DiagramVerb class final

A named, typed edit: the one way every surface changes a diagram.

The property panel, canvas overlays, toolbars, keyboard shortcuts, menus, agents and typed Dart extensions all call DiagramController.perform. A verb declares its parameters so it can be discovered, answers DiagramController.canPerform with a reason and performs one undoable edit through the controller.

Verbs are contributed by the definitions that own them: element verbs by extensions, a shape's own verbs by its ShapeDefinition, text verbs by the DiagramTextDefinition filling a slot and structured content verbs by the content layer. A shape binds its parts' verbs to its parts; callers never name slots.

final setCount = DiagramVerb.update<ShapeElement>(
  id: 'setCount',
  label: 'Set count',
  parameters: [DiagramVerbParameter.integer('count', minimum: 0)],
  update: (shape, call) => shape.copyWith(
    values: {...shape.values, 'count': call.arg<int>('count')},
  ),
);

Constructors

DiagramVerb({required String id, required String label, required DiagramVerbSymmetry symmetry, required EditResult perform(DiagramVerbCall call), String description = '', List<DiagramVerbParameter<Object?>> parameters = const [], DiagramVerbTarget target = DiagramVerbTarget.element, bool appliesTo(DiagramElement element, ShapeRegistry registry)?, bool admitsLockedTargets = false, EditResult? check(DiagramVerbCall call)?})

Properties

admitsLockedTargets → bool

Whether the verb may target locked elements, as unlocking does. Its edit is still admitted like any other.

final

description → String

final

hashCode → int

The hash code for this object.

no setter, inherited

id → String

The name callers perform, unique within a target's verb set.

final

label → String

A short human-readable name, such as "Insert row".

final

parameters → List<DiagramVerbParameter<Object?>>

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

symmetry → DiagramVerbSymmetry

final

target → DiagramVerbTarget

final

Methods

appliesTo(DiagramElement element, ShapeRegistry registry) → bool

Whether this verb applies to element at all.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

parameter(String name) → DiagramVerbParameter<Object?>?

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

update<E extends DiagramElement>({required String id, required String label, required E? update(E element, DiagramVerbCall call), String description = '', List<DiagramVerbParameter<Object?>> parameters = const [], DiagramVerbTarget target = DiagramVerbTarget.elements, bool appliesTo(DiagramElement element, ShapeRegistry registry)?, bool admitsLockedTargets = false, EditResult? check(DiagramVerbCall call)?, String editLabel(DiagramVerbCall call)?}) → DiagramVerb

A setter that replaces each target element of type E with update's result, as one edit labeled label. update returns the element unchanged, or null, when there is nothing to change.