Show total building block cost in multi-selection panel (relevant for temporary blueprint)

docs/requirements.md

@@ -461,7 +461,7 @@ The screen is divided into two columns: a main column (75% width) containing the
 - REQ-UI-SINGLE-SELECTION: When one building is selected, the panel shows: building name, current recipe or schematic selection, input buffer contents, and output buffer contents. Buffer counts are displayed as `a/b` where `a` is the current item count and `b` is the per-cycle amount (items consumed per run for inputs; items produced per run for outputs). For a selected construction site, the recipe/schematic selection (and, for a shipyard, the layout preview and "Configure" button) are shown but the buffer rows are omitted (REQ-BLD-SITE-CONFIG).
 - REQ-UI-PRODUCTION-PROGRESS: For buildings that produce items or ships (miner, smelter, assembler, reprocessing plant, shipyard), the selected building panel also shows: (a) the cycle time of the currently selected recipe or schematic in seconds, and (b) the completion percentage of the active production cycle as an integer (e.g. `42%`), or the text `idle` when no production cycle is active. When no recipe or schematic is selected, neither the cycle time nor the progress indicator is shown.
 - REQ-UI-MULTI-SELECT: The player selects multiple buildings by box-drag or by Ctrl+clicking individual buildings to add or remove them from the selection.
-- REQ-UI-MULTI-SELECTION: When multiple buildings are selected, the panel shows how many of each building type are selected. No per-building detail is shown.
+- REQ-UI-MULTI-SELECTION: When multiple buildings are selected, the panel shows how many of each building type are selected. No per-building detail is shown. The panel additionally shows the **total building block cost** of the selection — the sum of each selected building's placement cost (`buildings.toml [[building]].cost`, per REQ-BLD-COST), counting only player-placeable buildings (buildings with a button in the build button grid); non-player-placeable buildings (the HQ and defence stations) are excluded from the total, consistent with the blueprint total (REQ-UI-BLUEPRINT-BUTTON). Construction sites count at their building type's full placement cost regardless of construction progress.
 - REQ-UI-CONFIG-INLINE: Recipe and schematic configuration for a selected building is shown within this panel. Recipe selection (miner, assembler) and schematic selection (shipyard) use the selection button and dialog (REQ-UI-SELECT-BUTTON) rather than an inline control. For shipyards, the panel additionally shows the ship layout preview and "Configure" button below the schematic selection button (REQ-MOD-UI-PREVIEW).
 - REQ-UI-SELECT-BUTTON: **Recipe and schematic selection control.** Recipe selection (Miner ore type, Assembler recipe) and schematic selection (Shipyard) are each presented in the selected building panel as a single **selection button** whose caption is the name of the currently selected recipe or schematic, or a placeholder ("Select recipe" / "Select schematic") when none is selected. Clicking the button opens a modal **selection dialog** that pauses the game (speed set to 0×; on close, the speed is restored to what it was before the dialog was opened). The dialog contains a grid of option buttons, one per selectable option — only options that are currently unlocked are shown (REQ-LOCK-UI-RECIPE for recipes, REQ-LOCK-UI-SCHEMATIC for schematics). Hovering an option button shows the selection info tooltip (REQ-UI-SELECT-TOOLTIP). Clicking an option button selects that recipe/schematic, closes the dialog, and updates the selection button's caption in the selected building panel. The dialog can be dismissed without changing the current selection (e.g. closing it without clicking an option). Selecting a new recipe or schematic has the same effects as before (REQ-MAT-INPUT-BUFFER, REQ-MAT-OUTPUT-BUFFER, REQ-BLD-SHIPYARD).
 - REQ-UI-SELECT-TOOLTIP: **Selection info tooltip.** Hovering an option button in the selection dialog (REQ-UI-SELECT-BUTTON), and hovering the selection button in the selected building panel when a selection is set, displays an info tooltip:

src/lib/config/BuildingsConfig.h

@@ -31,4 +31,18 @@ struct BuildingDef
 struct BuildingsConfig
 {
     std::vector<BuildingDef> buildings;
+
+    // Returns the definition for the given building type, or nullptr if the
+    // type has no entry in buildings.toml.
+    const BuildingDef* findBuildingDef(BuildingType type) const
+    {
+        for (const BuildingDef& def : buildings)
+        {
+            if (def.type == type)
+            {
+                return &def;
+            }
+        }
+        return nullptr;
+    }
 };

src/ui/BlueprintPanel.cpp

@@ -157,14 +157,8 @@ Blueprint BlueprintPanel::createBlueprintFromSelection() const
     {
         const Building* b = m_sim->buildings().findBuilding(id);
         if (!b) { continue; }
-        const bool placeable = [&]() {
+        const BuildingDef* def = m_config->buildings.findBuildingDef(b->type);
-            for (const BuildingDef& def : m_config->buildings.buildings)
+        if (def && def->playerPlaceable) { entries.push_back({ b }); }
-            {
-                if (def.type == b->type) { return def.playerPlaceable; }
-            }
-            return false;
-        }();
-        if (placeable) { entries.push_back({ b }); }
     }
 
     if (entries.empty()) { return Blueprint{}; }
@@ -213,14 +207,8 @@ int BlueprintPanel::computeBlueprintCost(const Blueprint& bp) const
     int total = 0;
     for (const BlueprintBuilding& bb : bp.buildings)
     {
-        for (const BuildingDef& def : m_config->buildings.buildings)
+        const BuildingDef* def = m_config->buildings.findBuildingDef(bb.type);
-        {
+        if (def) { total += def->cost; }
-            if (def.type == bb.type)
-            {
-                total += def.cost;
-                break;
-            }
-        }
     }
     return total;
 }

src/ui/SelectedBuildingPanel.cpp

@@ -694,6 +694,7 @@ void SelectedBuildingPanel::buildMulti(const std::vector<BuildingId>& ids)
     }
 
     bool hasBelt = false;
+    int totalCost = 0;
     QString text;
     for (const std::pair<const BuildingType, int>& entry : counts)
     {
@@ -703,7 +704,15 @@ void SelectedBuildingPanel::buildMulti(const std::vector<BuildingId>& ids)
         {
             hasBelt = true;
         }
+        // Total placement cost counts only player-placeable buildings; the HQ
+        // and defence stations are excluded (REQ-UI-MULTI-SELECTION).
+        const BuildingDef* def = m_config->buildings.findBuildingDef(entry.first);
+        if (def && def->playerPlaceable)
+        {
+            totalCost += def->cost * entry.second;
+        }
     }
+    text += tr("Total: %1 Building Blocks").arg(totalCost);
     m_titleLabel->setText(text.trimmed());
     m_titleLabel->show();