In Windows, it is possible to say
CreateWindow("myclass",...,WS_CHILD,...);
or
CreateWindow("myclass",...,WS_OVERLAPPEDWINDOW,...);
It is also possible to switch appearance at will:
SetWindowLongPtr((HWND)handle,GWL_STYLE,style_1);
SetWindowPos((HWND)handle,HWND_TOP,0,0,0,0,SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);
SetWindowLongPtr((HWND)handle,GWL_EXSTYLE,style_0);
SetWindowPos((HWND)handle,HWND_TOP,0,0,0,0,SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);
if(style_1&WS_CHILD)
{
HWND owner=GetWindow((HWND)handle,GW_OWNER);
SetParent((HWND)handle,owner);
}
else
{SetParent((HWND)handle,NULL);}
It seems to me that most other GUI toolkits make a clear distinction between top-level windows and other widgets. The question is if and how it is possible to implement similar behavior in GTK on X