Re: VirtualBOX additions (again)

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

On Sat, Jan 12, 2019 at 20:36:58 +0000, Chavdar Ivanov wrote:

> Actually, resizing with ctwm works just fine, even the delay seems to
> be not more than a couple of seconds. What is not working for me is
> the screen menus for [c]twm. They work fine with xfce4 and lxde
> though, so its not like the event is not recognized. Strange.

I've just noticed this accidentally. It seems that sometimes X does
not deliver a button press event when it happens and only delivers it
when there's the next event to deliver.  If you use a real mouse (the
one you actually drag) it's easy to miss this problem b/c a slight
twitch of hand will cause the motion event to kick the button press
event delivery.  But if you use say trackpad buttons, the button press
will only get delivered along with the button release event.  You can
use xev(1) to see that and also to verify that twm *does* show you the
menu (on the press) only to immediately hide it on release (that
caused the press to be delivered).  Just click on the root a bit above
the xev window and you'll see visibility and expose events caused by
the menu.

Also it magically auto-heals sometimes, though I don't know what
causes it to auto-heal.  You can try scientific method and just wildly
move your mouse around, mashing mouse buttons and keybaord keys.
Voila!  Press events start to come when the mouse is actually pressed.

Note that 

  # hexdump -C /dev/wsmouse

always show the events immediately.

Selecting either PS/2 or USB tablet (which is preferred since it can
deliver absolute position events) for a pointing device doesn't seem
to affect this, though I didn't do rigorous testing.

Also note that the device setup is a bit funky.  There's "real"
(emulated) mouse device (wsmouse0 at pms0 or wsmouse1 at ums0, etc)
and there's guest additions mouse device (wsmouse2 at vboxguest0).  If
the GA device is opened (either directly or via /dev/wsmouse mux) it
delivers only the positional events, the button events will still be
delivered via the real (emulated) mouse.  You can see that hexdumping
the GA wsmouse device will only show you positional events.

So may be there is a VBox bug in the mouse emulation that doesn't
deliver presses (to wsmouse0) b/c reasons...  But then dumping the mux
(i.e. like X server would see it) seems to show the presses
immediately.

-uwe