This change adds support for the VMware Mouse Position
pseudo-encoding[1], which is used to notify VNC clients when X11 clients
call `XWarpPointer()`[2]. This function is called by SDL (and other
similar libraries)  when they detect that the server does not support
native relative motion, like some RFB clients.

With this, RFB clients can choose to adjust the local cursor position
under certain circumstances to match what the server has set. For
instance, if pointer lock has been enabled on the client's machine and
the cursor is not being drawn locally, the local position of the cursor
is irrelevant, so the RFB client can use what the server sends as the
canonical absolute position of the cursor. This ultimately enables the
possibility of games (especially FPS games) to behave how users expect
(if the clients implement the corresponding change).

Part of: #619

1: https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst#vmware-cursor-position-pseudo-encoding
2: https://tronche.com/gui/x/xlib/input/XWarpPointer.html
3: https://hg.libsdl.org/SDL/file/28e3b60e2131/src/events/SDL_mouse.c#l804

This is fine for simple structs but not class based objects.

Major restructuring of how streams work. Neither input nor output
streams are now blocking. This avoids stalling the rest of the client or
server when a peer is slow or unresponsive.

Note that this puts an extra burden on users of streams to make sure
they are allowed to do their work once the underlying transports are
ready (e.g. monitoring fds).

This makes our builds directly compatible with most distributions
without packagers/users having to specify extra flags.

We had an unintentional conflict with PixelBuffer::setSize() here.
But we can simplify this further as this initialization is only used
by the subclass DeviceFrameBuffer, and only once.

Provides safety against them accidentally becoming negative because
of bugs in the calculations.

Also does the same to CharArray and friends as they were strongly
connection to the stream objects.

Don't allow subclasses to just override dimensions or buffer details
directly and instead force them to go via methods. This allows us
to do sanity checks on the new values and catch bugs and attacks.

Window hooks aren't working well on modern systems so switch the
default to polling until we can fix things.

In prepartion for better clipboard extensions that can send Unicode
data between the client and server.

Change the internal clipboard API to use a request based model in
order to be prepared for more advanced clipboard transfers.

We now filter incoming data, which means we can start assuming the
clipboard data is always null terminated. This allows us to clean
up a lot of the internal handling.

This is required by the protocol so we should make sure it is
enforced. We are tolerant of clients that violate this though and
convert incoming clipboard data.

It is not enough to create an exception object, you need to throw
it as well.

It doesn't belong on each socket server object as timers are global.
Force implementations to call the Timer system directly instead,
avoiding any middle men.

Do a proper cleanup when one of the termination timeouts trigger
rather than just exiting on the spot. This makes sure we don't leave
stray stuff around, e.g. unix socket files.

Windows tries to do a copy of it, and it is too complex to survive
that. Just reference the object directly as we know the source of
the message here.

It is functionality specific to WinVNC, so move the code there
to make things more clear.

Removed the last parts of VNCSConnectionST's back door in to
VNCServerST and let the parent class fully handle coordination of
clients, and access to the desktop.

Our main web site now supports https, so update all references.

Make things simpler by making this a part of the SDesktop interface
that always needs to be implemented.

Force queryConnection() to always call back to approveConnection()
rather than return special values. This makes the flow easier to
follow as it will be the same in all cases.

Applets don't work anymore so remove everything that has to do
with serving them.

Shift+Alt often generates Meta on Unix systems. Assume this is the
same thing as Alt on Windows.

We use polymorphic exception objects, so catching by value invokes
the copy constructor and stuff that we don't really want.

Makes the code more general and not directly tied to specifically
TCP sockets.

It cannot keep itself in sync with the actual screen contents well
enough for CopyRect to work accurately. Graphical glitches could
be seen in some cases.

Ctrl+Alt+Delete requires special handling to trigger on Windows.
Make sure this works in raw keyboard mode as well.

Windows mostly follows the AT set 1 scan codes that we want, but
there are a few exceptions.

It was only used by WinVNC, so push it there instead.

If scan codes are available using QEMU Extended Keyboard Messages
from clients, use that to inject scancodes directly into the
system using the SendInput API.

No conversion is needed as Windows uses the same scancode encoding.

Signed-off-by: Rahul Kale <Rahul.Kale@barco.com>
Signed-off-by: Peter Korsgaard <peter.korsgaard@barco.com>

This adds the basic infrastructure and handshake for the QEMU
Extended Key Events extension. No viewer or server makes use of
the extra functionality yet though.

LED support added using Windows GetKeyState() API call.

The state is polled for change in CapsLock/NumLock/ScrollLock
status in the same code block where chages to Cursor shape is polled.

Signed-off-by: Rahul Kale <Rahul.Kale@barco.com>
Signed-off-by: Peter Korsgaard <peter.korsgaard@barco.com>

This will allow us to use better formats that preserve the entire
alpha channel.

Use the platform independent primitives instead.

We've changed the service name a couple of times for various
reasons. Make sure the old versions are removed when the new one
is registered.