iOS TextField, Japanese conversion candidates not showing with physical Romaji keyboard input

[paxbun]

Describe the bug

• Conversion candidate list is not showing with physical Romaji keyboard input
• When the return key is pressed, the conversion result is duplicated.
• When the backspace key is pressed, the last character of the phrase to be converted is duplicated.

The latter two bugs are fixed by JetBrains/compose-multiplatform-core#699.

Affected platforms

• iOS

Versions

• Kotlin version*: 1.8.20
• Compose Multiplatform version*: 1.4.1
• OS version(s)* (required for Desktop and iOS issues): 16.5.1
• OS architecture (x86 or arm64): arm64

To Reproduce

1. Modify the App.kt of the Android & iOS template like the following.

MaterialTheme {
    Column {
        Text("OS: ${getPlatformName()}")
        var text by remember { mutableStateOf(TextFieldValue()) }
        TextField(text, onValueChange = { text = it })
    }
}

2. Type "kousyou" with Romaji keyboard input.

   kousyou こうしょう can be converted into many sino-japanese words (e.g., 交渉 or 公証). You can see a list of 51 candidates here.
   kousyou and koushou are equivalent.

3. Press the <space> or <down arrow> keys.

   This must show the full list of conversion candidates of kousyou こうしょう.

4. Press the <return> key to end the conversion.

   You can see that 交渉 is duplicated.
   With Support singleLine and KeyboardAction on iOS compose-multiplatform-core#699, 交渉 is not duplicated.

5. Type "kousho" (Not the u at the end!) with Romaji keyboard input.

   kousho corresponds to こうしょ.

6. Press the <backspace> key.

   Since the text field contained こうしょ, the text field must contain こうし now, but you can see the text field contains こうしこうし.
   With Support singleLine and KeyboardAction on iOS compose-multiplatform-core#699, こうし is not duplicated.

Expected behavior
The candidate list must appear near the text field. For example, in the system-default Notes app:

RPReplay_Final1690426965.MP4

Screenshots
Reproduction:

RPReplay_Final1690426818.MP4

Reproduction with JetBrains/compose-multiplatform-core#699:

RPReplay_Final1690427408.MP4

Additional context
For those not used to the Japanese writing system, please refer to the Wikipedia page.

[dima-avdeev-jb]

Thanks for such a greate description!

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.