Decide what to do about text input on iOS

[gnprice]

​There are several issues in the Flutter tracker where people are unhappy with the Flutter text-input widget, mainly on iOS.

Our basic options for handling this are:

• Live with the issues.
• Dig into a couple of the issues that most affect us, and fix those. Live with the rest.
• Use a native text-input widget instead.
  • There's an existing plugin flutter_native_text_input some people have built for this. Or we could build our own, using Flutter's general facilities for interoperating with platform features.
  • This is effectively what we already get in the React Native app.

This is an umbrella issue for exploring the different options and deciding what to go with.

Some particular Zulip features we should build in order to best explore text inputs:

• A compose box: compose: Prototype compose box, using Material TextField widget #9.
• Autocomplete/typeahead in the message part of the compose box, in particular @-mention typeahead/autocomplete #49.

We should also:

• Experiment with a native iOS text input #48

[gnprice]

Details on specific Flutter issues in this category:

• Emoji size is off on iOS flutter/flutter#28894

  • Some people on that thread are direly unhappy: “not usable for any typing intensive app (social media, chat, …”; “all people trying my app candidly described textfield as ‘weird’ and ‘defective’: weird/ugly emojis, [other non-emoji issues]”
  • The issue turns out to be in SkParagraph (part of Skia, a layer below Flutter). It actually reproduces in Chrome on iOS, with no Flutter involved.

• Autocorrect tooltips don't appear on iOS flutter/flutter#12920

  • Only appears if a certain system setting is off. More context:

    What I've noticed is that people who are long time iPhone users have this feature disabled by default and don't even know it exists. If you're using an iPhone on an account that isn't many years old then you might not realize that iOS had this tooltip feature. It seems that when this feature was added it was disabled by default and saved to iCloud settings. But new accounts have it enabled by default.

  • Descriptions of impact:

    I just had a UX testing session with someone entering tags and they were having a really hard time getting by without tooltips. They noticed it within 3 seconds of typing and it was a serious usability issue.
    /
    [When this applies,] the typing experience is simply broken. Some replacements that are usually shown using the white tooltip before being applied do not appear, creating confusion and straight inability to prevent said replacement.

• (fixed 2023-01) Dragging the iOS text selection handles is jumpy flutter/flutter#106703

[gnprice]

We'll stick with Flutter's own text input. We haven't heard anything from our own users about the sorts of issues above; if we do, we can invest in getting them fixed upstream.