--- a/OrthancStone/Sources/Viewport/IViewport.h	Wed Sep 23 17:25:25 2020 +0200
+++ b/OrthancStone/Sources/Viewport/IViewport.h	Thu Sep 24 16:40:30 2020 +0200
@@ -62,6 +62,14 @@
       virtual ViewportController& GetController() = 0;
 
       virtual void Invalidate() = 0;
+
+
+      /**
+       * This function must be called when the layout has changed, and
+       * thus the size of the canvas must be re-computed. Avoid
+       * calling this method too often for performance.
+       **/
+      virtual void RefreshCanvasSize() = 0;
     };   
     
     virtual ~IViewport()