Flutter Awesome Way To Do Overlays

What the Google Flutter GDE’s will not tell you is that the Flutter SDK Overlay and OverlayEntry combo sucks, as it’s not declarative, and thus you cannot reliably theme it. I am going to show you instead how to use the Flutter Portal package, which is basically a declarative overlay system.

Flutter Portal

Flutter Portal was started by Remi Rousselet who is the original developer of the Provider package. It’s now kept up-to-date by Fzyzcjy:

flutter_portal | Flutter Package

Now, let me explain the small API. We have a Portal widget that has a child parameter and can have a PortalTarget and PortalFollower that are rendered. An Anchor tells how the PortalFollower element should be positioned in the layout in relation to the target. A PortalTarget will render its followers in a different part of the widget tree:

Flutter Portal API docs