Scroll events

John M McIntosh johnmci at
Fri Mar 18 20:31:49 UTC 2005

I'm sure this is a change from our original thoughts to generate  
unicode values for the keydown/keyup. I'll note you could be using a  
input palette and not a keyboard device so you won't get any key  
up/down events, and you imply that you are supplying unicode values for  
the keystroke, versus the historical MacRoman? So how does a  unicode  
character flow up in Windows?

For the most part I am using the unix keyboard logic for os-x to track  
the key up/down strokes, so given your accented character

a) we remember the keyDown,
b) translation input services gives us the unicode for  á (accented-a)  
which I generate as a keyDown  unicode. This is after translation  
services has digested all the keystrokes and made a decision on what it  
all means.
c) I translate that into the macroman character for  á (accented-a)  
which could depending on your language choice be different than the  
unicode, which I generate as a KeyChar
d) when the key goes up I have remembered the unicode for  á  
(accented-a) which I generate as a keyUp.

*If input services gives us a unicode, or input  palette services give  
us a unicode for which there is no MacRoman translation then the  
keyChar value is unicode. I'll note that input  palette services can  
give us a string of unicode which is translated into synthetic  
keydown/keychar/keyup values.

It could be possible under os-x to generate the keydown/keyup and  
keychar as suggested but I'm not sure what that would break.  The only  
information I have is the keycodes which are values mapped to keys and  
depend on the keyboard used and would require a translation table in  

On Mar 18, 2005, at 10:59 AM, Andreas Raab wrote:

> the image as EventKeyChar. For example, here is a sequence that will  
> generate the "á" character on my keyboard:
> keyDown: ´ (accent key)
> keyUp: ´ (accent key)
> keyDown: A
> keyUp: A
> keyStroke: á (accented-a)
> Note that the accent *key* did NOT generate an accent *character* - it  
> was subsumed by the subsequent combination with the A key to generate  
> the accented á character.
John M. McIntosh <johnmci at> 1-800-477-2659
Corporate Smalltalk Consulting Ltd.

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