TweetFollow Us on Twitter

Programming Menus
Volume Number:1
Issue Number:3
Column Tag:BASIC School

Programming Menus

By Dave Kelly

This month's BASIC School features programming menus on the MAC. One of the first things I do when I start a program is the menu. This way I'm sure that I know what I want to do in the program and it helps me to organize in a "top-down" fashion. Hopefully, after reading this you will know the basics of menu programming. The best thing is to experiment and test your own programs out using ideas you may gain from reading here.

First a bit of a rundown on the syntax for Programming menus in Microsoft BASIC (version 2.0). The statements we have at our disposal are:

• MENU menu-id, item-id, state   [,title-string]
• MENU 
• MENU RESET

Menu-id is a number from 1 to 10 representing the menu bar selected. Item-id is a number from 1 to 20 representing the menu item selected. If Item-id is 0, the entire menu is selected.

The words menu-id and item-id make good descriptive variable names for the functions they perform. Use 0 for state to disable the menu or menu item, 1 to enable it or 2 to enable it and place a check mark by it. The title-string ( optional ) is a string representing the title of the selected menu bar or the selected item in the menu.

The MENU command used by itself returns the current menu selection to normal black-on-white video. MENU RESET is used to set all the menu bars back to the menus used by BASIC. It is also a way to erase your custom menus when returning back to basic from a program.

Two more functions (called function syntax) are used to poll the status of the menu selection from within a program:

• MENU(0)
• MENU(1)

MENU(0) returns a number corr- esponding to the number of the last menu bar selection. Once it is executed, MENU(0) is reset to 0. MENU(1) returns a number which corresponds to the number of the last menu item selected. The function syntaxes are executed by setting the function equal to a variable (example: Menuid = MENU(0)). In most of the sample programs I have seen the variables Menuid and Itemid are used for MENU(0) and MENU(1) respectively. Any legal variable name could be used but these seem to describe the functions quite well.

OK, now we know all about menu commands. The example program was written to demonstrate the menu functions. I was hungry at the time I started writing the program, so you can see how it came out. The program sets up a lunch "menu" and asks you to select what you would like. If there isn't anything you like, the program could be modified to include just the things you like or even your own routines. Then when you have made which ever combination of lunch selections you may then "Eat it". After that you may return to make more selections, but only those items which have not been previously selected. When everything has been eaten or you are tired of eating, you may stop the program and return to BASIC.

Now a more detailed explaination of how the menu options are controlled in the program. The first 9 menu statements set up my custom menu. Since this is the first time that each item has been used I have given each menu item a name. If no name had been specified, the menu item would have been blank. To erase previous menu items you can use "" (Null) as the title-string option in each menu item you want to erase. Don't erase menus you may need later. It is better to deselect the menu or menu item with the state argument.

The menu-id is set to 6 because I use the 6th menu bar in order to preserve the BASIC menus. The BASIC menus could be written over and the new menu would take its place. The second argument, item-id, is numbered from 0 to 8, representing a different menu item. (A zero represents the entire menu). The state is set to 1 to enable each menu item.

After some setup of variables, the statement ON MENU GOSUB, enables event trapping for the menus. Event trapping will be covered at a later time, however for this case, this statement indicates what will happen as soon as any menu is selected. In this case, the program will jump to the subroutine named 'loop'. However, this event trapping is not enabled until the statement, MENU ON is executed. After the MENU ON statement the program goes into an infinite loop where it will wait for a menu to be selected. You should especially be careful when in infinite loops to be sure that there will eventually be some way to get out of the loop. If you had erased the BASIC menus and then somehow become stuck in a loop someplace, the only way out it the command-".". Beware when error trapping the break key (command-".") using the BREAK statements, there may be now way out of an endless loop without doing a system reset or turning off the power.

The program then jumps to the 'loop' routine. There the variables, MenuId and ItemId are set equal to the functions MENU(0) and MENU(1) so that the program can tell which of the menu items was selected. The ON ItemId GOSUB statement specifies which subroutine the selection will cause the program to branch to.

When the program begins, all of the items are selected, but none have a check mark by them. Take a look at one of the subroutines, say the starting at the label titled "Hamburger". Using labels makes it clear which routine does what, especially if the labels describe what the routine is about. All the routines are similar and will show the same technique. The var- iable 'Hamburger.select' is set to 1 to indicate that the menu is active, with no check mark. If the menu item is selected, the 'Hamburger.select' variable is toggled between 1 and 2 each time it is selected (unless the menu item has been disabled by setting the variable to 0. The MENU 6,3,Hamburger.select statement sets up the condition of the menu, 0 for disabled, 1 for enabled (no checkmark), 2 for enabled with checkmark. The 'Eat it' subroutine will disable any menus which have been enabled with the checkmark. This makes it impossible to eat more than one hamburger. (Fortunately, there is still alot of other things to eat.) If no items have been checked and 'Eat it' is selected from the menu, the entire menu is returned to the normal black-on white video with the MENU statement before exiting from the 'Eat it' routine.

After making the menu selection, the program branches back to the infinite loop where it started before being "event trapped" by the menu selection. When 'Stop' is selected, the program initiates the MENU RESET statement and returns to BASIC.

Since this program was designed for study (it serves no real function, especially since it isn't edible), I would advise that you use the trace and step functions to see just how each statement effects the program. If you want to get really creative you could have the program draw the food for you after each selection.

The program uses the method of looping in an infinite loop while waiting for a menu selection to interupt the loop. Another method which takes much more caution when writing the program involves using Event Trap Programming. This is explained briefly starting on page 68 of the Microsoft BASIC 2.0 manual (Advanced topics). Three commands, MENU ON, MENU OFF, MENU STOP are used liberally to determine when menus can be accessed and what events can occur when they are accessed. The problems occur when several menus call the same routines and use the same variables. When the menu is selected and event trapping is enabled, the menu will interupt the program wherever it is and go run the selected routine, possibly changing variables that were being used when the program was interupted. Event Trap Programming will be covered at a later time, hopefully when more of the basics of programming Macintosh BASIC have been covered. Next time we will open up some windows and explore some more keys to Programming BASIC on the MAC.


'----------------------------
'           Dave's Lunch Menu
'              by Dave Kelly
'      MACTECH  © February 1985
'----------------------------
MENU 6,0,1,"Dave's Menu"  'New menu
MENU 6,1,1,"Sandwich"
MENU 6,2,1,"Potato Chips"
MENU 6,3,1,"Hamburger"
MENU 6,4,1,"Hot Dog"
MENU 6,5,1,"Soda Pop"
MENU 6,6,1,"Ice Cream"
MENU 6,7,1,"Eat it"
MENU 6,8,1,"Stop"
Sandwich.select=1:Potato.select=1:
 Hamburger.select=1:Hot.select=1
 Soda.select=1:Ice.select=1:count=0
PRINT "What's for lunch?"
PRINT"Please Select from Dave's Menu."
ON MENU GOSUB loop
MENU ON
Pause:GOTO Pause   'Wait for menu selection in infinite loop
Loop:
MenuId = MENU(0)   'Menu # selected
ItemId = MENU(1)   'Item # selected
ON ItemId GOSUB Sandwich, Potato.Chips,Hamburger,Hot.Dog, Soda.Pop,Ice.Cream,Eat.it,Stopit
RETURN
Sandwich:
IF Sandwich.select=1 THEN Sandwich.select=2:GOTO Set.Sandwich
IF Sandwich.select=2 THEN Sandwich.select=1
Set.Sandwich:MENU 6,1,Sandwich.select
RETURN
Potato.Chips:
IF Potato.select=1 THEN Potato.select=2:GOTO Set.Potato
IF Potato.select=2 THEN Potato.select=1
Set.Potato:MENU 6,2,Potato.select
RETURN
Hamburger:
IF Hamburger.select=1 THEN Hamburger.select=2:GOTO Set.Ham
IF Hamburger.select=2 THEN Hamburger.select=1
Set.Ham:MENU 6,3,Hamburger.select
RETURN
Hot.Dog:
IF Hot.select=1 THEN Hot.select=2:GOTO Set.Hot
IF Hot.select=2 THEN Hot.select=1
Set.Hot:MENU 6,4,Hot.select
RETURN
Soda.Pop:
IF Soda.select=1 THEN Soda.select=2:GOTO Set.Soda
IF Soda.select=2 THEN Soda.select=1
Set.Soda:MENU 6,5,Soda.select
RETURN
Ice.Cream:
IF Ice.select=1 THEN Ice.select=2:GOTO Set.Ice
IF Ice.select=2 THEN Ice.select=1
Set.Ice:MENU 6,6,Ice.select
RETURN
Eat.it:
PRINT:PRINT"You have just eaten:"
old.count=count
IF Sandwich.select=2 THEN Sandwich.select=0: MENU 6,1,0:PRINT "Sandwich":count=count+1
IF Potato.select=2 THEN Potato.select=0: MENU 6,2,0:PRINT"Potato Chips":count=count+1
IF Hamburger.select=2 THEN Hamburger.select=0:MENU 6,3,0: PRINT"Hamburger":count=count+1
IF Hot.select=2 THEN Hot.select=0:MENU 6,4,0: PRINT"Hot Dog":count=count+1
IF Soda.select=2 THEN Soda.select=0:MENU 6,5,0:PRINT"Soda Pop":count=count+1
IF Ice.select=2 THEN Ice.select=0:MENU 6,6,0:PRINT"Ice Cream":count=count+1
IF count=6 THEN MENU 6,7,0:PRINT"The food is all gone."
IF old.count=count THEN PRINT"Nothing":MENU     ' Deselect current menu 
selection
RETURN
Stopit:MENU RESET      'reset the BASIC menu bars and then END the program
END

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Capto 1.2.9 - $29.99
Capto (was Voila) is an easy-to-use app that takes capturing, recording, video and image editing to the next level. With an intelligent file manager and quick sharing options, Capto is perfect for... Read more
Opera 51.0.2830.40 - High-performance We...
Opera is a fast and secure browser trusted by millions of users. With the intuitive interface, Speed Dial and visual bookmarks for organizing favorite sites, news feature with fresh, relevant content... Read more
GarageSale 7.0.13 - Create outstanding e...
GarageSale is a slick, full-featured client application for the eBay online auction system. Create and manage your auctions with ease. With GarageSale, you can create, edit, track, and manage... Read more
1Password 6.8.7 - Powerful password mana...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
Evernote 7.0.1 - Create searchable notes...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
MacUpdate Desktop 6.2.0 - $20.00
MacUpdate Desktop brings seamless 1-click app installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on... Read more
HoudahSpot 4.3.5 - Advanced file-search...
HoudahSpot is a versatile desktop search tool. Use HoudahSpot to locate hard-to-find files and keep frequently used files within reach. HoudahSpot will immediately feel familiar. It works just the... Read more
EtreCheck 4.0.4 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
WhatsApp 0.2.8361 - Desktop client for W...
WhatsApp is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for... Read more
iClock 4.2 - Customize your menubar cloc...
iClock is a menu-bar replacement for Apple's default clock but with 100x features. Have your Apple or Google calendar in the menubar. Have the day, date, and time in different fonts and colors in the... Read more

Latest Forum Discussions

See All

The best games like Florence
Florence is a great little game about relationships that we absolutely adored. The only problem with it is it's over a little too soon. If you want some other games with some emotional range like Florence, check out these suggestions: [Read more] | Read more »
Angry Birds Champions adds cash prizes t...
Collaborating with developer Rovio Entertainment, GSN Games has released a twist on the Angry Birds formula. Angry Birds Champions features the same bird-flinging gameplay, but now you can catapult Red and co for cash. | Read more »
Around the Empire: What have you missed...
148Apps is part of a family. A big family of sites that make sure you're always up to date with all the portable gaming news. Just like a real family, I guess. I don't know, my mum never told me anything about Candy Crush to be fair. [Read more] | Read more »
The Battle of Polytopia Guide - Tips for...
The addition of multiplayer to The Battle of Polytopia has catapulted the game from a fun enough time waster to a fully-fledged 4X experience on your phone. We've been playing quite a few matches over the past week or so, and we've put together a... | Read more »
All the best games on sale for iPhone an...
Hi there, and welcome to our round up of all the best games that are on sale for iOS at the moment. It's not a vintage week in terms of numbers, but I'm pretty sure that every single one of these is worth picking up if you haven't already played... | Read more »
Disc Drivin' 2 Guide - Tips for the...
We're all still playing quite a bit of Disc Drivin' 2 over here at 148Apps, and we've gotten pretty good at it. Now that we've spent some more time with the game and unlocked more powerups, check out some of these more advanced tips: | Read more »
Alto's Odyssey Guide - How to Tackl...
Alto’s Odyssey is a completely stunning and serene runner, but it can also be a bit tricky. Check out these to try and keep your cool while playing this endless runner: Don’t focus too much on tasks [Read more] | Read more »
Here's everything you need to know...
Alto's Odyssey is a really, really good game. If you don't believe me, you should definitely check out our review by clicking this link right here. It takes the ideas from the original Alto's Adventure, then subtly builds on them, creating... | Read more »
Alto's Odyssey (Games)
Alto's Odyssey 1.0.1 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.1 (iTunes) Description: Just beyond the horizon sits a majestic desert, vast and unexplored. Join Alto and his friends and set off on an endless... | Read more »
Vainglory 5v5: Everything you need to kn...
Vainglory just got bigger. [Read more] | Read more »

Price Scanner via MacPrices.net

Use your Apple Education discount and save up...
Purchase a new Mac using Apple’s Education discount, and take up to $400 off MSRP. All teachers, students, and staff of any educational institution with a .edu email address qualify for the discount... Read more
Apple Canada offers 2017 21″ and 27″ iMacs fo...
 Canadian shoppers can save up to $470 on the purchase of a 2017 current-generation 21″ or 27″ iMac with Certified Refurbished models at Apple Canada. Apple’s refurbished prices are the lowest... Read more
9″ iPads available online at Walmart for $50...
Walmart has 9.7″ Apple iPads on sale for $50 off MSRP for a limited time. Sale prices are for online orders only, in-store prices may vary: – 9″ 32GB iPad: $279.99 $50 off – 9″ 128GB iPad: $379.99 $... Read more
15″ Apple MacBook Pros, Certified Refurbished...
Save $360-$420 on the purchase of a 2017 15″ MacBook Pro with Certified Refurbished models at Apple. Apple’s refurbished prices are the lowest available for each model from any reseller. An standard... Read more
Amazon restocks MacBook Pros with models avai...
Amazon has restocked 15″ and 13″ Apple MacBook Pros with models on sale for up to $251 off MSRP. Shipping is free. Note that stock of some Macs may come and go (and some sell out quickly), so check... Read more
Lowest price of the year: 15″ 2.8GHz Apple Ma...
Amazon has the 2017 Space Gray 15″ 2.8GHz MacBook Pro on sale today for $251 off MSRP. Shipping is free: – 15″ 2.8GHz Touch Bar MacBook Pro Space Gray (MPTR2LL/A): $2148, $251 off MSRP Their price is... Read more
Apple restocks full line of Certified Refurbi...
Apple has restocked a full line of Apple Certified Refurbished 2017 13″ MacBook Pros for $200-$300 off MSRP. A standard Apple one-year warranty is included with each MacBook, and shipping is free.... Read more
Lowest sale price available for 13″ 1.8GHz Ma...
Focus Camera has the 2017 13″ 1.8GHz/128GB Apple MacBook Air on sale today for $829 including free shipping. Their price is $170 off MSRP, and it’s the lowest price available for a current 13″... Read more
21-inch 2.3GHz iMac on sale for $999, $100 of...
B&H Photo has the 2017 21″ 2.3GHz iMac (MMQA2LL/A) in stock and on sale for $999 including free shipping plus NY & NJ tax only. Their price is $100 off MSRP. Read more
Apple refurbished Mac minis in stock again st...
Apple has restocked Certified Refurbished Mac minis starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: – 1.4GHz Mac mini: $419 $80 off MSRP – 2.6GHz Mac... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 113523441 Orange, CA, California, United States Posted: 21-Feb-2018 Weekly Hours: 40.00 **Job Summary** Are you passionate Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.