Prep for image support in windows.

src/ui_elements/desktop_elements/IPlatformWindow.h

@@ -2,10 +2,23 @@
 
 #include <memory>
 
+namespace mt
+{
+    class Screen;
+}
+
 class IPlatformWindow
 {
 public:
     virtual ~IPlatformWindow() = default;
+
+    virtual void show() const = 0;
+
+    virtual void map() const = 0;
+
+    virtual void clear() const = 0;
+
+    virtual void paint(mt::Screen* screen) const = 0;
 };
 
 using IPlatformWindowPtr = std::unique_ptr<IPlatformWindow>;