Added TokenizingTextBox automation peer

[jamesmcroft]

Fixes #3910

Introduce an automation peer for the TokenizingTextBox based on a ListViewBaseAutomationPeer with the additional IValueProvider capability to return the value of the autosuggest text box.

This change improves the UI automation tree hierarchy to ensure that the control and its children are nested correctly.

PR Type

What kind of change does this PR introduce?

• Feature

What is the current behavior?

The TokenizingTextBox does not have an automation peer.

What is the new behavior?

An automation peer has been introduced that improves the interaction of the control through UI automation tooling.

The change includes the ability to interact with the AutoSuggestBox element by getting and setting the text value, and surfacing up through the automation peer.

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Pull Request has been submitted to the documentation repository instructions. Link:
• Sample in sample app has been added / updated (for bug fixes / features)
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• New major technical changes in the toolkit have or will be added to the Wiki e.g. build changes, source generators, testing infrastructure, sample creation changes, etc...
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Header has been added to all new source files (run build/UpdateHeaders.bat)
• Contains NO breaking changes

Other information

[ghost]

Thanks jamesmcroft for opening a Pull Request! The reviewers will test the PR and highlight if there is any conflict or changes required. If the PR is approved we will proceed to merge the pull request 🙌

[michael-hawker]

Thanks @jamesmcroft! We'll check this out with the accessibility tools. It should show up with Narrator, eh? @Kyaa-dost think you could test it out too and compare against the current store based sample app?

@azchohfi I think this would be a candidate to possibly take for 7.0.1 for added value to fix some accessibility? Assuming we can close on it soon and are still waiting on the Notifications and Sample App Caching fixes?

[michael-hawker]

@jamesmcroft build error:

 D:\a\1\s\Microsoft.Toolkit.Uwp.UI.Controls.Input\TokenizingTextBox\TokenizingTextBoxAutomationPeer.cs(32,21): error SA1623: The property's documentation summary text should begin with: 'Gets a value indicating whether' [D:\a\1\s\Microsoft.Toolkit.Uwp.UI.Controls.Input\Microsoft.Toolkit.Uwp.UI.Controls.Input.csproj]

[jamesmcroft]

@jamesmcroft build error:

 D:\a\1\s\Microsoft.Toolkit.Uwp.UI.Controls.Input\TokenizingTextBox\TokenizingTextBoxAutomationPeer.cs(32,21): error SA1623: The property's documentation summary text should begin with: 'Gets a value indicating whether' [D:\a\1\s\Microsoft.Toolkit.Uwp.UI.Controls.Input\Microsoft.Toolkit.Uwp.UI.Controls.Input.csproj]

Apologies @michael-hawker, I copied the comments from the base implementation on that one. Should be sorted now

[michael-hawker]

I forgot to flag this to 7.0.1 and already kicked it off. We didn't have a tracking issue either, so forgot about that too. We'll still get it reviewed soon and merged though for whichever next release we do.

[jamesmcroft]

I forgot to flag this to 7.0.1 and already kicked it off. We didn't have a tracking issue either, so forgot about that too. We'll still get it reviewed soon and merged though for whichever next release we do.

Sorry that was my bad. I was working through bringing more WCT control support to Legerity.

I chose this one then got blocked so came to put a fix in, completely forgot to raise an item. I'll sort that out and link

[Rosuavio]

Tested with narrator, the behavior seems very usable, but I just have a few question.

[jamesmcroft]

Tested with narrator, the behavior seems very usable, but I just have a few question.

I think the suggestions were fair. The likelihood of someone using whitespace for these values is probably slim 👍

[Rosuavio]

Thanks @jamesmcroft, it's looking good!

[marcelwgn]

I think it's worth adding a test ensuring that the actual list of tokens is also being presented to UIA. Currently, we wouldn't notice if this breaks and as such leaving out crucial information to users using UIA.

[jamesmcroft]

Apologies for the huge delay looking into these comments. I've added the additional test for checking the children of the automation peer.

To select the items, I used the SelectAllTokensAndText method on the TokenizingTextBox but noted in the test, this will select an empty text item and append it to the collection.

[michael-hawker]

@jamesmcroft think you can address @chingucoding's comments?

[michael-hawker]

Thanks @jamesmcroft! @chingucoding this look good to you now? Might make sense to merge this one before your other TTB PR #4101? (though I don't think they conflict)

[marcelwgn]

Looks good to me, thank you for adding the automation peer and making TokenizingTextBox accessible @jamesmcroft ! @michael-hawker I think we can merge this now, this shouldn't interfere with my PR (and if it does, so be it) :)