164) How do I have more buttons than three in a box? I want to have
something like a MessageBox (or other widget) with more than three buttons,
but with the same nice appearance.
[Last modified: May 93]
Answer: The Motif 1.2 MessageBox widget allows extra buttons to be added after
the OK button. Just create the extra buttons as children of the MessageBox.
Similarly with the SelectionBox.
Pre-Motif 1.2, you have to do one of the following methods.
A SelectionBox is created with four buttons, but the fourth (the Apply button)
is unmanaged. To manage it get its widget ID via
XmSelectionBoxGetChild(parent, XmDIALOG_APPLY_BUTTON) and then XtManage it.
Unmanage all of the other bits in the SelectionBox that you don't want. If
you want more than four buttons, try two SelectionBoxes (or similar) together
in a container, where all of the unwanted parts of the widgets are unmanaged.
Alternatively, build your own dialog:
/* Written by Dan Heller. Copyright 1991, O'Reilly && Associates.
* This program is freely distributable without licensing fees and
* is provided without guarantee or warranty expressed or implied.
* This program is -not- in the public domain. This program is
* taken from the Motif Programming Manual, O'Reilly Volume 6.
*/
/* action_area.c -- demonstrate how CreateActionArea() can be used
* in a real application. Create what would otherwise be identified
* as a PromptDialog, only this is of our own creation. As such,
* we provide a TextField widget for input. When the user presses
* Return, the Ok button is activated.
*/
#include <Xm/DialogS.h>
#include <Xm/PushBG.h>
#include <Xm/PushB.h>
#include <Xm/LabelG.h>
#include <Xm/PanedW.h>
#include <Xm/Form.h>
#include <Xm/RowColumn.h>
#include <Xm/TextF.h>
typedef struct {
char *label;
void (*callback)();
caddr_t data;
} ActionAreaItem;
static void
do_dialog(), close_dialog(), activate_cb(),
ok_pushed(), cancel_pushed(), help();
main(argc, argv)
int argc;
char *argv[];
{
Widget toplevel, button;
XtAppContext app;
toplevel = XtVaAppInitialize(&app, "Demos",
NULL, 0, &argc, argv, NULL, NULL);
button = XtVaCreateManagedWidget("Push Me",
xmPushButtonWidgetClass, toplevel, NULL);
XtAddCallback(button, XmNactivateCallback, do_dialog, NULL);
XtRealizeWidget(toplevel);
XtAppMainLoop(app);
}
/* callback routine for "Push Me" button. Actually, this represents
* a function that could be invoked by any arbitrary callback. Here,
* we demonstrate how one can build a standard customized dialog box.
* The control area is created here and the action area is created in
* a separate, generic routine: CreateActionArea().
*/
static void
do_dialog(w, file)
Widget w; /* will act as dialog's parent */
char *file;
{
Widget dialog, pane, rc, label, text_w, action_a;
XmString string;
extern Widget CreateActionArea();
Arg args[10];
static ActionAreaItem action_items[] = {
{ "Ok", ok_pushed, NULL },
{ "Cancel", cancel_pushed, NULL },
{ "Close", close_dialog, NULL },
{ "Help", help, "Help Button" },
};
/* The DialogShell is the Shell for this dialog. Set it up so
* that the "Close" button in the window manager's system menu
* destroys the shell (it only unmaps it by default).
*/
dialog = XtVaCreatePopupShell("dialog",
xmDialogShellWidgetClass, XtParent(w),
XmNtitle, "Dialog Shell", /* give arbitrary title in wm */
XmNdeleteResponse, XmDESTROY, /* system menu "Close" action */
NULL);
/* now that the dialog is created, set the Close button's
* client data, so close_dialog() will know what to destroy.
*/
action_items[2].data = (caddr_t)dialog;
/* Create the paned window as a child of the dialog. This will
* contain the control area (a Form widget) and the action area
* (created by CreateActionArea() using the action_items above).
*/
pane = XtVaCreateWidget("pane", xmPanedWindowWidgetClass, dialog,
XmNsashWidth, 1,
XmNsashHeight, 1,
NULL);
/* create the control area (Form) which contains a
* Label gadget and a List widget.
*/
rc = XtVaCreateWidget("control_area", xmRowColumnWidgetClass, pane, NULL);
string = XmStringCreateSimple("Type Something:");
XtVaCreateManagedWidget("label", xmLabelGadgetClass, rc,
XmNlabelString, string,
XmNleftAttachment, XmATTACH_FORM,
XmNtopAttachment, XmATTACH_FORM,
NULL);
XmStringFree(string);
text_w = XtVaCreateManagedWidget("text-field",
xmTextFieldWidgetClass, rc, NULL);
/* RowColumn is full -- now manage */
XtManageChild(rc);
/* Set the client data "Ok" and "Cancel" button's callbacks. */
action_items[0].data = (caddr_t)text_w;
action_items[1].data = (caddr_t)text_w;
/* Create the action area -- we don't need the widget it returns. */
action_a = CreateActionArea(pane, action_items, XtNumber(action_items));
/* callback for Return in TextField. Use action_a as client data */
XtAddCallback(text_w, XmNactivateCallback, activate_cb, action_a);
XtManageChild(pane);
XtPopup(dialog, XtGrabNone);
}
/*--------------*/
/* The next four functions are the callback routines for the buttons
* in the action area for the dialog created above. Again, they are
* simple examples, yet they demonstrate the fundamental design approach.
*/
static void
close_dialog(w, shell)
Widget w, shell;
{
XtDestroyWidget(shell);
}
/* The "ok" button was pushed or the user pressed Return */
static void
ok_pushed(w, text_w, cbs)
Widget w, text_w; /* the text widget is the client data */
XmAnyCallbackStruct *cbs;
{
char *text = XmTextFieldGetString(text_w);
printf("String = %s0, text);
XtFree(text);
}
static void
cancel_pushed(w, text_w, cbs)
Widget w, text_w; /* the text field is the client data */
XmAnyCallbackStruct *cbs;
{
/* cancel the whole operation; reset to NULL. */
XmTextFieldSetString(text_w, "");
}
static void
help(w, string)
Widget w;
String string;
{
puts(string);
}
/*--------------*/
/* When Return is pressed in TextField widget, respond by getting
* the designated "default button" in the action area and activate
* it as if the user had selected it.
*/
static void
activate_cb(text_w, client_data, cbs)
Widget text_w; /* user pressed Return in this widget */
XtPointer client_data; /* action_area passed as client data */
XmAnyCallbackStruct *cbs; /* borrow the "event" field from this */
{
Widget dflt, action_area = (Widget)client_data;
XtVaGetValues(action_area, XmNdefaultButton, &dflt, NULL);
if (dflt) /* sanity check -- this better work */
/* make the default button think it got pushed. This causes
* "ok_pushed" to be called, but XtCallActionProc() causes
* the button appear to be activated as if the user selected it.
*/
XtCallActionProc(dflt, "ArmAndActivate", cbs->event, NULL, 0);
}
#define TIGHTNESS 20
Widget
CreateActionArea(parent, actions, num_actions)
Widget parent;
ActionAreaItem *actions;
int num_actions;
{
Widget action_area, widget;
int i;
action_area = XtVaCreateWidget("action_area", xmFormWidgetClass, parent,
XmNfractionBase, TIGHTNESS*num_actions - 1,
XmNleftOffset, 10,
XmNrightOffset, 10,
NULL);
for (i = 0; i < num_actions; i++) {
widget = XtVaCreateManagedWidget(actions[i].label,
xmPushButtonWidgetClass, action_area,
XmNleftAttachment, i? XmATTACH_POSITION : XmATTACH_FORM,
XmNleftPosition, TIGHTNESS*i,
XmNtopAttachment, XmATTACH_FORM,
XmNbottomAttachment, XmATTACH_FORM,
XmNrightAttachment,
i != num_actions-1? XmATTACH_POSITION : XmATTACH_FORM,
XmNrightPosition, TIGHTNESS*i + (TIGHTNESS-1),
XmNshowAsDefault, i == 0,
XmNdefaultButtonShadowThickness, 1,
NULL);
if (actions[i].callback)
XtAddCallback(widget, XmNactivateCallback,
actions[i].callback, actions[i].data);
if (i == 0) {
/* Set the action_area's default button to the first widget
* created (or, make the index a parameter to the function
* or have it be part of the data structure). Also, set the
* pane window constraint for max and min heights so this
* particular pane in the PanedWindow is not resizable.
*/
Dimension height, h;
XtVaGetValues(action_area, XmNmarginHeight, &h, NULL);
XtVaGetValues(widget, XmNheight, &height, NULL);
height += 2 * h;
XtVaSetValues(action_area,
XmNdefaultButton, widget,
XmNpaneMaximum, height,
XmNpaneMinimum, height,
NULL);
}
}
XtManageChild(action_area);
return action_area;
}
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