Automatically cancelling modifiers

[Quentin Stafford-Fraser]

I have been guilty, I find, of misinforming the VNC mailing list. :-(

I stated in the past that the Windows vncviewer would cancel any modifiers
when it lost the focus.

This is important because if you press, for example, Alt-Tab under windows,
the 'Alt down' gets sent to the remote server, but the 'Alt up' goes to
whichever local application now has the focus.  The remote server is thus
left thinking that the Alt key is still pressed, and when you switch back to
the viewer window, things won't work quite as expected.  A similar situation
occurs with a local Ctrl-Alt-Del.

The solution was to send an 'up' message for all of the modifiers whenever
vncviewer loses focus, and an early version of the viewer did exactly this,
but I discover that the code didn't make it through one of the transitions,
and the recent versions don't do it, despite my assertions.

It will be back in the next release (due in the next couple of weeks), but
until then the solution is to press the relevant modifier key so that a down
& up message gets sent; this will reset the state.

Also coming in the next Windows viewer: a '-viewonly' option which still
displays the sreen but does not send mouse and keyboard events -particularly
useful for teaching & demo situations.
Also a '-restricted' option which removes most of the commands from the
system menu so that the user can't, for example, send a Ctrl-Alt-Del in the
middle of the lesson!

Quentin

----
Dr Quentin Stafford-Fraser
The Olivetti & Oracle Research Lab
http://www.orl.co.uk/~qsf