sliver_tree/tree_drag_handle library

Caller-placed drag handles for a SliverReorderableTree row.

The package ARMS a child; it does not decide where that child sits. Put a TreeDragHandle anywhere inside a row: across the top of a card, at the leading edge, inline with a title, or two of them. The row is wrapped for you either way, so a handle-less row still hides itself while dragged, still exposes its reorder semantics actions, and is still a drop TARGET.

Ownership follows Flutter's ReorderableDragStartListener in widgets/reorderable_list.dart: the handle owns NO recognizer. It reports a single pointer-down to the enclosing row through TreeRowDragScope, and the ROW owns the recognizer, the per-pointer bookkeeping, and one Drag per gesture. That is what makes two handles in one row safe, a handle inside a nested scrollable harmless, and an unmounted handle a non-event for a live drag.

Classes

TreeDelayedDragHandle

A TreeDragHandle that waits for a long press before lifting the row.

TreeDragHandle

Arms child as a drag handle for the row that encloses it.

TreeRowDragScope

Published by each reorderable row; found by TreeDragHandle.build.