At 12:00am -0700 01-05-18, Palm Developer Forum digest wrote:
>Subject: Invalid char passed to TxtCharAttr?
>From: "John Crouch" <[EMAIL PROTECTED]>
>Date: Thu, 17 May 2001 18:17:14 -0400
>X-Message-Number: 63
>
>When a user is entering text into a text field in our app (gremlins) we get
>this error. This happens when running on the OS 3.5 debug rom. I think on
>the physical unit (Symbol 1740 OS 3.5.2) we get a fatal error with less
>description.
This would surprise me. The "invalid character" error is a non-fatal
alert, so if you get a crash on a release ROM, then something else is
going wrong.
>I understand that the TxtCharAttr function is being called with a character
>that is larger than 0xFF (255). But we don't control any of this code. This
>happens during text input into a field.
Do you have a stack crawl? Without that, it might be difficult to
figure out what's really happening. The two most likely reasons for
your problem are:
a. Sign-extension of Char to WChar (already discussed).
b. A virtual character is somehow getting processed as a regular
character. Normally this means that the command bit in the modifiers
field of the keyDown event is getting "lost" - either explicitly
cleared, or a virtual keyDown event gets reposted without the command
bit set.
>Can someone tell me how to stop this from happening? We're running an
>English only program, so wide characters are not needed.
The issue isn't wide characters. If a non-virtual character code >
255 gets passed to a ROM routine on a Latin device, then something
has gone wrong in either the app code or the OS. Normally character
attributes are derived by indexing into a table w/the character code.
Since this table only has 256 entries, you'd get bogus results
without this check for bad character codes.
-- Ken
Ken Krugler
TransPac Software, Inc.
<http://www.transpac.com>
+1 530-470-9200
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