flutter_scroll_to_top

a wrapper to show a scroll to top prompt to the user on scrollable widgets.

installing

add the following dependency to your pubspec.yaml file:

dependencies:
  flutter_scroll_to_top: ^1.1.0

import the package

import 'package:flutter_scroll_to_top/flutter_scroll_to_top.dart';

scrollwrapper

just wrap the scrollable widget you want to show the scroll to top prompt over with a scrollwrapper, and supply the scrollcontroller of the scrollable widget to the wrapper.

scrollwrapper(
        scrollcontroller: scrollcontroller,
        child: listview.builder(
          controller: scrollcontroller,
          itembuilder: (context, index) => padding(
            padding: const edgeinsets.all(8.0),
            child: listtile(
              title: text('tile $index'),
              tilecolor: colors.grey.shade200,
            ),
          ),
        ),
      ),

customisation

you can pass the following parameters to customise the prompt accordingly

• promptscrolloffset – at what scroll offset to show the prompt on.
• promptalignment – where on the widget to align the prompt.
• promptduration – duration it takes for the prompt to come into view/vanish.
• promptanimationcurve – animation curve that the prompt will follow when coming into view.
• promptanimationtype – promptanimation that the prompt follows when animating. has three options, fade, scale and size.
• scrolltotopduration – duration it takes for the page to scroll to the top on prompt button press.
• scrolltotopcurve – animation curve for scrolling to the top.
• prompttheme – you can pass promptbuttontheme to modify the prompt button further. it has the following parameters:
  • padding – padding around the prompt button.
  • iconpadding – padding around the icon inside the button.
  • icon – the icon inside the button.
  • color – color of the prompt button.

scrollwrapper(
        scrollcontroller: scrollcontroller,
        promptalignment: alignment.topcenter,
        promptanimationcurve: curves.elasticinout,
        promptduration: duration(milliseconds: 400),
        promptscrolloffset: 300,
        prompttheme: promptbuttontheme(
            icon: icon(icons.arrow_circle_up, color: colors.amber),
            color: colors.deeppurpleaccent,
            iconpadding: edgeinsets.all(16),
            padding: edgeinsets.all(32)),
        child: listview.builder(
          controller: scrollcontroller,
          itembuilder: (context, index) => padding(
            padding: const edgeinsets.all(8.0),
            child: listtile(
              title: text('tile $index'),
              tilecolor: colors.grey.shade200,
            ),
          ),
        ),
      ),

custom prompt widget

you can replace the default prompt widget with a widget of your choosing by passing it off in the promptreplacementbuilder parameter.

scrollwrapper(
        scrollcontroller: scrollcontroller,
        promptreplacementbuilder: (buildcontext context, function scrolltotop) {
          return materialbutton(
            onpressed: () {
              scrolltotop();
            },
            child: text('scroll to top'),
          );
        },
        child: listview.builder(
          controller: scrollcontroller,
          itembuilder: (context, index) => padding(
            padding: const edgeinsets.all(8.0),
            child: listtile(
              title: text('tile $index'),
              tilecolor: colors.grey.shade200,
            ),
          ),
        ),
      )

nestedscrollview implementation

the implementation is similar, just wrap your scrollable body with the scrollwrapper and pass off the controller of the parent nestsedscrollview to the wrapper.

check the example for code.