Fix autocomplete not triggering on mobile (CM5 input handling)

[aashu2006]

Issue:

Fixes #4007

This PR builds on the issue identified and discussed by @skyash-dev and me at Discord. We focused on investigating the mobile input behavior in CodeMirror and then I implementing a fix for the autocomplete trigger.

Autocomplete suggestions were not triggering reliably on mobile devices due to differences in CodeMirror’s input handling (IME + contenteditable path in CM5)

Demo:

Tested on a real Android device (Chrome). Autocomplete now appears while typing with the virtual keyboard.

Changes:

• Added mobile compatible autocomplete triggering using:
  • change (desktop input)
  • compositionend (word commit on mobile)
  • compositionupdate (IME typing support)
• Introduced triggerHint helper to unify logic
• Handled trailing spaces e.g. "bac " to ensure correct token detection
• Cleaned up debug code and simplified the logic

Notes:

• This PR focuses on fixing the autocomplete trigger issue on mobile (CM5).
• Keyboard focus behavior (virtual keyboard closing on suggestions) is not addressed here and I am thinking of handling it separately from this.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• has no typecheck errors (npm run typecheck)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123
• meets the standards outlined in the accessibility guidelines

[aashu2006]

@raclim would appreciate your thoughts here as well, especially since this relates to the earlier discussion around mobile autocomplete behavior, thanks!

[raclim]

Thanks so much for your collaboration on this @aashu2006 and @skyash-dev, it's really awesome to see how the both of you pulled this together! I think this looks great, and will hold the fort until CM6 comes out!

[skyash-dev]

@aashu2006 last time when i tested this mobile keyboard issue was not solved...

is this solved?

ref: "the keyboard closes when the hint menu appears because focus seems to shift away from the editor. i tried removing .click() usage, preventing default on hint interactions, and simplifying to e.pick()-based selection, but it still closes the keyboard."

[aashu2006]

@skyash-dev Yes, the autocomplete trigger part is fixed now, but the keyboard still closes on mobile when the hint menu appears.

I did try few approaches like refocusing after showHint, preventing default on hint interactions, tweaking some CM5 internals, but couldn’t resolve it. mentioned this on Discord as well.. seems like it’s tied more to how the browser/CM5 handles the hint UI.

we handle this as a follow up PR since it’s a separate issue from the trigger fix.