Events in libcons

[Marco Gerards]

Hi,

In libcons there are various events: keypresses, output to the
display, bell events.  When it gets mouse support it will also have
mouse events like mouse movement and mouse button presses.

I want to make it configurable when the mouse cursor is shown
(normally when the mouse is moved) and when it is hidden (normally
when a key is pressed).  An example is when to show the cursor:

      --mouse-show=EVENTS    One or more of the events MOUSEMOVE, MOUSEBUTTON,
                             KEYPRESS, OUTPUT (default is MOUSEMOVE), if one of
                             these events occur the mouse cursor will be made
                             visible

So the user can use --mouse-show=MOUSEBUTTON to show the cursor, or
multiple like --mouse-show=MOUSEBUTTON,MOUSEMOVE.  The --mouse-hide
arguments works just the same.

I have noticed that some other arguments, like `--jump-down-on-input',
`--no-jump-down-on-input', `--jump-down-on-output' and
`--no-jump-down-on-output' can work just the same.  For example
`--jump-down=KEYPRESS,OUTPUT'.

The same can be done for the screensaver.  This way there will be a
uniform and central way to control how the screensaver will be
stopped.

I am still thinking what will be the cleanest way to handle this for
the screensaver.  Should the console client implement a
cons_vcons_screensaver_event function that will be called on any event
bound to the screensaver?  Although I really like to hear opinions
about this, for now it matters that this works just like the other
events.

I will implement this for libcons.  First only for the mouse, after
that for the rest of libcons.  I will also add a bell event, that will
be nice for the screensavers I think.

Thanks,
Marco