carousel_options.dart

import 'package:flutter/material.dart';

enum CarouselPageChangedReason { timed, manual, controller }

enum CenterPageEnlargeStrategy { scale, height }

class CarouselOptions {
  /// Set carousel height and overrides any existing [aspectRatio].
  final double? height;

  /// Aspect ratio is used if no height have been declared.
  ///
  /// Defaults to 16:9 aspect ratio.
  final double aspectRatio;

  /// The fraction of the viewport that each page should occupy.
  ///
  /// Defaults to 0.8, which means each page fills 80% of the carousel.
  final double viewportFraction;

  /// The initial page to show when first creating the [CarouselSlider].
  ///
  /// Defaults to 0.
  final int initialPage;

  ///Determines if carousel should loop infinitely or be limited to item length.
  ///
  ///Defaults to true, i.e. infinite loop.
  final bool enableInfiniteScroll;

  /// Reverse the order of items if set to true.
  ///
  /// Defaults to false.
  final bool reverse;

  /// Enables auto play, sliding one page at a time.
  ///
  /// Use [autoPlayInterval] to determent the frequency of slides.
  /// Defaults to false.
  final bool autoPlay;

  /// Sets Duration to determent the frequency of slides when
  ///
  /// [autoPlay] is set to true.
  /// Defaults to 4 seconds.
  final Duration autoPlayInterval;

  /// The animation duration between two transitioning pages while in auto playback.
  ///
  /// Defaults to 800 ms.
  final Duration autoPlayAnimationDuration;

  /// Determines the animation curve physics.
  ///
  /// Defaults to [Curves.fastOutSlowIn].
  final Curve autoPlayCurve;

  /// Determines if current page should be larger then the side images,
  /// creating a feeling of depth in the carousel.
  ///
  /// Defaults to false.
  final bool? enlargeCenterPage;

  /// The axis along which the page view scrolls.
  ///
  /// Defaults to [Axis.horizontal].
  final Axis scrollDirection;

  /// Called whenever the page in the center of the viewport changes.
  final Function(int index, CarouselPageChangedReason reason)? onPageChanged;

  /// Called whenever the carousel is scrolled
  final ValueChanged<double?>? onScrolled;

  /// How the carousel should respond to user input.
  ///
  /// For example, determines how the items continues to animate after the
  /// user stops dragging the page view.
  ///
  /// The physics are modified to snap to page boundaries using
  /// [PageScrollPhysics] prior to being used.
  ///
  /// Defaults to matching platform conventions.
  final ScrollPhysics? scrollPhysics;

  /// Set to false to disable page snapping, useful for custom scroll behavior.
  ///
  /// Default to `true`.
  final bool pageSnapping;

  /// If `true`, the auto play function will be paused when user is interacting with
  /// the carousel, and will be resumed when user finish interacting.
  /// Default to `true`.
  final bool pauseAutoPlayOnTouch;

  /// If `true`, the auto play function will be paused when user is calling
  /// pageController's `nextPage` or `previousPage` or `animateToPage` method.
  /// And after the animation complete, the auto play will be resumed.
  /// Default to `true`.
  final bool pauseAutoPlayOnManualNavigate;

  /// If `enableInfiniteScroll` is `false`, and `autoPlay` is `true`, this option
  /// decide the carousel should go to the first item when it reach the last item or not.
  /// If set to `true`, the auto play will be paused when it reach the last item.
  /// If set to `false`, the auto play function will animate to the first item when it was
  /// in the last item.
  final bool pauseAutoPlayInFiniteScroll;

  /// Pass a `PageStoragekey` if you want to keep the pageview's position when it was recreated.
  final PageStorageKey? pageViewKey;

  /// Use `enlargeStrategy` to determine which method to enlarge the center page.
  final CenterPageEnlargeStrategy enlargeStrategy;

  /// Whether or not to disable the `Center` widget for each slide.
  final bool disableCenter;

  CarouselOptions({
    this.height,
    this.aspectRatio: 16 / 9,
    this.viewportFraction: 0.8,
    this.initialPage: 0,
    this.enableInfiniteScroll: true,
    this.reverse: false,
    this.autoPlay: false,
    this.autoPlayInterval: const Duration(seconds: 4),
    this.autoPlayAnimationDuration = const Duration(milliseconds: 800),
    this.autoPlayCurve: Curves.fastOutSlowIn,
    this.enlargeCenterPage = false,
    this.onPageChanged,
    this.onScrolled,
    this.scrollPhysics,
    this.pageSnapping = true,
    this.scrollDirection: Axis.horizontal,
    this.pauseAutoPlayOnTouch: true,
    this.pauseAutoPlayOnManualNavigate: true,
    this.pauseAutoPlayInFiniteScroll: false,
    this.pageViewKey,
    this.enlargeStrategy: CenterPageEnlargeStrategy.scale,
    this.disableCenter: false,
  });
}