R devel - May 2022 - Rgui.exe 4.2.0 does not receive characters via the Windows API's PostMessage function

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?

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]]

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 at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel