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flutterlistviewgesture

Flutter - ReorderableListView on drag

Is it possible to communicate to the children of a ReorderableListView that a drag/reorder attempt has begun? I have a ReorderableListView with custom widget children (not ListTile widgets) and I would like to be able to update their view when one of them begins to be dragged. For example, in this case:

ReorderableListView(
  onReorder: (oldIndex, newIndex) {},
  children: [
    _CustomWidget(0),
    _CustomWidget(1),
    _CustomWidget(2),
  ]
);

I'd like to reduce the opacity of _CustomWidget(0) and _CustomWidget(2) if _CustomWidget(1) has begun to be dragged. I've tried using a GestureDetector to determine if a widget is being dragged but that obviously absorbs the gesture and the ReorderableListView no longer begins the drag.

Is there a way to either allow the dragged widget to recognize its being dragged, or have the ReorderableListView somehow communicate to its parent when one of its children are being dragged?

Solution

  • Looks like there is a PR currently awaiting for approval which would help you achieve that !
    https://github.com/flutter/flutter/pull/96049

    Once it'll be merged, you'll be able to detect when the reorder has started in order to change the opacity of the other items.

    If you don't want to wait for the PR to be merged, you can also add the fork with the modification to your project instead of the official ReorderableListview