RFC 5 · Where should the IME candidate window appear when input is vertical?

[jihoons0]

Labels: RFC ime

CJK Input Method Editors render the candidate window horizontally by default. In a vertical context it must not cover the composition point — but platform IME APIs rarely expose enough control to place it well, which is part of why text-field keeps the input horizontal while the label is vertical.

Where it shows up here: search, text-field.

Open questions:

• Is a deliberately horizontal input the right trade, or can a truly vertical composition surface work today?
• What can be influenced through writing-mode + caret positioning vs. what is locked by the OS IME?
• How should the candidate window behave differently across macOS/iOS/Windows/Android?

Write-up: https://vertically.works/challenges#ime-vertical
Propose your answer as a PR. Strong answers get merged into the spec.