Qt: Initial hotkey implementation

src/duckstation-qt/inputbindingwidgets.h

@@ -0,0 +1,35 @@
+#pragma once
+#include "core/types.h"
+#include <QtWidgets/QPushButton>
+
+class QTimer;
+
+class QtHostInterface;
+
+class InputButtonBindingWidget : public QPushButton
+{
+  Q_OBJECT
+
+public:
+  InputButtonBindingWidget(QtHostInterface* host_interface, QString setting_name, QWidget* parent);
+  ~InputButtonBindingWidget();
+
+protected:
+  void keyPressEvent(QKeyEvent* event) override;
+  void keyReleaseEvent(QKeyEvent* event) override;
+
+private Q_SLOTS:
+  void onPressed();
+  void onInputListenTimerTimeout();
+
+private:
+  bool isListeningForInput() const { return m_input_listen_timer != nullptr; }
+  void startListeningForInput();
+  void stopListeningForInput();
+
+  QtHostInterface* m_host_interface;
+  QString m_setting_name;
+  QString m_current_binding_value;
+  QTimer* m_input_listen_timer = nullptr;
+  u32 m_input_listen_remaining_seconds = 0;
+};