/// Return true if specified window is owned by this window
  FXbool isOwnerOf(const FXWindow* window) const;

  /// Return true if specified window is ancestor of this window
  FXbool isChildOf(const FXWindow* window) const;

  /// Return true if this window contains child in its subtree
  FXbool containsChild(const FXWindow* child) const;

  /// Return the child window at specified coordinates
  FXWindow* getChildAt(FXint x,FXint y) const;

  /// Return the number of child windows for this window
  FXint numChildren() const;

  /**
  * Return the index (starting from zero) of the specified child window,
  * or -1 if the window is not a child or NULL
  */
  FXint indexOfChild(const FXWindow *window) const;

  /**
  * Return the child window at specified index,
  * or NULL if the index is negative or out of range
  */
  FXWindow* childAtIndex(FXint index) const;

  /// Return the common ancestor of window a and window b
  static FXWindow* commonAncestor(FXWindow* a,FXWindow* b);