TweetFollow Us on Twitter

Easy FKEY
Volume Number:8
Issue Number:2
Column Tag:Pascal Workshop

Related Info: File Manager Event Manager

FKEYs in THINK Pascal, Easy

Have you ever had to restart because a file was left open? No more! Read on.

By Roy Lovejoy, Sunnyvale, California

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

About the author

Roy Lovejoy is a Software Engineer at Calera Recognition Systems. He was previously working at Claris Corporation as one of the MacWrite II engineers. This is his first article for MacTutor. What do you think?

A Bit of History

When the Macintosh arrived on the scene in February of 1984, the world knew it was unique; its profile, screen, and keyboard were all different from the then-standard IBM PC. One of the attributes that IBM-ers scoffed at was the lack of "Function keys". You know function keys, those funky little buttons that do an infinitely many different things (depending on which program you are running). Well, we have news for the scoffers. The Macintosh has had function keys, or FKEY’s as they are called, since its inception.

The FKEY’s that were included were ones to eject the internal and external floppy disk, take a snapshot of the screen and save it to a MacPaint file, and print the screen, or the front window. These FKEY’s were assigned numbers 1 , 2, 3, and 4 respectively and were triggered by the Command key followed by the associated digit. Since the introduction of different size and depth screens, and printers, they of course had to be modified. Many people have written other useful FKEY's, and some have become very well known (i.e., switch-a-roo).

FKEY's are a pretty safe bet. Since they are trapped during a GetNextEvent or WaitNextEvent, they are available in a large percentage of applications. Since Desk Accessories are going the way of the brontosaurus, or so they say, FKEY’s are (hopefully) a safe utility feature in the future.

General

Now these function keys are in no way difficult to code. They are just simply different to code. I have found that if I need a utility, an FKEY is always my first choice, then comes a Desk Accessory, then an Application. (You don’t have all of the DRVR problems that are inherent in a desk accessory.) Basically an FKEY is a procedure that has no true globals (true globals are ones that are referenced off of the 68000 register A5) and is compiled to an 'FKEY' resource. There are many safe, and many sneaky ways to have a 'global' area, but that will be good subject matter for a future article.

An FKEY can be completely Modal - it might simply bring up a Dialog and let you set/reset a value, or it can have a robust user interface, complete with menus and windows. This article will describe the former.

In THINK Pascal, an FKEY is simply a unit that is compiled into a resource, of type FKEY. See figure for Project Setup. The unit must have the entry procedure be called ‘main’ and have no parameters. There must not be a ‘program’. See Figure 1.

Figure 1: Set Project Dialog (set for FKEY #5)

Why did I write this?

As an applications programmer I have many times (read > 300) written file I/O routines that save and retrieve program’s data structures. Naturally, in the course of human events, errors happen, sunspots appear, neutrinos expire, all after you open a data file, but before you get a chance to close it properly. This problem leads to a file, on your storage device, that is marked busy. This file can not be closed by your program (your variables have since committed electronic suicide, and your FileRefNum has gone with them), and you can not throw the file out, (because the busy bit is set). So, what do you do? Well, the busy bit is reset when the volume gets dismounted. That is acceptable for a floppy disk, but if it is your currently-booted hard disk, that poses a problem. What I wanted to do was an FSClose on the file, regardless of how it got opened. I was very frustrated, logged countless hours on networks looking for a utility to ease my woes. Finally I said, forget it, I’ll do it myself. Here it is.

What does it do?

Basically, when you (or any application) do an FSOpen or equivalent, memory is allocated for the file’s information. This FKEY simply tries to open the file; if the file is already open, it makes a parameter block call to get the file reference number, then uses that to close the file. If the file was not open originally, it is now because of the FSOpen, and so the FKEY goes ahead and closes it. A diagnostic dialog makes everything friendly.

A Bit of Style

The final resting place of an FKEY is either the System File or an exterior resource opened by a Suitcase-like program. This does not mean you can’t debug it elegantly. Oh, sure. “It’s a code resource. Those are hard to debug!!” I have some Arizona beach front property for you, too. What I do is have two Think projects. One has the standard Runtime.Lib and an extra file that is just a program stub that calls ‘Main’. I can then go on and debug in the glorious THINK environment. The other project has the DRVRruntime.lib and no ‘program’ file. This one has debugging turned off and the project type set to code resource. See Figures 2 and 3.

Figure 2: Project Set Up for debugging

Figure 3: Project Set Up for compiling

Listing

{======================}
unit FKEY;
{======================}
interface
{======================}
 procedure Main;
{======================}
implementation
{======================}
 procedure Main;
 var
 dlgOrigin: Point; {Top-left corner of dialog box}
 theReply: SFReply;{Data returned by SFGet dialog}
 theFile: INTEGER; {Reference number of file}
 resultCode: OSErr;{I/O error code}
 TypeList: SFTypeList;  {Type List to search for }
 Block: ParamBlockRec;  {Used to get file ref number}
 WIND: WindowPtr;{Display Window }
 bounds: Rect; {window rectangle Rectangle }
 OldPort: GrafPtr; {Graf Port set upon entry}
 dummy: LONGINT; {parameter of Delay}
{======================}
{ CenterDraw}
{ Input: String to Draw , line number to draw on.}
{ (String is centered horizontally on the window.)}
{======================}
 procedure CenterDraw (s: Str255; y: INTEGER);
 var
 x: INTEGER;
 begin
 with WIND^.portRect do
 begin
 x := (right + left) div 2 - StringWidth(s) div 2;
 MoveTo(x, y * 16);
 end;
 DrawString(s);
 end;
{======================}
 begin
 GetPort(OldPort);
 SetRect(bounds, 85, 40, 420, 100);
 WIND := NewWindow(nil, bounds, '', TRUE, dBoxProc, pointer(-1), FALSE, 
0);
 SetPort(WIND);
 TextFace([underline]);
 CenterDraw('Close File FKEY', 1);
 TextFace([]);
 CenterDraw('Select the file you wish to close.', 2);

 SetPt(dlgOrigin, 85, 120);         {Set up dialog origin}
 SFGetFile(dlgOrigin, '', nil, -1, TypeList, nil, TheReply);

 with TheReply do
 if good then
 begin
{Try to open file}
 resultCode := FSOpen(fname, vRefNum, theFile);
{if it was already open, get the file ref number}
 if resultCode = opWrErr then
 with Block do
 begin
 ioNamePtr := @fName;
 ioVRefNum := vRefNum;
 ioFDirIndex := -1;
 resultCode := PBGetFInfo(@Block, false);  {Get Finder info}
 theFile := ioFRefNum;
 CenterDraw(Concat('“', fName, '” is now closed.'), 3);
 end
 else
 CenterDraw(Concat('“', fName, '” was not open.'), 3);
{Do the actual closing... regardless if it was open before the FKEY or 
not}
 ResultCode := fsClose(theFile);
 end;
 Delay(45, dummy);{Wait a while 3/4 of second}

 DisposeWindow(WIND); {Close up}
 SetPort(OldPort);
 end;
{======================}
end.
{======================}

program Test;
 uses
 FKEY;
begin
 Main;
end.

 
AAPL
$100.86
Apple Inc.
-0.77
MSFT
$46.76
Microsoft Corpora
+0.52
GOOG
$579.95
Google Inc.
+6.85

MacTech Search:
Community Search:

Software Updates via MacUpdate

Capture One Pro 8.0.0.433 - RAW workflow...
Capture One Pro 8 is a professional RAW converter offering you ultimate image quality with accurate colors and incredible detail from more than 300 high-end cameras -- straight out of the box. It... Read more
Adobe Acrobat Pro 11.0.09 - Powerful PDF...
Adobe Acrobat allows users to communicate and collaborate more effectively and securely. Unify a wide range of content in a single organized PDF Portfolio. Collaborate through electronic document... Read more
Adobe Reader 11.0.09 - View PDF document...
Adobe Reader allows users to view PDF documents. You may not know what a PDF file is, but you've probably come across one at some point. PDF files are used by companies and even the IRS to... Read more
iFFmpeg 4.6.1 - Convert multimedia files...
iFFmpeg is a graphical front-end for FFmpeg, a command-line tool used to convert multimedia files between formats. The command line instructions can be very hard to master/understand, so iFFmpeg does... Read more
NTFS 11.3.62 - Provides full read and wr...
Paragon NTFS breaks down the barriers between Windows and OS X. Paragon NTFS effectively solves the communication problems between the Mac system and NTFS, providing full read and write access to... Read more
OS X Yosemite 10.10 DP8 - Developer Prev...
Note: This is a Developer Preview. You must be a registered Apple Mac Developer to download this update. You can also sign up for the free OS X Beta Program to download and preview public beta... Read more
FotoMagico 4.5 - Powerful slideshow crea...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
Screenshot Path 1.2.1 - Change the defau...
Screenshot Path lets you change the folder where OS X saves screenshots. Screenshots are saved by default to the user’s desktop. This is handy for the occasional screenshot but those looking to take... Read more
Fantastical 1.3.16 - Create calendar eve...
Fantastical is the Mac calendar you'll actually enjoy using. Creating an event with Fantastical is quick, easy, and fun: Open Fantastical with a single click or keystroke Type in your event details... Read more
GIMP 2.8.14 - Powerful, free image editi...
GIMP is a multi-platform photo manipulation tool. GIMP is an acronym for GNU Image Manipulation Program. The GIMP is suitable for a variety of image manipulation tasks, including photo retouching,... Read more

Latest Forum Discussions

See All

Zynga Unveils First Look at Looney Tunes...
Zynga Unveils First Look at Looney Tunes Dash! Posted by Ellis Spice on September 16th, 2014 [ permalink ] Be vewy, vewy qwiet. I’m hunting wunners featuwing wabbits, and luckily, it’s duck season wunner season. | Read more »
Guardians on the Go – How to Connect to...
At this point I’m relatively certain most of the country is familiar with Destiny. And for those looking to augment their game a bit, Bungie has changed their Bungie Mobile Companion App to Destiny Companion. | Read more »
Kunin Review
Kunin Review By Jordan Minor on September 16th, 2014 Our Rating: :: SHURIKEN DO ITUniversal App - Designed for iPhone and iPad Kunin is a nervous test of ninja reflexes.   Developer: Dodreams Price: FREE Version Reviewed: 1.0.1... | Read more »
4 KEMCO Titles are Just $0.99 for a Limi...
4 KEMCO Titles are Just $0.99 for a Limited Time Posted by Jessica Fisher on September 16th, 2014 [ permalink ] KEMCO RPGs Destiny Fantasia, Infinite Dunamis, Bonds of the Sk | Read more »
Introducing Flash, the Latest Wearable F...
Introducing Flash, the Latest Wearable Fitness Monitor from Misfit Posted by Jessica Fisher on September 16th, 2014 [ permalink ] The Misfit Flash is the newly-released fitness and sleep monitor from | Read more »
Hyper Trip Review
Hyper Trip Review By Jennifer Allen on September 16th, 2014 Our Rating: :: HYPER TWITCHYUniversal App - Designed for iPhone and iPad Tough and unforgiving, Hyper Trip is a bit like Snake – if Snake was really harsh.   | Read more »
Collectible Card Game Earthcore: Shatter...
Collectible Card Game Earthcore: Shattered Elements is Set to Arrive on iOS in 2015 Posted by Ellis Spice on September 16th, 2014 [ permalink ] Polish developers | Read more »
Boogey Boy Review
Boogey Boy Review By Jennifer Allen on September 16th, 2014 Our Rating: :: PRETTY BUT BASICUniversal App - Designed for iPhone and iPad It looks delightful but lack of Game Center support and more variety really affects the fun... | Read more »
Vizzywig 4K (Photography)
Vizzywig 4K 1.0 Device: iOS iPhone Category: Photography Price: $999.99, Version: 1.0 (iTunes) Description: REQUIRES: iOS 7 on iPhone 5S with 32GB or 64GB. (Do not use iOS 8)The world's FIRST mobile 4K video capture, editing and... | Read more »
The Sleeping Prince Review
The Sleeping Prince Review By Jennifer Allen on September 15th, 2014 Our Rating: :: RESTRICTIVE KINGDOM SAVINGUniversal App - Designed for iPhone and iPad The Sleeping Prince looks and feels great to play, but its lack of peril and... | Read more »

Price Scanner via MacPrices.net

2.5GHz Mac mini remains on sale for $549, sav...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Apple refurbished iMacs available for up to $...
The Apple Store has Apple Certified Refurbished iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... Read more
13″ 2.5GHz MacBook Pro offered for $100 off M...
B&H Photo has the 13″ 2.5GHz MacBook Pro on sale for $999.99 including free shipping plus NY sales tax only. Their price is $100 off MSRP. Read more
Free GIMP Professional Grade Graphics App Ver...
The latest 2.8.14 version of the oddly-named GIMP (acronym for: GNU Image Manipulation Program) open source, high-end image editing and creation alternative to Adobe’s Photoshop and refuge from... Read more
Apple Announces Record Pre-orders for iPhone...
Apple has released metrics showing a record number of first day pre-orders of iPhone 6 and iPhone 6 Plus, with over four million sold in the first 24 hours. Demand for the new iPhones exceeds the... Read more
10% off iPhone 6 and 6 Plus Otterbox cases
Get 10% off on popular Otterbox iPhone 6 and iPhone 6 Plus cases at MacMall through September 19th. Use code OTTERBOX10 to see the discount. Read more
15-inch MacBook Pros on sale for up to $125 o...
Amazon has the new 2014 15″ Retina MacBook Pros on sale for up to $125 off MSRP including free shipping: - 15″ 2.2GHz Retina MacBook Pro: $1899.99 save $100 - 15″ 2.5GHz Retina MacBook Pro: $2374... Read more
27-inch 3.2GHz iMac on sale for $1698, $101 o...
Abt has the 27″ 3.2GHz iMac on sale for $1698 including free shipping. Their price is $101 off MSRP. Read more
More To Making A Larger iPad Than Expanded Sc...
CNET’s Ross Rubin has posted a thoughtful analysis of prospects for a larger display iPad Pro, noting that Microsoft and Samsung currently have the large-display touchscreen tablet category to... Read more
SwiftKey Keyboard Finally Coming To iPhone An...
At the TechCrunch Disrupt event in San Francisco, Swiftkey unveiled the first details about SwiftKey Keyboard for iPhone, iPad & iPod touch. SwiftKey’s philosophy is that you should be able to... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.