NAME

       XmRedisplayWidget  —  Synchronously  activates  the  expose method of a widget to draw its
       content

SYNOPSIS

       #include <Xm/Xm.h>
       voidXmRedisplayWidget(
       Widgetwidget);

DESCRIPTION

       This function is a convenience routine that hides the details of the Xt internals  to  the
       application programmer by calling the expose method of the given widget with a well formed
       Expose event and Region corresponding to the total area  of  the  widget.  If  the  widget
       doesn't have an Expose method, 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.

       XmRedisplayWidget  doesn't  clear  the  widget  window prior to calling the expose method,
       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,
            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);
       }

       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)

                                                                             XmRedisplayWidget(3)