Writing a new tool-window for IntelliJ? If not, well, ‘sup? Nice to see you here. Good enthusiasm.
When IntelliJ launches, it kicks off an almighty (depending on project size / computer condition) indexing effort. Until this effort is complete, it’s running in “dumb” mode, which isn’t great.
If your tool-window launches during this time, you’ll probably get an ugly, empty window, which refuses to populate.
Luckily, IntelliJ offers a way to delay execution until it’s smarter. The DumbService will take a Runnable and execute it once indexing is complete, as such:
// do stuff