polls: Add UI feedback on vote button while request pending

[gnprice]

Voting in a Zulip poll can be slow — roughly 700-800ms in recent testing on chat.zulip.org, measuring from the vote request to when the resulting event arrives at the client: #mobile > /poll on Mobile App @ 💬

While that request is outstanding, we currently don't show any UI feedback indicating that something's happening. This can make it appear that the vote attempt just didn't work, resulting in reports like this:

polls aren't working too well on mobile app. There's no option shown to add new options once a poll has been made [i.e., #167], and voting is also glitchy

We should add some feedback.

A minimal version would be an ink-splash just for tapping the button, without tying it to the vote request or the resulting event. That would give some reassurance that the button-tap was received.

A fancier version would provide some indicator until the event is received: e.g. deactivate the button, and/or show a spinner.

References

• User report, and discussion thread: #mobile > /poll on Mobile App @ 💬

[MritunjayTiwari14]

Hello Moderators of Zulip Flutter, this is Mritunjay Tiwari. This is my first ever Contribution to Zulip.
Here are my solution:-

Implementation Video and Images:

record.mp4

I have researched many days about what are the best practices to implement a Circular Loading indicator, at the end i found that its very hard and not efficient to implement a Progress indicator to an unawaited process on which the Poll Request Depends, so i came up with a efficient solution by converting the unawaited process to await process so as to capture the moment easily of the loading and then implement a Circular loading indicator within the function itself.

Code Snippet:

If you guys agree with the solution, then i can proceed pushing the changes can creating a pull request.
Thank you.
@gnprice

[MritunjayTiwari14]

Edit: I accidentally uploaded the video i shoot without Touch Indicator On, Sorry for the large image size, i dont know how to make the screenshot size small as i am new to this posting things stuff.

[nooblag]

Thanks for the PR. Good to have something to start with.

[MritunjayTiwari14]

Thank you for your feedback. I have created a PR for the same. Please Have a look and notify if any UI related changes as per Zulip's need to be done.