XwcLookupString(3)

NAME

   XmbLookupString, XwcLookupString, Xutf8LookupString - obtain composed
   input from an input method

SYNTAX

   int XmbLookupString(XIC ic, XKeyPressedEvent *event, char
          *buffer_return, int bytes_buffer, KeySym *keysym_return, Status
          *status_return);

   int XwcLookupString(XIC ic, XKeyPressedEvent *event, wchar_t
          *buffer_return, int wchars_buffer, KeySym *keysym_return, Status
          *status_return);

   int Xutf8LookupString(XIC ic, XKeyPressedEvent *event, char
          *buffer_return, int bytes_buffer, KeySym *keysym_return, Status
          *status_return);

ARGUMENTS

   buffer_return
             Returns a multibyte string or wide character string (if any)
             from the input method.

   bytes_buffer
   wchars_buffer
             Specifies space available in the return buffer.

   event     Specifies the key event to be used.

   ic        Specifies the input context.

   keysym_return
             Returns the KeySym computed from the event if this argument
             is not NULL.

   status_return
             Returns a value indicating what kind of data is returned.

DESCRIPTION

   The XmbLookupString, XwcLookupString and Xutf8LookupString functions
   return the string from the input method specified in the buffer_return
   argument.  If no string is returned, the buffer_return argument is
   unchanged.

   The KeySym into which the KeyCode from the event was mapped is returned
   in the keysym_return argument if it is non-NULL and the status_return
   argument indicates that a KeySym was returned.  If both a string and a
   KeySym are returned, the KeySym value does not necessarily correspond
   to the string returned.

   XmbLookupString and Xutf8LookupString return the length of the string
   in bytes, and XwcLookupString returns the length of the string in
   characters.  Both XmbLookupString and XwcLookupString return text in
   the encoding of the locale bound to the input method of the specified
   input context, and Xutf8LookupString returns text in UTF-8 encoding.

   Each string returned by XmbLookupString and XwcLookupString begins in
   the initial state of the encoding of the locale (if the encoding of the
   locale is state-dependent).

   Note: To ensure proper input processing, it is essential that the
   client pass only KeyPress events to XmbLookupString, XwcLookupString
   and Xutf8LookupString.  Their behavior when a client passes a
   KeyRelease event is undefined.

   Clients should check the status_return argument before using the other
   returned values.  These three functions each return a value to
   status_return that indicates what has been returned in the other
   arguments.  The possible values returned are:

   XBufferOverflow   The input string to be returned is too
                     large for the supplied buffer_return.  The
                     required size (for XmbLookupString,
                     Xutf8LookupString in bytes; for
                     XwcLookupString in characters) is returned
                     as the value of the function, and the
                     contents of buffer_return and keysym_return
                     are not modified.  The client should recall
                     the function with the same event and a
                     buffer of adequate size to obtain the
                     string.
   XLookupNone       No consistent input has been composed so
                     far.  The contents of buffer_return and
                     keysym_return are not modified, and the
                     function returns zero.
   XLookupChars      Some input characters have been composed.
                     They are placed in the buffer_return
                     argument, using the encoding described
                     above, and the string length is returned as
                     the value of the function.  The content of
                     the keysym_return argument is not modified.
   XLookupKeySym     A KeySym has been returned instead of a
                     string and is returned in keysym_return.
                     The content of the buffer_return argument
                     is not modified, and the function returns
                     zero.
   XLookupBoth       Both a KeySym and a string are returned;
                     XLookupChars and XLookupKeySym occur
                     simultaneously.

   It does not make any difference if the input context passed as an
   argument to XmbLookupString, XwcLookupString and Xutf8LookupString is
   the one currently in possession of the focus or not.  Input may have
   been composed within an input context before it lost the focus, and
   that input may be returned on subsequent calls to XmbLookupString,
   XwcLookupString or Xutf8LookupString even though it does not have any
   more keyboard focus.

   The function Xutf8LookupString is an extension introduced by The
   XFree86 Project, Inc. in their 4.0.2 release. Its presence is indicated
   by the macro X_HAVE_UTF8_STRING.

SEE ALSO

   XLookupKeysym(3), Compose(5)
   Xlib - C Language X Interface

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