Qt: Restore fullscreen resolution when regaining focus

Source/Core/DolphinQt2/MainWindow.cpp

@@ -482,6 +482,10 @@ void MainWindow::ConnectRenderWidget()
   m_rendering_to_main = false;
   m_render_widget->hide();
   connect(m_render_widget, &RenderWidget::Closed, this, &MainWindow::ForceStop);
+  connect(m_render_widget, &RenderWidget::FocusChanged, this, [this](bool focus) {
+    if (m_render_widget->isFullScreen())
+      SetFullScreenResolution(focus);
+  });
 }
 
 void MainWindow::ConnectHost()
@@ -874,6 +878,10 @@ void MainWindow::HideRenderWidget(bool reinit)
 
     m_render_widget->installEventFilter(this);
     connect(m_render_widget, &RenderWidget::Closed, this, &MainWindow::ForceStop);
+    connect(m_render_widget, &RenderWidget::FocusChanged, this, [this](bool focus) {
+      if (m_render_widget->isFullScreen())
+        SetFullScreenResolution(focus);
+    });
   }
 }
 

Source/Core/DolphinQt2/RenderWidget.cpp

@@ -52,6 +52,8 @@ RenderWidget::RenderWidget(QWidget* parent) : QWidget(parent)
           Qt::DirectConnection);
   connect(this, &RenderWidget::SizeChanged, Host::GetInstance(), &Host::ResizeSurface,
           Qt::DirectConnection);
+  connect(this, &RenderWidget::FocusChanged, Host::GetInstance(), &Host::SetRenderFocus,
+          Qt::DirectConnection);
 
   emit HandleChanged((void*)winId());
 
@@ -145,14 +147,16 @@ bool RenderWidget::event(QEvent* event)
     emit HandleChanged((void*)winId());
     break;
   case QEvent::WindowActivate:
-    Host::GetInstance()->SetRenderFocus(true);
     if (SConfig::GetInstance().m_PauseOnFocusLost && Core::GetState() == Core::State::Paused)
       Core::SetState(Core::State::Running);
+
+    emit FocusChanged(true);
     break;
   case QEvent::WindowDeactivate:
-    Host::GetInstance()->SetRenderFocus(false);
     if (SConfig::GetInstance().m_PauseOnFocusLost && Core::GetState() == Core::State::Running)
       Core::SetState(Core::State::Paused);
+
+    emit FocusChanged(false);
     break;
   case QEvent::Resize:
   {

Source/Core/DolphinQt2/RenderWidget.h

@@ -28,6 +28,7 @@ signals:
   void HandleChanged(void* handle);
   void StateChanged(bool fullscreen);
   void SizeChanged(int new_width, int new_height);
+  void FocusChanged(bool focus);
 
 private:
   void HandleCursorTimer();