[Lazarus] 1 keypress gives multiple letters ONLY in program written in Lazarus in raspbian jessie Pi 2

[Giuliano Colla]

Il 10/04/2016 21:16, Michael Thompson ha scritto:
> Giuliano: Do you know if any of the steps listed here would have 
> helped?  If not, can you let me know how you disabled the Input 
> Manager, and I'll update the wiki accordinly.

I have only hearsay knowledge, from this list complaints, and from some 
search on Internet I made because of that.
I'm not using Ubuntu or any other Debian/Ubuntu derived distro, and I do 
not have a direct experience.
I'm using the Red Hat distros line (RHEL, Fedora and CentOs) and I did 
never stumble into a similar problem.
Therefore take what I say with appropriate caution (and most of all do 
not use it in tribunal .)

However the problem appears to arise from the Keyboard Input Methods 
being enabled by default, even when no actual Input Method is assigned. 
 From what I gathered, this problem popped up as with Ubuntu 11, and 
should be related to Gnome Desktop.
Previous versions were immune, but I can't tell if it was because ibus 
service wasn't used, or because Keyboard Input Methods were not enabled.

However the full picture is the following:

Input Methods are those methods which allow to accommodate languages 
with ideographic symbols which cannot possibly fit in a normal sized 
keyboard, such as Chinese.

Those user need also to enter Latin alphabet characters for system 
commands, therefore a keyboard shortcut is required to toggle on and off 
the Input Method.

The standard shortcut to toggle Input Method is ctrl-space, which 
happens also to be the standard code completion shortcut of Lazarus. 
This alone can be a cause of troubles.
Moreover, if the Input Methods are enabled, but no actual Input method 
is defined, toggling may lead to weird results, such as characters being 
entered twice, characters being lost etc.

The steps to overcome the problem are:

1) If Input Methods are required (e.g. a Chinese user), one of the two 
shortcuts must be changed.

2) If no Input Methods are required, they should be disabled. No general 
rule can be given on how to do that, because each Desktop environment 
does it its way. Gnome provides in System Settings an "Input Method" 
entry. KDE provides an Icon in the systray, but only if a specific Input 
Method package has been installed, otherwise the Input Methods are disabled.

3) If no Input Methods are required and the user is unable to disable 
the Input Methods, one can simply stop the ibus service, whose only 
purpose appears to be that of supporting the Input Methds. Again, how to 
do that is strongly system dependent.

I can't say if the steps indicated in the Wiki page are useful in 
general. From what I read GTK_IM_MODULE=gtk-im-context-simple
should be a better choice than gtk-im-context-xim which enables the old 
XIM (X Input Method) framework.
But it would require some testing in Ubuntu or Ubuntu siblings, and with 
different locale.

That's all I can tell.

Giuliano