NarrativeInterpreter class

NarrativeInterpreter - Core logic engine for sentence execution

A service responsible for interpreting and executing individual BaseNarrativeModel instructions during in-game conversations.

It decouples the engine's core loop from UI and system concerns (e.g., TTS, navigation), and instead delegates execution logic via injected handlers such as onRead, onWrite, etc.

Key Responsibilities:

  • Parse and interpret the instruction field from a BaseNarrativeModel
  • Trigger one or multiple handlers based on the instruction contents:
    • read - Read aloud via TTS
    • write - Display message in chat
    • ask - Ask the player a question and wait for answer
    • navigate - Forward to a new screen and wait
    • wait - Await user input (e.g. "Tap to continue")
  • Support chaining or combining instructions (e.g. read + write)
  • Expose a fallback onUnhandled if none of the above matched

Usage Example:

final interpreter = NarrativeInterpreter(
  engine: sentenceEngine,
  onRead: (text) => ttsService.speak(text),
  onWrite: (s) => chatBox.write(s),
  onAsk: (s) => ui.askQuestion(s),
);

await interpreter.interpret(sentence);

Constructors

NarrativeInterpreter({required NarrativeEngine engine, Future<void> onRead(String text)?, Future<void> onWrite(BaseNarrativeModel sentence)?, Future<void> onAsk(BaseNarrativeModel sentence)?, Future<void> onNavigate(BaseNarrativeModel sentence)?, Future<void> onWait(BaseNarrativeModel sentence)?, Future<void> onUnhandled(BaseNarrativeModel sentence)?})
Constructor with injected behavior handlers.

Properties

currentPhase ↔ String
Tracks the current phase for navigation control.
getter/setter pair
engine → NarrativeEngine
Reference to the parent engine for control flow operations.
final
hashCode → int
The hash code for this object.
no setterinherited
onAsk → Future<void> Function(BaseNarrativeModel sentence)?
Callback to show a question prompt and await a response.
final
onNavigate → Future<void> Function(BaseNarrativeModel sentence)?
Callback to trigger navigation and wait for resume.
final
onRead → Future<void> Function(String text)?
Callback to read the sentence text using TTS.
final
onUnhandled → Future<void> Function(BaseNarrativeModel sentence)?
Called when the sentence instruction does not match any known type.
final
onWait → Future<void> Function(BaseNarrativeModel sentence)?
Callback to pause until the user taps or resumes manually.
final
onWrite → Future<void> Function(BaseNarrativeModel sentence)?
Callback to write the sentence to the chat UI.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

interpret(BaseNarrativeModel sentence) → Future<void>
Interprets a single BaseNarrativeModel and executes the defined handlers
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

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