[Rd] Rgui.exe 4.2.0 does not receive characters via the Windows API's PostMessage function

[Tomas Kalibera]

On 5/6/22 07:03, jcfaria wrote:
> Dear Duncan,
> I believe the problem is of a different nature.
> I get TRUE 3 times running the code below:
>
> procedure TfMain.btnPasteClick(Sender: TObject);
> var
>   i: integer;
>   sTmp: string;
>   hBN: HWND;
>   j: bool;
>
> begin
>   hBN:= FindWindowA(nil,
>                     'R Console (64-bit)');
>
>   sTmp:= 'sd';
>
>   for i:= 1 to Length(sTmp) do begin
>     j:= PostMessage(hBN,
>                     WM_CHAR,
>                     Ord(sTmp[i]),
>                     0);
>
>     ShowMessage(BoolToStr(j,
>                           True));
>   end;
>
>   j:= PostMessage(hBN,
>               WM_KEYDOWN,
>               VK_RETURN, 0);
>
>   ShowMessage(BoolToStr(j,
>                         True));
> end;
>
> That is, Rgui is receiving the message of the characters (via 
> PostMessage), but it is blocking because it does not show them in the 
> console.
> The only thing Rgui blames is Carriage Return, as it adds an 
> additional prompt with each run.

I can't provide a good guess what impacted your use, but if you could 
give me a full example, ideally in C, which can be compiled with 
Rtools42 (so gcc, MinGW) and I can edit/recompile, and works with R 4.1, 
I am happy to help debugging on 4.2.

Rgui now uses GraphApp Unicode windows on systems where it didn't 
before, because it uses UTF-8 also on systems it didn't before (on 
systems that would use a single-byte locale in R 4.1). These Unicode 
windows are a different code path and there may be bugs not reported 
previously, including processing inputs (recently I fixed handling of 
accents, for example). Otherwise indeed R now uses UTF-8 as native 
encoding and UCRT as the C runtime.

Best
Tomas


>
> >
> >
>
> Best,
> ///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\
> Jose Claudio Faria
> UESC/DCET/Brasil
> joseclaudio.faria at gmail.com
> Telefones:
> 55(73)3680.5545 - UESC
> 55(73)99966.9100 - VIVO
> ///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\
> If you have software to deal with statistics, you have arms,
> if you have good software, you have arms and legs,
> if you have software like R, you have arms, legs and wings...
> the height of your flight depends only on you.
>
> ------ Mensagem original ------
> De: "Duncan Murdoch" <murdoch.duncan using gmail.com>
> Para: "jcfaria" <joseclaudio.faria using gmail.com>; r-devel using r-project.org
> Enviado(s): 05/05/2022 13:17:53
> Assunto: Re: [Rd] Rgui.exe 4.2.0 does not receive characters via the 
> Windows API's PostMessage function
>
>> On 05/05/2022 11:17 a.m., jcfaria wrote:
>>> Hello,
>>>
>>> Rgui.exe 4.2.0 does not receive characters via the Windows API's
>>> PostMessage function.
>>>
>>> The Tinn-R project sends messages to Rgui.exe (SDI mode) via the 
>>> Windows
>>> API's PostMessage function.
>>> A simplification of the code (in object Pascal) can be seen below.
>>>
>>> procedure TfMain.btnPasteClick(Sender: TObject);
>>> var
>>>     i: integer;
>>>     sTmp: WideString;
>>>     hBN: HWND;
>>>
>>> begin
>>>     hBN:= FindWindowA(nil,
>>>                       'R Console (64-bit)');
>>>
>>>     sTmp:= 'sd';
>>>
>>>     for i:= 1 to Length(sTmp) do begin
>>>       PostMessage(hBN,
>>>                   WM_CHAR,
>>>                   Ord(sTmp[i]),
>>>                   0);
>>>     end;
>>>
>>>     PostMessage(hBN,
>>>                 WM_KEYDOWN,
>>>                 VK_RETURN, 0);
>>> end;
>>>
>>> This code has always worked fine for all versions of Rgui.exe with the
>>> exception of the last one released, ie 4.2.0.
>>>
>>> We've been trying to get around the problem on the Object Pascal side,
>>> but without success so far.
>>>
>>> Does anyone connected to the compilation of Rqui.exe know what the
>>> problem is?
>>
>> It could be that the new build enforces Windows security more 
>> stringently.  More details are described in the answer to this 
>> question:  https://stackoverflow.com/a/40139498/2554330, but at a 
>> minimum you should be checking the return value from PostMessage.
>>
>> Duncan Murdoch
>>
>>>
>>> Best,
>>> ///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\
>>> Jose Claudio Faria
>>> UESC/DCET/Brasil
>>> joseclaudio.faria at gmail.com
>>> Telefones:
>>> 55(73)3680.5545 - UESC
>>> 55(73)99966.9100 - VIVO
>>> ///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\///\\\
>>> If you have software to deal with statistics, you have arms,
>>> if you have good software, you have arms and legs,
>>> if you have software like R, you have arms, legs and wings...
>>> the height of your flight depends only on you.
>>>
>>>     [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-devel using r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>
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