Mouse users have more input options. They can use a wheel
or scrollbar to scroll, which generally eliminates the need
for dedicated drag handles. If you look at the macOS
Finder or Windows Explorer, you’ll see that they work
this way: you just select an item and start dragging.

In Flutter, you can implement drag and drop in many
ways. Discussing specific implementations is outside
the scope of this article, but some high level options
are:

Use the Draggable and DragTarget APIs
directly for a custom look and feel.

Hook into onPan gesture events,
and move an object yourself within a parent Stack.

Use one of the pre-made list packages on pub.dev.

Educate yourself on basic usability principles

Of course, this page doesn’t constitute an exhaustive list
of the things you might consider. The more operating systems,
form factors, and input devices you support,
the more difficult it becomes to spec out every permutation in design.