replace combined stateUpdated signal with individual events

src/ui/MainWindow.cpp

@@ -11,6 +11,7 @@
 
 #include "BlueprintPanel.h"
 #include "BuildButtonGrid.h"
+#include "BuildingBlocksChangedEvent.h"
 #include "BuildingSystem.h"
 #include "ConfigLoader.h"
 #include "GameWorldView.h"
@@ -52,15 +53,6 @@ MainWindow::MainWindow(Simulation* sim, const std::string& configDir, QWidget* p
     connect(m_gameWorldView, &GameWorldView::selectionChanged,
             m_selectedBuildingPanel, &SelectedBuildingPanel::onSelectionChanged);
 
-    connect(m_gameWorldView, &GameWorldView::stateUpdated,
-            m_headerBar, &HeaderBar::onStateUpdated);
-
-    connect(m_gameWorldView, &GameWorldView::stateUpdated,
-            this, &MainWindow::onStateUpdated);  // for affordability
-
-    connect(m_gameWorldView, &GameWorldView::stateUpdated,
-            m_selectedBuildingPanel, &SelectedBuildingPanel::onStateUpdated);
-
     connect(m_gameWorldView, &GameWorldView::gameOver,
             this, &MainWindow::onGameOver);
 
@@ -90,9 +82,6 @@ MainWindow::MainWindow(Simulation* sim, const std::string& configDir, QWidget* p
     connect(m_gameWorldView, &GameWorldView::selectionChanged,
             m_blueprintPanel, &BlueprintPanel::onSelectionChanged);
 
-    connect(m_gameWorldView, &GameWorldView::stateUpdated,
-            m_blueprintPanel, &BlueprintPanel::onStateUpdated);
-
     connect(m_blueprintPanel, &BlueprintPanel::blueprintPlacementRequested,
             m_gameWorldView, &GameWorldView::enterBlueprintMode);
 
@@ -132,6 +121,13 @@ MainWindow::MainWindow(Simulation* sim, const std::string& configDir, QWidget* p
             m_layoutBlueprints.clear();
         }
     }
+
+    registerForEvent();
+}
+
+MainWindow::~MainWindow()
+{
+    unregisterForEvent();
 }
 
 void MainWindow::resizeEvent(QResizeEvent* event)
@@ -172,9 +168,9 @@ void MainWindow::layoutPanels()
     m_bottomPanel->setGeometry(0, headerH + gameH, totalW, panelH);
 }
 
-void MainWindow::onStateUpdated(Tick /*tick*/, int blocks, double /*speed*/)
+void MainWindow::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event)
 {
-    m_buildButtonGrid->updateAffordability(blocks);
+    m_buildButtonGrid->updateAffordability(event->blocks);
 }
 
 void MainWindow::onEscapeMenuRequested()