Such an indicator would need to activate the laptop screen whilst set to external output. This would require overriding the laptop interrupt system, which would be difficult or impossible. Also, such an implementation if it were possible wouldn't be generic, but specific to particular models. Also, not everyone would want the internal screen activated to give this information. (I have used the monitor toggle on thinkpads as a method to quickly disable the screen to save battery).
Such an indicator system, if it were widely required, should be implemented by IBM in the laptop BIOS like the volume control OSD. If you feel strongly that such a system should be in place, please consider investigating the workings of different laptop models for a method to achieve this, and have someone write an implementation released under a free sofware license such as the GPL. The implementation may then be integrated into different GNU/Linux distros. If the indicator system were possible as part of the operating system,, it would be on a wish list for a so-far non-existent package, which perhaps not everyone would want. The bug should be closed. -- IBM T23: no OSD indication when toggling VGA / LCD display modes https://launchpad.net/bugs/37333 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
