I was using flutter_draggable_gridview 0.0.1, before you refactored your code without any issues.

After upgrading to 0.0.3 and you drag the image, it doesn't move the other images to make place for the dragged image on the gridview, as it did in the past, but the gird just remains static, and when you drop the image, it returns to its original place.

I tested using your example code from this repo, and exactly the same thing happens when I run your example code.

Can you please look into this problem.

Thx

I've been looking at this repo's example, and a Medium article using this package, but I haven't been able to see any dragging work. Neither does the UI demonstrate any click-and-drag behavior, neither is the dragging callback function ever being called.

What might be happening?

DraggableGridItem currently has no way to know if it's being dragged. Instead of a Widget child argument, a builder argument with (BuildContext context, bool isDragging) could be provided

version: 0.0.4

file drag_target_grid.dart, line 84: DraggableGridItem(child: EmptyItem(), isDraggable: true);

should be :

DraggableGridItem(child: widget.placeHolder ?? EmptyItem(), isDraggable: true);

Could you please fix this ASAP and release a new version 0.0.5? Otherwise I have to use source code to integrate into my project. Thanks a lot!

In my app, I don't need the user to reorder the contents but they are done when some filters are enabled.

Use case:

Grids show cars. When user presses red color, I want to show only the red colored cars And I want this filtering to happen in an animated way. So there might be several cars that are removed from different places of the cars array. When the filter is removed, all cars should be added in place with ordering animation.

Can I use this package for this need?

Right now the only callback I see for when the grid changes is onDragAccept(List<DraggableGridItem> list). However, DraggableGridItem doesn't have any provisions for attaching a data payload, and it doesn't contain before or after indices, so it's not clear how we're expected to handle these grid changes.

There are a lot of abstract classes where a callback would do. I have had to build three wrapping classes to get callback functionality.

class DragCompletionCallback extends DragCompletion {
  DragCompletionCallback(this.callback);

  final void Function(List<DraggableGridItem> list) callback;

  @override
  void onDragAccept(List<DraggableGridItem> list) {
    callback(list);
  }
}

class DragChildWhenDraggingCallback extends DragChildWhenDragging {
  DragChildWhenDraggingCallback(this.callback);

  final Widget Function(List<DraggableGridItem> list, int index) callback;

  @override
  Widget dragChildWhenDragging(List<DraggableGridItem> list, int index) {
    return callback(list, index);
  }
}

class DragPlaceHolderCallback extends DragPlaceHolder {
  DragPlaceHolderCallback(this.callback);

  final PlaceHolderWidget Function(List<DraggableGridItem> list, int index)
      callback;

  @override
  PlaceHolderWidget placeHolder(List<DraggableGridItem> list, int index) {
    return callback(list, index);
  }
}