XAllocClassHint(3) XLIB FUNCTIONS XAllocClassHint(3)
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 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
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 man-
agers 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), 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 1.7.1 XAllocClassHint(3)
xorg-libX11 1.7.1 - Generated Sat May 22 16:01:30 CDT 2021