by Charles Williams

One of the major reasons that Mac

applications seem so interactive is that

they are “event driven” that is, the user

can freely redirect the program to a com-

pletely different activity at any time with

just a single mouse click. The ability to

easily create a customized user menu

facility that supports this kind of behavior

is one of the features that distinguishes

the Macversion of Foxbase from its DOS

cousins. Faxbase /Mac not only provides

the commands to build a custom menu

facility that meets Mac standards, but it

also provides a menu “trap” that reacts

automatically and immediately to a user

mouse click on any menu command.

Since Foxbase responds to “menu hits”

whenever the currently executing pro-

gram encounters a READ, a program

containing a looping construct with a

READ in it will give what appears to be

instantaneous response to a menu click.

Although Fox hasn’t provided a slick

graphically-based tool for this purpose, as

they do for screen building and report

generation, the five commands and two

special functions used to create a menu

facility are not difficult to understand and

use. Based on the description in a recent

George Goley column, building a menu

facility in FoxPro with similar behavior is

far more complex. However, since the

Fox documentation in this area leaves

something to be desired, and since it does

take some experimenting to get a proper-

ly working menu, I offer the following

very condensed description as an ap-

proach that works. I think it will get you

on the right track the first time you have

to create a menu.

This approach contains five basic

steps. The objective is to construct a

menu bar across the top of the display

screen, with each menu on that bar having

an associated set of individual commands

that are activated by just sliding the

mouse to the desired one and releasing,

and with immediate action or program

redirection corresponding to the chosen

command. The result will be two

programs - one becomes part of the in-

itialization routine of the application, and

the other is a separate menu processing

program. Foxbase commands support

two ways of thinking about menus; this

approach thinks in terms of arrays - the

menu bar isan array and each set of menu

commands is an array.

In Step 1 you dimension the menu

bar, name the individual menus, and use

a specific menu command to “install” the

menu bar.

DIMENSION mbartop(4)

mbartop(1) = Plain”

mbartop(2) = “Fancy”

mbartop(3) = “Fancier

mbartop(4) = “Very Fancy”

MENU BAR mbaitop

You have now told Foxbase to make

a menu bar with 4 separate, named

menus at the top of the screen.

In Step 2 you dimension, name and

install the list of commands on each of

those 4 menus. Here are two samples:

DIMENSION mbarl (3)

mbarl(1) = “First”

mbarl(2) = “Second’

mbarl(3) = ‘Third”

MENU 1, mbarl

DIMENSION mbar3(4)

mbar3(1) = “Primary”

mbar3(2) = “Secondary”

mbar3(3) = ‘Tertiary”

mbar3(4) = “Quaternary”

MENU 3, mbar3

You have now told Foxbase that the

menu in position 1 in the menu bar has

three commands, and the one in position

3 has 4 commands.

In Step 3 you add a submenu (hierar-

chical menu) to one of the commands on

menu three. The approach is the same,

but the install command uses a different

option.

DIMENSION sub3l(4)

sub3l(1) = ‘Number One’

sub3l (2) = ‘Number Two”

sub3l (3) = “Number Three’

sub3l (4) = ‘Number Four

MENU 3, sub3l,4,1

You have now told Foxbase that there

is a submenu with 4 commands attached

to the first command on the menu in

position 3 on the menu bar.

In Step 4you install the menu trap and

make a connection to a menu processing

program. This step uses a special menu

command and two special functions

designed just for this purpose. (This is the

command that FoxPro doesn’t have yet.)

ON MENU DO menuproc.prg;

WITH MENU(O), MENU(1)

You have now told Foxbase that

whenever the user clicks a menu, it should

transfer control to the menuproc pro-

gram, and pass it the contents of two

MENU functions. The first function

returns the number of the menu the user

clicked, and the second function returns

the number of the particular command

on that menu. One puzzling question

that is not treated in the documentation

is what the MENU functions return in the

case of submenus. By experiment it

seems that MENU(O) returns the next

number beyond the last full menu, so the

best approach to keep the menu numbers

straight is to define the whole set of

menus first and then define the sub-

menus. You can easily check the num-

bers by just running a debug window to

watch the MENU(O) and MENU(1)

functions as you click the menu

In Step 5 you build the menuproc pro-

gram to take action based on the users

choice. This program is usually nothing

continued on page 14

LA. FOX

The Other Foxbase

Foxbase +/Mac

L.A. FOX

A monthly publication of the

Los Angeles FoxPro/Foxbase User Group

Published at

2616 Vargas Way

Redondo Beat CA 90278

(213)371-6035

This newsletter is designed to provide

a forum for users of FoxPro, Foxbase +,

and Foxbase+/Mac to share informa-

tion, perspectives, and techniques.

Please note: This group has no formal

connection with Fox Software, Inc..

Opinions expressed and liberties taken

herein are the sole responsibility of the

direct perpetrators. Don’t blame Fox

Software.

Editor Greg Dunn

Newsletter Design and Production

Gay Dunn

LA. FOX St eering Committee:

President: Greg Dunn

Treasurer George Dvorak

Mem&r Benefits Randy Unruh

Secretary: Charles Williams

Member-at-Large Kris Dahhn

Please send newsletter material to:

Greg Dunn

2616 Vargas Way

Redondo Beach, CA 90278

(213)371.6035

All contents Copyright 1990 by LA.

Fox, unless indicated otherwise.

2