I had the same problem. Here's how I associated a multi-line list field with
a vertical scrollbar:
In the code that loads the field, it must update the scroll bar:
FieldPtr fP;
ScrollBarPtr sbP;
Word vPos;
Word nLines;
Word vLines;
Word max;
...
fP = GetObjectPtr(MainResponseField);
sbP = GetObjectPtr(MainListScrollBar);
.. (code here sets the field contents and calls FldDrawField)
// Get the scrolling info from the field
FldGetScrollValues(fP, &vPos, &nLines, &vLines);
// Ensure scrollbar works OK when there are less lines of text than
there are in the field
max = ( nLines > vLines ) ? nLines - vLines : 0;
// Set the scrollbar
SclSetScrollBar(sbP, vPos, 0, max, vLines);
...
Now, in the event handler (AppHandleEvent, in the source generated by CW6)
you need to
handle the scrollbar events and scroll the field. I did this by calling a
common update
function. Note the Boolean variable "handled" which is returned to the
caller. This needs
to be false on the sclRepeatEvent, or the thing won't scroll smoothly:
...
switch ( eventP->eType )
{
...
case sclExitEvent:
updateListField(eventP->data.sclExit.newValue);
handled = true;
break;
case sclRepeatEvent:
updateListField(eventP->data.sclRepeat.newValue);
handled = false;
break;
...
}
return handled;
Here's the esential parts of the update function:
void updateListField(Word newPos)
{
FieldPtr fldP;
Word linesToScroll;
Word pos;
DirectionType dir;
Word txtHeight;
Word fldHeight;
fldP = GetObjectPtr(MainResponseField);
FldGetScrollValues(fldP, &pos, &txtHeight, &fldHeight);
if ( newPos >= pos )
{
dir = down;
linesToScroll = newPos - pos;
}
else
{
dir = up;
linesToScroll = pos - newPos;
}
FldScrollField(fldP, linesToScroll, dir);
}
> -----Original Message-----
> From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]]
> Sent: Thursday, February 17, 2000 9:29 AM
> To: Palm Developer Forum
> Subject: hasScrollbar Field Attribute Question ...
>
> Hi All,
>
> I have seen the field attribute hasScrollbar and am now playing around
> with
> this flag.
>
> Unfortunately I can't get this to work and would like to ask for some
> hint's
> on how to use that.
>
> I have simply set this to true programaticaly expecting a scrollbar to
> appear. Obviously a wrong assumption .
> I placed a scrollbar on the form and am looking for a way to associate the
> scrollbar to the field.
>
> Am I completely on the wrong track or how would I handle a field with 500
> chars that must be scrollable with a scrollbar.
>
> Any pointers/advices are greatly appreciated
> Thanks in advance
> Ole
>
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