An easy way to show a flutter custom popup widget.

cd ./example
flutter create .
flutter run

dependencies:
  easy_popup: ^1.0.0

Define your custom popup widget with EasyPopupChild, and implement dismiss function which does work that need to be done while dismiss, eg. show dismiss animation

class CustomWidget extends StatefulWidget with EasyPopupChild {

  ...

  @override
  dismiss() {
    ...
  }
}

EasyPopup.show(context, CustomWidget());