Selectable mouse type on Linux, part 1

src/qt/qt_rendererstack.hpp

@@ -64,6 +64,11 @@ public:
             rendererWindow->onResize(width, height);
     }
 
+    void (*mouse_init)() = nullptr;
+    void (*mouse_poll)() = nullptr;
+    void (*mouse_capture)(QWindow *window) = nullptr;
+    void (*mouse_uncapture)() = nullptr;
+
 signals:
     void blitToRenderer(int buf_idx, int x, int y, int w, int h);
     void rendererChanged();