General Contributing Guidelines ​

The Material Components contributing policies and procedures can be found in the main Material Components documentation repository’s contributing page.

For larger feature requests we might ask you to write a Design Doc.

To make a contribution, you'll need to be able to build the library from source and run our tests.

Pull Request Process ​

Because the material-components-android code is stored in two locations (i.e., GitHub and Google), PRs are not directly merged into the repository. Instead, once a PR is complete (i.e., cla signed, CI passing, design reviewed, code reviewed), the PR will be converted to a commit sourced to the original author that is synced into the repository. Even though the PR list shows no merged PRs, we do accept contributions.

Building From Source ​

Take a look at our instructions on how to build the library from source.

Running Tests ​

Material Components for Android has JVM tests as well as Emulator tests.

To run the JVM tests, do:

./gradlew test

To run the emulator tests, ensure you have a virtual device set up and do:

./gradlew connectedAndroidTest

Code Conventions ​

Since we all want to spend more time coding and less time fiddling with whitespace, Material Components for Android uses code conventions and styles to encourage consistency. Code with a consistent style is easier (and less error-prone!) to review, maintain, and understand.

Be consistent ​

If the style guide is not explicit about a particular situation, the cardinal rule is to be consistent. For example, take a look at the surrounding code and follow its lead, or look for similar cases elsewhere in the codebase.

Java ​

We follow the Google Java Style Guide.

XML ​

• 2 space indentation
• Resource naming (including IDs) is lowercase_with_underscores
• Attribute ordering:
  1. xmlns:android
  2. other xmlns:
  3. android:id
  4. style
  5. android:layout_ attributes
  6. android:padding attributes
  7. other android: attributes
  8. app: attributes
  9. tool: attributes

Useful Links ​

• Getting Started
• Using Snapshot Version
• Building From Source
• Catalog App
• Class documentation
• MDC-Android on Stack Overflow
• Android Developer’s Guide
• Material.io
• Material Design Guidelines