xpaconvert (7)

This document describes tips for converting from xpa 1.0 (Xt-based xpa) to xpa 2.0 (socket-based xpa).

The following are tips for converting from xpa 1.0 (Xt-based xpa) to xpa 2.0 (socket-based xpa). The changes are straight-forward and almost can be done automatically (we used editor macros for most of the conversion).

• The existence of the cpp \s-1XPA_VERSION\s0 directive to distinguish between 1.0 (where it is not defined) and 2.0 (where it is defined).

• Remove the first widget argument from all send and receive server callbacks. Also change first 2 arguments from XtPointer to void *. For example: #ifdef \s-1XPA_VERSION\s0 static void XPAReceiveFile(client_data, call_data, paramlist, buf, len)

       void *client_data;
       void *call_data;
       char *paramlist;
       char *buf;
       int len;
  

  #else static void XPAReceiveFile(w, client_data, call_data, paramlist, buf, len)

       Widget w;
       XtPointer client_data;
       XtPointer call_data;
       char *paramlist;
       char *buf;
       int len;
  

  #endif

• Server callbacks should be declared as returning int instead of void. They now should return 0 for no errors, \-1 for error.

• The mode flags have changed when defining \s-1XPA\s0 server callbacks. The old S flag (save buffer) is replaced by freebuf=false. The old E flag (empty buffer is \s-1OK\s0) is no longer used (it was an artifact of the X implementation).

• Change NewXPACommand() to XPAcmdNew(), with the new calling sequence:

    xpa = NewXPACommand(toplevel, NULL, prefix, NULL);
  

  is changed to: xpa = XPACmdNew(xclass, name);

• Change the AddXPACommand() subroutine name to XPACmdAdd (with the same calling sequence): AddXPACommand(xpa, "file", "\tdisplay a new file\n\t\t requires: filename", NULL, NULL, NULL, XPAReceiveFile, text, NULL); is changed to: XPACmdAdd(xpa, "file", "\tdisplay a new file\n\t\t requires: filename", NULL, NULL, NULL, XPAReceiveFile, text, NULL);

• The XPAXtAppInput() routine should be called just before XtAppMainLoop() to add xpa fds to the Xt event loop: /* add the xpas to the Xt loop */ XPAXtAddInput(app, NULL);

  /* process events */ XtAppMainLoop(app);

• Change NewXPA() to XPANew() and call XPAXtAddInput() if the XtAppMainLoop routine already has been entered: xpa = NewXPA(saotng->xim->toplevel, prefix, xparoot, "FITS data or image filename\n\t\t options: file type", XPASendData, new, NULL, XPAReceiveData, new, "SE"); is changed to: sprintf(tbuf, "%s.%s", prefix, xparoot); xpa = XPANew("SAOTNG", tbuf, "FITS data or image filename\n\t\t options: file type", XPASendData, new, NULL, XPAReceiveData, new, "SE"); XPAXtAddInput(XtWidgetToApplicationContext(saotng->xim->toplevel), xpa);

• Change XPAInternalReceiveCommand() to XPACmdInternalReceive() remove first argument in the calling sequence): XPAInternalReceiveCommand(im->saotng->xim->toplevel, im->saotng, im->saotng->commands, "zoom reset", NULL, 0); is changed to: XPACmdInternalReceive(im->saotng, im->saotng->commands, "zoom reset", NULL, 0);

• Change DestroyXPA to XPAFree: DestroyXPA(im->dataxpa); is changed to: XPAFree(im->dataxpa);

See xpa(7) for a list of \s-1XPA\s0 help pages