Provide a renderer callback when the overlay data changes

app/streaming/video/overlaymanager.h

@@ -2,25 +2,40 @@
 
 #include <QString>
 
+namespace Overlay {
+
+enum OverlayType {
+    OverlayDebug,
+    OverlayMinorNotification,
+    OverlayMajorNotification,
+    OverlayMax
+};
+
+class IOverlayRenderer
+{
+public:
+    virtual ~IOverlayRenderer() = default;
+
+    virtual void notifyOverlayUpdated(OverlayType type) = 0;
+};
+
 class OverlayManager
 {
 public:
-    enum OverlayType {
-        OverlayDebug,
-        OverlayMinorNotification,
-        OverlayMajorNotification,
-        OverlayMax
-    };
-
     OverlayManager();
 
     bool isOverlayEnabled(OverlayType type);
     char* getOverlayText(OverlayType type);
+    void setOverlayTextUpdated(OverlayType type);
     void setOverlayState(OverlayType type, bool enabled);
 
+    void setOverlayRenderer(IOverlayRenderer* renderer);
+
     struct {
         bool enabled;
-        int updateSeq;
         char text[512];
     } m_Overlays[OverlayMax];
+    IOverlayRenderer* m_Renderer;
 };
+
+}