@ -44,8 +44,9 @@ protected:
         // REQ-BLD-SALVAGE-BAY) or has no recipe or schematic selected yet: the
         // production section is then not shown (REQ-UI-PRODUCTION-PROGRESS).
         bool runsProduction = false;
-        // 0 while an auto-recipe building sits between cycles, when no single recipe
-        // names a cycle time; the progress line then reads "idle".
+        // 0 only when no recipe describes the cycle at all -- an auto-recipe building
+        // that has yet to run one (REQ-UI-RECIPE-SUMMARY). The progress line reads
+        // "idle" whenever no cycle is actually running, whatever this says.
         double durationSeconds = 0.0;
     };