qt: Only register graphics debugger as observer if visible. (#6875)

src/citra_qt/debugger/graphics/graphics.cpp

@@ -64,15 +64,22 @@ void GPUCommandStreamItemModel::OnGXCommandFinishedInternal(int total_command_co
 }
 
 GPUCommandStreamWidget::GPUCommandStreamWidget(QWidget* parent)
-    : QDockWidget(tr("Graphics Debugger"), parent) {
+    : QDockWidget(tr("Graphics Debugger"), parent), model(this) {
     setObjectName(QStringLiteral("GraphicsDebugger"));
 
-    GPUCommandStreamItemModel* command_model = new GPUCommandStreamItemModel(this);
-    g_debugger.RegisterObserver(command_model);
-
-    QListView* command_list = new QListView;
-    command_list->setModel(command_model);
+    auto* command_list = new QListView;
+    command_list->setModel(&model);
     command_list->setFont(GetMonospaceFont());
 
     setWidget(command_list);
 }
+
+void GPUCommandStreamWidget::showEvent(QShowEvent* event) {
+    g_debugger.RegisterObserver(&model);
+    QDockWidget::showEvent(event);
+}
+
+void GPUCommandStreamWidget::hideEvent(QHideEvent* event) {
+    g_debugger.UnregisterObserver(&model);
+    QDockWidget::hideEvent(event);
+}

src/citra_qt/debugger/graphics/graphics.h

@@ -37,5 +37,10 @@ class GPUCommandStreamWidget : public QDockWidget {
 public:
     GPUCommandStreamWidget(QWidget* parent = nullptr);
 
+protected:
+    void showEvent(QShowEvent* event) override;
+    void hideEvent(QHideEvent* event) override;
+
 private:
+    GPUCommandStreamItemModel model;
 };