[Vm-dev] Re: [Pharo-dev] Substitution of ' to " in
TextEditor>>shiftEnclose
J. Vuletich (mail lists)
juanlists at jvuletich.org
Thu Aug 28 12:48:00 UTC 2014
Hi Folks,
(below)
Quoting Eliot Miranda <eliot.miranda at gmail.com>:
> On Wed, Aug 27, 2014 at 4:27 PM, Nicolas Cellier
> <nicolas.cellier.aka.nice at gmail.com> wrote:
>
>> I encountered this in Squeak too, because French keyboard is not better
>> than german one :(
>>
>> Nicolas Cellier uploaded a new version of ST80 to project The Trunk:
>> http://source.squeak.org/trunk/ST80-nice.136.mcz
>>
>> ==================== Summary ====================
>>
>> Name: ST80-nice.136
>> Author: nice
>> Time: 4 August 2011, 10:43:00.836 am
>> UUID: 6f8b2f4c-8c8c-48a8-ba32- bb5b37d827d0
>> Ancestors: ST80-ul.135
>>
>> #shiftEnclose: is hardcoding the keyboard layout, which is not
>> compatible with foreign keyboards and modern VM, and prevents correct
>> enclosing to work.
>
>
> +1. This is the issue that must be fixed. It must be understood
> properly (is the VM answering adequate information or not?).
>
The information provided by the VMs in keystroke events is not
perfect, and it could be enhanced. I see 2 main problems (in what
follows, $x denotes Character x, and [x] denotes the physical keyboard
key labelled 'x'):
Problem 1)
On the mac, when control or command are pressed, for any keystroke the
unshifted code is returned, even if shift is pressed. For instance,
let's assume an US keyboard. So, [shift]+[,] generates $< and
[shift]+[.] generates $>. If you run 'Sensor kbdTest' and press
[shift]+[,] you correctly get $<, but if you press
[control]+[shift]+[,] or [command]+[shift]+[,] you get $,. This is
bad, because to detect [command]+[<] or [control]+[<] you need to
write code that not only needs to know about the platform, but also
about the keyboard layout, as in many layouts $< is not generated by
doing [shift]+[,], but by some other combination. The same happens
with most non-alphabetic keys, that usually differ in different
keyboard layouts.
Problem 2)
There is a completely separated issue, and it happens both in Windows
and Mac. Here, [ctrl] + [an alphabetic key] substracts 64 from the
code. So, [ctrl]+[c] generates code 3. This is consistent with the
traditional meaning of the ctrl key (in dumb terminals and DOS), but
it makes impossible for the image to tell (for example) between
[ctrl]+[Enter] and [ctrl]+[m]. The image might want to use these
keystrokes for different things, so it would be much better not to
substract 64 in the VM and let the image handle it. I know it could be
done by handling key down and key up events, but this would also
require code that is not only platform dependent but also needs to
know the mapping between key codes and characters in each platform.
I haven't tested on Linux or platforms other than Windows and Mac, but
things like these could also happen.
In general, [control], [command] and [alt/option] should not affect
the character code of a keystroke, they should only set the
appropriate flag so the image can decide what to do with them. The
character code should be the same as if [control], [command] and
[alt/option] were not pressed.
This is completely different for [shift], as [shift] does indeed
modify the character generated, as [shift]+[8] means $* in some
keyboards and $( on others. If [shift]+[someKey] is pressed, the
keystroke character code should be the same as the user would get
elsewhere in the platform, irrespectively of [control], [command]
and/or [alt/option] being pressed or not.
Fixing these, and making the behavior consistent between platforms,
would enable a few simplifications in the image. It would also enable
the use of some keystroke combinations involving [command] and/or
[control] that are problematic today.
>
> best, Eliot
Thanks,
Juan Vuletich
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