Hi, community,

on Pi computers under Raspbian controlled over VNC the Lazarus code editor doesn't recognize keystrokes with AltGr and therefore characters like {[]}\ can't be put in. That's a known issue since 2016 (https://bugs.freepascal.org/view.php?id=30544#c107874).

Unfortunately, this report is still unassigned and it seems nobody of the developers cares about it. So, the 70+ million Raspberry Pi users all over the world cant' develop Lazarus programs when controlling their Pis over the VNC Server built into Raspbian.

The contributor of the VNC Server built into Raspian Stretch is RealVNC. I asked them for help concerning this problem. Yesterday I got this from Linda, RealVNC Product Support:

"We did manage to reproduce this from Windows with a German keyboard layout. We can confirm that it only affects this particular application. Lazarus does appear to discard key events with the same timestamp, which I think is not correct behaviour, which they would need to fix to make this work. There's not really much we can do to fix this, since we don't explicitly generate the timestamps on the events - the X server is doing this. Given that the X server is ok with sending the key events to the Lazarus application with the same timestamp, I think it should be handling this ...
Please log a bug with the Lazarus developer."

Steps to reproduce the problem:
Prepare a SD card with Raspbian Stretch, current version, and boot a Pi with it. Enable VNC and install Lazarus (current version under Raspian  is Lazarus 1.6.2). Now, from a Windows 10 computer, using VNCViewer 6.0.3. x64 from RealVNC, connect to the Pi, open Lazarus, click in the code Editor Window and depress AltGr + {. The charcter is not shown.

Please, could one of the developers have a look at this?

Regards --  Joe

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I added a comment. Can you help me?

Mattias

Mattias,

Unfortunately, actually I don't know how to get and compile Lazarus code. Is there a step by step introduction anywhere how to do it under Raspian Stretch or a script helping with this?

Another possibility: I can open a Pi 3B+ via RDP for you, so you could have complete control over this system. One possible way to connect to this Pi over RDP is: Under Windows 10 (64), start
c:\windows\system32\mstsc.exe.

Joe

This sounds like an issue with VNC. Can you ask there? VNC needs to accurately reproduce what you are typing for Lazarus to see it.

Cheers,
R0b0t1

[...] Unfortunately, actually I don't know how to get and compile Lazarus code. Is there a step by step introduction anywhere how to do it under Raspian Stretch or a script helping with this?

Try this:
http://wiki.freepascal.org/Getting_Lazarus#Getting_Lazarus_SVN_development_version

svn co https://lazarus.svn.sourceforge.net/svnroot/lazarus/trunk lazarus cd lazarus
make clean all OPT=-dLCLGtk2Fix30544
./lazarus

Mattias

Joe wrote

on Pi computers under Raspbian controlled over VNC the Lazarus code editor doesn't recognize keystrokes with AltGr and therefore characters like {[]}\ can't be put in. That's a known issue since 2016 (https://bugs.freepascal.org/view.php?id=30544#c107874).

In actual fact it is older than this....
I stareted a few threads on this very issue years ago:

2015-10-11: "Lazarus eats comment characters using Swedish keyboard" 2015-10-24: "Clipboard problem with Lazarus using VNC" 2016-02-24: "Keys not recognized by Lazarus 1.6 code editor"

I made extensive tests to narrow down the problem and it condenses to this:

1) Appears when the Raspberry Pi is accessed via VNC (TightVNC in these discussions, I never tested RealVNC at the time). When using the RPi in console mode with a display and keyboard attached there are no ) Problem: The non-US characters cannot be entered into the Lazarus code editor window, nothing at all happens when one tries.

3) But in the Lazarus property editor window they arrive just fine! So Lazarus itself can handle them but the code editor apparently discards these characters if sent via VNC.

4) In all other editors or other applications I tested that are bundled with Raspbian there are no problems whatsoever with these characters. So the characters are properly supplied to the operating system and should appear inside Lazarus as well, but do no.

5) There is also a clipboard problem, where the copied text needs to be passed through for example GEdit in order to be possible to paste into the Lazarus code editor

Since the community was not able to come up with a solution I have had to use the GEdit trick such that I open a Gedit window in Raspbian and there I enter the problem characters. Then when I need them in Lazarus I switch to GEdit, copy the appropriate character and then return to the Lazarus code editor to paste it in. This works, but is a bit of a tedious workaround.

Bo Berglund wrote

Since the community was not able to come up with a solution I have had to use the GEdit trick such that I open a Gedit window in Raspbian and there I enter the problem characters.

Bo, there is another (ugly?) work around:

In the code editor, type Control+Shift+M to open the Character Map, and in this map click on the character you want to insert.

--  Joe

The same or a similar problem I see using Lazarus 1.6 under Ubuntu 16.04 LTS, running X11 VNC Server 0.9.13-1.2build1.

I connected from a windows 10 computer with VNCViewer 6.1.0 from RealVNC to the Ubuntu machine, opened Lazarus and tried to insert a '[' char with AltGr+8 in the Lazarus code editor window. Alternately, no char or wrong chars were inserted. The same happened, when I tried to insert other AltGr combinations like { and ].

Added a note to case 30544 in the Lazarus Bug Tracker.

-- Joe

The same or a similar problem I see using Lazarus 1.6 under Ubuntu 16.04 LTS, running X11 VNC Server 0.9.13-1.2build1.

I connected from a windows 10 computer with VNCViewer 6.1.0 from RealVNC to the Ubuntu machine, opened Lazarus and tried to insert a '[' char with AltGr+8 in the Lazarus code editor window. Alternately, no char or wrong chars were inserted. The same happened, when I tried to insert other AltGr combinations like { and ]. Country and keyboards settings on both machines: Germany.

Added a note to case 30544 in the Lazarus Bug Tracker.

-- Joe
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Joe wrote

The same or a similar problem I see using Lazarus 1.6 under Ubuntu 16.04 LTS, running X11 VNC Server 0.9.13-1.2build1.

Under Ubuntu 18.04 LTS with Lazarus 1.8.2+dfsg-3 and FPC 3-04 the AltGr keystroke combinations work fine. Same VNC-Server and VNC-Viewer. --  Joe

As tested, with revision 57898, the AltGr problem under Raspbian is fixed now.
Thank you, Mattias and Ondrej.
--  Joe