LstGlueGetTopItem should do the checking and retrieving for you, shouldn't it?
-- Keith
At 4:27 PM -0600 2/28/02, Richard Bell wrote:
>Ok I got my function to work by defining ALLOW_ACCESS_TO_INTERNALS_OF_LISTS
>before including the Palmos headers. I'd still like someone to tell me if
>there is a better/safer way to do this. I want to maintain compatability
>with future Palm OS releases.
>
>Thanks again.
>Richard
>
>----- Original Message -----
>From: "Richard Bell" <[EMAIL PROTECTED]>
>To: "Palm Developer Forum" <[EMAIL PROTECTED]>
>Sent: Thursday, February 28, 2002 4:16 PM
>Subject: Problem with LstGetTopItem
>
>
>> I'm using SDK 4.0 and made use of the call LstGetTopItem so I can store
>the
>> top item of a list. The call works fine if I'm using an OS 4.0 or higher
>> device but fails on an OS 3.5 device. I attempted to create a function
>that
>> would detect the version and use the older method but it will not compile.
>> I recieve the error:
>>
>> Error: illegal use of incomplete struct/union/class 'ListType'
>>
>> I've seen that error reported before here in the forum and know its
>related
>> to me attempting to access the internals of a structure. I'll be happy
>not
>> to do it if someone can tell me how to generate a prc that will work on my
>> 3.5 devices as well as my 4.0.
>>
>> And if I'm just doing something really stupid, I'm happy to accept that
>too.
>>
>> Here is my attempt at a function to get around the problem:
>>
>> Int16 MyLstGetTopItem(const FormType *frmP, UInt16 objIndex)
>> {
>> Int16 ret;
>> Int32 requiredVersion;
>> UInt32 romVersion;
>>
>> // we can only use LstGetTopItem if the os is 4.0 or better
>> requiredVersion = sysMakeROMVersion(4,0,0,sysROMStageRelease,0);
>>
>> FtrGet(sysFtrCreator, sysFtrNumROMVersion, &romVersion);
>>
>> if (romVersion < requiredVersion)
>> { // we have to do it the hard way
>> // and access the internal structures
>> #undef DO_NOT_ALLOW_ACCESS_TO_INTERNALS_OF_STRUCTS
>> ListType *pLst;
>> pLst = (ListType *)FrmGetObjectPtr (frmP, objIndex);
>> ret = pLst->topItem;
>> #define DO_NOT_ALLOW_ACCESS_TO_INTERNALS_OF_STRUCTS
>> }
>> else
>> {
>> ret = LstGetTopItem ((ListType *)FrmGetObjectPtr(frmP, objIndex));
>> }
>>
>> return ret;
>> }
>>
>>
>> --
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>>
>
>
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