From 594c3b93c59766472167b9ae89a4dfe1797b5848 Mon Sep 17 00:00:00 2001
From: mlangkabel <malte.langkabel@gmail.com>
Date: Mon, 3 Aug 2026 21:04:43 +0200
Subject: [PATCH] make HeaderBar read block stock and expansion cost from the
 simulation

---
 src/ui/HeaderBar.cpp  | 27 ++++++++++++++++-----------
 src/ui/HeaderBar.h    | 17 ++++++++++-------
 src/ui/MainWindow.cpp |  2 +-
 3 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/src/ui/HeaderBar.cpp b/src/ui/HeaderBar.cpp
index b034626..c221082 100644
--- a/src/ui/HeaderBar.cpp
+++ b/src/ui/HeaderBar.cpp
@@ -17,6 +17,7 @@
 #include "EventManager.h"
 #include "IconCaption.h"
 #include "ItemIconCache.h"
+#include "Simulation.h"
 #include "SpeedChangeRequestedEvent.h"
 #include "Tick.h"
 
@@ -30,11 +31,12 @@ namespace
 const double HeaderBar::kSpeeds[]   = { 0.0, 0.5, 1.0, 2.0, 10.0 };
 const int    HeaderBar::kSpeedCount = 5;
 
-HeaderBar::HeaderBar(const GameConfig* config, const std::string& itemsIconDir,
-                     QWidget* parent)
+HeaderBar::HeaderBar(const Simulation* sim, const GameConfig* config,
+                     const std::string& itemsIconDir, QWidget* parent)
     : QWidget(parent)
     , m_itemIcons(std::make_unique<ItemIconCache>(
           QString::fromStdString(itemsIconDir)))
+    , m_sim(sim)
 {
     QHBoxLayout* layout = new QHBoxLayout(this);
     layout->setContentsMargins(8, 4, 8, 4);
@@ -115,16 +117,14 @@ void HeaderBar::handleEvent(std::shared_ptr<const TickAdvancedEvent> event)
             .arg(totalSeconds % 60, 2, 10, QChar('0')));
 }
 
-void HeaderBar::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event)
+void HeaderBar::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> /*event*/)
 {
-    m_blocks = event->blocks;
     updateBlocksLabel();
     updateExpandButton();
 }
 
-void HeaderBar::handleEvent(std::shared_ptr<const ExpansionCostChangedEvent> event)
+void HeaderBar::handleEvent(std::shared_ptr<const ExpansionCostChangedEvent> /*event*/)
 {
-    m_expansionCost = event->cost;
     updateExpandButton();
 }
 
@@ -138,32 +138,37 @@ QPixmap HeaderBar::blockIcon() const
 
 void HeaderBar::updateBlocksLabel()
 {
+    const int blocks = m_sim->getBuildingBlocksStock();
+
     const QPixmap icon = blockIcon();
     if (icon.isNull())
     {
         // Fallback text form when no building_block icon exists (REQ-UI-BLOCKS-ICON).
-        m_blocksLabel->setText(tr("Stock: %1 Blocks").arg(m_blocks));
+        m_blocksLabel->setText(tr("Stock: %1 Blocks").arg(blocks));
         return;
     }
     m_blocksLabel->setPixmap(renderCaptionWithIcon(
-        tr("Stock: %1").arg(m_blocks), icon, font(),
+        tr("Stock: %1").arg(blocks), icon, font(),
         m_blocksLabel->palette().color(QPalette::WindowText)));
 }
 
 void HeaderBar::updateExpandButton()
 {
-    m_expandButton->setEnabled(m_blocks >= m_expansionCost);
+    const int blocks        = m_sim->getBuildingBlocksStock();
+    const int expansionCost = m_sim->getCurrentExpansionCost();
+
+    m_expandButton->setEnabled(blocks >= expansionCost);
 
     const QPixmap icon = blockIcon();
     if (icon.isNull())
     {
         // Fallback text form when no building_block icon exists (REQ-UI-EXPAND-BUTTON).
         m_expandButton->setIcon(QIcon());
-        m_expandButton->setText(tr("Expand: %1 Blocks").arg(m_expansionCost));
+        m_expandButton->setText(tr("Expand: %1 Blocks").arg(expansionCost));
         return;
     }
 
-    const QString text = tr("Expand: %1").arg(m_expansionCost);
+    const QString text = tr("Expand: %1").arg(expansionCost);
     const QPalette& pal = m_expandButton->palette();
     const QPixmap normal = renderCaptionWithIcon(
         text, icon, m_expandButton->font(), pal.color(QPalette::ButtonText));
diff --git a/src/ui/HeaderBar.h b/src/ui/HeaderBar.h
index 865c0e7..118e298 100644
--- a/src/ui/HeaderBar.h
+++ b/src/ui/HeaderBar.h
@@ -20,6 +20,7 @@
 class QLabel;
 class QPushButton;
 class ItemIconCache;
+class Simulation;
 
 class HeaderBar : public QWidget,
                   public CombinedEventHandler<TickAdvancedEvent,
@@ -35,8 +36,8 @@ public:
     // itemsIconDir holds the per-item icon SVGs (REQ-UI-ITEM-ICON); used to show the
     // building_block icon in the stock display and expand button (REQ-UI-BLOCKS-ICON,
     // REQ-UI-EXPAND-BUTTON).
-    HeaderBar(const GameConfig* config, const std::string& itemsIconDir,
-              QWidget* parent = nullptr);
+    HeaderBar(const Simulation* sim, const GameConfig* config,
+              const std::string& itemsIconDir, QWidget* parent = nullptr);
     ~HeaderBar() override;
 
 private slots:
@@ -54,9 +55,10 @@ private:
     // expansion cost and building block stock (REQ-UI-EXPAND-BUTTON).
     void updateExpandButton();
 
-    // Refreshes the building blocks stock display from m_blocks: `Stock: <n>` with
-    // the building_block icon after it, or the `Stock: <n> Blocks` text fallback when
-    // no icon file exists (REQ-UI-BLOCKS-ICON).
+    // Refreshes the building blocks stock display from the simulation:
+    // `Stock: <n>` with the building_block icon after it, or the
+    // `Stock: <n> Blocks` text fallback when no icon file exists
+    // (REQ-UI-BLOCKS-ICON).
     void updateBlocksLabel();
 
     // The building_block icon at the header's text height, or a null pixmap when no
@@ -73,8 +75,9 @@ private:
 
     std::unique_ptr<ItemIconCache> m_itemIcons;
 
-    int                      m_blocks        = 0;
-    int                      m_expansionCost = 0;
+    // The simulation is the single source of truth for the block stock and the
+    // expansion cost; the change events are only refresh signals.
+    const Simulation*        m_sim;
 
     static const double kSpeeds[];
     static const int    kSpeedCount;
diff --git a/src/ui/MainWindow.cpp b/src/ui/MainWindow.cpp
index f572a29..ae97fc8 100644
--- a/src/ui/MainWindow.cpp
+++ b/src/ui/MainWindow.cpp
@@ -47,7 +47,7 @@ MainWindow::MainWindow(Simulation* sim, const std::string& configDir,
     const std::string itemsIconDir = QDir::cleanPath(
         QString::fromStdString(m_configDir) + "/../icons/items").toStdString();
 
-    m_headerBar = new HeaderBar(&sim->getConfig(), itemsIconDir, this);
+    m_headerBar = new HeaderBar(sim, &sim->getConfig(), itemsIconDir, this);
 
     m_gameWorldView = new GameWorldView(sim, &sim->getConfig(), &m_visuals, m_configDir,
                                         m_replay.get(), this);