The demonstration of the ToolTalk service is simple: while using a simple text editor, you can ask an interface for selecting font names to change the font displayed in the loaded file. The ToolTalk demo consists of two applications from X11R4:
Use any standard editor, such as vi, to make these modifications and to create the ptype file.
Next, you need to add code to the Xedit.c file to set the ToolTalk session, make a button for the font change function, and to allow Xedit to receive and process ToolTalk messages. These changes to the file are shown with commented explanations in Code Example B-2.
Now add code to the commands.c file so that Xedit can tell the Xfontsel application to send a reply when the font change has been completed, or to notify it if the operation failed. You also need to add code that tells Xfontsel what operation Xedit wants performed. These changes to the file are shown with commented explanations in Code Example B-3.
The final modification you need to make to the Xedit program is to change the Makefile so that it uses the ToolTalk libraries. To do this, add the -ltt option as follows:
LOCAL_LIBRARIES = -ltt $(XAWLIB) $(XMULIB) $(XTOOLLIB) $(XLIB)
After you have made the indicated changes to the Xedit files, compile the Xedit program.
For the ToolTalk demonstration, Xfontsel needs to know:
Next, modify the Makefile for the Xfontsel program so that it uses the ToolTalk libraries. To do this, add the -ltt option to the as follows:
LOCAL_LIBRARIES = -ltt $(XAWLIB) $(XMULIB) $(XTOOLLIB) $(XLIB)
The ToolTalk types mechanism is designed to help the ToolTalk service route messages. You first define a process type (ptype), and then compile the ptype with the ToolTalk type compiler, tt_type_comp. For the ToolTalk demonstration, you need to create a ptype file for the Xfontsel application, as shown in Figure B-1.
Figure B-1 The Xfontsel.ptype File
ptype xfontsel { /* Process type identifier */
start "/directory_name/xfontsel"; /* Start string */
handle: /* Receiving process */
/* A signature is divided
* into two parts by the => as follows:
* Part 1 specifies how the message is to be matched;
* Part 2 specifies what is to be taken when
* a match occurs.
*/
session GetFontName(out string fontname) => start;
}
After you have created the ptype file, you need to install the ptype. To do this, run the ToolTalk type compiler as follows:
machine_name% tt_type_comp xfontsel.ptype
where xfontsel.ptype is the name of your ptype file.After you have made the indicated changes to the Xfontsel files, created a ptype file, and installed the pytpe, compile the Xfontsel program.
To start Xedit, enter the command as follows:
machine_name% xedit
A screen similar to the one shown in Figure B-2 is displayed.Figure B-2 The Xedit Screen
A screen similar to the one shown in Figure B-3 is displayed.
Figure B-3 The Xedit Screen
a. Click in the `changefont' button on the Xedit screen.
A screen similar to the one shown in Figure B-4 is displayed.
Figure B-4 The Xedit Screen
b. Select the new font on the Xfontsel screen.
c. Click in the `apply' button on the Xfontsel screen.
A screen similar to the one shown in Figure B-5 is displayed.
Figure B-5 The Xedit Screen Showing the Font Change
#include <desktop/tt_c.h> /* ToolTalk header */
Code Example B-1 Modify the Xedit.h File
/*
* rcs_id[] = "$XConsortium: xedit.h,v 1.18 89/07/21 19:52:58 kit Exp $";
*/
...
#include <X11/Xaw/Viewport.h>
#include <X11/Xaw/Cardinals.h>
/*
* For the ToolTalk demonstration, add the following include line.
*/
#include <desktop/tt_c.h> /* ToolTalk header */
Fail if no default session
extern struct _app_resources {
Boolean enableBackups;
char *backupNamePrefix;
char *backupNameSuffix;
...
/* externals in xedit.c */
extern void Feep();
/*
* For the ToolTalk demonstration, add the following externals.
*/
extern void processToolTalkMessage(); /* Process ToolTalk message */
extern void dieFromToolTalkError(); /* Fail if error occurs */
extern Display *CurDpy; /* Display */
...
/* externs in commands.c */
...
extern void DoChangeFont(); /* Change font */
Code Example B-2 Modified Xedit.c File
#if (!defined(lint) && !defined(SABER))
static char Xrcsid[] = "$XConsortium: xedit.c,v 1.23 89/12/07
19:19:17 kit Exp $";
#endif /* lint && SABER */
...
void
main(argc, argv)
int argc;
char **argv;
{
Widget top;
String filename = NULL;
static void makeButtonsAndBoxes();
/*
* For the ToolTalk demonstration, add the following lines:
*/
int ttmark; /* ToolTalk mark */
int ttfd; /* ToolTalk file descriptor */
char *procid; /* Process identifier */
Tt_status ttrc; /* ToolTalk status */
top = XtInitialize( "xedit", "Xedit", NULL, 0, &argc, argv);
...
XtRealizeWidget(top);
XDefineCursor(XtDisplay(top),XtWindow(top),
XCreateFontCursor( XtDisplay(top), XC_left_ptr));
/*
* For the ToolTalk demonstration, add the following lines
* to make the top of stack the ToolTalk session and set
* it to be the default session.
*/
ttmark = tt_mark();
ttrc = tt_default_session_set( /* set the default session .. */
tt_X_session( /* .. to the X session for .. */
DisplayString( /* .. the X server displaying ..*/
XtDisplay(top)))); /* .. our top window... */
/*
* Fail if no default session
*/
dieFromToolTalkError("tt_default_session_set",ttrc);
procid = tt_open(); /* Initialize ToolTalk */
/*
* Fail if no process identifier
*/
dieFromToolTalkError("tt_open",tt_ptr_error(procid));
ttfd = tt_fd(); /* ToolTalk file descriptor */
/*
* Fail if no file descriptor
*/
dieFromToolTalkError("tt_fd",tt_int_error(ttfd));
/*
* Activate file descriptor
*/
XtAddInput(ttfd, (XtPointer)XtInputReadMask, processToolTalkMessage, 0);
XtMainLoop();
}
...
MakeCommandButton(b_row, "load", DoLoad);
/*
* For the ToolTalk demonstration, add the next line to make
* a button for the font change command:
*/
MakeCommandButton(b_row, "changefont", DoChangeFont);
filenamewindow = MakeStringBox(b_row, "filename", filename);
}
XtCreateManagedWidget("bc_label", labelWidgetClass, outer, NULL, ZERO);
...
void
Feep()
{
XBell(CurDpy, 0);
/*
*For the ToolTalk demonstration, add the following lines to receive and
* process an incoming message:
*/
}
void processToolTalkMessage() /* Process ToolTalk message */
{
int ttmark; /* ToolTalk mark */
Tt_message incoming; /* Incoming message */
ttmark = tt_mark(); /* ToolTalk mark */
incoming = tt_message_receive(); /* Receive incoming message */
/*
* The callback should process the message, so we should never
* get a message returned.
*/
if (incoming == 0) return; /* Return incoming message */
if (tt_is_err(tt_ptr_error(incoming))) {
dieFromToolTalkError("tt_message_receive",
tt_ptr_error(incoming));
}
/*
* This is not a message we recognize.
* If it is a request, or a notice that caused us to start, fail it.
*/
if (tt_message_class(incoming) == TT_REQUEST ||
tt_message_status(incoming) == TT_WRN_START_MESSAGE) {
tt_message_fail(incoming);
}
tt_message_destroy(incoming); /* Destroy message */
tt_release(ttmark); /* Free space */
}
void dieFromToolTalkError(procname, errid)
char *procname;
Tt_status errid;
/* Fail if error occurs */
{
/*
* Don't die on warnings or TT_OK.
*/
if (tt_is_err(errid)) {
fprintf(stderr,"%s returned ToolTalk error: %s\n",
procname, tt_status_message(errid));
exit(1);
}
}
#if (!defined(lint) && !defined(SABER))
static char Xrcsid[] = "$XConsortium: commands.c,v 1.27 89/12/10
17:08:26 rws Exp $";
#endif /* lint && SABER */
...
#ifdef USG
int rename (from, to)
char *from, *to;
{
(void) unlink (to);
if (link (from, to) == 0) {
unlink (from);
return 0;
} else {
return -1;
}
}
#endif
/*
* For the ToolTalk demonstration, add the following lines to have Xfontsel
* send a callback that the operation has either completed or failed:
*/
static Tt_callback_action FinishChangeFont(m,p) /* ToolTalk message callback */
Tt_message m; /* ToolTalk message */
Tt_pattern p; /* ToolTalk pattern */
{
static XFontStruct *fs; /* Font structure */
int ttmark; /* ToolTalk mark */
ttmark = tt_mark(); /* ToolTalk mark */
/*
* If operation fails, notify user
*/
if (TT_FAILED==tt_message_state(m)) {
XeditPrintf("Font change failed\n");
tt_message_destroy(m); /* Destroy message */
} else if (TT_HANDLED==tt_message_state(m)) {
XFontStruct *newfs;
/* Try to load the new font */
newfs = XLoadQueryFont(CurDpy,tt_message_arg_val(m,0));
/* If the new font is OK, and there is an old font,
* unload the old font. Then use the new font
*/
if (newfs) {
if (fs) {
XUnloadFont(CurDpy, fs->fid);
}
XtVaSetValues(textwindow, XtNfont, newfs, 0);
fs = newfs;
}
tt_message_destroy(m); /* Destroy message */
}
tt_release(ttmark); /* Release mark */
/*
* Process callback to notify sender operation completed
*/
return TT_CALLBACK_PROCESSED;
}
void
DoChangeFont() /* Change font */
{
Tt_message m; /* ToolTalk message */
Tt_status ttrc; /* ToolTalk status */
/*
* Create request
*/
m = tt_prequest_create(TT_SESSION, "GetFontName");
/*
* Add arguments to message
*/
tt_message_arg_add(m,TT_OUT,"string",(char *)NULL);
/*
* Add callback to notify when change complete
*/
tt_message_callback_add(m,FinishChangeFont);
/*
* Send message
*/
ttrc = tt_message_send(m);
/*
* Fail if error occurs
*/
dieFromToolTalkError("tt_message_send",ttrc);
}
void
DoSave()
{
Code Example B-4 Modified Xfontsel.c File
#ifndef lint
static char Xrcsid[] = "$XConsortium: xfontsel.c,v 1.16 89/12/12 14:10:48 rws
Exp $";
#endif
...
#include <X11/Xaw/Viewport.h>
#include <X11/Xmu/Atoms.h>
/*
* For the ToolTalk demonstration, add the following line to include
* the ToolTalk header file:
*/
#include <desktop/tt_c.h> /* ToolTalk header file */
#define MIN_APP_DEFAULTS_VERSION 1
...
void SetCurrentFont();
Boolean IsXLFDFontName();
/*
* For the ToolTalk demonstration, add the following lines to tell
* Xfontsel how to handle a ToolTalk message:
*/
void dieFromToolTalkError(); /* Fail if error occurs */
void processToolTalkMessage(); /* Process ToolTalk message */
void ReplyToMessage(); /* Reply to ToolTalk message */
Tt_message replymsg;
typedef void (*XtProc)();
...
int matchingFontCount;
static Boolean anyDisabled = False;
Widget ownButton;
/*
* For the ToolTalk demonstration, add the next line to add
* the apply button to change the font:
*/
Widget applyButton; /* Add apply button */
Widget fieldBox;
/*
* For the ToolTalk demonstration, add the next line to add
* a command box to make the font change:
*/
Widget commandBox; /* Make commandBox global */
Widget countLabel;
...
void main(argc, argv)
unsigned int argc;
char **argv;
{
Widget topLevel, pane;
/*
* For the ToolTalk demonstration, add the following lines:
*/
int ttmark, ttfd; /* ToolTalk mark, ToolTalk file descriptor */
char *procid; /* Process identifier */
Tt_status ttrc; /* ToolTalk status */
topLevel = XtInitialize( NULL, "XFontSel", options, XtNumber(options),
&argc, argv );
...
pane = XtCreateManagedWidget("pane",panedWidgetClass,topLevel,NZ);
{
/*
* For the ToolTalk demonstration, make the command box widget
* global; change the line
* Widget commandBox, /* fieldBox, currentFontName,*/ viewPort;
* as follows:
*/
Widget /* commandBox, fieldBox, currentFontName,*/ viewPort;
commandBox = XtCreateManagedWidget("commandBox",formWidgetClass,pane,NZ);
{
...
ownButton =
XtCreateManagedWidget("ownButton",toggleWidgetClass,commandBox,NZ);
/*
* For the ToolTalk demonstration, add the following lines to create
* an apply button for the font change:
*/
applyButton =
XtVaCreateManagedWidget("applyButton",
commandWidgetClass,
commandBox,
XtNlabel, "apply",
XtNfromHoriz, ownButton,
XtNleft, XtChainLeft,
XtNright, XtChainLeft,
0);
countLabel =
XtCreateManagedWidget("countLabel",labelWidgetClass,commandBox,NZ);
XtAddCallback(quitButton, XtNcallback, Quit, NULL);
XtAddCallback(ownButton,XtNcallback,OwnSelection,(XtPointer)True);
/*
* For the ToolTalk demonstration, add the following line to notify
* Xedit when the apply button has been pressed:
*/
XtAddCallback(applyButton, XtNcallback,ReplyToMessage, NULL);
}
fieldBox = XtCreateManagedWidget("fieldBox", boxWidgetClass, pane, NZ);
...
{
int f;
for (f = 0; f < FIELD_COUNT; f++) currentFont.value_index[f] = -1;
}
/*
* For the ToolTalk demonstration, add the following lines
* to make the top of stack the ToolTalk session and set
* it to be the default session.
*/
ttmark = tt_mark();
ttrc = tt_default_session_set( /* set the default session .. */
tt_X_session( /* .. to the X session for .. */
DisplayString( /* .. the X server displaying ..*/
XtDisplay(top)))); /* .. our top window... */
/*
* Fail if no default session
*/
dieFromToolTalkError("tt_default_session_set",ttrc);
procid = tt_open();
/*
* Fail if no proces identifier
*/
dieFromToolTalkError("tt_open",tt_ptr_error(procid));
ttfd = tt_fd();
/*
* Fail if no ToolTalk file descriptor
*/
dieFromToolTalkError("tt_fd",tt_int_error(ttfd));
ttrc = tt_ptype_declare("xfontsel");
/*
* Fail if ptype not declared
*/
dieFromToolTalkError("tt_ptype_declare",tt_int_error(ttfd));
ttrc = tt_session_join(tt_default_session());
/*
* Fail if unable to join session
*/
dieFromToolTalkError("tt_session_join",ttrc);
/*
* Add input
*/
XtAddInput(ttfd, (XtPointer)XtInputReadMask, processToolTalkMessage, 0);
XtAppMainLoop(appCtx);
tt_close(); /* End ToolTalk session */
tt_release(ttmark); /* Free space */
}
...
Boolean field_bits[FIELD_COUNT];
int max_field;
if (*fontName == DELIM) field++;
/*
*
* For the ToolTalk demonstration, use the standard routines
* instead of BSD; change the line
* bzero( field_bits, sizeof(field_bits) );
* to read as follows:
*
*/
memset( field_bits, 0, sizeof(field_bits) );
if (Matches(pattern, fontName++, field_bits, &max_field)) {
...
XtDisownSelection(w, XA_PRIMARY, time);
XtSetSensitive(currentFontName, False);
}
/*
* For the ToolTalk Demonstration, add the following lines:
*/
}
void dieFromToolTalkError(procname, errid) /* Fail if error occurs */
char *procname; /* Process name */
Tt_status errid; /* Error identifier */
{
/*
* Don't die on warnings or TT_OK.
*/
if (tt_is_err(errid)) {
fprintf(stderr,"%s returned ToolTalk error: %s\n",
procname, tt_status_message(errid));
exit(1);
}
}
void processToolTalkMessage() /* Process message */
{
int ttmark; /* ToolTalk mark */
Tt_message incoming; /* Incoming message */
ttmark = tt_mark();
incoming = tt_message_receive(); /* Receive message */
/*
* It's possible that the file descriptor may become active but
* there's not actually a ToolTalk message for us.
*/
if (incoming == 0) return;
if (tt_is_err(tt_ptr_error(incoming))) {
dieFromToolTalkError("tt_message_receive",
tt_ptr_error(incoming));
}
if (0==strcmp(tt_message_op(incoming),"GetFontName")) {
/*
* This is the message we expected. If we're already
* busy, reject it. Otherwise activate the "apply" button.
*/
if (replymsg) {
tt_message_reject(incoming);
tt_message_destroy(incoming);
tt_release(ttmark);
return;
}
XtVaSetValues(applyButton, XtNsensitive, TRUE, 0);
replymsg = incoming;
tt_release(ttmark);
return;
}
/*
* This is not a message we recognize.
* If it's a request, or a notice that caused us to start, fail it.
*/
if (tt_message_class(incoming) == TT_REQUEST ||
tt_message_status(incoming) == TT_WRN_START_MESSAGE) {
tt_message_fail(incoming);
}
tt_message_destroy(incoming);
tt_release(ttmark);
}
/*
* Called when the Apply button is pressed. Replies to the outstanding
* message and turn off the Apply button.
*/
/* ARGSUSED */
void ReplyToMessage(w, msg, wdata)
Widget w;
caddr_t msg;
caddr_t wdata;
{
tt_message_arg_val_set(replymsg, 0, currentFontNameString);
tt_message_reply(replymsg);
tt_message_destroy(replymsg);
replymsg = 0;
XtVaSetValues(applyButton, XtNsensitive, FALSE, 0);
}