Tcl/Tk Documentation > TkLib > SetClass
- Tk_Window tkwin (in)
- Token for window.
- char *class (in)
- New class name for window.
For main windows, Tk automatically propagates the name and class to the WM_CLASS property used by window managers. This happens either when a main window is actually created (e.g. in Tk_MakeWindowExist), or when Tk_SetClass is called, whichever occurs later. If a main window has not been assigned a class then Tk will not set the WM_CLASS property for the window.
Tk_Class is a macro that returns the current value of tkwin's class. The value is returned as a Tk_Uid, which may be used just like a string pointer but also has the properties of a unique identifier (see the manual entry for Tk_GetUid for details). If tkwin has not yet been given a class, then Tk_Class will return NULL.class, unique identifier, window, window manager