Tk_BackgroundError - report Tcl error that occurred in background processing
#include <tk.h>
Tk_BackgroundError(interp)
- Tcl_Interp *interp (in)
-
Interpreter in which the error occurred.
This procedure is typically invoked when a Tcl error occurs during
``background processing'' such as executing a Tcl command in response
to a button press or menu entry invocation.
When such an error occurs, the error condition is reported to Tk
or to a widget or some other C code, and there is not usually any
obvious way for that code to report the error to the user.
In these cases the code calls Tk_BackgroundError with an
interp argument identifying the interpreter in which the
error occurred.
Tk_BackgroundError attempts to invoke the tkerror
Tcl command to report the error in an application-specific fashion.
If no tkerror command exists, or if it returns with an error condition,
then Tk_BackgroundError reports the error itself by printing
a message on the standard error file.
Tk_BackgroundError does not invoke tkerror immediately
(in some cases this could interfere with scripts that are in process
at the time the error occurred).
Instead, it invokes tkerror later as an idle callback.
Tk_BackgroundError saves the values of the errorInfo and
errorCode variables and restores these values just before
invoking tkerror.
It is possible for many background errors to accumulate before
tkerror is invoked. When this happens, each of the errors
is processed in order. However, if tkerror returns a
break exception, then all remaining error reports for the
interpreter are skipped.
background, error, tkerror
Copyright © 1992-1994 The Regents of the University of California.
Copyright © 1994 Sun Microsystems, Inc.
Copyright © 1995 Roger E. Critchlow Jr.