Support drag and drop

[stuartmorgan]

This will require #96, but also some notion of a widget being able to declare itself as a drag target and/or source.

It's not entirely clear how much of this will need to be on the native side vs. the Dart side. I suspect dropping into the app will be easier to support than dragging out, but both will require careful thought about how to straddle the native/Dart divide (e.g., how to track rectangles for drag targets).

[RazaGR]

lovely...
will it support dataType like in HTML? https://developer.mozilla.org/en-US/docs/Web/API/HTML_Drag_and_Drop_API/Recommended_drag_types
Text, Image, Files etc

[stuartmorgan]

I don't know what the specific API will look like, but if you are primarily asking whether this would support more than just text, yes.

[stuartmorgan]

Moved to flutter/flutter#30719