Qt: Move some functionalty from OpenGLDisplayWindow into QtDisplayWindow

src/duckstation-qt/qtdisplaywindow.h

@@ -0,0 +1,36 @@
+#pragma once
+#include <QtGui/QWindow>
+
+class QKeyEvent;
+
+class HostDisplay;
+
+class QtHostInterface;
+
+class QtDisplayWindow : public QWindow
+{
+  Q_OBJECT
+
+public:
+  QtDisplayWindow(QtHostInterface* host_interface, QWindow* parent);
+  virtual ~QtDisplayWindow();
+
+  virtual HostDisplay* getHostDisplayInterface();
+
+  virtual bool createDeviceContext(QThread* worker_thread);
+  virtual bool initializeDeviceContext();
+  virtual void destroyDeviceContext();
+
+  virtual void Render();
+
+protected:
+  virtual bool createImGuiContext();
+  virtual void destroyImGuiContext();
+  virtual bool createDeviceResources();
+  virtual void destroyDeviceResources();
+
+  void keyPressEvent(QKeyEvent* event) override;
+  void keyReleaseEvent(QKeyEvent* event) override;
+
+  QtHostInterface* m_host_interface;
+};