ConnectionStyle class abstract

Abstract base class for connection styles.

Single Responsibility: Create Segments

A connection style has ONE job: create path segments from parameters. That's it. Everything else (path generation, hit testing, bend points) is derived from segments using utility methods.

Architecture

final result = style.createSegments(params);  // Call ONCE
  ↓
  ├─→ style.buildPath(result.start, result.segments) → Path
  ├─→ style.buildHitTestRects(result.start, result.segments, tolerance) → List<Rect>
  └─→ style.extractBendPoints(result.start, result.segments) → List<Offset>

Usage

Callers (like ConnectionPathCache) should:

Call createSegments(params) ONCE to get the segments
Store/cache the segments
Use static utility methods to derive path, hit test rects, etc.

Example Implementation

class MyConnectionStyle extends ConnectionStyle {
  @override
  String get id => 'my-style';

  @override
  String get displayName => 'My Style';

  @override
  ({Offset start, List<PathSegment> segments}) createSegments(
    ConnectionPathParameters params,
  ) {
    // Calculate waypoints
    final waypoints = WaypointBuilder.calculateWaypoints(...);
    // Convert to segments
    final segments = WaypointBuilder.waypointsToSegments(waypoints);
    return (start: params.start, segments: segments);
  }
}

Implementers

Available extensions

ConnectionStyleExtension

Constructors

ConnectionStyle(): const

Properties

defaultHitTolerance → double: Default hit tolerance for this connection style. Some styles may need different tolerances based on their geometry.
no setter
displayName → String: Human-readable display name
no setter
hashCode → int: The hash code for this object.
no setteroverride
id → String: Unique identifier for this connection style
no setter
isBuiltIn → bool: Available on ConnectionStyle, provided by the ConnectionStyleExtension extension
Check if this is a built-in connection style
no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

buildHitTestPath(List<Rect> rects) → Path: Builds a hit test path from rectangle bounds.
buildHitTestRects(Offset start, List<PathSegment> segments, double tolerance) → List<Rect>: Builds hit test rectangles from segments.
buildPath(Offset start, List<PathSegment> segments) → Path: Builds a Path from segments.
createSegments(ConnectionPathParameters params) → ({List<PathSegment> segments, Offset start}): Creates the path segments for this connection.
extractBendPoints(Offset start, List<PathSegment> segments) → List<Offset>: Extracts bend points from segments.
isEquivalentTo(ConnectionStyle other) → bool: Check if two connection styles are equivalent. This is used for caching decisions and theme comparisons.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toString() → String: A string representation of this object.
override

Operators

operator ==(Object other) → bool: The equality operator.
override