Windows Japanese IME conversion pop-up behaves strangely

[yuriks]

Is your issue REALLY a bug?

• My issue is indeed a bug!
• I am not crazy! I will not fill out this form just to ask a question or request a feature. Pinky promise.

Is there an existing issue for this?

• I have searched the existing issues.

Is this issue related to iced?

• My hardware is compatible and my graphics drivers are up-to-date.

What happened?

Appears to be similar to #2792 but on Windows and with different criteria triggering it.

When trying to input text using the Windows Japanese IME, the kanji conversion popup behaves strangely in seemingly random ways. These are unfortunately not reliably reproducible, but appear to be related to switching keyboard languages (using the Win+Space shortcut). The two behaviors I've seen are:

• When typing after alt-tabbing to the iced window, the first character typed additionally appears inside a tiny white box, this seems to be mostly reliable.
• When typing after switching layouts, and before typing any normal characters with the IME in latin mode (A instead of あ in the system tray), sometimes the conversion popup appears in the bottom-right corner of the screen. Usually, further popups will appear in the right place, but occasionally the bug "sticks" and they keep appearing on the corner of the screen. A reliable way to trigger this seems to be to start the iced app with a non-IME layout, immediately switch to the Japanese IME, then out of latin mode with Alt-`, and type a character. (See second video below.)

Unfortunately I have not been able to find 100% reliable ways of triggering each issue. But here's a video demonstrating both problems on the iced Todos example: (though the same thing happens in a simple app containing just a textbox.)

explorer_4dwqoe5iSm.mp4

explorer_SBXixfO4cB.mp4

What is the expected behavior?

• No extraneous white box with the first typed character.
• Conversion popup reliably appears below the cursor.

Version

master

Operating System

Windows

Do you have any log output?