RFR: 8305418: [Linux] Replace obsolete XIM as Input Method Editor [v31]

[Helly Guo]

On Thu, 12 Dec 2024 10:15:19 GMT, Helly Guo <duke at openjdk.org> wrote:

>> @hellyguo I can't reproduce the problem you're seeing. I configured a Debian Bookworm system with Fcitx5 and Pinyin and tested this PR and everything worked. The Linux and Fcitx version numbers are the same as yours. I also installed fcitx5 on my existing Ubuntu 24.10 system and it worked there, also.
>> 
>> The behavior seems a little odd but it matches the behavior of other Linux apps (I see Roman letters inserted into the JavaFX TextField until I select Chinese text in the IM). In your screen capture the input method window was clearly in the wrong location but in my testing it was correctly positioned near the JavaFX caret.
>
> @beldenfox , you are right.
> I created a brand new env in virt-manager:
> 
> 
> virt at virtdeb:~$ uname -a
> Linux virtdeb 6.1.0-28-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.119-1 (2024-11-22) x86_64 GNU/Linux
> 
> virt at virtdeb:~$ cat /etc/os-release 
> PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"
> NAME="Debian GNU/Linux"
> VERSION_ID="12"
> VERSION="12 (bookworm)"
> VERSION_CODENAME=bookworm
> ID=debian
> HOME_URL="https://www.debian.org/"
> SUPPORT_URL="https://www.debian.org/support"
> BUG_REPORT_URL="https://bugs.debian.org/"
> 
> virt at virtdeb:~$ java -version
> openjdk version "23.0.1" 2024-10-15
> OpenJDK Runtime Environment (build 23.0.1+11-39)
> OpenJDK 64-Bit Server VM (build 23.0.1+11-39, mixed mode, sharing)
> 
> virt at virtdeb:~$ fcitx5 -v
> 5.0.21
> 
> 
> After tested, I found that what you said is true. Forgot what I said, go ahead.
> 
> Thanks again for your(@tsayao / @beldenfox ) amazing working.
> [Screencast from 2024-12-12 17-55-44.webm](https://github.com/user-attachments/assets/d2935d8a-9a5a-4603-a9d0-23f59b2b8f4d)

Finally, I got the point. Fcitx5 has a setting entry: `Show preedit in application`. If this is on, it works well. If this is off, the value `im_ctx.on_preedit` will get `false` when im(`fcitx5`) finished input-action. Then, the input will not show in the TextField.

![wechat_2024-12-12_193021_345](https://github.com/user-attachments/assets/9cab3844-8166-43fe-b69d-bda00f422e90)

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PR Review Comment: https://git.openjdk.org/jfx/pull/1080#discussion_r1881903187