`MouseTracker` and related symbols are moved from the `gestures` package, resulting in error messages such as undefined classes or methods. Import them from `rendering` package instead.
Original behavior
Prior to this change `MouseTracker` was part of the `gestures` package. This brought troubles when we found out that code related to `MouseTracker` often wanted to import from the `rendering` package.
New behavior
The file `mouse_tracking.dart` has been moved from the `gestures` package to `rendering`. All symbols in the said file have been moved without keeping backward compatibility.
- Who is affected
- Applications and packages relying on the previous behaviour or signature. Code that uses MouseTracker, MouseDetectorAnnotationFinder, MouseTrackerAnnotation and related APIs.
- Practical impact
- Behaviour or API differences that can break builds or change runtime behaviour.
- What action should I take?
- Follow the official migration guide below, update affected call sites, run `dart fix --apply` where a fix is available, then run your tests.
Official migration guide (excerpt, © The Flutter Authors, CC BY 3.0)
If you see error of "Undefined class" or "Undefined name" of the following symbols:
- [
MouseDetectorAnnotationFinder][] - [
MouseTracker][] - [
MouseTrackerAnnotation][] - [
PointerEnterEventListener][] - [
PointerExitEventListener][] - [
PointerHoverEventListener][]
You should add the following import:
import 'package:flutter/rendering.dart';AI_PROVIDER (for example to openai-compatible with a local Ollama or LM Studio endpoint) to enable grounded explanations. Everything else on this page works without an AI provider.Listed in the official breaking-changes index (docs.flutter.dev/release/breaking-changes).
An official announcement or migration guide documents an intended behaviour or API change. A verified source change (git diff) shows code changed but does not by itself prove a public API is breaking. AI interpretations are labelled and never used to classify a change.
- Official migration guide
- MouseDetectorAnnotationFinder
- MouseTracker
- MouseTrackerAnnotation
- PointerEnterEventListener
- PointerExitEventListener
- PointerHoverEventListener
- Transform mouse events to the local coordinate system
- Move annotations to a separate tree
- Move mouse_tracking.dart to rendering
- Source commit
- b3045439b7c0
- Source last updated
- Oct 21, 2026
- Last synchronized
- Oct 21, 2026
- Publication status
- published
Publication history
- Oct 21, 2026, 8:31 PM: new → published (ingestion) — Backed by an official breaking-change/migration guide.
AI_PROVIDER (for example to openai-compatible with a local Ollama or LM Studio endpoint) to enable grounded explanations. Everything else on this page works without an AI provider.