Interface: System

Defined in: types/desktop-engine.d.ts:3396

System services (DesktopEngine.system)

Extends

• EventedObject<SystemEventMap>

Properties

appearance

readonly appearance: Appearance;

Defined in: types/desktop-engine.d.ts:3398

The current system appearance

---

onappearancechange

onappearancechange: 
  | EventHandler<System, {
  appearance: Appearance;
}>
  | null
  | undefined;

Defined in: types/desktop-engine.d.ts:3400

appearancechange callback

---

onparameterschange

onparameterschange: 
  | EventHandler<System, ParametersChangePayload>
  | null
  | undefined;

Defined in: types/desktop-engine.d.ts:3404

parameterschange callback

Methods

addEventListener()

addEventListener<K>(type, listener): void;

Defined in: types/desktop-engine.d.ts:128

Adds an event listener; type may be given with or without the on prefix

Type Parameters

Type Parameter
K extends "appearancechange" | "parameterschange"

Parameters

Parameter	Type
type	K | `on${K}`
listener	EventHandler<System, SystemEventMap[K]>

Returns

void

Inherited from

EventedObject.addEventListener

---

cpuUsage()

cpuUsage(): number;

Defined in: types/desktop-engine.d.ts:3410

CPU usage of the whole system since the previous call (0–1); the first call returns the average since boot. Needs the system-info permission, throws without it

Returns

number

---

destroy()

destroy(): void;

Defined in: types/desktop-engine.d.ts:132

Clears all event listeners and on callbacks so the object can be garbage-collected; components also process their children recursively

Returns

void

Inherited from

EventedObject.destroy

---

memoryUsage()

memoryUsage(): object;

Defined in: types/desktop-engine.d.ts:3412

Memory usage in bytes; used matches Memory Used in Activity Monitor. Needs the system-info permission, throws without it

Returns

object

Name	Type	Defined in
free	number	types/desktop-engine.d.ts:3412
total	number	types/desktop-engine.d.ts:3412
used	number	types/desktop-engine.d.ts:3412

---

offappearancechange()

offappearancechange(): void;

Defined in: types/desktop-engine.d.ts:3402

Removes the onappearancechange callback

Returns

void

---

offparameterschange()

offparameterschange(): void;

Defined in: types/desktop-engine.d.ts:3406

Removes the onparameterschange callback

Returns

void

---

removeEventListener()

removeEventListener<K>(type, listener): void;

Defined in: types/desktop-engine.d.ts:130

Removes the given event listener

Type Parameters

Type Parameter
K extends "appearancechange" | "parameterschange"

Parameters

Parameter	Type
type	K | `on${K}`
listener	EventHandler<System, SystemEventMap[K]>

Returns

void

Inherited from

EventedObject.removeEventListener

---

triggerGC()

triggerGC(): void;

Defined in: types/desktop-engine.d.ts:3408

Asks the runtime to run a garbage collection (asynchronously)

Returns

void