Hi !
I am working on a plug in that differs little with what you need.
The plug in consists of a message panel that is very similar to the "Search results".
Take it and add a read only editor on the left to preview search results.
The search will be run on click events in editors in a separate thread not to monopolize application.
User will be able to disable it and to specify open files, project files, workspace files and directories.
I hope I am clear enough and that it will solve your problem.
As it is my first plug-in developement, it will take (a little) time before delivering it.
User interface is OK but I have difficulties with debugging.
Dje