This patch adds a simple GMessageBox that can run in a nested event loop.
Here's how you use it:
GMessageBox box("Message text here", "Message window title");
int result = box.exec();
The next step is to make the WindowServer respect the modality flag of
these windows and prevent interaction with other windows in the same
process until the modal window has been closed.
Clicking the button generates a WindowCloseRequest event which the client app
then has to deal with. The default behavior for GWindow is to close() itself.
I also added a flag, GWindow::should_exit_event_loop_on_close() which does
what it sounds like it does.
This patch exposed some bugs in GWindow and GWidget teardown.
GObjects can now register a timer with the GEventLoop. This will eventually
cause GTimerEvents to be dispatched to the GObject.
This needed a few supporting changes in the kernel:
- The PIT now ticks 1000 times/sec.
- select() now supports an arbitrary timeout.
- gettimeofday() now returns something in the tv_usec field.
With these changes, the clock window in guitest2 finally ticks on its own.
