PerformanceCapture class

Captures performance data from the running Flutter app via VM service.

Primary source: Flutter.Frame events on the VM's Extension stream — the stable, documented interface DevTools itself uses (build, raster, elapsed in microseconds per frame). Timeline parsing is kept only as a fallback for engines that don't emit them.

Constructors

PerformanceCapture({required VmService vmService, required String isolateId})

Properties

hashCode → int

The hash code for this object.

no setter, inherited

isolateId → String

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

vmService → VmService

final

Methods

captureWindow({required String screenName, int durationMs = 2000}) → Future<ScreenPerformance>

Quick snapshot — captures a 2 second window of frames

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

startRecording() → Future<void>

Start recording — call this before interacting with a screen

stopAndAnalyse(String screenName) → Future<ScreenPerformance>

Stop recording and analyse — call this after screen interaction

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Properties

frameBudgetMs ↔ double

Per-frame budget in ms. 16.0 (60Hz) unless the device's real refresh rate was detected (see parseDisplayRefreshRate) — set once at startup.

getter/setter pair