Flutter DevTools

Performance tools for Flutter.

What is this?

This repo is a companion repo to the main flutter repo. It contains the source code for a suite of Flutter performance tools.

But there's not much here?

It's still very early in development - stay tuned.

Development

• git clone https://github.com/flutter/devtools
• cd devtools
• pub get

From a separate terminal:

• cd <path/to/flutter-sdk>/examples/flutter_gallery
• ensure the iOS Simulator is open (or a physical device is connected)
• flutter run

From the devtools directory:

• pub run webdev serve

Then, open a browser window to the local url specified by webdev. After the page has loaded, append ?port=xxx to the url, where xxx is the port number of the service protocol port, as specified by the flutter run output.

For more productive development, launch your flutter application specifying --observatory-port so the observatory is available on a fixed port. This lets you avoid manually entering the observatory port parameter each time you launch the application.

• flutter run --observatory-port=8888
• open http://localhost:8080/?port=8888

pub run webdev provides a fast development server that incrementally rebuilds the portion of the application that was edited each time you reload the page in the browser. If initial app load times become slow as this tool grows, we can integrate with the hot restart support in webdev.

Deployment

The strategy to deploy these performance tools has not yet been finalized.

The development steps build the application using dartdevc, which provides a productive development experience. The application, however, will be deployed using the Dart2Js compiler, which generates significantly faster JS. Before optimizing slow code, make sure there is still a performance issue when running the application with Dart2js.