Hojun-Cho
bfcd9f6786
Backspace, Enter, Tab, Escape and the arrow and page keys are matched by keysym alone -- strans.c:852, 875 and 882 name them, and searchkey names the same set at strans.c:746-786. Every other key above Kspec falls through to the catch-all at strans.c:898, `ks >= Kspec || chord(mod)`, and goes to the application. So the special keys strans knows by name are the ones it takes under a modifier, and the ones it does not know are the ones it hands over. That is backwards: a named special key under a modifier is exactly the one the application has a binding for. In Korean a syllable is pending for nearly all the time anyone is typing, ko.c holding one and no more, and the guards at strans.c:876 and 883 return 0 only when nothing is pending -- so the key is eaten precisely when it is wanted. Type 안녕하세요 and reach for Ctrl+Backspace to take the word back: 요 loses ㅛ, then ㅇ, and the word itself goes on the third press. Ctrl+Enter in a chat box, Ctrl+Tab in a browser and Ctrl+PageDown in either are the same key eaten by the same lines. before after Korean 가, Ctrl+Backspace eaten, pre ㄱ passed, commit 가 Korean 가, Alt+Backspace eaten, pre ㄱ passed, commit 가 Korean 가, Super+Backspace eaten, pre ㄱ passed, commit 가 Korean 가, Backspace eaten, pre ㄱ unchanged Korean 가, Shift+Backspace eaten, pre ㄱ unchanged かく, Ctrl+Enter eaten, commit かく passed, commit かく かく, Ctrl+Tab eaten, commit かく passed, commit かく かく Space, Ctrl+PageDown eaten, sel 0 -> 9 passed, commit 確 かく Space, PageDown eaten, sel 0 -> 9 unchanged かく Space, Shift+Tab eaten, sel 0 -> 30 unchanged Ctrl+E sm, Ctrl+Backspace eaten, query s passed, commit sm Ctrl+E sm, Backspace eaten, query s unchanged chord() cannot be reused here. It is `(mod & ~Mshift) != 0 && mod != Mctrl` and the exclusion is deliberate, since Ctrl+letter is strans's whole command set and chord() has to let plain Ctrl through. The rule this needs is the other one -- any modifier that is not Shift -- and Shift must stay in: Shift+Tab cycles the candidates backwards, pinned by engine/candidate-completion and engine/emoji-navigation at engine_test.c:914 and 1649, and Shift on a Korean key is what makes ㅃ. One line serves both paths because it sits above the searchkey dispatch, and it has to sit below the switch at strans.c:829: 한자, 한/영, 変換 and 無変換 arrive as keys above Kspec and are rewritten there into the Ctrl chords they stand for. Above the switch, 한자 would commit and pass instead of opening the Hanja list; below it, pressing it with Ctrl held still opens the list, because the switch sets the modifier itself. What this does not cover: Space, which is below Kspec, so searchkey:763 still picks a candidate on Ctrl+Space inside a search. transition tests !(mod & ~Mshift) for its own Space at strans.c:865, so the two disagree there. Left alone: what Ctrl+Space should mean wants its own argument, not a widened guard.
7.5 KiB
strans
strans is a small, single-user input method for Korean, Japanese, English,
emoji and symbols, with Vietnamese Telex as a compatibility mode. One
engine serves four frontends: zwp_input_method_v2 on Wayland — sway and
any other compositor that offers it — IBus, which GTK 4 and Qt use, XIM,
and a GTK 3 module.
Modes
| Key | Mode |
|---|---|
Ctrl+S |
Korean Hangul (2-beolsik) |
Ctrl+N |
Japanese Hiragana, converting to Kanji |
Ctrl+K |
Japanese Katakana |
Ctrl+T |
English |
Ctrl+V |
Vietnamese Telex |
Ctrl+E |
Emoji and symbol search |
Ctrl+H |
One-shot Hanja and symbol search |
Only a plain Ctrl chord is a strans key: with Shift, Alt or Super
held it commits what is pending and goes to the application, so
Ctrl+Shift+V still pastes. Backspace, Enter, Tab, Esc and the
arrow and page keys do the same under Ctrl, so Ctrl+Backspace still
deletes a word. The mode switched to — 한, あ, ア, ă, A — shows
in the popup until the next key. A Korean keyboard's 한/영 and 한자 keys
stand for Ctrl+S/Ctrl+T and Ctrl+H; a Japanese one's 半角/全角,
ひらがな/カタカナ, 変換 and 無変換 for the kana modes, Space and English.
Composing
Japanese composes a whole reading and then offers its Kanji with none
chosen. Space and Tab step through the candidates and wrap (Shift
reverses), the reading in Katakana last, so a word the dictionary lacks
converts with one Space; Up/Down and PageUp/PageDown move without
wrapping. Enter commits the chosen candidate, or the reading, as 0 and
typing on always do. Once a candidate is chosen 1-9 take that row of
the page shown; before that the digits type. Backspace deletes the last
kana shown, and romaji that made no kana stays as typed until it is mended;
Esc cancels the reading, and on a chosen candidate both go back to it.
The dictionary keys verbs and adjectives by stem and okurigana, so kaku
offers かく's readings and then 書く and its kin — typing the okurigana
with Shift, as SKK does, kaKu, asks for that split first. Katakana
mode does not convert.
Korean composes one syllable at a time. Enter, Tab, Esc and any key
that is not a jamo commit the syllable and go on to the application, so
Esc still leaves insert mode. Two lone consonants join into the compound
final they make (rt → ㄳ), and a vowel typed before its consonant is
reordered under it (kr → 가), as in libhangul.
A search takes the keys until Enter, Space or 1-9 picks a result or
Esc cancels, then returns to the previous mode. Emoji matches the typed
keys, and what they spell in the current mode, against a prefix of every
emoji's CLDR name and keywords in English, Korean and Japanese, and against
ASCII aliases such as -> and <=. Ctrl+H takes the syllable being
composed as its query and composes on from it, converting a word as well as
a syllable — 한자 gives 漢字, 대한민국 gives 大韓民國 — and Esc gives the
syllable back. A lone consonant is a reading too, and answers with the
symbol table a Korean keyboard's 한자 key has always offered: ㅁ gives ※ ○
△ ㈜, ㄴ the brackets 「」『』, ㄹ the units ℃ ㎏ ℓ, ㅇ the circled numbers
①②③. Text already committed belongs to the application and cannot be
converted.
Dead keys and Compose sequences are composed by strans itself for the
Wayland, XIM and IBus frontends, from XCOMPOSEFILE or the locale; the
GTK 3 module leaves them to GtkIMContextSimple.
Preedit and candidates
| Frontend | Preedit | Candidates |
|---|---|---|
| Wayland input method | inline in the client | popup |
| GTK 3 and IBus | inline in the client | popup |
| XIM PreeditCallbacks | inline through XIM callbacks | popup |
| XIM PreeditPosition, PreeditNothing | popup | popup |
On Wayland the popup is a surface the compositor places at the text cursor,
flipping it above the line when there is no room below. Elsewhere it is an
X11 window, placed from the XIM spot or from the GTK caret, and XIM text
travels as COMPOUND_TEXT. Either way GDK_SCALE sizes it for HiDPI
displays.
Build and test
git submodule update --init
make docker-image
make docker-build
That leaves strans, the daemon, and gtk/im-strans.so, the GTK 3 module.
Tests come in three tiers:
make check # generated-map validation and unit tests
make check-live # one IBus, GTK, XIM and IPC daemon smoke each
make check-stress # randomized, capacity, collision, failure and restart
make docker-check runs all three in the container, and
make docker-valgrind the unit suite under Valgrind; rerun
make docker-image after changing Dockerfile. UNITARGS=hangul filters
the unit suite alone, not the other tiers.
A native build wants a C toolchain, Make, pkg-config and Plan 9 port, plus
development files for D-Bus, XCB and xcb-imdkit, Wayland and
wayland-scanner, xkbcommon, Pango and Cairo, and GTK 3; the tests also
want Xvfb, Python 3 and fonts covering Latin, CJK and emoji.
Dockerfile names the exact packages.
Run
./run.sh # restart the daemon in the background
./strans map # or run it in the foreground
./strans DIR reads hira.map, kata.map, telex.map, kanji.dict,
emoji.dict and hanja.dict from DIR at runtime; nothing but the GTK
module is installed. A service supervisor wants the session's
XDG_RUNTIME_DIR and its WAYLAND_DISPLAY or DISPLAY: the GTK module
finds the daemon at $XDG_RUNTIME_DIR/strans.sock, else
/tmp/strans.UID, and IBus clients through the address file libibus
expects under ~/.config/ibus/bus/, which strans writes as ibus-daemon
would.
strans shows one popup per session, so it picks a frontend at startup: a
compositor offering zwp_input_method_v2 gets the Wayland frontend, and
then neither XIM nor the X11 popup runs; every other session gets XIM. The
IBus endpoint and the GTK 3 module are served in both.
On Wayland, then, set none of the variables below. GTK, Qt and Firefox
speak text-input-v3 themselves — GTK 4 binds it with GTK_IM_MODULE unset
— and setting these is what pushes them off the path that works: such a
client still composes inline but shows no candidates, because the popup
belongs to the Wayland frontend. Chromium is beyond help either way, since
it asks for text-input-v1, which wlroots does not implement.
export XMODIFIERS=@im=strans # XIM
doas make -C gtk install # GTK 3 module
export GTK_IM_MODULE=strans
GLFW_IM_MODULE=ibus kitty # IBus client example
strans provides its own IBus endpoint, so ibus-daemon and fcitx are not
needed. Building the GTK module wants GTK development files; installing
one built elsewhere does not. The install target takes GTK_MODULE_DIR
when set, else asks GTK where its modules live; doas make -C gtk uninstall
removes it. With neither WAYLAND_DISPLAY nor DISPLAY the daemon still
serves IBus and its socket, but nothing draws a popup.
Dictionary data
After changing an input source, regenerate and verify:
python3 map/mktelex.py >map/telex.map
map/mkemoji >map/emoji.dict
map/mkhanja >map/hanja.dict
make verify-map
map/README says where the emoji, Hanja and Japanese data
comes from.
Benchmark
make bench builds bench/bench. With the daemon stopped, ./bench.sh
starts one, warms it up and records the workload with Linux perf into
bench/perf.data.
Licensing
Third-party notices are in LICENSES. The repository declares
no license for the strans source as a whole.