make devices movable

gui/include/DeviceRenderer.hpp

@@ -13,8 +13,11 @@ public:
     void Render(SDL_Renderer* renderer) const;
     void Deselect();
 
+    bool PropagateEvent(SDL_Event* event);
+
 private:
     SDL_FRect bbox;
     bool selected;
+    bool grabbed;
     std::shared_ptr<Device> device;
 };

gui/include/NetworkRenderer.hpp

@@ -11,6 +11,8 @@ public:
     void AddDevice(std::shared_ptr<Device> device, uint16_t x, uint16_t y);
     void Render(SDL_Renderer* renderer) const;
 
+    void PropagateEvent(SDL_Event* event);
+
 private:
     Network& network;
     std::vector<DeviceRenderer> devices;