drag_and_drop_lists

Description:

drag and drop lists

drag_and_drop_lists #
Two-level drag and drop reorderable lists.
Features #

Reorder elements between multiple lists
Reorder lists
Drag and drop new elements from outside of the lists
Vertical or horizontal layout
Use with drag handles, long presses, or short presses
Expandable lists
Can be used in slivers
Prevent individual lists/elements from being able to be dragged
Easy to extend with custom layouts










Known Issues #
There is currently (as of flutter v. 1.24.0-1.0.pre) an issue only on web where dragging an item with some descendant that includes an InkWell widget with an onTap method will throw an exception. This includes having a ListTile with an onTap method defined.
This seems to be resolved by using a GestureDetector and its onTap method instead of the InkWell.
See the following issues:

#14
Flutter #69774
Flutter #67044
Flutter #66887

Usage #
To use this plugin, add drag_and_drop_lists as a dependency in your pubspec.yaml file.
For example:
dependencies:
drag_and_drop_lists: ^0.2.1
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Now in your Dart code, you can use: import 'package:drag_and_drop_lists/drag_and_drop_lists.dart';
To add the lists, add a DragAndDropLists widget. Set its children to a list of DragAndDropList. Likewise, set the children of DragAndDropList to a list of DragAndDropItem.
For example:
// Outer list
List<DragAndDropList> _contents;

@override
void initState() {
super.initState();

// Generate a list
_contents = List.generate(10, (index) {
return DragAndDropList(
header: Text('Header $index'),
children: <DragAndDropItem>[
DragAndDropItem(
child: Text('$index.1'),
),
DragAndDropItem(
child: Text('$index.2'),
),
DragAndDropItem(
child: Text('$index.3'),
),
],
);
});
}

@override
Widget build(BuildContext context) {
// Add a DragAndDropLists. The only required parameters are children,
// onItemReorder, and onListReorder. All other parameters are used for
// styling the lists and changing its behaviour. See the samples in the
// example app for many more ways to configure this.
return DragAndDropLists(
children: _contents,
onItemReorder: _onItemReorder,
onListReorder: _onListReorder,
);
}

_onItemReorder(int oldItemIndex, int oldListIndex, int newItemIndex, int newListIndex) {
setState(() {
var movedItem = _contents[oldListIndex].children.removeAt(oldItemIndex);
_contents[newListIndex].children.insert(newItemIndex, movedItem);
});
}

_onListReorder(int oldListIndex, int newListIndex) {
setState(() {
var movedList = _contents.removeAt(oldListIndex);
_contents.insert(newListIndex, movedList);
});
}

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For further examples, see the example app or view the example code directly.