TaskNavigator class abstract

Abstract navigator that drives step-by-step progression through a SurveyDefinition. Subclasses implement the step resolution logic for ordered and branching flows.

Implementers

Constructors

TaskNavigator(SurveyDefinition task)

Properties

countSteps → int
Total number of steps in the survey.
no setter
hashCode → int
The hash code for this object.
no setterinherited
history → ListQueue<Step>
A stack of steps the user has visited, used to support back-navigation.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
task → SurveyDefinition
The survey definition this navigator operates on.
final

Methods

currentStepIndex(Step step) → int
Returns the zero-based index of step in the survey's step list.
firstStep() → Step?
Returns the first step to display, respecting SurveyDefinition.initialStep if set.
hasPreviousStep() → bool
True when there is at least one step in history to go back to.
nextInList(Step? step) → Step?
Returns the step immediately after step in the ordered list, or null if step is the last.
nextStep({required Step step, required List<StepResult> previousResults, StepResult? questionResult}) → Step?
Returns the step to show after step, given previousResults and the current questionResult. Returns null when the survey is finished.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
peekHistory() → Step?
Returns the most recently visited step without removing it from history.
previousInList(Step step) → Step?
Returns the step before step for back-navigation purposes.
record(Step step) → void
Adds step to the navigation history.
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited