Observe the currently selected theme. A value of undefined means no specific theme has been selected.
Get the current theme ID. Returns undefined if no specific theme is selected.
Get a list of available themes.
Set a specific theme to use in the app, overriding the default theme selection.
Clear the selection by passing in undefined.
OptionalthemeId: string
The AppThemeApi gives access to the current app theme, and allows switching to other options that have been registered as a part of the App.