ReorderableGrdiView #

Copy from official ReorderableListView

Usage: #

dependencies:
  reorderable_list_view: 0.0.1

Example #

class _MyHomePageState extends State<MyHomePage> {
  final data = [1, 2, 3, 4, 5];

  @override
  Widget build(BuildContext context) {
    Widget buildItem(String text) {
      return Card(
        key: ValueKey(text),
        child: Text(text),
      );
    }

    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: ReorderableGridView(
          crossAxisSpacing: 10,
          mainAxisSpacing: 10,
          crossAxisCount: 3,
          children: this.data.map((e) => buildItem("$e")).toList(),
          onReorder: (oldIndex, newIndex) {
            setState(() {
              final element = data.removeAt(oldIndex);
              data.insert(newIndex, element);
            });
          },
          footer: [
            Card(
              child: Center(
                child: Icon(Icons.add),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

Note #

I don't know how to calculate the child's size and the gap size. So when there's crossAxisSpacing or mainAxisSpacing. The position has deviation.

If you know how to do it, please teach me.