Spec draft: Support adaptive elements for title of ChoiceSet/Toggle

[andrewleader]

Solves requests

• Ability for ChoiceSet and Toggle text to wrap so that the text is all displayed (Request: Ability for ChoiceSet and Toggle text to wrap so that the text is all displayed #1821)
• Rich content inside Toggle rather than just a string of text (Request: Rich content inside Toggle rather than just a string of text #1981)

Summary

Allow specifying adaptive elements for the toggles and choice sets. That way, when authors also want to control the text size, or max lines, or use images, we don't have to add new properties for each of those - we already have those properties on TextBlock, etc.

Schema

New property on Input.Toggle and Input.ChoiceSet

Property	Type	Required	Description
content	AdaptiveElement	false	A rich adaptive element to be displayed instead of the string-based title.

Example

{
  "type": "Input.Toggle",
  "title": "This is a very long title",
  "content": {
    "type": "TextBlock",
    "text": "This is a very long title",
    "wrap": true
  }
}

Host Config

No changes.

Down-level impact

Low. The rich content doesn't get displayed, but it never did anyways. The title is a required property, so authors will always have to provide it, so their cards will still work well down-level even if they're not explicitly designing for it.

Host burden

None. Renderer handles it all.

Renderer Requirements

1. A renderer should display the content instead of the title if possible.

[andrewleader]

Proposal approved. Note however that we need to look at priorities and see if we should do this in 1.2 or not, since the text wrapping feature is being handled by a more simple proposal of just adding a wrap property. So this feature would specifically be solving requests for richer content.