allow navigation to event listeners and publishers in Eclipse environments

[martinlippert]

At the moment, the support for navigate from event listeners to event publishers and vice versa is implemented on the language server side and can be accessed in VSCode via the Find References menu item.

Unfortunately, this isn't really nicely accessible in the Java editor in Eclipse environments. Opening Java source code with the generic editor in Eclipse shows that the feature works in general, but that is really far from usable when working with Java source code.

One idea would be to use gutter icons for this kind of navigation, maybe there are other ways to do this, too. We need to look into the best way to do this integrated into the regular Java editing experience. We need to take into account that there might be several references that users would like to jump to, too.

[davidsoles]

I think using gutter icons is a great starting point for immediate navigation. To make this feature even more robust and user-friendly, we could complement the icons with a dedicated View (list), similar to how SonarQube or the 'Search Results' work in Eclipse.

Here are a few specific ideas for the implementation:

• Hybrid Navigation: For users who find gutter icons intrusive, we should provide an option to disable them in the settings. These users could then rely solely on the dedicated View to navigate between publishers and listeners.
• Detailed View Content: The list view should be searchable and include:
  • The file name and line number of the publishEvent call.
  • A clear mapping of who is listening to that specific event (target methods/classes).
• Handling Multiple References: If a publisher has multiple listeners, clicking the gutter icon could automatically populate this View, allowing the user to explore all connections without losing context in the editor.
• Iterative Approach: If implementing both simultaneously is too complex, we could start with the View (list) only. This would provide immediate value while we evaluate how other open-source projects (like SonarQube) handle similar UI/UX challenges before moving to gutter icons.

This approach balances quick navigation with the depth needed for complex event-driven architectures.

I would like to highlight how SonarQube handles this in Eclipse: it injects numeric markers directly into the Java source code (as seen in the attached image).