XmRedisplayWidget(3X) UNIX System V XmRedisplayWidget(3X)
NAME
XmRedisplayWidget - Synchronously activates the expose
method of a widget to draw its content
SYNOPSIS
#include <Xm/Xm.h>
voidXmRedisplayWidget(
Widgetwidget);
VERSION
This page documents Motif 2.1.
DESCRIPTION
This function is a convenience routine that hides the
details of the Xt internals to the application programmer by
calling the exposemethod of the given widget with a well
formed Exposeevent and Regioncorresponding to the total area
of the widget. If the widget doesn't have an Exposemethod,
the function does nothing.
This is primarily used in the context of X Printing if the
programming model chosen by the application is synchronous;
that is, it doesn't rely of X Print events for the driving
of page layout but wants to completely control the sequence
of rendering requests.
XmRedisplayWidgetdoesn't clear the widget window prior to
calling the exposemethod, since this is handled by calls to
XpStartPage.
widget The widget to redisplay.
RETURN VALUE
None.
ERRORS/WARNINGS
Not applicable
EXAMPLES
In the following, a simple application wants to print the
content of a multi-page text widget (similar to dtpad).
PrintOKCallback(print_dialog...)
/*-------------*/
{
pshell = XmPrintSetup (print_dialog, pbs->print_screen,
"Print", NULL, 0);
XpStartJob(XtDisplay(pshell), XPSpool);
/**** here I realize the shell, get its size, create my widget
hierarchy: a bulletin board, and then a text widget,
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XmRedisplayWidget(3X) UNIX System V XmRedisplayWidget(3X)
that I stuff with the video text widget buffer */
/* get the total number of pages to print */
XtVaGetValues(ptext, XmNrows, &prows,
XmNtotalLines, n_lines, NULL);
n_pages = n_lines / prows;
/***** now print the pages in a loop */
for (cur_page=0; cur_page != n_pages; cur_page++) {
XpStartPage(XtDisplay(pshell), XtWindow(pshell), False);
XmRedisplayWidget(ptext); /* do the drawing */
XpEndPage(XtDisplay(pshell));
XmTextScroll(ptext, prows); /* get ready for next page */
}
/***** I'm done */
XpEndJob(XtDisplay(pshell));
}
Of course, one could change the above code to include it in
a fork()branch so that the main program is not blocked while
printing is going on. Another way to achieve a "print-in-
the-background" effect is to use an Xt workproc. Using the
same sample application, that gives us:
Boolean
PrintOnePageWP(XtPointer npages) /* workproc */
/*-------------*/
{
static int cur_page = 0;
cur_page++;
XpStartPage(XtDisplay(pshell), XtWindow(pshell), False);
XmRedisplayWidget(ptext); /* do the drawing */
XpEndPage(XtDisplay(pshell));
XmTextScroll(ptext, prows); /* get ready for next page */
if (cur_page == n_pages) { /***** I'm done */
XpEndJob(XtDisplay(pshell));
XtDestroyWidget(pshell);
XtCloseDisplay(XtDisplay(pshell));
}
return (cur_page == n_pages);
}
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XmRedisplayWidget(3X) UNIX System V XmRedisplayWidget(3X)
PrintOKCallback(...)
/*-------------*/
{
pshell = XmPrintSetup (widget, pbs->print_screen,
"Print", NULL, 0);
XpStartJob(XtDisplay(pshell), XPSpool);
/**** here I get the size of the shell, create my widget
hierarchy: a bulletin board, and then a text widget,
that I stuff with the video text widget buffer */
/* get the total number of pages to print */
/* ... same code as above example */
/***** print the pages in the background */
XtAppAddWorkProc(app_context, PrintOnePageWP, n_pages);
}
SEE ALSO
XmPrintSetup(3), XmPrintShell(3)
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