Dec 91 Mousehole

Volume Number:		7
Issue Number:		2
Column Tag:		Mousehole

STR# Hurdles

By Larry Nedry, Mousehole BBS SysOp

From: Jslee

Re: STR# Resource

From the frying pan, now into the fire. As you all know the Mac has a toolbox call called GetIndString. This is really cool, but I need to do the same function in reverse, that is, how can I add additional STR# resources to a list of resources? I have yet to find a code fragment demonstrating this technique. What I want to do is add a series of strings to the STR# resource via C (Think to be precise). Looking at IM I-476 I see that STR# resource consists of 2 bytes containing the number of strings then m bytes as the strings. Can I take this to mean:

typdef struct {
  short num_of_strings;
  str63 the_strings[max_strings];
} str_def;

Is this right? If not, how would I do it? I need to have a handle to each string item so that I can write it back to the resource. Any ideas would be great.

From: Mrteague

Re: STR# Resource

You have it partly wrong - because the “strings” are Pascal strings (and it wouldn’t matter of they were C strings), they are NOT of fixed size, which means you can’t use a struct as you have defined. There would be a number of different ways of doing what you need to do, but generally it involves parsing the resource structure yourself - i.e.

{1}

tempHandle = GetResource(‘STR#’,someID);
HLock(tempHandle); tempPtr = *tempHandle;
numStrings = *(short *)tempPtr;
tempPtr += sizeof(short);
for (i = 1; i <= numStrings; i++)
 {
 char tempchar[256];
 short theLength = *tempPtr++;

 strncpy(tempchar, tempPtr, theLength);
 dosomethingwithstring(tempchar);
 tempPtr += theLength;
 }

Then you have to output the new resource - either you have to create a new resource from scratch and add each string to it at a time (sort of the reverse of above), or you can attempt to modify the existing resource in place (remember to detach resource first) - this gets tricky when you insert strings, delete strings, or modify the length of existing strings.

I wrote a HyperCard XMCD that did something similar to this a long time ago, so if you are still stuck after trying my suggestions, I will see what I can do to help.

From: Jslee

Re: Writing to an STR# resource

Hurdle # 1: Parse out the strings from an STR# resource.

Hurdle # 2: Find out how the STR# is organized so you can write back to the resource file.

Hurdle # 3: How can I write out the data in my string to the STR# resource.

I figured out hurdle #1 and #2. #3 is a bit more perplexing. What I did was to create a string that looks like this: “/0/3/5Test1/5Test2/0”. The reason why the string is formatted this way is because this is the way the STR#128 resource (my own resource file in the THINK C project) looks. Now when I create a handle to this string, and try to write out the resource using AddResource nothing is written. When I perform a SizeResource to my handle it returns a -1 which means that the handle to the resource does not exist. I would like to create a handle to my string, then write it out to the STR# resource with a new id. Here is a code fragment:

/* 2 */

do_write()
{
OSErr oserr;
Handle dstHdl;
Ptr destPtr;
int newID;
int checkdigit;
int my_resfile;
OpenResFile(“\pNewRes”);
my_resfile = OpenResFile(“\pNewRes”);
UseResFile(my_resfile);
/*
newStr looks like this:
 “/0/3/5Test1/5Test2/0”
*/
dstHdl = NewHandle(sizeof((char *)&newStr));
oserr = PtrToHand((char *)&newStr,dstHdl,(long)sizeof(newStr));
if (oserr)
{
/*check os error here */
}
HLock(dstHdl);
newID = UniqueID(‘STR#’);
AddResource(dstHdl,’STR#’,newID,”\p”);
WriteResource(dstHdl);
checkdigit = HomeResFile(dstHdl);
/* always shows up as a -1
   meaning that this is not a handle to the resource
   why?,why?,why?
*/
HUnlock(dstHdl);
CloseResFile(my_resfile);
}

From: Mikel

Re: OOP Ignorance

When you say “get at” the Button, are you referring to getting control when the button’s smacked? If so (mind you, I’ve not used THINK C objects, just MacApp), odds are you should declare a class descendent from the type of AcceptButton (TButton, perhaps?) and override the appropriate method. Hope this makes sense.

From: Smug1

Re: OOP Ignorance

Thanks for the help, and I will try in that region. What I want to do is, When someone clicks on that button, to be able to send the message to my routine to do “Whatever”. Sort of like an “On MouseDown” script in HyperCard. I HAVE tried to make a Subclass; maybe I am doing it wrong. Using the same code as before, When I declare a new class (MyButton) and then try to access it, it tells me that “Acceptbutton is not declared. Do I redo the “new(AcceptButton)” routine ?

From: Mikel

Re: OOP Ignorance

I took a peek at some THINK C OOP code and saw that your CButton, when pressed, can send a message to its supervisor (I assume that’s the container view). Call the button’s SetClickCmd method with the appropriate command number (of your choosing). When the user presses the button, the supervisor’s DoCommand method is called with the button’s clickCmd.

In other words, don’t bother creating a new button class. The support is already there.

From: Smug1

Re: OOP Ignorance

Thanks for more of the help. I will give that a try. I figured it was that or “DoGoodClick” but I was not real sure where to assign it. (I am programming in Think Pascal w/TCL, by the way) I will keep marching on, and let you know how it goes.

From: Smug1

Re: OOP Ignorance (Still)

Sorry to keep bothering everyone. If I could get a hint...

Using Think Pascal 3.0 w/TCL & AppMaker, trying to get control of my controls (Mainly, my OK & Cancel buttons). They are made in my window initialization (AppMaker Generated). I try to get a hold of them by using:

Type

MyButton = Object(Cbutton)

Procedure DoGoodClick(WhichPart:integer);

Override;

end;

It shows up in the “Class Browser”, and compiles fine, but in my code area I put:

procedure MyButton.DoGoodClick(WhichPart:Integer);

begin

{Nothing here but a “stop sign” to wait for the step through}

end;

I was just check to see if it would use it, but when I put a “Stop” there, it never goes near it. It stops at CButton’s “DoGood Click” but not mine. Is it my breath ? Any help would be appreciated.

From: Mikel

Re: OOP Ignorance (Still)

Sounds like your object isn’t the one getting into your view. Are you sure your initialization code instantiates a MyButton and not a CButton?

From: Smug1

Re: OOP Ignorance (Still)

Thanks for all the assistance and help. I finally called Bowers Development to ask them if there was a “Suggested” method of overriding their buttons that they have generated.

(Some Background) If you have never used AppMaker (which is a neat program, I think and now supports MacApp) It generates 2 “Modules” for each area--a regular module, and one with a “Z” prefix. The “Z” module should remain unchanged, because it will be regenerated should you change something later with the AppMaker program. But the regular module will be untouched, so you can override & code away, safe in knowing that you won’t wipe out your work if you make a change in the interface.

So I called Bowers, and they said that although it is not recommended to change the “Z” module, you HAVE to change it to assign a “SetClickCmd” to the button, or else recode EVERYTHING. They said they will automatically do this for future versions, but as of yet, this is the way to do it. I feel a little sheepish, but it’s better than still not knowing. Such a simple solution, but the manual said...

From: Smug1

Re: OOP Ignorance (Still)

A better way for me to get control of my button (or anything else for that matter) is NOT to modify the “Z” module of AppMaker, but to override the “IMainWindow” method of the “Z” module in the regular module, “inherit” the “IMainWindow” methods & instance variables, and add the “SetClickCmd there instead. That way, the “Z” module” remains pristine (i.e. no extra coding should I regenerate it). This is getting interesting (dare I say it, almost “Fun”!).

From: Mikel

Re: OOP Ignorance (Still)

Bizarre. Anyway, I’m currently using ViewEdit with MacApp, which is pretty cool, but I’d certainly like to hear more about AppMaker. Do you have their phone number?

From: Smug1

Re: OOP Ignorance (Still)

Yes, I do. As a side note, I ordered this from Japan, as a trade up from Prototyper, and I got it in about 3 days after the transfer of funds reached them. Anyway, the number is: (508) 369-8175 (EST 9-5) or (508) 369-8224 FAX number. Compuserve 70731,3710. Applelink D1721. As I learn more about OOP, and find that AppMaker helps a lot in “Getting idea”, but it must be ok for others too.

From: Midiman