This is a workaround for corrupted non-square cursors seen on some
Windows 7 machines with NVIDIA cards. The corruption only happens when
the screen is in portrait mode.

The MPL 2.0 license is a "file-level" copyleft license vs the
"project-level" nature of the L/GPL. The intention of noVNC has
always been that it should be easy to incorporate into existing
projects and sites whether free/open or proprietary/commercial. The MPL
2.0 is designed for this sort of combination project but still
requires that any distributed modifications to noVNC source files must
also be published under the same license.

In addition, the MPL 2.0 allows the code to be used in L/GPL projects
(the secondary license clause). This means that any projects that are
already incorporating noVNC should not be impacted by this change and
in fact it should clarify the licensing situation (the exact
application of the L/GPL to web applications and interpreted code is
somewhat ambiguous).

The HTML, CSS, image and font files continue to be under more
permissive licenses (see LICENSE.txt). The included websockify python
code remains under a LGPLv3 license although the include/websock.js
file from the websockify component is now under MPL 2.0 as well.

Permission was received from other noVNC authors to make this change to their
code license on the following dates:

    - Chris Gordon (UI): Jun 24, 2012
    - Antoine Mercadal (DOM,*util.js): Oct 10, 2012
    - William Lightning (UltraVNC repeater): Oct 10, 2012
    - Mike Tinglof (tight encoding): Oct 15, 2012

Clarify in LICENSE.txt that the noVNC core library is the part that is
LGPLv3 licensed. The HTML, CSS, images and fonts are separate from the
core library and can be modified and distributed with the noVNC core
but under their own license conditions.

HTML and CSS: 2-Clause BSD
Fonts: SIL OFL 1.1
Images: CC BY SA 3.0

In other words, you can modify the layout and appearance of of noVNC
to integrate with an existing or new web site or application without
having to publish the source for those modifications under the LGPLv3.
However, use of and modification of the noVNC core library (i.e. the
core Javascript that makes up noVNC) must still be according to the
LGPLv3.

Chris Gordon was the other contributor to the HTML, CSS, and images
included with noVNC and gave permission for this license clarification
on June 23, 2012.

This will keep copyrect rendering actions in order with tight and tightPNG
rendering actions (otherwise you can get visual image corruption when
they are mixed together).

Warning:

RAW, RRE and HEXTILE still use immediate render commands so there is
still the risk of out-of-order rendering if RAW, RRE, and HEXTILE are
mixed with tight and tightPNG. Copyrect will work with either because
the renderQ_push function will render copyrects immediately if they
are the only thing being pushed on the queue.

The imgQ code in RFB should be a generic rendering queue system in
Display.

The reason for the render queue in the first place is that images
loaded from raw data URI strings aren't immediately ready to display
so we have to wait for them to complete 'loading'. However, when data
URI images are mixed with other types of rendering actions then things
can get out of order. This is the reason for the rendering queue.

Currently this only keeps display actions for tight and tightPNG
related actions in order (because they use a mix of fills, raw pixel
data and data URI images).

Fixes https://github.com/kanaka/noVNC/issues/163

When using an encoding with raw images (tight, tightPNG) we need to
draw those image relative to the viewport so that clipping works when
the viewport isn't at 0, 0.

Switched to using: http://www.jshint.com/

Move viewportChange(), getCleanDirtyReset(), absX() and absY() to the
public API section. Also add some function comments.

Display API change:
    - getTile -> startTile (no longer returns a tile)
    - setSubTile -> subTile (drop img/tile first parameter)
    - putTile -> finishTile (no longer takes img/tile paramter)

The Display tile logic uses canvas image data directly and
caches/reuses a 16x16 imageData tile (for other sizes, the tile is
create for each call). This gives a 30% speedup on Chrome
13 (and no significant change for Firefox 3.6/4.0).

Other:

- Remove rgbxImageFill and cmapImageFill routines.

- Simplify constructor tests and just error if createImageData is not
  supported by canvas instead of .

- Remove webkit canvas bug workaround that effects Chrome 7. Chrome
  7 usage share is now less than 0.5 percent and the workaround is
  ugly. Drop the function wrapping in the constructor and the canvas
  flush() routine.

- Remove support for getImageData (Opera 11+ now required)

Update browser support list:

    - Chrome 8+ (really any except 7)
    - Firefox 3.6+
    - Safari 4+
    - Opera 11+
    - IE9+
    - iOS 4.2+

Cleanup:

- remove unused changeViewportMeta function from include/ui.js
- remove some debug output and debug CSS.
- rename panel toggle functions and put them in same location in the
  code.
- refactor some code from updateState to updateVisualState routine
  (renamed from updateSettingsState).

API changes (forward compatible):

- Display: add 'viewport' conf option to turn on and off viewport
  mode.
- RFB: add 'viewportDrag' option to enable/disable viewport dragging
  mode.

Other:

- Add clip mode setting to default UI. For touch devices, clipping is
  forced on.
- Use CSS media queries to adjust visual elements based on screen
  size. Especially disconnected logo size/position and button text size.
- Catch page unload while connected and give a confirm dialog.
- Change mouse button selector to a single button that changes between
  ' ', 'L', 'M', 'R' when clicked (empty means mouse is just being
  moved and doesn't send clicks).
- include/ui.js:setViewClip() routine sets the clipping of the
  viewport to the current size of the viewport area (if clipping is
  enabled).
- include/ui.js:setViewDrag() toggles/enables/disables viewport
  dragging mode.
- Add several images for the UI and for Apple devices:
    - images/clipboard.png: clipboard menu icon
    - images/connect.png: connect menu icon
    - images/disconnect.png: disconnect button icon
    - images/keyboard.png: show keyboard button
    - images/move.png: viewport drag/move toggle button
    - images/settings.png: settings menu icon
    - images/screen_320x460.png: iOS app/desktop link start image
    - images/screen_57x57.png: iOS app icon
    - images/screen_700x700.png: full size noVNC image

Part of mobile device support:
https://github.com/kanaka/noVNC/issues/48

The Display object is redefined as a larger display region with
an equal or smaller visible viewport. The size of the full display
region is set/changed using resize(). The viewport is set/changed
using viewportChange().

All exposed routines that draw on the display now take coordinates
that are absolute (relative to the full display region). For example,
the result of fillRect(100, 100, 10, 10, [255,0,0]) will appear in the
canvas at (0,0) if the viewport is set to (100,100).

Details:

- Move the generic part of the viewport code from tests/viewport.html
  into include/display.

- Add two new routines to the Display interface:

    - viewportChange(deltaX, deltaY, width, height)
        - This adjusts the position of the visible viewport and/or the
          size of the viewport.

        - deltaX and deltaY specify how the position of the viewport
          should be shifted. The position of the viewport is clamped
          to the full region size (i.e. cannot outside the display
          region).

        - The clean and dirty regions of the display are updated based
          on calls to this routine. For example, if the viewport width
          is increased, then there is now a dirty box on the right
          side of the viewport. Another example, if the viewport is
          shifted down and to the left over the display region, there
          are now two dirty boxes: one on the left side and one
          on the bottom of the viewport.

    - getCleanDirtyReset()
        - This returns an object with the clean box and a list of
          dirty boxes (that need to be redrawn).

            {'cleanBox':
                {'x': x, 'y': y, 'w': w, 'h': h},
             'dirtyBoxes':
                [{'x': x, 'y': y, 'w': w, 'h': h}, ...]
             }

        - The coordinates in the clean and dirty boxes are absolute
          coordinates (relative to the full display region) but they
          are clipped to the visible viewport.

        - Calling this function also resets the clean rectangle to be
          the whole viewport (i.e. nothing visible needs to be redrawn
          dirty) so the caller of this routine is responsible for
          redrawing any

Instead of R,G,B (red-shift of 0, green-shift of 8, and blue-shift
of 16), use the default ordering of B,G,R (red-shift of 16, green-shift of 8, and blue-shift
of 0) that tightvncserver uses (and that VMWare's VNC server seems to
require). Also, warn in the console if the server does not default to
the new format.

Fix the tests/canvas.html test. This is a general fix with regards to
the rename/refactor of canvas.js into display.js and not specific to
the color re-ordering.

- Add conf_defaults which accepts an array of configuration
  attributes.
- Split out user configuration defaults from the actual configuration
  object.
- Add mode field and enforce read-only, write-once, read-write modes.

API changes:
    - include/canvas.js renamed to include/display.js
    - Display.rescale() method removed from API. Use Display.set_scale() instead.
    - Make logo configuration attribute of Display and display it when
      clear() is called if it is set.

API deprecations:
    - use RFB onUpdateState instead of updateState.
    - use RFB onClipboard instead of clipboardReceive.

See https://github.com/kanaka/noVNC/wiki/ModuleAPI for detailed noVNC
modules and API description.

Expand and normalize the event/callback interfaces. Standize on
"onEventName" form for callbacks.

    Callback Renames:
        - RFB updateState -> onUpdateState
        - RFB clipboardReceive -> onClipboard
        - Keyboard keyPress -> onKeyPress
        - Mouse mouseButton -> onMouseButton
        - Mouse mouseMove -> onMouseMove

    Callback Additions:
        - RFB onPasswordRequired
        - RFB onBell
        - RFB onFBUReceive
        - RFB onFBUComplete

Other:
- Add array type support to Util.conf_default()
- Removed a bunch of routines from the Display API that were just used
  internally and not actually by noVNC: flush, setFillColor,
  imageDataGet, imageDataCreate, rgbxImageData, rgbxImageFill,
  cmapImageData, cmapImageFill.
- More keyboard/mouse logging when debug turned on.
- Some JSLinting

Still buggy so not yet activated in the UI, but the hooks are at least
here.

API change: for intergrators that explicitly include the Javascript
files (that do not use include/vnc.js)js, include/input.js is a new
file that must also be included.

The mouse and keyboard handling could be useful on its own so split it
out into a Keyboard and Mouse class in include/input.js.

This refactoring is preparation to deal with issue #21 - non-US
keyboard layouts.

Fix mouse button mapping in IE9. All browsers have converged on
a standard left=0, middle=1, right=2 ... all except IE that is.

Add html5 doctype to tests.

In vnc_perf test, use do_test instead of start for function name since
start is a keyword in IE.

In error about Flash give a link to Adobe's download page.

Opera 11 native WebSockets (if enabled) seems to have bad behavior for
the bufferedAmount so add change from websockify project to allow max
bufferedAmount (before send queue is delay) to be configured.

Also, Opera 11 and 10.60 behave like Mozilla regarding the '-' key so
translate it correctly.

Issue #8: https://github.com/kanaka/noVNC/issues#issue/8

Issues #27 (safari cursor rendering messed up) and #29 (firefox 3.6.10
segault).

Finally found some better reference on the icon/cursor format which is
added to the docs/links file.

It seems like I was missing the XOR section. So setting the cursor
would cause corruptin in Safari rendering or the segfault for firefox.

Check keyLocation and translate numpad keys into numbers. keyLocation
is not widely supported yet, but it should start percolating into
browsers eventually:
http://www.w3.org/TR/DOM-Level-3-Events/#events-KeyboardEvent

This change is based on:
https://github.com/leeor/noVNC/commit/8e59e3772c91eaffaa0f6d53270b97f1fe8510b4

wswrapper:

    Getting the wswrapper.c LD_PRELOAD model working has turned out to
    involve too many dark corners of the glibc/POSIX file descriptor
    space. I realized that 95% of what I want can be accomplished by
    adding a "wrap command" mode to wsproxy.

    The code is still there for now, but consider it experimental at
    best. Minor fix to dup2 and add dup and dup3 logging.

wsproxy Wrap Command:

    In wsproxy wrap command mode, a command line is specified instead
    of a target address and port. wsproxy then uses a much simpler
    LD_PRELOAD library, rebind.so, to move intercept any bind() system
    calls made by the program. If the bind() call is for the wsproxy
    listen port number then the real bind() system call is issued for
    an alternate (free high) port on loopback/localhost.  wsproxy then
    forwards from the listen address/port to the moved port.

    The --wrap-mode argument takes three options that determine the
    behavior of wsproxy when the wrapped command returns an exit code
    (exit or daemonizing): ignore, exit, respawn.

    For example, this runs vncserver on turns port 5901 into
    a WebSockets port (rebind.so must be built first):

        ./utils/wsproxy.py --wrap-mode=ignore 5901 -- vncserver :1

    The vncserver command backgrounds itself so the wrap mode is set
    to "ignore" so that wsproxy keeps running even after it receives
    an exit code from vncserver.

wstelnet:

    To demonstrate the wrap command mode, I added WebSockets telnet
    client.

    For example, this runs telnetd (krb5-telnetd) on turns port 2023
    into a WebSockets port (using "respawn" mode since telnetd exits
    after each connection closes):

        sudo ./utils/wsproxy.py --wrap-mode=respawn 2023 -- telnetd -debug 2023

    Then the utils/wstelnet.html page can be used to connect to the
    telnetd server on port 2023. The telnet client includes VT100.js
    (from http://code.google.com/p/sshconsole) which handles the
    terminal emulation and rendering.

rebind:

    The rebind LD_PRELOAD library is used by wsproxy in wrap command
    mode to intercept bind() system calls and move the port to
    a different port on loopback/localhost. The rebind.so library can
    be built by running make in the utils directory.

    The rebind library can be used separately from wsproxy by setting
    the REBIND_OLD_PORT and REBIND_NEW_PORT environment variables
    prior to executing a command. For example:

        export export REBIND_PORT_OLD="23"
        export export REBIND_PORT_NEW="65023"
        LD_PRELOAD=./rebind.so telnetd -debug 23

    Alternately, the rebind script does the same thing:

        rebind 23 65023 telnetd -debug 23

Other changes/notes:

- wsproxy no longer daemonizes by default. Remove -f/--foreground
  option and add -D/--deamon option.

- When wsproxy is used to wrap a command in "respawn" mode, the
  command will not be respawn more often than 3 times within 10
  seconds.

- Move getKeysym routine out of Canvas object so that it can be called
  directly.

Related to issue Non-US keyboard layout option issue:
https://github.com/kanaka/noVNC/issues#issue/21

Rename the $() selector to $D() so that it doesn't collide with
the jQuery name.

The API change is that the 'target' option for Canvas and RFB objects
must now be a DOM Canvas element. A string is no longer accepted
because this requires that a DOM lookup is done and the Canvas and RFB
should have no UI code in them. Modularity.

- With a strict doctype, the margin size needs a "px" suffix.

This is WebKit bug https://bugs.webkit.org/show_bug.cgi?id=46319

The workaround is to wrap Canvas render functions with a function that
sets a flush timer. The flush function sets the right margin and then
1ms later sets it back. This triggers the canvas to redraw with the
correct contents.

Two downsides:
- rendering is slower, but only on the busted versions of webkit.
  Correct and useful is better than fast and useless.
- There is a barely perceptible jitter of the control buttons because
  the canvas size is changing by one pixel.

To support this functionality, we also have to read out the exact
webkit version from the user agent in the render engine detection code
in include/util.js.

- Make sure that canvas exists (i.e. didn't throw an error) before
  trying to call canvas method get_canvas_uri.

- Typos in HTML render engine debug output.

- Style caching gives a small performance speedup in firefox, but not
  much. Might not be worth complexity, but leave it in for now.

Read the render mode selected by canvas and report it in the initial
page loaded status message.

- include/util.js: Add type and desc field to conf_default routine.
  Make comment descriptions of settings into desc parameters that can
  be queried. Also, use set_FOO in conf_default to set or coerce the
  current setting so that we always have the right type for the value.

- include/rfb.js, include/default_config.js: add connectTimeout
  setting to address situations with slow connections that may need
  more than 2 seconds.