Disable scroll at negative index ListView, ScrollPhysics flutter

Question

I am using this indexed_list_view extension to jump to a particular index in my finite ListView. This extension has limitations because of which if I scroll in the reverse direction, empty space is visible.

Limitation(as written on package readme): The list is always infinite both to positive and negative indexes. In other words, it can be scrolled indefinitely both to the top and to the bottom.

I want to disable reverse swipe when at first index in my ListView. I am using custom scroll physics to disable the left swipe, but I want to modify it so that the reverse scroll is disabled at top of the ListView, not always. Any help would be highly appreciable. Thanks.

import 'package:flutter/material.dart';

class CustomScrollPhysics extends ScrollPhysics {
  CustomScrollPhysics({ScrollPhysics? parent}) : super(parent: parent);

  bool isGoingLeft = false;

  @override
  ScrollPhysics applyTo(ScrollPhysics? ancestor) {
    return CustomScrollPhysics(parent: buildParent(ancestor)!);
  }

  @override
  double applyPhysicsToUserOffset(ScrollMetrics position, double offset) {
    isGoingLeft = offset < 0;
    return offset;
  }

  @override
  double applyBoundaryConditions(ScrollMetrics position, double value) {
    //print("applyBoundaryConditions");
    assert(() {
      if (value == position.pixels) {
        throw FlutterError(
            '$runtimeType.applyBoundaryConditions() was called redundantly.\n'
            'The proposed new position, $value, is exactly equal to the current position of the '
            'given ${position.runtimeType}, ${position.pixels}.\n'
            'The applyBoundaryConditions method should only be called when the value is '
            'going to actually change the pixels, otherwise it is redundant.\n'
            'The physics object in question was:\n'
            '  $this\n'
            'The position object in question was:\n'
            '  $position\n');
      }
      return true;
    }());
    if (value < position.pixels &&
        position.pixels <= position.minScrollExtent) {
      return value - position.pixels;
    }
    if (position.maxScrollExtent <= position.pixels &&
        position.pixels < value) {
      return value - position.pixels;
    }
    if (value < position.minScrollExtent &&
        position.minScrollExtent < position.pixels) {
      return value - position.minScrollExtent;
    }

    if (position.pixels < position.maxScrollExtent &&
        position.maxScrollExtent < value) {
      return value - position.maxScrollExtent;
    }

    if (!isGoingLeft) {
      return value - position.pixels;
    }
    return 0.0;
  }
}

Answer 1

I think if you just apply a controller to the ListView it should stop scrolling negatively.