RFR: 8305418: [Linux] Replace obsolete XIM as Input Method Editor [v17]

[Martin Fox]

On Mon, 25 Dec 2023 20:48:09 GMT, Thiago Milczarek Sayao <tsayao at openjdk.org> wrote:

>> This replaces obsolete XIM and uses gtk api for IME.
>> Gtk uses [ibus](https://github.com/ibus/ibus)
>> 
>> Gtk3+ uses relative positioning (as Wayland does), so I've added a Relative positioning on `InputMethodRequest`.
>> 
>> [Screencast from 17-09-2023 21:59:04.webm](https://github.com/openjdk/jfx/assets/30704286/6c398e39-55a3-4420-86a2-beff07b549d3)
>
> Thiago Milczarek Sayao has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add check for jview

modules/javafx.graphics/src/main/native-glass/gtk/glass_window_ime.cpp line 163:

> 161:         g_signal_connect(im_ctx.ctx, "preedit-changed", G_CALLBACK(on_preedit_changed), this);
> 162:         g_signal_connect(im_ctx.ctx, "preedit-end", G_CALLBACK(on_preedit_end), this);
> 163:         g_signal_connect(im_ctx.ctx, "commit", G_CALLBACK(on_commit), this);

On Ubuntu 22.04 using the Japanese (Mozc) input method I get a bunch of debug output from IBus. The message reads

`IBUS-WARNING **: 08:50:12.994: java has no capability of surrounding-text feature`

I was able to silence this by connecting to the surrounding text signal and simply returning TRUE from the callback.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1080#discussion_r1439638790