myscript/iinkts-preprod/manager-patterns

Manager Patterns

Responsibility Rule

One manager = one responsibility. When a manager grows several unrelated concerns, extract a sub-manager (see manager/interactive/math/) or move per-type logic onto the symbol's util.

Creating a New Interactive Manager

Interactive managers extend IIAbstractManager (src/manager/interactive/IIAbstractManager.ts). They receive the canvas and read their dependencies from it through inherited getters — model, renderer, client, configuration — so a manager always sees the canvas's current instances.

import type { TInteractiveInkCanvas } from "@/canvas"
import { LoggerCategory } from "@/logger"
import { IIAbstractManager } from "./IIAbstractManager"
export class IIMyFeatureManager extends IIAbstractManager {
  protected managerName = "IIMyFeatureManager"
  constructor(canvas: TInteractiveInkCanvas) {
    super(canvas, LoggerCategory.MANAGER)
  }
  async doThing(symbolId: string): Promise<void> {
    const symbol = this.model.getSymbol(symbolId)
    if (!symbol) return
    this.logger.info("doThing", { symbolId })
    // ... logic
  }
  protected onDestroy(): void {
    // remove listeners, clear timers
  }
}

Rules:

• Members protected, not #private, unless truly internal state: integrators subclass managers
• this.logger comes from the base (LoggerManager.getLogger(category)), pick the matching LoggerCategory
• Optional hooks: onInit() (end of the base constructor) and onDestroy() (called by destroy())
• Async methods return Promise<void> or Promise<T>, never fire-and-forget
• No hidden side-effects — if you emit an event or mutate the model, it must be obvious from the method name
• Never mutate a committed symbol: model.draftSymbol(id) → change → model.commitSymbol(draft)

Extending IIAbstractTransformManager

For managers that apply a geometric transform to symbols. The class is IIAbstractTransformManager, in src/manager/interactive/transform/AbstractTransformManager.ts:

import type { MatrixTransform } from "@/core"
import { symbolRegistry } from "@/symbol-utils"
import type { TSymbol } from "@/symbol"
import { IIAbstractTransformManager } from "./AbstractTransformManager"
export class IIMyTransformManager extends IIAbstractTransformManager {
  protected managerName = "IIMyTransformManager"
  // The one abstract member: delegate to the symbol's util, never switch on symbol.type
  protected applyThroughUtil(symbol: TSymbol, matrix: MatrixTransform): void {
    symbolRegistry.getUtilFor(symbol).translate(symbol, { matrix })
  }
}

The base provides applyMatrix(symbols, matrix), applyToSymbol(symbol, matrix), live preview (previewTransform, previewElementTransform), history recording (recordTransformed), followed/anchored symbols and finalizeTransform(). Read an existing subclass before writing a new one.

Existing subclasses: IITranslateManager, IIRotationManager, IIResizeManager, orchestrated by IITransformManager.

Manager Registration

Managers are instantiated in the InteractiveInkCanvas constructor with the canvas, and exposed as public properties:

// In InteractiveInkCanvas.ts
this.myFeature = new IIMyFeatureManager(this)
// In destroy()
this.myFeature.destroy()

Also:

• declare the property on TInteractiveInkCanvas (src/canvas/TInteractiveInkCanvas.ts) — managers are typed against it, and test/unit/__mocks__/createCanvasMock.ts must provide it
• export the class from its folder barrel (src/manager/interactive/index.ts)
• call its destroy() from the canvas's destroy() if it holds listeners or timers

Anti-Patterns