[Rd] Writing in R // R 4.2.0 on Windows doesn't work with Dasher

Paulo Barata pb @end|ng |rom |n|o||nk@com@br
Sun May 15 19:09:45 CEST 2022

Following Mr. Murdoch's suggestion, I installed R Studio (2022.02.2 
build 485) on my Windows 10 Professional.

When opening R Studio, it showed R 4.2.0 patched, the most recent 
version of R I had installed here. As it happens with the standalone R 
4.2.0, Dasher did not work with R Studio with that version of R -- 
please see below what happened.

I unistalled R 4.2.0 patched and also R 4.2.0, so then my latest version 
of R was R 4.1.3 patched. This was now the version of R that R Studio 
used. Dasher also did not work in R Studio with R 4.1.3 patched -- 
please see below what happened. Please note that the standalone R 4.1.3 
patched does work perfectly well with Dasher.

What happens in R Studio with both R 4.2.0 patched and R 4.1.3 patched: 
when I open R studio and start writing with Dasher, the first character 
that I write is now the character that always appears on the R Studio 
console, no matter what other characters I am commanding with Dasher. 
For R Studio, strangely, Dasher seems to be stuck in the first character.

For example, if I wish to write a plot command in R Studio, the first 
Dasher "p" is accepted by R Studio, but the next "lot" appears on the R 
Studio console as "ppp". This is is contrast with what happens with 
Dasher on R 4.2.0, where, except for the "Enter" character, no other 
character is accepted by R 4.2.0, the R 4.2.0 screen just does not 
respond to Dasher.

Both in R 4.2.0 and in R Studio, the "Enter" character of Dasher work 
well, it makes the R prompt to jump to the next line.

So, Dasher does not work with R Studio either, but in a different way 
than it happens with R 4.2.0.


Paulo Barata

Paulo Barata
Rua Almirante Alexandrino 1808 apt. 102
Santa Teresa
20241-263  Rio de Janeiro - RJ

Paulo Barata
Sub-Síndico - Condomínio do Edifício Dois Irmãos
Rua Almirante Alexandrino 1808 - Santa Teresa

E-mail: pb using infolink.com.br

On 15/05/2022 13:27, Duncan Murdoch wrote:
> On 15/05/2022 10:58 a.m., Ivan Krylov wrote:
>> On Sun, 15 May 2022 11:10:49 -0300
>> Paulo Barata <pb using infolink.com.br> wrote:
>>> I noticed today that R 4.2.0 responds to the "Enter" character of
>>> Dasher version 5.0.0 beta in "Direct Entry" mode. An "Enter" in
>>> Dasher causes the R prompt to jump to the next line, as an "Enter"
>>> should do.
>>> No other characters (letters, digits, special characters like + = & ~
>>> | # $) are accepted by R 4.2.0 through Dasher.
>> This seems to be very similar to the problem discussed here:
>> https://stat.ethz.ch/pipermail/r-devel/2022-May/081683.html
>> For the record, here's the part of Dasher responsible for "Direct
>> Entry" on Windows:
>> https://github.com/dasher-project/dasher/blob/0ec7d646dbaadf06b8eebfc11b784738a20e75af/Src/Win32/Widgets/Edit.cpp#L302 
>> MSDN says:
>>>> If KEYEVENTF_UNICODE is specified, SendInput sends a WM_KEYDOWN or
>>>> WM_KEYUP message to the foreground thread's message queue with
>>>> wParam equal to VK_PACKET. Once GetMessage or PeekMessage obtains
>>>> this message, passing the message to TranslateMessage posts a
>>>> WM_CHAR message with the Unicode character originally specified by
>>>> wScan.
>> <https://docs.microsoft.com/en-us/windows/win32/api/winuser/ns-winuser-keybdinput> 
> As far as I can see, Graphapp never looks for VK_PACKET.
>> Previously, Tomas Kalibera has mentioned:
>>> For Unicode Windows, GraphApp uses WM_IME_COMPOSITION messages to
>>> read the keys instead of WM_CHAR, which it uses for non-Unicode
>>> windows.
>> I think that for a combination of R >= 4.2 and Dasher, this means an
>> impasse. Either Dasher should be taught to send WM_IME_COMPOSITION
>> messages to R (?), or R should learn to understand WM_CHAR messages in
>> its Unicode windows in addition to WM_IME_COMPOSITION it currently uses.
> Another possible solution for Paulo is to use R via some other front end 
> besides RGui, e.g. RStudio, but there are other possibilities too.
> Duncan Murdoch

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