At the Qt Contributors Summit, Johannes‘ showed me his Qt/Caca Lighthouse plugin. Caca is a graphics library to output text instead of pixels. So this plugin lets you run Qt programs on the console
His code needed some love, so I forked it and cleaned it up. Caca does not provide a event fd and so we have to keep polling caca for events. Since this wasn’t ideal, I moved the event handling to a separate thread and blocked for events. Unfortunately, I found that the caca library is not thread-safe and rendering and processing events in separate threads makes caca crash at randomly. So, I ended up moving the rendering to the event processing thread and having to resurrect the 20ms event timer again The cool thing though is that now Qt renders to QImage in the main ui thread and hands it off to caca. Caca opens a X connection (or similar), converts the image into text, displays a window and handles events in another thread. With some refactoring and thanks to QMetaObject::invokeMethod, the threaded and non-threaded rendering are pretty much the same and can be switched using an environment variable (THREADED_CACA=1).
If you want to hack further, code is on gitorious. (Caca doesn’t seem to deliver gpm events with ncurses, so that would be a nice fix to have)
Update: Welcome slashdot readers