XAllocClassHint(3) XLIB FUNCTIONS XAllocClassHint(3)

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

SYNTAX
       XClassHint *XAllocClassHint(void);

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

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

ARGUMENTS
       display   Specifies the connection to the X server.

       classhints
                 Specifies the XClassHint structure that is to be used.

       classhintsreturn
                 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 avail‐
       able, XAllocClassHint returns NULL.  To free the memory allocated to
       this structure, use XFree.

       The XSetClassHint function sets the class hint for the specified win‐
       dow.  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 win‐
       dow 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.  Other‐
       wise, the result is implementation-dependent.  It returns a nonzero
       status on success; otherwise, it returns a zero status.  To free
       resname and resclass when finished with the strings, use XFree on
       each individually.

       XGetClassHint can generate a BadWindow error.

PROPERTIES
       WMCLASS  Set by application programs to allow window and session man‐
                 agers to obtain the application's resources from the resource
                 database.

STRUCTURES
       The XClassHint structure contains:

       typedef struct {
               char *resname;
               char *resclass;
       } XClassHint;

       The resname member contains the application name,
       and the resclass member contains the application class.
       Note that the name set in this property may differ from the name set as WMNAME.
       That is, WMNAME 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 WMCLASS 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), XSetWM‐
       ClientMachine(3), XSetWMColormapWindows(3), XSetWMIconName(3), XSetWM‐
       Name(3), XSetWMProperties(3), XSetWMProtocols(3), XStringListTo‐
       TextProperty(3)
       Xlib - C Language X Interface



X Version 11                     libX11 1.6.5               XAllocClassHint(3)