dialog.c

`smith.motif.tar.Z includes the source code for the book "Designing X clients with Xt/Motif," by Je

{
	XtRealizeWidget(dObject->dialogShell);
}	/* dialog_realize */


/*
dialog_activate() maps the dialog box.  If the dialog box has a
modal configuration, it blocks the application until the user
selects a command button.  See dialog_modal_prompt() for an
alternative approach for activating a modal dialog box.
*/

void dialog_activate(dObject)
Dialog dObject;
{
	if (dObject->dialogText && !dObject->remember_string_response)
		XmTextSetString(dObject->dialogText, "");		/* clean slate */

	position_dialog(dObject);
	if (dObject->modal_dialog)
		popup_and_wait_for_button_response(dObject);
	else
		XtPopup(dObject->dialogShell, XtGrabNone);
}	/* dialog_activate */


/*
dialog_deactivate() removes the dialog box.
*/

void dialog_deactivate(dObject)
Dialog dObject;
{
	XtPopdown(dObject->dialogShell);
}	/* dialog_deactivate */


/*
dialog_modal_prompt() maps the dialog box, waits for a response,
and returns the (integer) index of the chosen button, zero-based.
It does not return the value of the client data stored with the
chosen button.  See dialog_activate() for an alternative approach
for activating a dialog box.
*/

int dialog_modal_prompt(dObject, prompt)
Dialog dObject;
char *prompt;
{
	if (dObject->modal_dialog) {
		if (dObject->dialogText && !dObject->remember_string_response)
			XmTextSetString(dObject->dialogText, "");	/* clean slate */

		position_dialog(dObject);
		dialog_set_prompt(dObject, prompt);
		popup_and_wait_for_button_response(dObject);
		return dObject->button_pressed;
	}
	else
		return dialog_BTN_NULL;
}	/* dialog_modal_prompt */


/*
dialog_set_prompt() allows the application to set the
dialog box's prompt, independent of invoking the dialog
box.  The temporary `XmString' variable is freed--this
function could be called a zillion times.
*/

void dialog_set_prompt(dObject, prompt)
Dialog dObject;
char *prompt;
{
	if (prompt && *prompt) {
		Arg args[1];
		XmString str_prompt = XmStringCreateLtoR(prompt, dObject->char_set);

		XtSetArg(args[0], XmNlabelString, (XtArgVal) str_prompt);
		XtSetValues(dObject->dialogPrompt, args, 1);	/* fixed */
		XmStringFree(str_prompt);
	}
}	/* dialog_set_prompt */


/*
dialog_get_text() returns the user's string response from
the text edit widget.  The caller must free the text with
XtFree().  Note that string response may not be enabled for
a particular dialog box instance.
*/

char *dialog_get_text(dObject)
Dialog dObject;
{
	return (dObject->dialogText) ?
		(char *) XmTextGetString(dObject->dialogText) : NULL;
}	/* dialog_get_text */


/*
dialog_set_text() allows the application to set, or update,
the user's string response from the text-edit widget.
*/

void dialog_set_text(dObject, string)
Dialog dObject;
char *string;
{
	if (dObject->dialogText && string && *string)
		XmTextSetString(dObject->dialogText, string);
}	/* dialog_set_text */


/*
dialog_forget_text() modifies the behavior of a dialog box
with a string-response field, so that the dialog is mapped each
time with an empty text entry field.
*/

void dialog_forget_text(dObject)
Dialog dObject;
{
	dObject->remember_string_response = False;
}	/* dialog_forget_text */


/*
dialog_remember_text() modifies the behavior of a dialog box
with a string-response field, so that the dialog is mapped each
time without clearing the text entry field.
*/

void dialog_remember_text(dObject)
Dialog dObject;
{
	dObject->remember_string_response = True;
}	/* dialog_remember_text */


/*
dialog_get_most_recent_button_response() returns the user's most
recent button response/selection.
*/

XtPointer dialog_get_most_recent_button_response(dObject)
Dialog dObject;
{
	return dObject->most_recent_button_data;
}	/* dialog_get_most_recent_button_response */


/*
dialog_cancel() can be used to cancel a dialog box without
waiting for a user's response. For example, if the user selects
the window manager's "Close" button in a modal dialog, the
application can call this function to terminate the dialog.
In most cases, the application will interpret this action to
be equivalent to selecting one of the dialog's button, for
example, the "Cancel" button.
*/

void dialog_cancel(dObject, button_pressed)
Dialog dObject;
int button_pressed;
{
	dObject->button_pressed = button_pressed;
	XtPopdown(dObject->dialogShell);
}	/* dialog_cancel */


/*
For the following functions dialog_<widget_name>() returns
the widget IDs of the internal widgets.  Many of these
aren't really needed and could be deleted.  Using macros is
another possibility.  And, of course, Xt provides functions
for obtaining this information.
*/

Widget dialog_dialogShell(dObject)
Dialog dObject;
{
	return dObject->dialogShell;
}	/* dialog_dialogShell */


Widget dialog_instance(dObject)
Dialog dObject;
{
	return dObject->instance;
}	/* dialog_instance */


Widget dialog_class(dObject)
Dialog dObject;
{
	return dObject->class;
}	/* dialog_class */


Widget dialog_dialogPane(dObject)
Dialog dObject;
{
	return dObject->dialogPane;
}	/* dialog_dialogPane */


Widget dialog_dialogControl(dObject)
Dialog dObject;
{
	return dObject->dialogControl;
}	/* dialog_dialogControl */


Widget dialog_dialogPrompt(dObject)
Dialog dObject;
{
	return dObject->dialogPrompt;
}	/* dialog_dialogPrompt */


Widget dialog_dialogText(dObject)
Dialog dObject;
{
	return dObject->dialogText;
}	/* dialog_dialogText */


Widget dialog_dialogAction(dObject)
Dialog dObject;
{
	return dObject->dialogAction;
}	/* dialog_dialogAction */


/*
Private callback functions:
*/

/*
DialogDismiss() is a private callback that removes
the dialog box.
*/
/*ARGSUSED*/
static void DialogDismiss(w, client_data, call_data)
Widget w;
XtPointer client_data;
XtPointer call_data;
{
	Dialog dObject = (Dialog) client_data;

	XtPopdown(dObject->dialogShell);
}	/* DialogDismiss */


/*
UpdateButtonResponse() is a private callback that records
the data associated with the most recent button selection.
It also sets an indicator variable that signals that a
button has been selected; the latter is used only with
dialogs configured for modal behavior.
*/
/*ARGSUSED*/
static void UpdateButtonResponse(w, client_data, call_data)
Widget w;
XtPointer client_data;
XtPointer call_data;
{
	Dialog dObject = (Dialog) client_data;
	Arg args[1];
	XtPointer user_data;
	int i;

	XtSetArg(args[0], XmNuserData, &user_data);
	XtGetValues(w, args, 1);	/* fixed */
	dObject->most_recent_button_data = user_data;
	for (i = 0; i < dObject->num_buttons; i++)
		if (w == dObject->buttons[i]) {
			dObject->button_pressed = i;
			break;
		}
}	/* UpdateButtonResponse */


/*
Private support functions:
*/

/*
popup_and_wait_for_button_response() is called to
synchronize execution for a modal dialog.
*/

static void popup_and_wait_for_button_response(dObject)
Dialog dObject;
{
	dObject->button_pressed = dialog_BTN_NULL;
	XtPopup(dObject->dialogShell, XtGrabExclusive);
	while (dObject->button_pressed == dialog_BTN_NULL) {
		XEvent event;

		XtAppNextEvent(dObject->app, &event);
		XtDispatchEvent(&event);
	}
}	/* popup_and_wait_for_button_response */


/*
position_dialog() positions the dialog on the screen.  Currently, this
function does not enforce any dialog placement policy.  That is, it
allows the programmer to position a top-level shell, even though it
is generally accepted that this should be left up to the user--the
programmer is in control.
*/

static void position_dialog(dObject)
Dialog dObject;
{
	Arg args[3];
	int i;
	Dimension width, height;

/*	if (dObject->max_win_mgr)
		return;*/
	if (dObject->dialog_position == dialog_DEFAULT)
		return;
	if (!XtIsRealized(dObject->dialogShell))
		return;
	i = 0;
	XtSetArg(args[i], XmNwidth, &width); i++;
	XtSetArg(args[i], XmNheight, &height); i++;
	XtGetValues(dObject->dialogShell, args, i);
	if (dObject->dialog_position == dialog_CENTER) {
		Screen *screen = XtScreen(dObject->dialogShell);

		i = 0;
		XtSetArg(args[i], XmNx,
			(XtArgVal) ((XWidthOfScreen(screen) - (int) width) / 2)); i++;
		XtSetArg(args[i], XmNy,
			(XtArgVal) ((XHeightOfScreen(screen) - (int) height) / 2)); i++;
	}
	else if (dObject->dialog_position == dialog_POINTER) {
		Window dummy_win;
		int root_x, root_y, dummy_xy;
		unsigned int dummy_keys;

		XQueryPointer(XtDisplay(dObject->dialogShell),
			XtWindow(dObject->dialogShell),  &dummy_win, &dummy_win,
			&root_x, &root_y, &dummy_xy, &dummy_xy, &dummy_keys);
		/*
		Motif will keep it on-screen:
		*/
		i = 0;
		XtSetArg(args[i], XmNx, (XtArgVal) (root_x - ((int) width / 2))); i++;
		XtSetArg(args[i], XmNy, (XtArgVal) (root_y - ((int) height / 2))); i++;
	}
	XtSetValues(dObject->dialogShell, args, i);
}	/* position_dialog */