Thanks for your interest in this project.
See the following description for how to contribute a feature or a bug fix to SWT.
Information regarding source code management, builds, coding standards, and more and be found under the following link.
Before your contribution can be accepted by the project, you need to create and electronically sign the Eclipse Foundation Contributor License Agreement (CLA).
Contact the project developers via the project's "dev" list.
This project uses Bugzilla to track ongoing development and issues.
Be sure to search for existing bugs before you create another one. Remember that contributions are always welcome!