Tk_BackgroundError(3Tk)Tk_BackgroundError(3Tk)NAME
Tk_BackgroundError - report Tcl error that occurred in background
processing
SYNOPSIS
#include <tk.h>
Tk_BackgroundError(interp)ARGUMENTS
Tcl_Interp *interp (in) Interpreter in which the error occurred.
DESCRIPTION
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.
KEYWORDS
background, error, tkerror
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