dnd_kit_core 0.1.0-dev.0

Pure Dart core primitives and algorithms for dnd_kit.

dnd_kit_core

dnd_kit_core contains the pure Dart foundation for dnd_kit.

Use this package when you need drag-and-drop primitives, geometry, collision detection, modifiers, registry contracts, or sensor contracts without depending on Flutter.

Import

import 'package:dnd_kit_core/dnd_kit_core.dart';

What It Provides

• DndId for stable application-owned identifiers.
• DndPoint, DndSize, DndRect, and DndTransform for toolkit geometry.
• DndState, DndDragSession, and drag events for lifecycle modeling.
• DndCollisionDetector plus built-in detectors such as DndCollisionDetectors.closestCenter, DndCollisionDetectors.closestCorners, DndCollisionDetectors.rectIntersection, and DndCollisionDetectors.pointerWithin.
• DndModifier plus built-in modifiers such as DndModifiers.restrictToVerticalAxis, DndModifiers.restrictToHorizontalAxis, DndModifiers.restrictToBoundary, and DndModifiers.snapToGrid.
• DndRegistry and diagnostics hooks for draggable and droppable metadata.

Example

final activeRect = const DndRect(left: 0, top: 0, width: 80, height: 40);
final targets = <DndId, DndRect>{
  const DndId('todo'): const DndRect(left: 0, top: 80, width: 240, height: 200),
  const DndId('done'): const DndRect(left: 280, top: 80, width: 240, height: 200),
};

final result = DndCollisionDetectors.closestCenter(
  DndCollisionInput(activeRect: activeRect, droppableRects: targets),
);

final overId = result.firstOrNull?.id;

Package Boundary

dnd_kit_core intentionally has no Flutter dependency. It does not import package:flutter/*, dart:ui, BuildContext, RenderBox, Offset, Rect, or Size.

Flutter widgets, measuring, overlays, auto-scroll, and stable sortable presets live in the main dnd_kit package.