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.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Capo 3.2 - Slow down and learn to play y...
Capo lets you slow down your favorite songs so you can hear the notes and learn how they are played. With Capo, you can quickly tab out your songs atop a highly-detailed OpenCL-powered spectrogram... Read more
OmniOutliner 4.2.3 - Organize your ideas...
OmniOutliner is a flexible program for creating, collecting, and organizing information. Give your creativity a kick start by using an application that's actually designed to help you think. It's... Read more
pwSafe 4.0.1 - Secure password managemen...
pwSafe provides simple and secure password management across devices and computers. pwSafe uses iCloud to keep your password databases backed-up and synced between Macs and iOS devices. It is... Read more
WALTR 1.5.4 - Drag-and-drop any media fi...
WALTR is designed to make it easy to upload and convert any music or video file to an iPad or iPhone format for native playback. It supports a huge variety of media file types, including MP3, MP4,... Read more
Audio Hijack 3.1 - Record and enhance au...
Audio Hijack (was Audio Hijack Pro) drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio... Read more
PopChar 7.1 - Floating window shows avai...
We're also selling a 5-license family pack for only $25.99! PopChar helps you get the most out of your font collection. With its crystal-clear interface, PopChar X provides a frustration-free way to... Read more
BBEdit 11.1.1 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
Picasa 3.9.139 - Organize, edit, and sha...
Picasa and Picasa Web Albums allows you to organize, edit, and upload your photos to the Web from your computer in quick, simple steps. Arrange your photos into folders and albums and erase their... Read more
Mac DVDRipper Pro 5.0.5 - Copy, backup,...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
NetShade 6.2 - Browse privately using an...
This promotion is for NetShade and 1 year of Proxy and VPN services NetShade is an anonymous proxy and VPN app+service for Mac. Unblock your Internet through NetShade's high-speed proxy and VPN... Read more

Block Fortress has a Big New Update for...
Block Fortress is a survival-style game that's as fun as it is blocky. It's also just gotten a rather sizeable update that adds a lot more cool stuff. [Read more] | Read more »
Simple and Surreal Star Base Sim rymdkap...
I really like rymdkapsel. Not just because I'm a sucker for games that are cleverly simple or highly stylisitc, but because it's fun and challenging. Actually it's extremely challenging, which is why I was excited to learn that it's getting a couple... | Read more »
Check out the anticipated Angel Stone in...
Fincon has finally revealed Angel Stone in action in the first ever official gameplay trailer for the anticipated hack and slasher. Angel Stone is set in a post-apocalyptic world in which humanity is in danger of being wiped out by the demonic... | Read more »
Moleskine Timepage is an All-New Calenda...
Moleskine Timepage is a bit of a departure for the notebook manufacturer (since it has little to do with notebooks), but it certainly carries their simple and elegant style quite well. [Read more] | Read more »
Jog on Over and Check Out the New Runtas...
Runtastic has put out a fair number of apps to help you sleep, track excercise, and train various parts of your body. Now it's time for your legs to have their own time in the spotlight with Runtastic Leg Trainer. [Read more] | Read more »
It's Lights Out in the Upcoming Pla...
Ember’s Journey is a stark puzzle platformer with a twist: the entire game is played in darkness. The only light you can see by is the one emanating from your own character. [Read more] | Read more »
MooVee - Your Movies Guru (Entertainmen...
MooVee - Your Movies Guru 1.0 Device: iOS iPhone Category: Entertainment Price: $1.99, Version: 1.0 (iTunes) Description: MooVee helps you effortlessly manage your movies, on your iPhone. | Read more »
Geometry Wars 3: Dimensions (Games)
Geometry Wars 3: Dimensions 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: Enjoy the next chapter in the award-winning Geometry Wars franchise and enjoy stunning, console-quality... | Read more »
CHAOS RINGS Ⅲ (Games)
CHAOS RINGS Ⅲ 1.0.0 Device: iOS Universal Category: Games Price: $19.99, Version: 1.0.0 (iTunes) Description: The newest addition to the popular smartphone RPG series is finally here! ・CHAOS RINGS Overview | Read more »
The Popular Insight Series of Travel Gui...
Getting around in a country when you can't understand the primary language can be tough. Fortunately there are several options available to help wold travellers with the important stuff like giving directions to a cab driver or asking where the... | Read more »

Price Scanner via MacPrices.net

Apple restocks refurbished Mac minis for up t...
The Apple Store has restocked Apple Certified Refurbished 2014 Mac minis, with models available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz... Read more
13-inch 2.4GHz Retina MacBook Pro (refurbishe...
The Apple Store has 2013 Apple Certified Refurbished 13″ 2.4GHz/128GB Retina MacBook Pros available for $879–$320 off original MSRP. Apple’s one-year warranty is standard, and shipping is free: - 13... Read more
Apple refurbished iPad Air 2s now available f...
The Apple Store is now offering Apple Certified Refurbished iPad Air 2s for up to $140 off the price of new models. Apple’s one-year warranty is included with each model, and shipping is free: -... Read more
MacBook Airs on sale for up to $80 off MSRP
Save up to $80 on the purchase of a new 2015 13″ or 11″ 1.6GHz MacBook Air at the following resellers. Shipping is free with each model: 11" 128GB MSRP $899 11" 256GB... Read more
Free Glide Live Video Messaging App Brings Ne...
Glide, an Israeli startup whose popular live video messenger has attracted more than 15 million users, has released significant updates to its free iOS app. Glide for iOS now gives users more control... Read more
Top Markets Saturation To Slow Global Smartph...
According to a new mobile phone forecast from the International Data Corporation (IDC) Worldwide Quarterly Mobile Phone Tracker, smartphone shipments are expected to grow 11.3% in 2015 — down from 27... Read more
Apple’s Education discount saves up to $300 o...
Purchase a new Mac or iPad at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free,... Read more
13-inch 2.5GHz MacBook Pro (refurbished) avai...
The Apple Store has Apple Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.... Read more
Apple refurbished 2014 13-inch Retina MacBook...
The Apple Store has Apple Certified Refurbished 2014 13″ Retina MacBook Pros available for up to $400 off original MSRP, starting at $979. An Apple one-year warranty is included with each model, and... Read more
What Would the ideal Apple Productivity Platf...
For the past four years I’ve kept a foot in both the Mac and iPad camps respectively. my daily computing hours divided about 50/50 between the two devices with remarkable consistency. However, there’... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Program Manager, *Apple* Community Support...
**Job Summary** Apple Support Communities ( discussions. apple .com) helps customers get the most from their Apple products and services by providing access to Read more
Senior Data Scientist, *Apple* Retail - Onl...
**Job Summary** Apple Retail - Online sells Apple products to customers around the world. In addition to selling Apple products with unique services such as iPad Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
*Apple* Watch SW Application Project Manager...
**Job Summary** The Apple Watch software team is looking for an Application Engineering Project Manager to work on new projects for Apple . The successful candidate Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.