|
Volume Number: | 5 | |
Issue Number: | 6 | |
Column Tag: | Basic School |
Help for HELP Software
By Dave Kelly, MacTutor Editorial Board
In spite of the fact that Apple has referred to the Macintosh as the computer for “the rest of us”, there are some people that still have trouble with computers of any kind, even the Macintosh. I think that Macintosh users sometimes look for complexity that is not there. So there are many training courses, classes, etc. which may be taken to console those that may not feel comfortable with the application or system environment they are working with.
Many commercial application programs have developed help systems which allow the user to access on-line documentation of the application. The About menu item (in the Apple menu) is typically the place to go to find some kind of help information. Users look for and expect consistency as they divide their time across several applications. This consistent atmosphere is why Macintosh users tend to use more different software applications than other computer users. On other systems users select a group of 3-4 applications and learn them well, but don’t usually pick up other applications because of the time it takes to learn the new program’s layout and how to get it to work. With the Macintosh, the consistent placement of the menus in the standard order (Apple Menu, File Menu, Edit Menu, etc.) helps to reduce the learning curve of new applications.
Even with this consistency, users sometimes don’t have the manual handy or can’t quite remember everything that the application does. This is the purpose of the on-line documentation. Help Software has recognized the need for a consistent help system. They have devised a system which developers may use to create on-line documentation quickly and easy for the user to use. Zedcor uses this help system to support on-line help for the ZBasic compiler. By typing HELP or accessing the About ZBasic™ dialog, the HELP DA is accessed and the ZBasic Help file is opened. Applications may access the HELP DA directly and request that specific messages be displayed in the HELP DA window. These are referred to as context sensitive or extended alerts by the HELP system.
I’m sure you can see the benefits of having an on-line documentation system as part of your application. For example, the user can type cmd-? or hit the help button (on the extended keyboard) and then click or select some object or control in the current application and the help system will provide a help message specific to the object selected. This is the type of system that MS Word and some other Microsoft products have implemented. But with HELP Software’s DA, you don’t have to write the on-line help system, it’s already written for you.
It is the purpose of this column to introduce you to the HELP Software Desktop Help system and demonstrate a way to access context sensitive help messages from within your ZBasic application. Typically this involves more than just opening up the Help DA. Under Multifinder, DAs load via the DA Handler unless the option key is held down when the DA is selected. For context sensitive help or extended alert messages, the application program needs to pass the message number to the Help DA so that the desired message can be displayed.
The LS Pascal code is divided into two projects. The Help project calls the Help DA with the option key pressed. The ContextHelp project calls the Help DA with the option key pressed and receives a integer message number which is passed from the calling application. Both projects are similar except for the message being passed. This code originated from the C example that Help Software provides with the Desktop Help system. The major difference is that the C code is a function instead of a procedure. I changed to a procedure because ZBasic doesn’t provide an easy way to call a function. The CALL statement is meant for calling machine language or procedures from Pascal or C. Since it was tricky to get the return (error) value from the function, I decided to ignore the error and change to a procedure. The error flag would only be used to tell the user that the help system was not found or the help data file could not be loaded. An easier method may have been to rewrite the code to be executed directly in ZBasic. Due to time constraints I have not been able to try that yet; I’ll leave that to you.
Since DAs don’t load into the application space when Multifinder is active, the option key press is simulated. To do this the variable theKeyMap is used to pointed to the location $178 where the key map offset to the option key is located. Modifier keys themselves do not generate keyboard events (see Inside Macintosh, I-246). The Help Software programmer followed the GetKey procedure with TMON and found the “master KeyMap” (theKeyMap). He decided to simulate an Option key press by putting there he same thing that pressing and holding the key would. The location of the option key at $178 is not documented anywhere, but works on all ROMS from the 128K Mac thru the Plus, SE, II, IIx, and SE/30. If Apple doesn’t change the key mapping then there shouldn’t be any problem. One thing to remember is that if you press the option key this way, be sure to unpress the option key by changing theKeyMap back. The statement:
LongPtr(theKeyMap)^ :=BitOr(LongPtr(theKeyMap)^, 4);
presses the option key and:
LongPtr(theKeyMap)^ := 0;
releases the option key.
The help file is created with the Desktop Help system with the Help Editor. This file should be created after the application has been completely written, though may be updated and modified with the Help Editor throughout the entire development process. The file type of the help file should be set (with ResEdit) to the name of the creator of your application so that the help file which “belongs” to the application. DeskTop Help costs about $395 and allows you to edit your own on-line documentation files for any or all applications you desire (even commercial ones). To distribute the Help DA you pay a yearly license of $150 after the first year. The Help Editor should never be distributed, but can be purchased by anyone by buying the complete Desktop Help package.
The see how the context sensitive help works in the sample ZBasic program, press the cmd-? key to change the cursor to the “help mode”. The program will then respond to menu selections and call a specific message corresponding to the message set up in the help file. The help key or the About menu item will also select the help DA (with the option key pressed). If Multifinder is never used, the Help DA may be loaded directly without calling the Pascal procedure by using the OPENDESKACC function.
The ZBasic program loads the Pascal code into memory with the GETRESOURCE function. Next the code is locked in memory (so it won’t move on us) and the ZBasic CALL statement executes the code. We can execute the code resource directly because LightSpeed Pascal puts a branch to the actual code at the beginning of the code header. After executing the code, the code is unlocked and the handle is released to free up memory.
These routines may be used with Pascal programs and BASIC without a lot of time and effort. The whole idea is to save time and provide a consistent way for the user to access on-line documentation or help.
Desktop Help is available from Help Software, 10659A Maplewood Road, Cupertino, Calif. 95014, tel. 408-257-3815. NOT COPY PROTECTED!
unit getHelp; {Procedure for Calling the Help desk accessory } {for Context Sensitive Help and Extended Alert Messages} {{Copyright ©1988 , Help Software , Inc . } { Modified by Dave Kelly for MacTutor, April 1989 } { Source code in Lightspeed Pascal 2.0 } { This procedure will open the Help DA } { Under MultiFinder , this procedure will install the Help DA in * the } { application heap . } interface procedure main; implementation procedure main; type LongPtr = ^LONGINT; var error, Help: integer; { Help is the da refnum } myhandle: Handle; name: string; theKeyMap: longint; theKeyMapPtr: LongPtr; begin theKeyMap := $178; Help := 0; name := CONCAT(CHR(0), ‘Help’); SetResLoad(FALSE); { Don’t load it,} myhandle := GetNamedResource(‘DRVR’, name); { ...just get the handle } error := ResError; { -192 = Help not available } SetResLoad(TRUE); { Reset SetResLoad } if (error = noErr) then begin { Help is available} EmptyHandle(myhandle); { Try to purge the Help DA } if myhandle = nil then { If handle=NIL, it’s not loaded, } begin ResrvMem(SizeResource(myhandle)); { ...reserve memory for it } error := MemError; { -108 = Not enough room in heap } end; if error = noErr then { all go .. . } begin LongPtr(theKeyMap)^ := BitOr(LongPtr(theKeyMap)^, 4); { Required to work properly with MultiFinder } { Press the Option key } Help := OpenDeskAcc(name); { Open the Help DA } if (Help < 0) and (Help = (WindowPeek (FrontWindow)^.windowKind)) then { If the Help DA open } begin end { end if Is the Help DA open } else begin error := 1; { Let the caller know that the Help DA was not opened } LongPtr(theKeyMap)^ := 0; { Release the Option key } end; end else begin { Display an Alert : Not enough memory to open Help DA } end end {Help is Available } else begin { Display an Alert : Help DA not available } end; { End No Help Available} end; {of Help procedure } end.
unit getContextHelp; {Procedure for Calling the Help desk accessory } {for Context Sensitive Help and Extended Alert Messages} {{Copyright ©1988 , Help Software , Inc . } { Modified by Dave Kelly for MacTutor, April 1989 } { Source code in Lightspeed Pascal 2.0 } { This procedure will open the Help DA and pass it the number} {of the Help message to be displayed . } { Under MultiFinder , this procedure will install the Help DA in * the application heap . } interface procedure main (message: integer); { message: number of message to display } implementation procedure main (message: integer); type LongPtr = ^LONGINT; var error, Help: integer; {Help is desk accessory refnum } param: ParamBlockRec; {parameter blck for control call } myhandle: Handle; name: string; theKeyMap: longint; theKeyMapPtr: LongPtr; begin theKeyMap := $178; Help := 0; name := CONCAT(CHR(0), ‘Help’); SetResLoad(FALSE); { Don’t load it,} myhandle := GetNamedResource(‘DRVR’, name); error := ResError; { -192 = Help not available } SetResLoad(TRUE); { Reset SetResLoad } if (error = noErr) then begin { Help is available} EmptyHandle(myhandle); { Try to purge the Help DA } if myhandle = nil then { If handle=NIL, it’s not loaded, } begin ResrvMem(SizeResource(myhandle)); { ...reserve memory for it } error := MemError; { -108 = Not enough room in heap } end; if error = noErr then { all go .. . } begin LongPtr(theKeyMap)^ := BitOr(LongPtr(theKeyMap)^, 4); { Required to work properly with MultiFinder } { Press the Option key } Help := OpenDeskAcc(name); { Open the Help DA } if (Help < 0) and (Help = (WindowPeek(FrontWindow)^.windowKind)) then { If the Help DA open } begin param.ioCompletion := nil; param.ioRefNum := Help; { Help is the value returned} { by the OpenDeskAcc call } param.csCode := 5000; { 5000 tells the Help DA: “This is} {a context sensitive help call” } param.csParam[0] := message; { Help message to display } error := PBControl(@param, TRUE); { asynchronous control call tells Help DA what to show ! } end { end if Is the Help DA open } else begin error := 1; { Let the caller know that the Help DA was not opened } LongPtr(theKeyMap)^ := 0; { Release the Option key } end; end else begin { Display an Alert : Not enough memory to open Help DA } end end {Help is Available } else begin { Display an Alert : Help DA not available } end; { End No Help Available} { main:=error; for function} end; {of GetContextHelp ( message ) procedure } end.
‘This program demonstrates the use of the ‘ZBasic 5.0 CALL statement when calling ‘a (LS) PASCAL CODE resource. ‘©1989 MacTutor ‘By Dave Kelly WINDOW OFF COORDINATE WINDOW DEF MOUSE=-1 MOUSE ON BREAK ON DEFSTR LONG:T&=CVI(“CODE”) DEF LEN=255 DIM B%(7) GOSUB “Define Help Cursor” APPLE MENU “About Call Help” MENU 1,0,1,”File” MENU 1,1,1,”Open ” MENU 1,2,1,”Close” MENU 1,3,0,”-” MENU 1,4,1,”Save” MENU 1,5,1,”Save As ” MENU 1,6,0,”-” MENU 1,7,1,”Page Setup ” MENU 1,8,1,”Print ” MENU 1,9,0,”-” MENU 1,10,1,”Quit” EDIT MENU 2 Message%=0 ‘Set up string parameters HelpCursor%=0 ‘Find out screen size. CALL GETWMGRPORT(WMgrPort&) PortTop=PEEK WORD(WMgrPort&+8) PortLeft=PEEK WORD(WMgrPort&+10) PortBottom=PEEK WORD(WMgrPort&+12) PortRight=PEEK WORD(WMgrPort&+14) WINDOW 1,”Main Window”,(10,44)-(PortRight-4,PortBottom-4),5 GET WINDOW #1, WindowPtr& ON MENU GOSUB “Do MenuEvent” ON DIALOG GOSUB “Do DialogEvent” MENU ON:DIALOG ON:BREAK ON “Loop” CALL GETKEYS(B%(0)) LONG IF B%(2)=16 AND B%(3)=-32767 GOSUB “ChangeCursor” END IF GOTO “Loop” DIALOG OFF:MENU OFF “Do MenuEvent” Menunumber=MENU(0) Menuitem=MENU(1) MENU SELECT Menunumber CASE 255 Message%=0 GOSUB “Do Call” CASE 1 GOSUB “Do File Menu” END SELECT HelpCursor%=1 Message%=0 GOSUB “ChangeCursor” RETURN “Do File Menu” LONG IF HelpCursor%=0 SELECT Menuitem CASE 1 ‘Open CASE 2 ‘Close CASE 4 ‘Save CASE 5 ‘Save As CASE 7 ‘Page Setup DEF PAGE CASE 8 ‘Print DEF LPRINT CASE 10 ‘Quit GOTO “Quit” END SELECT XELSE SELECT Menuitem CASE 1 ‘Open Message%=1 GOSUB “Do Call” CASE 2 ‘Close Message%=2 GOSUB “Do Call” CASE 4 ‘Save Message%=4 GOSUB “Do Call” CASE 5 ‘Save As Message%=5 GOSUB “Do Call” CASE 7 ‘Page Setup Message%=7 GOSUB “Do Call” CASE 8 ‘Print Message%=8 GOSUB “Do Call” CASE 10 ‘Quit Message%=10 GOSUB “Do Call” END SELECT END IF RETURN “Quit” END “Do DialogEvent” D=DIALOG(0):DI=DIALOG(D) SELECT D CASE 1 ‘Button CASE 2 ‘Edit Field CASE 3 ‘Inactive Window CASE 4 ‘Close Box GOTO “Quit” CASE 5 ‘Window Update CASE 6 ‘Return Key CASE 7 ‘Tab Key CASE 8 ‘Zoom-in CASE 9 ‘Zoom-out CASE 10 ‘Shift-Tab CASE 11 ‘Clear Key CASE 12 ‘Left-Arrow CASE 13 ‘Right-Arrow CASE 14 ‘Up-Arrow CASE 15 ‘Down-Arrow CASE 16 ‘Event inkey$ IF DI=5 THEN GOSUB “Do Call” CASE 17 ‘Disk Insert END SELECT RETURN “Do Call” LONG IF Message%=0 Id=500 ‘Help DA XELSE Id=501 ‘Context Sensitive Help END IF Result&=0:Y%=0 SCode&= FN GETRESOURCE(T&,Id) ‘load the call into memory IF SCode&=0 THEN PRINT “Opps”:END ‘End if there is no call to call Y%=FN HLOCK(SCode&) ‘ Lock a Relocatable Memory Block ActualCode&=PEEK LONG (SCode&) LONG IF Message%=0 CALL ActualCode&‘Call the Help procedure XELSE CALL ActualCode&(Message%) ‘Call the Context Sensitive Help function END IF CALL RELEASERESOURCE(SCode&) Y%=FN HUNLOCK(SCode&) ‘Unlock a “Locked” Handle Y%=FN DISPOSHANDLE(SCode&) ‘Dispose of Memory block pointed to by a ‘Handle Message%=0 ‘Set up string parameters RETURN “Define Help Cursor” DIM A%(40) A%(0)=&H0000:A%(1)=&H3F80:A%(2)=&H7FC0:A%(3)=&H60C0 A%(4)=&H60C0:A%(5)=&H00C0:A%(6)=&H01C0:A%(7)=&H0380 A%(8)=&H0700:A%(9)=&H0E00:A%(10)=&H0C00:A%(11)=&H0C00 A%(12)=&H0000:A%(13)=&H0C00:A%(14)=&H0C00:A%(15)=&H0000 A%(16)=&H3F80:A%(17)=&H7FC0:A%(18)=&HFFE0:A%(19)=&HFFE0 A%(20)=&HF1E0:A%(21)=&HF1E0:A%(22)=&H03E0:A%(23)=&H07C0 A%(24)=&H0F80:A%(25)=&H1F00:A%(26)=&H1E00:A%(27)=&H1E00 A%(28)=&H1E00:A%(29)=&H1E00:A%(30)=&H1E00:A%(31)=&H1E00 A%(32)=&H0004:A%(33)=&H0002 HelpCursor%=0 RETURN “ChangeCursor” LONG IF HelpCursor%=0 CALL SETCURSOR(A%(0)) CALL SHOWCURSOR HelpCursor%=1 XELSE CURSOR=0 HelpCursor%=0 END IF WHILE B%(2)=16 AND B%(3)=-32767 CALL GETKEYS(B%(0)) WEND RETURN
- SPREAD THE WORD:
- Slashdot
- Digg
- Del.icio.us
- Newsvine