2 files changed, 3 insertions, 1 deletions
diff --git a/include/cru/platform/gui/Window.h b/include/cru/platform/gui/Window.h
index 742ef798..f877545e 100644
--- a/include/cru/platform/gui/Window.h
+++ b/include/cru/platform/gui/Window.h
@@ -72,6 +72,8 @@ struct INativeWindow : virtual IPlatformResource {
   // The lefttop of the rect is relative to screen lefttop.
   virtual void SetWindowRect(const Rect& rect) = 0;
 
+  // Return true if window gained the focus. But the return value should be
+  // ignored, since it does not guarantee anything.
   virtual bool RequestFocus() = 0;
 
   // Relative to client lefttop.
diff --git a/include/cru/platform/gui/xcb/Window.h b/include/cru/platform/gui/xcb/Window.h
index ba4798a5..346cbd55 100644
--- a/include/cru/platform/gui/xcb/Window.h
+++ b/include/cru/platform/gui/xcb/Window.h
@@ -42,7 +42,7 @@ class XcbWindow : public XcbResource, public virtual INativeWindow {
   Rect GetWindowRect() override;
   void SetWindowRect(const Rect& rect) override;
 
-  virtual bool RequestFocus() = 0;
+  bool RequestFocus() override;
 
   // Relative to client lefttop.
   virtual Point GetMousePosition() = 0;