No SDL_TextEditingEvent on linux

[tomooda]

Pharo does not receive SDL_TextEditingEvent on Ubuntu Linux.
Translation buffer opens at the bottom of the screen instead of inline editing.
After fixating the translation buffer, SDL_TextInputEvent is received by RubAbstractTextArea.

Pharo version: 9.0
SDL2: 2.0.7
IM: ibus - mozc

Maybe some initialization of SDL2 to use ibus IM is required.
Tried SDL_IM_MODULE=ibus in /etc/environment, but no success.

[tomooda]

need to confirm if the libsdl2 used in the pharo VM is configured with --enable-ime option and SDL_USE_IME is defined in the compilation.

[guillep]

Take a look at: https://github.com/pharo-project/opensmalltalk-vm/blob/pharo-9/cmake/importSDL2.cmake#L56

There are three possibilities:

• we use the SDL version available in the system (we have no control on that)
• we download a pre-compiled version that we have stored in our file servers (I think compiled using the standard SDL2 instructions, maybe this deserves a wiki page)
• or we build SDL along with the VM => here we are for sure not setting that option (see function build_sdl in the link) unless that's ON by default

[tomooda]

I tried on Ubuntu 20.04.3 LTS and its /usr/lib/x86_64-linux-gnu/libSDL2-2.0.so.0.10.0 seems to be working at least to handle the IME events and inline IME (see the attached screendump).
We need to replace the libSDL2-2.0.so.0 if we really deserve the SDL_TextEditingEvent.

In a long run, it would be the best if the libSDL2 on the file server is compiled with ime support. I suspect the build environment might have missed ime/ibus/fcitx related headers. The configuration options --enable-ime, --enable-ibus and --enable-fcitx are all set to yes by default.

For now, I think we can offer the choices open to the user; either patch the SDL2 class to use the system libSDL2.so, or keep using Pharo without IM support.