After a switch, which IME state is current must remain continuously visible

What it is

After the switch, people still have to know, continuously, whether they are in pinyin or English, half-width or full-width, kana or direct input. Continuously visible means the state stays in view for the whole typing session, not a one-frame flash on the switch key. An 8-pixel “中” in the tray, a menu bar covered by a full-screen app, or a globe that exists only while the keyboard is up all equal blindness after the switch. Visibility answers “which layer am I on now,” not “how do I get there.”

Why it happens

IME state is a classic mode: the same physical key emits entirely different characters or composition strings. Mode errors classically follow from invisible state. Full screen, immersive players, games, and remote desktop clip the system tray; the web fullscreen API does too. After a soft keyboard dismisses, the status icon leaves with it, and the next focus cannot know the language until the keyboard rises again. While a candidate bar is up, gaze is on candidates, not a corner language icon, so the indicator belongs near the caret or on the keyboard itself. Drawing the state in Settings is not continuous visibility.

Studying it

With tray visible, tray occluded, and a badge beside the caret, have people type text that must match the current language immediately after a switch, and score mode errors (English intended, pinyin letters came out). Report full-screen and windowed separately. Eye tracking shows whether they looked at the indicator before the error. Do not only ask “do you know you are in Chinese”—verbal report overestimates.

Where it stops holding

Always-monolingual scenes with no half/full-width almost never look at the indicator, but it still serves occasional mis-switches. A hardware Caps Lock lamp must not stand in for IME; that is another state. Screen readers need the state change spoken; a visual badge is not enough. For eyes-free typists, an audible switch sound or haptic may beat an icon, but it must remain a queryable channel, not a one-shot click at the moment of switching.

Applying it

• Full-screen and immersive UIs should draw their own input-source badge on the caret or along the keyboard, not rely on a tray that may be clipped.
• Confirm a change with a short sound or badge motion, then keep the badge until the next switch.
• In web fullscreen, indicate via the browser or a custom badge so users are not reduced to trial-and-error on the current language.
• Verify by entering product fullscreen, switching source, and—without looking at the system menu bar—naming the current language and typing the first word correctly. If they must leave fullscreen to know, the indicator failed.

Related

• Same group: C6.25.1 Switching IMEs itself costs an operation—a chord, an icon click, or a gesture · C6.25.3 Whether IME state is kept when focus moves between apps differs by platform · C6.25.4 IME state and Caps Lock are independent states that are often confused
• Adjacent: C6.12 IME candidates · C6.21 Dead keys and layered layouts
• Search: IME indicator · mode visibility · input source badge