In this tutorial we will add basic support for .properties language and it's usages within Java code.

We will generate parser and PSI elements using Grammar-Kit plugin. The lexer class will be generated with JFlex.

This a step-by-step tutorial and it requires performing every step:

• 1. Prerequisites
• 2. Language and File Type
• 3. Grammar and Parser
• 4. Lexer and Parser Definition
• 5. Syntax Highlighter and Color Settings Page
• 6. PSI Helpers and Utilities
• 7. Annotator
• 8. Line Marker Provider
• 9. Completion Contributor
• 10. Reference Contributor
• 11. Find Usages Provider
• 12. Folding Builder
• 13. Go To Symbol Contributor
• 14. Structure View Factory
• 15. Formatter
• 16. Code Style Settings
• 17. Commenter
• 18. Quick Fix

The final code can be found in the SamplePlugin repo on GitHub.