TweetFollow Us on Twitter

About Box
Volume Number:7
Issue Number:1
Column Tag:Programmer's Workshop

The About Box

By Jack Edward Chor, Belleville, IL

This article presents a shell for creating a consistent and informative About dialog in your Macintosh™ applications. Although it is not the esoteric stuff of which Turing Awards are made, this shell does demonstrate the use of PICT resources and userItems in dialogs, the use of a filterProc function in a ModalDialog call, the wealth of information that is contained in a single call to SysEnvirons, and the ease with which the Sound Manager can be worked into dialogs. An example of the About dialog created by this shell is shown in Figure 1.

Figure 1

The dialog shown in Figure 1 consists of only two items. The first item is a PICT resource which draws everything shown in the dialog except the system information contained in the lower right-hand corner. The second item is a user item which draws the system information as returned from a SysEnvirons call.

The program was developed in Lightspeed™ Pascal and consists of six units. The build order and segmentation of the program are shown in Figures 2 and 3. The units used in the program are as follows:

1. xText. This is the interface file for the Text.lib library used in the program. A complete listing of the library is included in this article. The library consists of six short routines to display strings and integers in three different formats: left-justified, centered, and right-justified. There are two additional routines that get and set text-related grafPort parameters. All of these routines operate on the current grafPort.

2. Sound.p. This is the standard Sound Manager interface file included with Lightspeed Pascal.

3. About.Glob. This contains the global constants and variables used in the program.

4. About.Init. This contains the initialization routines for the program. This unit is contained in a separate segment so that it can be unloaded immediately after initialization is completed.

5. About.About. This contains the code for creating, displaying, and destroying the About dialog.

6. About.Main. This contains the event loop and menu dispatcher for the program. Since the purpose of this program is to merely illustrate the About dialog, the main unit is a bare-bones implementation of the classic Macintosh event loop.

At startup, the main program calls InitAbout to do initialization. Among other things, this routine loads the global variable AboutWorld with the SysEnvRec of the machine on which the program is running. In a fully functional program, a prudent programmer would screen AboutWorld at this point to determine whether the hardware and software configuration of the machine is acceptable to the program. After completing the initialization routine, UnloadSeg is called to unlock the initialization segment and free up the memory occupied by the initialization code. DoAboutBox is then called with the Boolean parameter PlayAboutSound set to TRUE. This displays the About dialog and tells the routine to load and play the ‘snd ‘ resource associated with the dialog box. Although the example program plays a melody on the note synthesizer, the sounds that can be played are limited only by the imagination of programmer and the capabilities of the Sound Manager. At the conclusion of the About melody, the About dialog is disposed and the program enters its event loop. The event loop looks for menu or command-key events and dispatches them through the DecodeMenu procedure. The program will terminate upon selection of the “Quit” menu item.

Figure 2

Figure 3

When DoAboutBox is called, the procedure first stores the current grafPort in the local variable oldPort. It then initializes the display rectangle for the dialog’s userItem. To display the system information retrieved from the SysEnvirons call in an understandable format, the numeric and Boolean fields of the SysEnvRec must be converted to character strings. This is done by the GetEnvStr procedure. GetEnvStr takes a SysEnvRec as a value parameter and returns an equivalent EnvStrList as a variable parameter. An EnvStrList is merely an array of seven strings, each representing an item of system information to be displayed in the About dialog. The names of the various Macintosh™ models, processors, and keyboards are stored in STR# resources. Because of peculiarities in the numeric values returned in the machineType and keyBoardType fields of the SysEnvRec, a one-to-one mapping between values of these fields and their corresponding indexed strings is not possible. Consequently, the numeric values must be modified slightly in order to get the correct index into the appropriate STR# resource. Also, the systemVersion field of the SysEnvRec returns the version number in a unique Apple format. As a result, a string conversion must be made. This is done in the GetSysVersStr function. Finally, in order to get the amount of free memory remaining, a call is made to PurgeSpace. This returns the total amount of memory which could be obtained by a general purge without actually doing the purge. It should be noted that this call is only available under the 128K ROM and can be replaced (less accurately) by the 64K ROM call FreeMem.

After the EnvStrList is returned from GetEnvStr, GetNewDialog is called to load the About dialog box into memory. When creating the dialog box in your resource editor, you should remember to make the dialog invisible. This will allow you to add the userItem to the dialog before the dialog box is actually displayed on the screen. After GetNewDialog loads the dialog into memory, a SetPort call makes the dialog the current grafPort. A SetDItem call is then used to place the userItem into the dialog’s item list. The userItem in the About dialog is a procedure called EnvItem. The only thing that EnvItem does is draw the strings in the EnvStrList in a column at the location specified in the constant declaration of the procedure. Since all of the dialog’s items are now in place, a call to ShowWindow is all that is needed to display it.

If PlayAboutSound is TRUE, this means that the calling program wants DoAboutBox to play the ‘snd ‘ resource associated with the dialog box. For some reason unbeknownst to your humble narrator, if the dialog box is not manually updated with the BeginUpdate-UpdtDialog-EndUpdate code sequence, the ‘snd ‘ resource will be played before anything is drawn in the dialog box. It should be noted that UpdtDialog is a 128K ROM call which can be replaced by the 64K ROM call DrawDialog. After the dialog box is drawn, a GetResource call loads the ‘snd ‘ and SndPlay plays it. After the sound is played, ReleaseResource is called to deallocate the memory used by the ‘snd ‘ resource. After the resource is released, DisposDialog makes the dialog disappear. If you want your dialog to hang around after the sound is played, simply remove the ELSE construct in the IF-THEN statement. If no sound is to be played, the sound routine is skipped and ModalDialog is called. The filterProc for the ModalDialog call is MouseKeyFilter. As its name implies and its code verifies, this filterProc waits for a mouseDown or keyDown event to occur. When one occurs, the filterProc function returns a nonzero value. This causes the the program to leave the REPEAT-UNTIL construct and call DisposDialog. Finally, SetPort is called to restore the grafPort which was current immediately prior to the DoAboutBox call.

Listing:  xText.p

UNIT xText;
INTERFACE
 PROCEDURE SetPortText (tFont, tSize, tMode: 
 INTEGER; tFace: Style);
 PROCEDURE GetPortText (VAR tFont, tSize, tMode: 
 INTEGER; VAR tFace: Style);
 PROCEDURE WriteTextAt (newH, newV: INTEGER;
 regStr: str255);
 PROCEDURE WriteNumAt (newH, newV: INTEGER;
 regNum: LONGINT);
 PROCEDURE WriteRJTextAt (newH, newV: INTEGER;
 regStr: str255);
 PROCEDURE WriteRJNumAt (newH, newV: INTEGER;
 regNum: LONGINT);
 PROCEDURE WriteCtrTextAt (newH, newV: INTEGER;
 regStr: str255);
 PROCEDURE WriteCtrNumAt (newH, newV: INTEGER;
 regNum: LONGINT);

IMPLEMENTATION
 CONST
 div2 = 1;
 VAR
 numStr: str255;

 PROCEDURE SetPortText;
 BEGIN
 WITH thePort^ DO
 BEGIN
 txFont := tFont;
 txSize := tSize;
 txMode := tMode;
 txFace := tFace;
 END;
 END;

 PROCEDURE GetPortText;
 BEGIN
 WITH thePort^ DO
 BEGIN
 tFont := txFont;
 tSize := txSize;
 tMode := txMode;
 tFace := txFace;
 END;
 END;

 PROCEDURE WriteTextAt;
 BEGIN
 WITH thePort^.pnLoc DO
 BEGIN
 h := newH;
 v := newV;
 END;
 DrawString(regStr);
 END;

 PROCEDURE WriteNumAt;
 BEGIN
 NumToString(regNum, numStr);
 WriteTextAt(newH, newV, numStr);
 END;

 PROCEDURE WriteRJTextAt;
 BEGIN
 newH := newH - StringWidth(regStr);
 WriteTextAt(newH, newV, regStr);
 END;

 PROCEDURE WriteRJNumAt;
 BEGIN
 NumToString(regNum, numStr);
 WriteRJTextAt(newH, newV, numStr);
 END;

 PROCEDURE WriteCtrTextAt;
 BEGIN
 newH := newH - BSR(StringWidth(regStr), div2);
 WriteTextAt(newH, newV, regStr);
 END;

 PROCEDURE WriteCtrNumAt;
 BEGIN
 NumToString(regNum, numStr);
 WriteCtrTextAt(newH, newV, numStr);
 END;

END.
Listing:  About.Glob

UNIT Glob;
INTERFACE
 CONST
 AboutMenu = 128;
 AboutItem = 1;
 QuitItem = 3;

 fSize9 = 9;

 toFront = -1;
 VAR
 AboutEvent: EventRecord;
 AboutWorld: SysEnvRec;

 AboutM: MenuHandle;

 TimeToQuit: BOOLEAN;
IMPLEMENTATION
END.
Listing:  Init.p

UNIT Init;
INTERFACE
 USES
 Glob;

 PROCEDURE InitAbout;

IMPLEMENTATION
 PROCEDURE InitAbout;
 CONST
 EnvReqNum = 2;
 VAR
 envErr: OSErr;
 BEGIN
 InitCursor;

 AboutM := GetMenu(AboutMenu);
 InsertMenu(AboutM, 0);
 DrawMenuBar;

 envErr := SysEnvirons(EnvReqNum, AboutWorld);

 TimeToQuit := FALSE;
 END;
END.
Listing:  About.About

UNIT About;
INTERFACE
 USES
 xText, Sound, Glob;

 PROCEDURE DoAboutBox (PlayAboutSound: BOOLEAN);

IMPLEMENTATION
 CONST
 macModel = 1;
 macSys = 2;
 macProc = 3;
 macFP = 4;
 macColorQD = 5;
 macKey = 6;
 macMemFree = 7;
 TYPE
 EnvStrList = ARRAY[macModel..macMemFree] OF str255;
 VAR
 envStr: EnvStrList;

 FUNCTION MouseKeyFilter (whichD: DialogPtr; VAR theEvent: EventRecord; 
VAR itemHit: INTEGER): BOOLEAN;
 CONST
 MKHit = 1;
 BEGIN
 MouseKeyFilter := FALSE;
 IF theEvent.what IN [keyDown, mouseDown] THEN
 BEGIN
 itemHit := MKHit;
 MouseKeyFilter := TRUE;
 END;
 END;

 PROCEDURE GetEnvStr (envWorld: SysEnvRec;
 VAR macEnvStr: EnvStrList);
 CONST
 MacNamesID = 1001;
 MacProcID = 1002;
 MacKeysID = 1003;

 unkS = ‘Unknown’;
 availS = ‘Available’;
 notAvailS = ‘Not Available’;

 PlusKbd = ‘Macintosh Plus’;
 XLKbd = ‘XL + Keypad’;

 oldM = 3;
 newM = 2;

 envMacIIcx = 6; {New constants}
 envSE30 = 7;
 envPortable = 8;
 envMacIIci = 9;

 env68030 = 4;

 envPortADBKbd = 6;
 envPortISOADBKbd = 7;
 envStdISOADBKbd = 8;
 envExtISOADBKbd = 9;
 VAR
 pTotal, pContig: LONGINT;
 FUNCTION GetSysVersStr (versNum: INTEGER): str255;
 CONST
 MajRevTenMask = $0000F000;
 MajRevOneMask = $00000F00;
 MinRevNumMask = $000000F0;
 BugFixNumMask = $0000000F;
 MajRevTenRot = 12;
 MajRevOneRot = 8;
 MinRevNumRot = 4;
 BugFixNumRot = 0;
 TenPlace = 10;
 VAR
 majRev, minRev, bugFix: LONGINT;
 decStr: str255;

 PROCEDURE AddNumToString (addNum: INTEGER;
 VAR numStr: str255; addDecPt: BOOLEAN);
 VAR
 tempStr: str255;
 BEGIN
 NumToString(addNum, tempStr);
 numStr := concat(numStr, tempStr);
 IF addDecPt THEN
 numStr := concat(numStr, ‘.’);
 END;

 BEGIN
 decStr := ‘’;
 majRev := BSR(BAND(versNum, MajRevTenMask),
 MajRevTenRot) * TenPlace;
 majRev := majRev + BSR(BAND(versNum, 
 MajRevOneMask), MajRevOneRot);
 minRev := BSR(BAND(versNum, MinRevNumMask), MinRevNumRot);
 bugFix := BSR(BAND(versNum, BugFixNumMask),
 BugFixNumRot);
 AddNumToString(majRev, decStr, TRUE);
 IF bugFix > 0 THEN
 BEGIN
 AddNumToString(minRev, decStr, TRUE);
 AddNumToString(bugFix, decStr,  FALSE);
 END
 ELSE
 AddNumToString(minRev, decStr, FALSE);
 GetSysVersStr := decStr;
 END;

 BEGIN
 WITH envWorld DO
 BEGIN
 CASE machineType OF
 envMac, envXL: 
 GetIndString(macEnvStr[macModel]
 , MacNamesID, machineType + oldM);
 env512KE..envMacIIci: 
 GetIndString(macEnvStr[macModel]
 , MacNamesID, machineType + newM);
 OTHERWISE
 macEnvStr[macModel] := unkS;
 END;
 macEnvStr[macSys] :=   GetSysVersStr(systemVersion);
 CASE processor OF
 env68000..env68030: 
 GetIndString(macEnvStr[macProc],
 MacProcID, processor);
 OTHERWISE
 macEnvStr[macProc] := unkS;
 END;
 IF hasFPU THEN
 macEnvStr[macFP] := availS
 ELSE
 macEnvStr[macFP] := notAvailS;
 IF hasColorQD THEN
 macEnvStr[macColorQD] := availS
 ELSE
 macEnvStr[macColorQD] := notAvailS;
 CASE keyBoardType OF
 envUnknownKbd: 
 IF machineType = envXL THEN
 macEnvStr[macKey] := XLKbd
 ELSE
 macEnvStr[macKey] :=   PlusKbd;
 envMacKbd..envExtISOADBKbd: 
 GetIndString(macEnvStr[macKey],
 MacKeysID, keyBoardType);
 OTHERWISE
 macEnvStr[macKey] := unkS;
 END;
 PurgeSpace(pTotal, pContig);
 NumToString(pTotal, macEnvStr[macMemFree]);
 END;
 END;

 PROCEDURE EnvItem (whichW: WindowPtr; whichItem: INTEGER);
 CONST
 envSpace = 12;
 envRMar = 364;
 envVStart = 210;
 VAR
 vCtr, currVLine: INTEGER;
 BEGIN
 SetPortText(geneva, fSize9, srcOr, []);
 currVLine := envVStart;
 FOR vCtr := macModel TO macMemFree DO
 BEGIN
 WriteRJTextAt(envRMar, currVLine, envStr[vCtr]);
 currVline := currVline + envSpace;
 END;
 END;

 PROCEDURE DoAboutBox;
 CONST
 AboutBoxID = 1001;
 AboutSoundID = 1001;
 infoItem = 2;
 drT = 201;
 drL = 279;
 drB = 284;
 drR = 371;
 noHit = 0;
 VAR
 AboutD: DialogPtr;
 AboutSnd: Handle;
 oldPort: GrafPtr;
 dispRect: Rect;
 itemHit: INTEGER;
 sndErr: OSErr;
 BEGIN
 GetPort(oldPort);
 WITH dispRect DO
 BEGIN
 left := drL;
 top := drT;
 right := drR;
 bottom := drB;
 END;
 GetEnvStr(AboutWorld, envStr);
 AboutD := GetNewDialog(AboutBoxID, NIL,
 DialogPtr(toFront));
 SetPort(AboutD);
 SetDItem(AboutD, infoItem, userItem,
 Handle(@EnvItem), dispRect);
 ShowWindow(AboutD);
 IF PlayAboutSound THEN
 BEGIN
 BeginUpdate(AboutD);
 UpdtDialog(AboutD, AboutD^.visRgn);
 EndUpdate(AboutD);
 AboutSnd := GetResource(‘snd ‘, AboutSoundID);
 sndErr := SndPlay(NIL, AboutSnd, FALSE);
 ReleaseResource(AboutSnd);
 END
 ELSE
 REPEAT
 ModalDialog(@MouseKeyFilter, itemHit);
 UNTIL itemHit <> noHit;
 DisposDialog(AboutD);
 SetPort(oldPort);
 END;
END.
Listing:  About.Main

PROGRAM AboutDemo;
 USES
 Glob, Init, About;
 VAR
 clickW: WindowPtr;
 keyChar: CHAR;
 PROCEDURE DecodeMenu (rawMenu: LONGINT);
 VAR
 theMenu, theItem: INTEGER;
 BEGIN
 theMenu := HiWord(rawMenu);
 IF theMenu = AboutMenu THEN
 BEGIN
 theItem := LoWord(rawMenu);
 CASE theItem OF
 AboutItem: 
 DoAboutBox(FALSE);
 QuitItem: 
 TimeToQuit := TRUE;
 END;
 HiliteMenu(0);
 END;
 END;

BEGIN
 InitAbout;
 UnloadSeg(@InitAbout);
 DoAboutBox(TRUE);
 REPEAT
 IF GetNextEvent(EveryEvent, AboutEvent) THEN
 WITH AboutEvent DO
 CASE AboutEvent.what OF
 mouseDown: 
 IF FindWindow(where, clickW) =
 inMenuBar THEN
 DecodeMenu(MenuSelect(where));
 keyDown: 
 BEGIN
 keyChar := chr(BAND(message, CharCodeMask));
 IF (BAND(modifiers, cmdKey)
 <> 0) AND (what <> autoKey) 
 THEN
 DecodeMenu(MenuKey(keyChar));
 END;
 END;
 UNTIL TimeToQuit;
END.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Latest Forum Discussions

See All

Can PokeMatch help you find love with Po...
The unofficial Pokemon GO companion app space has exploded almost as fast as the game itself over the last few weeks. Aspiring app developers, many of them working solo, have given us apps that locate Pokemon, keep track of the server status, and... | Read more »
How to get started with Prisma
If there's one thing people like to do more than taking pictures with their smartphones, it's tinkering with those photos in some way. Numerous apps have sprung up over the last several years that allow you to use filters and special effects to... | Read more »
6 Pokemon GO updates you can expect, acc...
Pokemon GO had a scheduled appearance at this year's San Diego Comic-Con for a while, but it was only relatively close to the show that it was upgraded to a spot in Hall H. That's the biggest venue at SDCC, one usually reserved for the largest... | Read more »
How to evolve Eevee in Pokemon GO
By now, almost everyone should be hip to how to evolve Pokemon in Pokemon GO (and if not, there's a guide for that). Just gather enough candy of the appropriate type, feed them all to the Pokemon, and evolution happens. It's a miracle that would... | Read more »
CSR Racing 2: Guide to all game modes
It might not seem like there are all that many ways to go fast in a straight line, but CSR Racing 2 begs to differ. [Read more] | Read more »
Bulb Boy (Games)
Bulb Boy 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Multi-award winning 2D point & click horror adventure about a boy with a glowing head. | Read more »
5 top free emoji keyboard apps
If we're not at peak emoji yet as a society, it feels like we definitely should be. The emoji concept has gone far beyond what anyone in Japan could have envisioned when the people there unleashed it on an unsuspecting world, but the West has... | Read more »
How to unlock more characters in Disney...
One of the big charms of Disney Emoji Blitz is seeing a wide variety of beloved Disney and Pixar characters transformed into smiling emojis. Even someone like the sneaky Randall from Monsters Inc., who probably never cracked a smile on film, is... | Read more »
Cubway (Games)
Cubway 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Cubway is a journey with an abstract story of lifecycle of rebirth, called Samsara. Guide the cube through the long way full of dangers... | Read more »
Colorcube (Games)
Colorcube 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Turn pieces and blend colours in this minimal yet visually stunning puzzler.Over 200 handcrafted and challenging levels. Features... | Read more »

Price Scanner via MacPrices.net

External Keyboard Innovations For iPad Pro (1...
I’m an input device aficionado. With non-touchscreen computers, which includes all Macs, the keyboard and mouse or trackpad are the tactile points of interface between user and machine, and the... Read more
GSK Rheumatoid Arthritis Study Leverages iPho...
Global healthcare products company GlaxoSmithKline (GSK) says that since 2014 they have begun transforming the way they conduct research, by leveraging state-of-the-art digital technologies — a... Read more
Clearance 12-inch Retina MacBooks, Apple refu...
Apple has Certified Refurbished 2015 12″ Retina MacBooks available starting at $929. Apple will include a standard one-year warranty with each MacBook, and shipping is free. The following... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina MacBook Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1199 $100 off MSRP - 13″ 2.7GHz/... Read more
13-inch 1.6GHz/128GB MacBook Air on sale for...
Amazon has the 13″ 1.6GHz/128GB MacBook Air on sale for $200 off MSRP for a limited time. Shipping is free: - 13″ 1.6GHz/128GB MacBook Air (sku MMGF2LL/A): $799.99 $200 off MSRP Their price is the... Read more
13-inch 1.6GHz/256GB MacBook Air on sale for...
Amazon has the 13″ 1.6GHz/256GB MacBook Air on sale for $200 off MSRP for a limited time. Shipping is free: - 13″ 1.6GHz/256GB MacBook Air (sku MMGG2LL/A): $999.99 $200 off MSRP Their price is the... Read more
Free iOS Business App notably* Helps Service...
PayStudio Inc. has introduced their new business app notably* 1.0, developed for iPhone and iPod touch. notably* was specifically developed to help service and trade professionals go digital and... Read more
27-inch iMacs on sale for $200 off MSRP
Amazon has 27″ iMacs on sale for $200 off MSRP including free shipping: - 27″ 3.3GHz iMac 5K: $2099 $200 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $1799.99 $200 off MSRP - 27″ 3.2GHz/1TB HD iMac 5K... Read more
Mac Pros on sale for $200 off MSRP
B&H Photo has Mac Pros on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2799, $200 off MSRP - 3.5GHz 6-core Mac Pro: $3799, $200... Read more
Save up to $600 with Apple refurbished Mac Pr...
Apple has Certified Refurbished Mac Pros available for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The following... Read more

Jobs Board

*Apple* Retail - Multiple Positions, Willow...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Evangelist - JAMF Software (United S...
The Apple Evangelist is responsible for building and cultivating strategic relationships with Apple 's small and mid-market business development field teams. This Read more
*Apple* Solutions Consultant - APPLE (United...
Job Summary As an Apple Solutions Consultant, you'll be the link between our future customers and our products. You'll showcase your entrepreneurial spirit as you Read more
*Apple* Professional Learning Specialist - A...
Job Summary The Apple Professional Learning Specialist is a full-time position for one year with Apple in the Phoenix, AZ area. This position requires a high Read more
*Apple* Picker - Apple Hill Orchard (United...
Apple Hill Orchard, Co. Rte. 21,Whitehall, NY 9/7/16-10/228/16. Pick fresh market or processing apples Productivity of 60 boxes and 80 boxes processing fruit per Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.