vyuh_diagram_core 2.14.0

Transactions, editor state, and history for Vyuh Diagram.

vyuh_diagram_core

The pure Dart engine of Vyuh Diagram: controller, verbs, undo and redo, rules and extensions.

Vyuh Diagram · Docs · Examples · API reference

Everything a diagram does, without Flutter: servers, agents and command-line tools use the same controller and verbs as the canvas. A Diagram holds the document, its DiagramConfiguration, one history and its participants; each DiagramController is one actor on it, with its own selection and undo.

Typed selection properties, connected creation and diagnostic repairs use the same controller admission and history. resolvedElementById(id) observes a single live identity, including preview geometry.

Install

dart pub add vyuh_diagram_core --hosted-url https://pub.vyuh.tech

Register your registry token first with dart pub token add https://pub.vyuh.tech; see package access.

Usage

import 'package:vyuh_diagram_codec_json/vyuh_diagram_codec_json.dart';
import 'package:vyuh_diagram_core/vyuh_diagram_core.dart';

final controller = DiagramController(
  configuration: DiagramConfiguration(extensions: [GridExtension(snap: true)]),
);

final a = controller.createShape(Shapes.rectangle, at: DiagramPoint.zero, text: 'A').requireId();
final b = controller.createShape(Shapes.rectangle, at: const DiagramPoint(240, 0), text: 'B').requireId();
controller.connect(a, b);

final json = controller.save(DiagramJsonCodec.new);

controller.select([a, b]);
controller.properties().require(ShapeProperties.fill)
    .set(const DiagramColor(0xff2457ff)).requireAllowed();

Fields expose shared, mixed and unavailable states, intersect constraints and check their captured revision. Declare kind-owned properties through ShapeDefinition.properties in extension_api.dart. Diagnostics and property fields belong to the main application import. See the controller API.

Every verb returns an EditResult; batch makes several verbs one undo step. Another actor, such as an agent, joins with DiagramController(diagram: controller.diagram, participant: DiagramParticipant.agent(id: 'agent', name: 'Agent')).

Key options

DiagramConfiguration configures a diagram once, shared by every controller on it:

Option	Purpose
extensions	The installed extensions, each with its own options.
bounds	CanvasBounds.infinite (default) or CanvasBounds.fit(padding:).
fonts, defaultFontFamily	The font families offered, and the family text uses by default.
rules	DiagramRules(beforeChange:, canCreate:, canConnect:) admission rules.
license	The license token that removes the canvas attribution.

Read an extension's options with controller.options<T>() and change them with controller.setOptions(value), such as GridOptions.

Extension authors also import extension_api.dart; engine internals are in adapter.dart, test helpers in testing.dart and native headless text in vyuh_diagram_pango.dart.

Learn more

• Diagram and controller
• Verbs
• Extensions and options
• Agents and headless use

License

Licensed under the Apache License, Version 2.0. Third-party materials retain their own licenses and notices.