Add sheetVisibility to ModalSheetRouteMixin
ModalSheetRouteMixin.sheetVisibility has been added, an Animation<double> that reports how much of the sheet is visible in a modal route. It can be used, for example, to easily create custom modal barriers that change its opacity or blurriness based on the sheet's visibility, something like this:
screen-20260802-183350-1785663219580.mp4.2.mp4
See the API documentation and this example for more details.