Size gadget width

How do I find out the size of the size gadget in my window?

If you need to obtain the sizes before opening the window use this approach:

On AmigaOS4:

struct DrawInfo *dri = GetScreenDrawInfo(screen);
GetGUIAttrs(NULL, dri,
GUIA_SizeGadgetWidth, &width,
GUIA_SizeGadgetHeight, &height,
TAG_DONE);
FreeScreenDrawInfo(screen, dri);

On AmigaOS3:

struct DrawInfo *dri = GetScreenDrawInfo(screen);
struct Image *img;
width = 18; /* default sizing gadget width */
height = 10; /* default sizing gadget height */
if((img = (struct Image *)NewObject(NULL, "sysiclass",
SYSIA_Size, MEDRES,
SYSIA_DrawInfo, dri,
SYSIA_Which, SIZEIMAGE,
TAG_DONE)))
{
width = img->Width;
height = img->Height;
DisposeObject((Object *)img);
}
FreeScreenDrawInfo(screen, dri);

@tboeckel

I knew it would be something easy (well, on OS4 anyway), thanks.