SnapPlugin class

A plugin that manages snap behavior through a delegate chain.

This plugin wraps a SnapDelegateChain and registers itself as the controller's snap delegate. Delegates are processed in order, with the first delegate to snap an axis "winning" that axis.

Master Enable Switch

The plugin has an enabled property that acts as a master switch for all snapping. When disabled (the default), no snapping occurs. Toggle with the 'N' key or programmatically:

snapPlugin.toggle();  // Toggle with N key
snapPlugin.enabled = true;  // Enable programmatically

Default Setup

By default, include GridSnapDelegate for grid snapping:

SnapPlugin([
  GridSnapDelegate(gridSize: 20.0),
])

With Alignment Guides

Add alignment snap delegates with higher priority:

SnapPlugin([
  SnapLinesDelegate(),              // Priority 1: alignment guides
  GridSnapDelegate(gridSize: 20.0), // Priority 2: grid snap fallback
])

Inheritance

• Object
• NodeFlowPlugin
• SnapPlugin

Implemented types

• SnapDelegate

Constructors

SnapPlugin(List<SnapDelegate> delegates, {bool enabled = false})

Properties

delegates → List<SnapDelegate>

The delegates in this plugin's chain.

no setter

enabled ↔ bool

Whether snapping is enabled globally.

getter/setter pair

gridSnapDelegate → GridSnapDelegate?

Gets the GridSnapDelegate from the chain, if present.

no setter

hashCode → int

The hash code for this object.

no setter, inherited

id → String

Unique identifier for this plugin.

no setter, override

layerPosition → LayerPosition

The position where this layer should be rendered.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

attach(NodeFlowController controller) → void

Called when the plugin is attached to a controller.

override

buildLayer(BuildContext context) → Widget?

Builds the layer widget to render.

detach() → void

Called when the plugin is detached from the controller.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

onDragEnd() → void

Called when the drag operation ends.

override

onDragStart(Set<String> nodeIds) → void

Called when a node drag operation starts.

override

onEvent(GraphEvent event) → void

Called when a graph event occurs.

override

snapPosition({required Set<String> draggedNodeIds, required Offset intendedPosition, required Rect visibleBounds}) → SnapResult

Calculate the snapped visual position from the intended position.

override

toggle() → void

Toggles the enabled state.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited