scrollable_positioned_list_extended

A flutter list that allows scrolling to a specific item in the list.

Also allows determining what items are currently visible.

New ❇️

The package has recently got abilities of scroll_to_index. One can access AutoScrollController, but with certain limitations.

Note

This is an extension of scrollable_positioned_list, which exposes helper methods like scrollToMax extent, jumpToMax extent and also scrollListener to listen notifications which has not implemented in that yet.

Added Features

1. scrollToMax For scrolling to maximum extent.
2. jumpToMax For jumping to maximum extent.
3. scrollToMin For scrolling to minimum extent.
4. jumpToMin For jumping to minimum extent.
5. scrollListener For listening ScrollNotifications like current offset ScrollPostition here.
6. Access AutoScrollController() with ItemScrollController.getAutoScrollController. This method must be called after ensuring ItemScrollController.isAttached == true.

AutoScrollController? _autoScrollController;
...
    if ( itemScrollController.isAttached ){
       _autoScrollController = itemScrollController.getAutoScrollController;
    }
...      

Usage

A ScrollablePositionedList works much like the builder version of ListView except that the list can be scrolled or jumped to a specific item.

Example

A ScrollablePositionedList can be created with:

final ItemScrollController itemScrollController = ItemScrollController();
final ItemPositionsListener itemPositionsListener = ItemPositionsListener.create();

ScrollablePositionedList.builder(
  itemCount: 500,
  itemBuilder: (context, index) => Text('Item $index'),
  itemScrollController: itemScrollController,
  itemPositionsListener: itemPositionsListener,
);

One then can scroll to a particular item with:

itemScrollController.scrollTo(
  index: 150,
  duration: Duration(seconds: 2),
  curve: Curves.easeInOutCubic);

or jump to a particular item with:

itemScrollController.jumpTo(index: 150);

One can monitor what items are visible on screen with:

itemPositionsListener.itemPositions.addListener(() => ...);

One can listen to scrollNotifications of primary ScrollController

   itemScrollController.scrollListener(
        (notification) {
          debugPrint(notification.position.maxScrollExtent.toString());
          /// do with notification
        },
      );

One can scroll to max

itemScrollController.scrollToMax(
  duration: Duration(seconds: 2),
  curve: Curves.easeInOutCubic);

or jump to maxExtent:

itemScrollController.jumpToMax();

One can scroll to min

itemScrollController.scrollToMin(
  duration: Duration(seconds: 2),
  curve: Curves.easeInOutCubic);

or jump to minExtent:

itemScrollController.jumpToMin();

limitations

• ItemScrollController.getAutoScrollController doesn't works with below methods.

  1. highlight().
  2. cancelAllHighlights().
  3. jumpTo().

---

A full example can be found in the example folder.