Brian Stevens wrote:


> My code now uses appearance buttons of the  
> _kControlEditUnicodeTextProc variety and now I need the  
> functionality of READ FIELD/WRITE FIELD/GET FIELD with this control- 
> based button. It appears from my rudimentary testing that these  
> statements don't work with control-based edit fields but only when  
> they are created via EDIT FIELD...... I'm reading a data file where  
> each unique record has a variable-sized data component. It could be  
> 20 characters,  50,000 characters or whatever. READ FIELD/WRITE  
> field is perfect for this because it writes a 4 byte (ZTXT) header  
> with the size. My fallback is to just get the handlesize to the  
> variable portion and write the size out myself using WRITE FILE  
> followed by the variable-sized data. I'm hoping someone has a more  
> elegant/better/simpler solution for use with control-based edit  
> fields.
>

You need a small suite of functions like those listed below.  They  
should work for _kControlEditTextProc and  
_kControlEditUnicodeTextProc buttons, and for HITextViews (only in OS  
X 10.4).  Caution: I haven't got around to testing these routines yet.


// myTextPtr = fn GetBtnTextAsPtr( txtBtnNum ) replaces  get field  
ztxtHandle, efID
local mode
local fn GetBtnTextAsPtr( txtBtnNum as long )
'~'1
dim as long  @ size
dim as Ptr     p

size = fn ButtonDataSize( txtBtnNum, _kControlEditTextPart,  
_kControlEditTextTextTag )
p = fn NewPtr( size )
def GetButtonData( txtBtnNum, _kControlEditTextPart,  
_kControlEditTextTextTag, size, #p, #0 )
end fn = p // caller must DisposePtr


// fn WritePtrToFile( fileID, myTextPtr ) replaces  write field  
fileID, ztxtHandle
local mode
local fn WritePtrToFile( fileID as long, p as Ptr )
'~'1
dim as long  @ size

size = fn GetPtrSize( p )
write fileID, size // write size
write file fileID, p, size // write text data from buffer
end fn


// myTextPtr = fn ReadPtrFromFile( fileID ) replaces  read field  
fileID, ztxtHandle
local mode
local fn ReadPtrFromFile( fileID as long )
'~'1
dim as long  @ size
dim as Ptr     p

read# fileNum, size // read size
p = fn NewPtr( size ) // make buffer
read file fileID, p, size // read text data into buffer
end fn = p // caller must DisposePtr


// fn SetBtnTextFromPtr( txtBtnNum, myTextPtr ) replaces  edit$ 
( efID ) = &ztxtHandle
local mode
local fn SetBtnTextFromPtr( txtBtnNum as long, p as Ptr )
'~'1
def SetButtonData( txtBtnNum, _kControlEditTextPart,  
_kControlEditTextTextTag, fn GetPtrSize( p ), #p )
end fn


/*
Remember to call  DisposePtr( myTextPtr )
when you have finished with the pointer block
*/


Robert P.