incorrectly handle insertText (macOS)

[ksqsf]

Description

Description

Currently, the implementation of insertText is insufficient to cover some input methods that can commit text without setting a preedit. (e.g. when the input method translates a certain key and directly commits the translation.)

Known affected downstream programs include Alacritty and Neovide.

Examples

• A typical example is the full-width punctuation. If you hit the period key with the input method enabled, it will commit 。 to the program without ever setting a preedit.
• Another example is SKK-style Japanese input methods, with which, e.g. a directly commits あ without any preedit. Currently, both full-width punctuation and SKK Japanese input method doesn't work properly.

Analysis

Upon inspection, I found that insertText will only commit text when there is a preedit. (Hence the description above.)

I removed the condition and it almost worked for me. However, it seems to be added in commit 3fd7384 for a good reason.

winit/src/platform_impl/apple/appkit/view.rs

Lines 406 to 411 in 7e819bb

	// Commit only if we have marked text.
	if unsafe { self.hasMarkedText() } && self.is_ime_enabled() && !is_control {
	self.queue_event(WindowEvent::Ime(Ime::Preedit(String::new(), None)));
	self.queue_event(WindowEvent::Ime(Ime::Commit(string)));
	self.ivars().ime_state.set(ImeState::Committed);
	}

Notes

By "almost" above, I mean it's still not fully satisfactory.

• On startup, the IME is disabled and only gets enabled after a preedit is set once. That is, for full-width punctuation to work, one has to input something to enter the IME state. For SKK, the situation could get a bit problematic. This should also be fixed. (I think this probably belongs to a separate issue? It could be fixed by setting Ground to be the default. But I might be missing some details here.)
• Some input methods support toggle keys. For example, in SKK, q toggles Hiragana and Katagana input. If I removed the preedit check, whenever I type q, the input method can receive q (toggling katagana) and another q will also be forwarded to the application.

Another thing is that I noticed the system input methods can commit full-width punctuation just fine. But to my surprise I didn't manage to find any difference in the logs. So I don't really understand what's going on.

macOS version

ProductName:		macOS
ProductVersion:		15.0
BuildVersion:		24A335

Winit version

0.30.3