可重新排序的网格视图

ReorderableGridView

Idea from official ReorderableListView

Usage:

dependencies:
  reorderable_grid_view: ^2.2.9-alpha.4

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(
        title: Text(widget.title),
      ),

      body: Center(
        // use ReorderableGridView.count() when version >= 2.0.0
        // else use ReorderableGridView()
        child: ReorderableGridView.count(
          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),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

Options

option	desc
dragWidgetBuilderV2	the drag widget builder
restrictDragScope	restrict drag scope to ReorderableGridView, not drag over the scree, default is false
dragStartDelay	the longPress time
scrollDirection	the scroll direction, default is Axis.vertical, supports Axis.horizontal
scrollSpeedController	control how speed when scroll down when drag out of viewport
OnDropIndexChange	the drop position changed, void (index, oldIndex), oldIndex = nil if is drag start.

dragWidgetBuilderV2

Normaly you can do like this:

dragWidgetBuilderV2: DragWidgetBuilderV2(
	isScreenshotDragWidget: false,
	builder: (index, child, screenshot) {
		return child;
	}
)

• child is you dragging widget.

And if you dragging widget has some state, the callback's child can't access the state. So you can do a screenshot like this.

dragWidgetBuilderV2: DragWidgetBuilderV2(
	isScreenshotDragWidget: true,
	builder: (index, child, screenshot) {
		return Image(screenshot);
	}
)

Constructors

• ReorderableGridView.builder
• ReorderableGridView.count
• ReorderableSliverGridView.count

custom reorderable

You can use ReorderableWrapperWidget to custom your reorderable. Use ReorderableWrapperWidget as root. and it's descendants is ReorderableItemView[] list

• ReorderableWrapperWidget(child: SomeCollection(children: ReorderableItemView))

Important

• the placeholderBuilder is not right when the list is very long, is not fixable for now. please see issue 47
• can drag out of scope in ReorderableSliverGridView, please see issue 52

TODO

fix placeholderBuilder is not right when the list is very long

Other link project

If this project is not fit your meet, you can try those other projects

• reorderables
• reorderable_grid
• flutter-reorderable-grid-view