anchor.diff:        final cursorPoint = calloc<POINT>()
           ..ref.x = LOWORD(lParam)
           ..ref.y = HIWORD(lParam);
  -      final titlebarRect = calloc<RECT>();
   
         try {
           ScreenToClient(hwnd, cursorPoint);
  
positive.code:   return minimizeRect;
  }
  
  int dpiScale(int value, int dpi) => value * dpi ~/ 96;
  
  int getWindowThemeDataHandle(int hwnd) {
    final classDataSection = 'WINDOW'.toNativeUtf16();
    final hTheme = OpenThemeData(hwnd, classDataSection);
    free(classDataSection);
    return hTheme;
  }
  
  void getTitlebarRect(int hwnd, Pointer<RECT> rect) {
    final titleBarSize = calloc<SIZE>();
    const topAndBottomBorders = 2;
  
    final hTheme = getWindowThemeDataHandle(hwnd);
    final dpi = GetDpiForWindow(hwnd);
    GetThemePartSize(hTheme, NULL, WINDOWPARTS.WP_CAPTION,
        CAPTIONSTATES.CS_ACTIVE, nullptr, THEMESIZE.TS_TRUE, titleBarSize);
    CloseThemeData(hTheme);
  
    final height = dpiScale(titleBarSize.ref.cy, dpi) + topAndBottomBorders;
  
    GetClientRect(hwnd, rect);
    rect.ref.bottom = rect.ref.top + height;
  
    free(titleBarSize);
  }
  
  void getFakeShadowRect(int hwnd, Pointer<RECT> rect) {
    GetClientRect(hwnd, rect);
    rect.ref.bottom = rect.ref.top + 1;
  }
  
  bool isWindowMaximized(int hwnd) {
    final windowPlacement = calloc<WINDOWPLACEMENT>()
      ..ref.length = sizeOf<WINDOWPLACEMENT>();
  
negative.code:   return maximizeRect;
  }
  
  /// Return the bounding box for the minimize button.
  Pointer<RECT> getMinimizeRect(int hwnd, Pointer<RECT> titleBarRect) {
    final dpi = GetDpiForWindow(hwnd);
    final buttonWidth = dpiScale(47, dpi);
  