TweetFollow Us on Twitter

Using Controls
Volume Number:1
Issue Number:4
Column Tag:Forth Forum

Using Controls

By Jörg Langowski

In this month’s column I want to introduce to you some concepts of control handling on the Macintosh under MacForth. Controls, as you might have guessed by now, are a very basic concept of the Macintosh user interface: a major part of mouse input to an application is done through controls.

The four main types of controls that show up to you when you work with an application are buttons, check boxes, radio buttons and dials, and these are the ones that we will be talking about this time.

All control handling routines are built into the toolbox ROM. Therefore, one can call them - in principle - from any programming environment as toolbox traps. MacForth, of course, makes this job a little easier by providing a large number of predefined routines. Interestingly enough, most of these routines are already present in Version 1.1, even though the manual says that 1.1 does not support controls. I suppose this was a typo. They wanted to say that it does not document controls. Well, the Inside Macintosh manual does that very extensively and as you will see, it is not hard to transfer those concepts into Forth.

Let’s first look at the definitions of the four control types, as they are given in IM:

Buttons are the little rounded rectangles that have a text inside. When you click a button with the mouse, you tell the application to perform some action as shown in the example below.

“Yes” and “No” are buttons and you may choose either one.

Check boxes show the state of a parameter that can be on or off, and can be clicked on/off with the mouse:

Radio buttons are sets of buttons, only one of which may be on. They are used to set and display parameters that can assume discrete values or states, such as integer numbers:

Dials, the scroll bar being the most familiar example, are used to set and display a parameter that can change continuously (or quasi-continuously, such as the position in a text file).

Generating a control in your active window is very simple, it requires only one toolbox call. Just putting a control into a window like that, however, is useless. You can click and point at it as long as you wish, it won’t do anything unless you tell it what to do. Clicking a control only generates an event that your program has to recognize. For instance, if a radio button is clicked you have to make sure that the corresponding parameter is set on and all others that belong to the same group of radio buttons are turned off. If the page region in a scroll bar is clicked you have to tell the system what to do, change the parameter value and show the scroll bar with its new value.

But then, there is not much more to do. The Control Manager will auto- matically determine if you clicked a control and which one, and will also ‘track’ the control, that is, display it changing while you perform some action on it with the mouse. It will also, if appropriate, inactivate a control, which is then displayed in a different way and any actions on it are ignored (like the scroll bars in the Finder windows if all the icons fit into the window).

Let’s assume we want to generate a window that contains the following controls:

• a scroll bar that can be changed through a range from 0 to 300

• a check box that is used to turn the scroll bar on and off.

An example program that does these functions is given below, and most of it should be self-explanatory. The Toolbox function NewControl that creates a new control in a window, however, has to be explained in a little more detail.

It expects 10 parameters on the stack, from bottom to top:

- 4 bytes for the function result ControlHandle

- WindowPtr, the pointer to the window that the new control belongs to

- boundsRect, the address of a rectangle that gives the control’s size and location in the window’s local coordinates

- title, a pointer to the control’s title

- visible, a boolean value (16 bit); if TRUE, the control is actually drawn inside the window, otherwise, it’s invisible

- value, a 16-bit integer, the control’s initial value

- min, 16-bit integer, the control’s minimum value

- max, 16-bit integer, the control’s maximum value

- procID, 16-bit integer, a number that defines the type of control:

- 0 - simple button, 1 - check box, 2 - radio button, 16 - scroll bar.

- refCon, 32-bit integer, a number that you may use as a unique reference number; it is not used by the Control Manager at all.

This set of parameters is rather impressive, and you can immediately see that none of the standard toolbox trap defining words in MacForth can be used to call this function. First, only function calls with at most one parameter are supported, for the others you have to include space for the result on the stack and use the MT defining word. Second, there are five 16-bit parameters between 32-bit ones, and Forth normally pushes 32-bit items on the stack.

MacForth 2.0 has the word ADD.CONTROL built in, which is called with the stack set up like above, only the integers are all 32-bit. ADD.CONTROL then converts visible, value, min, max, and procID to 16 bits and calls NewControl, which creates the control. However, if you have MacForth 1.1, you can define your own ADD.CONTROL by using the 16-bit push PUSHW that was defined in the last MacTech. The example below contains the definitions of PUSHW and ADD.CONTROL.

The scroll bar that we define is horizontal. The up button and page-up regions of a horizontal bar are on the left side, but the bar is incremented to the right (an inconsistency in the Control Manager). Therefore the program decrements the control’s value when the up button is clicked and increments it on the down button.

The only other control in the example is a check box that turns the scroll bar on and off. I have not included simple buttons or radio buttons; you may want to try them out on your own by setting procID to different values. Remember, if you define a set of radio buttons, your program has to keep track of which one is on and turn the others off. There is no way how the Control Manager could know which buttons belong to the same group.

( Demo program for using the Control Manager from Mac Forth )
( © 1985  MacTutor by J. Langowski  )

( pushw, new.control ) hex
: pushw s0 @ >R sp@ 2- s0 ! sp! r> s0 ! drop ;
A954 mt (new.control)
: add.control
  >r ( refCon )   >r ( procID )  >r ( max )   >r ( min )   >r ( value 
)
  pushw  ( visible ) r> pushw  ( value )
  r> pushw  ( min )  r> pushw ( max ) r> pushw  ( procID )  r> ( refCon 
)
 (new.control)  ;

( test window for new.control )              ( JL Jan 1985 )
decimal  new.window my.window  50 100 200 450 my.window w.bounds
close.box size.box + my.window w.attributes   my.window add.window
50 50 75 300 rect my.scroll
( set up scroll bar )
0 my.window my.scroll 
“  “ ( no title )
 -1  ( visible=true )
100  ( value )
0    ( min )
300  ( max )
16   ( procID for scroll bar )
here ( to get a unique ref # )
add.control 
constant my.control in.heap ( so that handle is released when FORGETting 
)

( on/off box for test window )
25 50 40 200 rect button.a.rect ( check box )
0 my.window button.a.rect “  Scroll Bar Off” -1 0 0 1 1 ( check box ) 

here add.control
constant my.button in.heap   my.window show.controls
80 50 95 150 rect text.rect  ( for output )

( control tracking )
( track control, given a control handle and mouse position, tracks a 
control )
: my.track this.control @ @mouse track.control ;

( get.control, given a control handle, gets the value of that control 
)
: show.value my.control get.control text.rect erase.rect
             0 textfont  50 90 move.to .” Value:” . .”    “  ;

( set.control, given a control handle and an integer, sets the control 
to 
  that integer value )

( scroll bar )
: do.thumb  my.track drop get.window show.controls show.value ;
: inc.scroll this.control @ dup get.control 1+ set.control show.value 
;
: dec.scroll this.control @ dup get.control 1- set.control show.value 
;
: inc10.scroll this.control @ dup get.control 10 + set.control show.value 
;
: dec10.scroll this.control @ dup get.control 10 - set.control show.value 
;

( scroll bar )
: do.scroll.bar  case in.thumb of  do.thumb   endof
           up.button of dec.scroll endof  down.button of inc.scroll endof
           page.up of dec10.scroll endof  page.down of inc10.scroll endof
                 endcase  ;


( check box )
( hilite.control, given control handle and integer value, sets the control
 active if value=0 and inactive if value=255 ) 
: do.button drop my.track if this.control @ dup get.control 1 swap -
                         my.control over 255 * hilite.control set.control 
then
     get.window show.controls ;

( control actions )
: do.controls swap  case my.control of  do.scroll.bar endof
                         my.button  of  do.button endof
                    endcase ;

( event loop for test window )
: my.action show.value if begin do.events
                          case mouse.down of  @mouse.dn get.window
                             find.control ?dup if do.controls then endof
                          endcase again
  else .” My Window Deactivated” then ;

my.window on.activate my.action

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

SpamSieve 2.9.37 - Robust spam filter fo...
SpamSieve is a robust spam filter for major email clients that uses powerful Bayesian spam filtering. SpamSieve understands what your spam looks like in order to block it all, but also learns what... Read more
Viber 11.3.1 - Send messages and make fr...
Viber lets you send free messages and make free calls to other Viber users, on any device and network, in any country! Viber syncs your contacts, messages and call history with your mobile device, so... Read more
Monosnap 3.6.1 - Versatile screenshot ut...
Monosnap lets you capture screenshots, share files, and record video and .gifs. Features Capture Capture full screen, just part of the screen, or a selected window Make your crop area pixel... Read more
WhatRoute 2.2.6 - Geographically trace o...
WhatRoute is designed to find the names of all the routers an IP packet passes through on its way from your Mac to a destination host. It also measures the round-trip time from your Mac to the router... Read more
MacFamilyTree 9.0.5 - Create and explore...
MacFamilyTree gives genealogy a facelift: modern, interactive, convenient and fast. Explore your family tree and your family history in a way generations of chroniclers before you would have loved.... Read more
WhatsApp 0.3.4375 - 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
Mactracker 7.8.1 - Database of all Mac m...
Mactracker provides detailed information on every Mac computer ever made, including items such as processor speed, memory, optical drives, graphic cards, supported OS X versions, and expansion... Read more
Boom 3D 1.3.1 - 3D surround sound and ph...
Boom 3D is a revolutionary app with 3D Surround Sound and phenomenally rich and intense audio that is realistic and works on any headphones. Features 3D surround sound Built-in audio player... Read more
OmniGraffle 7.11.2 - Create diagrams, fl...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
OmniGraffle Pro 7.11.2 - Create diagrams...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more

Latest Forum Discussions

See All

Steam Link Spotlight - Dicey Dungeons
Steam Link Spotlight is a new feature where we take a look at PC games that play exceptionally well with the Steam Link app. In case you missed it, our last entry focused on Faeria, a collectible card game that used to be available on the App Store... | Read more »
I can't believe Sky came out after...
I play games almost exclusively on mobile, and I’ve been doing so since around the time I started writing for 148Apps. This is why I’m late to the party on Journey. It wasn’t until last week that the game was playable on mobile, and it wasn’t until... | Read more »
Gigantic X guide - What you need to know...
Gigantic X continues to inspire loot lust over here at 148Apps, particularly because the game has already been updated just in its second week of release. Unfortunately, this 1.1.0 patch doesn’t bring a whole ton of new goodies with it, but it does... | Read more »
Steam Link Spotlight - Faeria
If you’ve been following 148Apps.com for a while, chances are you’ve seen me talk about Faeria. I reviewed it when it initially came out on iOS, and again when The Adventure Pouch: Oversky came out. I also put the game on my best games of 2017 list... | Read more »
Gigantic X guide - Tips and tricks for b...
Gigantic X has only been out for a little over a week, but it’s shaping up to be the mobile loot shooter of our dreams. That said, it’s not exactly the most friendly game out there. We noted in our review that you need to invest some time in the... | Read more »
Do Not Feed The Monkeys is one of the mo...
I’ve done a lot of messed up stuff in video games. I’ve beat people to death, slaghtered innocent animals, and even committed genocide. In doing all of that though, I’m not sure I’ve felt as uncomfortable as I have while playing Do Not Feed The... | Read more »
Civilization VI - What you need to know...
Last week, the mobile version of Civilization VI got updated to include the huge Rise and Fall expansion. Where previous updates to the game provided one or two new civilizations and maybe a few scenarios, Rise and Fall makes sweeping changes to... | Read more »
Combo Quest (Games)
Combo Quest 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: Combo Quest is an epic, time tap role-playing adventure. In this unique masterpiece, you are a knight on a heroic quest to retrieve... | Read more »
Hero Emblems (Games)
Hero Emblems 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: ** 25% OFF for a limited time to celebrate the release ** ** Note for iPhone 6 user: If it doesn't run fullscreen on your device... | Read more »
Puzzle Blitz (Games)
Puzzle Blitz 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Puzzle Blitz is a frantic puzzle solving race against the clock! Solve as many puzzles as you can, before time runs out! You have... | Read more »

Price Scanner via MacPrices.net

Price drop! B&H now has new 4-Core Mac mi...
B&H Photo has dropped prices on 2018 4-Core Mac minis to $100 off MSRP, only $699. They’re also offering a $100 discount on the 6-Core Mac mini. Shipping is free: – 3.6GHz Quad-Core mini: $699 $... Read more
Amazon is offering a 37% discount on Apple Sm...
Amazon has Apple Smart Keyboards for current-generation 10″ iPad Airs and previous-generation 10″ iPad Pros on sale today for $99.99 shipped. That’s a 37% discount over Apple’s regular MSRP of $159... Read more
12″ iPad Pros on sale today for up to $400 of...
Amazon has new 2018 Apple 12″ iPad Pros in stock today and on sale for up to $400 off Apple’s MSRP. These are the same iPad Pros sold by Apple in its retail and online stores. Be sure to select... Read more
Apple has 2019 iMacs, Certified Refurbished,...
Apple has Certified Refurbished 2019 21″ & 27″ iMacs now available starting at $929 and up to $350 off the cost of new models. Apple’s one-year warranty is standard, shipping is free, and each... Read more
Sale! New 11″ WiFi iPad Pros for up to $400 o...
Walmart has new 2018 Apple 11″ WiFi iPad Pros in stock today and on sale for up to $400 off Apple’s MSRP. These are the same iPad Pros sold by Apple in its retail and online stores. Choose free local... Read more
New 2019 15″ 2.3GHz 8-Core MacBook Pro on sal...
Apple resellers B&H Photo and Amazon are offering the new 2019 15″ 2.3GHz Silver 8-Core MacBook Pro for $2449. That’s $350 off Apple’s MSRP and the lowest price available for an 8-Core MacBook... Read more
B&H has new 4-Core and 6-Core Mac minis o...
B&H Photo has the new 2018 4-Core and 6-Core Mac minis on sale for $80-$100 off Apple’s standard MSRP. Shipping is free: – 3.6GHz Quad-Core mini: $719 $80 off MSRP – 3.0GHz 6-Core mini: $999 $... Read more
10″ iPad Airs on sale for up to $50 off Apple...
B&H Photo has new 10.5″ iPad Airs on sale today for $30-$50 off Apple’s standard MSRP including free overnight shipping to many address in the US: – 10.5″ 64GB WiFi iPad Air: $469 $30 off MSRP –... Read more
Apple has clearance 2018 13″ 2.3GHz Quad-Core...
Apple has Certified Refurbished 2018 13″ 2.3GHz 4-Core Touch Bar MacBook Pros available starting at $1489. Apple’s one-year warranty is included, shipping is free, and each MacBook has a new outer... Read more
Clearance 2018 13″ MacBook Airs drop to an al...
B&H Photo has clearance 2018 13″ MacBook Airs available for $300 off Apple’s original MSRP with prices starting at only $899. Overnight shipping, or expedited shipping, is free depending on your... Read more

Jobs Board

*Apple* Mobility Pro - Best Buy (United Stat...
**719892BR** **Job Title:** Apple Mobility Pro **Job Category:** Store Associates **Location Number:** 001096-Grove City-Store **Job Description:** At Best Buy, our Read more
Best Buy *Apple* Computing Master - Best Bu...
**719975BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Location Number:** 001198-East Orange-Store **Job Description:** The Read more
*Apple* Mobile Master - Best Buy (United Sta...
**721421BR** **Job Title:** Apple Mobile Master **Job Category:** Store Associates **Location Number:** 000878-Dubuque-Store **Job Description:** **What does a Best Read more
Best Buy *Apple* Computing Master - Best Bu...
**716411BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Location Number:** 001089-Watertown-Store **Job Description:** **What does a Read more
*Apple* Mobility Pro - Best Buy (United Stat...
**721359BR** **Job Title:** Apple Mobility Pro **Job Category:** Store Associates **Location Number:** 000952-Baytown-Store **Job Description:** At Best Buy, our Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.