NAME

       XAllocClassHint,  XSetClassHint,  XGetClassHint,  XClassHint  - allocate class hints structure and set or
       read a window's WM_CLASS property

SYNTAX

       XClassHint *XAllocClassHint(void);

       XSetClassHint(Display *display, Window w, XClassHint *class_hints);

       Status XGetClassHint(Display *display, Window w, XClassHint *class_hints_return);

ARGUMENTS

       display   Specifies the connection to the X server.

       class_hints
                 Specifies the XClassHint structure that is to be used.

       class_hints_return
                 Returns the XClassHint structure.

       w         Specifies the window.

DESCRIPTION

       The XAllocClassHint function allocates and returns a pointer to a XClassHint structure.   Note  that  the
       pointer  fields  in  the  XClassHint  structure  are  initially  set  to NULL.  If insufficient memory is
       available, XAllocClassHint returns NULL.  To free the memory allocated to this structure, use XFree.

       The XSetClassHint function sets the class hint for the specified window.  If the strings are not  in  the
       Host Portable Character Encoding, the result is implementation-dependent.

       XSetClassHint can generate BadAlloc and BadWindow errors.

       The  XGetClassHint function returns the class hint of the specified window to the members of the supplied
       structure.  If the data returned by the server is in the Latin  Portable  Character  Encoding,  then  the
       returned  strings  are in the Host Portable Character Encoding.  Otherwise, the result is implementation-
       dependent.  It returns a nonzero status on success;  otherwise,  it  returns  a  zero  status.   To  free
       res_name and res_class when finished with the strings, use XFree on each individually.

       XGetClassHint can generate a BadWindow error.

PROPERTIES

       WM_CLASS  Set  by  application  programs to allow window and session managers to obtain the application's
                 resources from the resource database.

STRUCTURES

       The XClassHint structure contains:

       typedef struct {
               char *res_name;
               char *res_class;
       } XClassHint;

       The res_name member contains the application name,
       and the res_class member contains the application class.
       Note that the name set in this property may differ from the name set as WM_NAME.
       That is, WM_NAME specifies what should be displayed in the title bar and,
       therefore, can contain temporal information (for example, the name of
       a file currently in an editor's buffer).
       On the other hand,
       the name specified as part of WM_CLASS is the formal name of the application
       that should be used when retrieving the application's resources from the
       resource database.

DIAGNOSTICS

       BadAlloc  The server failed to allocate the requested resource or server memory.

       BadWindow A value for a Window argument does not name a defined Window.

SEE ALSO

       XAllocIconSize(3), XAllocSizeHints(3), XAllocWMHints(3), XFree(3), XSetCommand(3),
       XSetTransientForHint(3), XSetTextProperty(3), XSetWMClientMachine(3), XSetWMColormapWindows(3),
       XSetWMIconName(3), XSetWMName(3), XSetWMProperties(3), XSetWMProtocols(3), XStringListToTextProperty(3)
       Xlib - C Language X Interface