available.
-Compiling from the sources
-==========================
-
-To compile all the .java files to .class files, simply do:
-
- % make all
-
-This will also generate a JAR (Java archive) file containing all the classes.
-Most JVM (Java Virtual Machine) implementations are able to use either a set
-of .class files, or the JAR archive.
-
-
Installation
============
-There are three basic ways to use TigerVNC Java viewer:
-
- 1. Running applet as part of TigerVNC server installation.
-
- Both the Unix and Windows versions of TigerVNC servers include small
- built-in HTTP server which can serve Java viewer to Web clients. This
- enables easy Web access to the shared desktop without need to install
- any software on the client computer. Unix and Windows versions of
- TigerVNC servers are different in the way they store the .class and .jar
- files: the Unix server (Xvnc) is able to serve any set of files present
- in a particular directory, while the Windows server (WinVNC) has all the
- .class and .jar files inside the WinVNC executable file. Therefore, for
- Xvnc, it's enough to copy the files into a correct directory, but for
- WinVNC, the server binaries should be rebuild if the built-in Java
- viewer should be updated.
-
- To install the Java viewer under Xvnc, copy all the .class files, the
- .jar file and the .vnc files to an installation directory (e.g.
- /usr/local/vnc/classes):
-
- cp *.class *.jar *.vnc /usr/local/vnc/classes
-
- Also, make sure that the vncserver script is configured to point to the
- installation directory (see the Xvnc manual page for the description of
- the -httpd command-line option).
-
- 2. Running applet hosted on a standalone Web server.
-
- Another possibility to use the Java viewer is to install it under a
- fully-functional HTTP server such as Apache or IIS. Obviously, this
- method requires running an HTTP server, and due to the Java security
- restrictions, it's also required that the server should be installed on
- the same machine which is running the TigerVNC server. In this case,
- installation is simply copying the .class and .jar files into a
- directory that is under control of the HTTP server. Also, an HTML page
- should be created which will act as a the base document for the viewer
- applet (see an example named index.html in this distribution).
-
- NOTE: Provided index.html page is an example only. Before using that
- file, edit it with a text editor. See more information inside
- index.html.
+There are three basic ways to use the TigerVNC Java Viewer:
+
+ 1. Running the applet as part of a TigerVNC Server installation.
+
+ Both the Unix and Windows versions of the TigerVNC Server include a small
+ built-in HTTP server that can serve the TigerVNC Java Viewer to web
+ clients. This enables easy access to the shared desktop without the need
+ to install any software on the client machine.
+
+ The Unix TigerVNC Server (Xvnc) is able to serve up any set of files that
+ are present in a particular directory, which is specified in the -httpd
+ argument to Xvnc. The default version of the vncserver script will look
+ for a directory called vnc/classes, one level up from the directory
+ containing the vncserver script, then it will look for a directory called
+ /usr/share/vnc/classes, then /usr/local/vnc/classes. It will set the
+ -httpd argument to Xvnc to the first one of these VNC classes directories
+ it finds. Thus, one can easily deploy a modified version of the TigerVNC
+ Java Viewer by simply copying a new version of VncViewer.jar and/or
+ index.vnc into the VNC classes directory.
+
+ In the case of the Windows TigerVNC Server, VncViewer.jar and index.vnc
+ are embedded as resources in the WinVNC executable, so deploying a
+ modified version of the TigerVNC Java Viewer on a Windows server requires
+ rebuilding WinVNC.
+
+ 2. Running the applet from a standalone web server.
+
+ Another possibility for using the TigerVNC Java Viewer is to install it
+ under a fully-functional HTTP server, such as Apache or IIS. Due to Java
+ security restrictions, the applet must be signed in order for it to
+ connect to a VNC server running on a different machine from the HTTP
+ server.
+
+ One can install the TigerVNC Java Viewer by simply copying the .class and
+ .jar files into a directory that is under the control of the HTTP server.
+ Also, an HTML page should be created to act as a the base document for the
+ TigerVNC Java Viewer applet (an example named index.html is provided in
+ this directory. Modify this file to suit your specific needs.)
3. Running the viewer as a standalone application.
- Finally, the Java viewer can be executed locally on the client machine,
- but this method requires installation of either JRE (Java Runtime
- Environment) or JDK (Java Development Kit). If all the .class files are
- in the current directory, the Java viewer can be executed like this,
- from the command line:
+ Finally, the TigerVNC Java Viewer can be executed locally on the client
+ machine, but this method requires installation of either a JRE (Java
+ Runtime Environment) or a JDK (Java Development Kit). If VncViewer.jar is
+ in the current directory, then the TigerVNC Java Viewer can be launched
+ with the following command line:
- java VncViewer HOST vnchost PORT 5900
+ java -jar VncViewer.jar [parameters]
- The HOST parameter is required, PORT defaults to 5900 if omitted, and
- there is a number of other optional parameters, see the Parameters
- section below.
+ Add an argument of -? to the above command line to print a list of
+ optional parameters supported by VncViewer.
Parameters
==========
-TigerVNC Java viewer supports a number of parameters allowing you to
-customize its behavior. Most parameters directly correspond to the settings
-found in the Options window. However, there are parameters that do not
-correspond to those settings. For such parameters, you can see a note "no GUI
-equivalent", in the documentation below.
+The TigerVNC Java Viewer accepts a number of optional parameters, allowing you
+to customize its behavior.
-Parameters can be specified in one of the two ways, depending on how the Java
-viewer is used:
+Parameters can be specified in one of the two ways, depending on how the
+TigerVNC Java Viewer is used:
- 1. When the Java viewer is run as an applet (embedded within an HTML
- document), parameters should be specified in the <PARAM> HTML tags,
- within the appropriate <APPLET> section. Here is an example:
+ 1. When the TigerVNC Java Viewer is run as an applet (embedded within an HTML
+ document), parameters should be specified using the <PARAM> HTML tags
+ within the appropriate <APPLET> section. Example:
- <APPLET CODE=VncViewer.class ARCHIVE=VncViewer.jar WIDTH=400 HEIGHT=300>
+ <APPLET CODE=com.tigervnc.vncviewer.VncViewer ARCHIVE=VncViewer.jar
+ WIDTH=400 HEIGHT=300>
<PARAM NAME="PORT" VALUE=5901>
- <PARAM NAME="Scaling factor" VALUE=50>
+ <PARAM NAME="ScalingFactor" VALUE=50>
</APPLET>
- 2. When run as a standalone application, the Java viewer reads parameters
- from the command line. Command-line arguments should be specified in
- pairs -- first goes parameter name, then parameter value. Here is a
- command line example:
-
- java VncViewer HOST vnchost PORT 5901 "Scaling factor" 50
-
-Both parameter names and their values are case-insensitive. The only
-exception is the "PASSWORD" parameter, as VNC passwords are case-sensitive.
-
-Here is the complete list of parameters supported in TigerVNC Java viewer:
-
---> "HOST" (no GUI equivalent)
-
- Value: host name or IP address of the VNC server.
- Default: in applet mode, the host from which the applet was loaded.
-
- This parameter tells the viewer which server to connect to. It's not
- needed in the applet mode, because default Java security policy allow
- connections from applets to the only one host anyway, and that is the
- host from which the applet was loaded. However, this parameter is
- required if the viewer is used as a standalone application.
-
---> "PORT" (no GUI equivalent)
-
- Value: TCP port number on the VNC server.
- Default: 5900.
-
- This parameter specifies TCP port number for outgoing VNC connection.
- Note that this port is not the one used for HTTP connection from the
- browser, it is the port used for VNC/RFB connection. Usually, VNC servers
- use ports 58xx for HTTP connections, and ports 59xx for RFB connections.
- Thus, most likely, this parameter should be set to something like 5900,
- 5901 etc.
-
---> "PASSWORD"
-
- Value: session password in plain text.
- Default: none, ask user.
-
- DO NOT EVER USE THIS PARAMETER, unless you really know what you are
- doing. It's extremely dangerous from the security point of view. When
- this parameter is set, the viewer won't ever ask for a password.
-
---> "ENCPASSWORD"
-
- Value: encrypted session password in hex-ascii.
- Default: none, ask user.
-
- The same as the "PASSWORD" parameter but DES-encrypted using a fixed key.
- Its value should be represented in hex-ascii e.g. "494015f9a35e8b22".
- This parameter has higher priority over the "PASSWORD" parameter. DO NOT
- EVER USE THIS PARAMETER, unless you really know what you are doing. It's
- extremely dangerous from the security point of view, and encryption does
- not actually help here since the decryption key is always known.
-
---> "Encoding"
-
- Values: "Auto", "Raw", "RRE", "CoRRE", "Hextile", "ZRLE", "Zlib", "Tight".
- Default: "Auto".
-
- The preferred encoding. If the value is "Auto", then the viewer will
- continuously estimate average network throughput and request encodings
- that are appropriate for current connection speed. "Hextile" is an
- encoding that was designed for fast networks, while "Tight" is better
- suited for low-bandwidth connections. From the other side, "Tight"
- decoder in the TigerVNC Java viewer seems to be more efficient than
- "Hextile" decoder so it may be ok for fast networks too. "ZRLE" encoding
- is similar to "Tight", but it does not support JPEG compression and
- compression levels. Unlike "Tight" encoding, "ZRLE" is supported in
- recent versions of RealVNC products. Other encodings are not efficient
- and provided for compatibility reasons.
-
---> "Compression level"
-
- Values: "Default", "1", "2", "3", "4", "5", "6", "7", "8", "9".
- Default: "Default". ;-)
-
- Use specified compression level for "Tight" and "Zlib" encodings. Level 1
- uses minimum of CPU time on the server but achieves weak compression
- ratios. Level 9 offers best compression but may be slow in terms of CPU
- time consumption on the server side. Use high levels with very slow
- network connections, and low levels when working over higher-speed
- networks. The "Default" value means that the server's default compression
- level should be used.
-
---> "JPEG image quality"
-
- Values: "JPEG off", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9".
- Default: "6".
-
- Use the specified image quality level in "Tight" encoding. Quality level
- 0 denotes bad image quality but very impressive compression ratios, while
- level 9 offers very good image quality at lower compression ratios. If
- the value is "JPEG off", the server will not use lossy JPEG compression
- in "Tight" encoding.
-
---> "Cursor shape updates"
-
- Values: "Enable", "Ignore", "Disable".
- Default: "Enable".
-
- Cursor shape updates is a protocol extension used to handle remote cursor
- movements locally on the client side, saving bandwidth and eliminating
- delays in mouse pointer movement. Note that current implementation of
- cursor shape updates does not allow a client to track mouse cursor
- position at the server side. This means that clients would not see mouse
- cursor movements if mouse was moved either locally on the server, or by
- another remote VNC client. Set this parameter to "Disable" if you always
- want to see real cursor position on the remote side. Setting this option
- to "Ignore" is similar to "Enable" but the remote cursor will not be
- visible at all. This can be a reasonable setting if you don't care about
- cursor shape and don't want to see two mouse cursors, one above another.
-
---> "Use CopyRect"
-
- Values: "Yes", "No".
- Default: "Yes".
-
- The "CopyRect" encoding saves bandwidth and drawing time when parts of
- the remote screen are moving around. Most likely, you don't want to
- change this setting.
-
---> "Restricted colors"
-
- Values: "Yes", "No".
- Default: "No".
-
- If set to "No", then 24-bit color format is used to represent pixel data.
- If set to "Yes", then only 8 bits are used to represent each pixel. 8-bit
- color format can save bandwidth, but colors may look very inaccurate.
-
---> "Mouse buttons 2 and 3"
-
- Values: "Normal", "Reversed".
- Default: "Normal".
-
- If set to "Reversed", then right mouse button (button 2) will act as it
- was middle mouse button (button 3), and vice versa.
-
---> "View only"
-
- Values: "Yes", "No".
- Default: "No".
-
- If set to "Yes", then all keyboard and mouse events in the desktop window
- will be silently ignored and will not be passed to the remote side.
-
---> "Scale remote cursor"
-
- Values: "No", "50%", "75%", "125%", "150%".
- Default: "No".
-
- If a percentage value is specified, the remote cursor is reduced
- or enlarged accordingly. Scaling takes place only when "View only"
- is set to "No", and "Cursor shape updates" is set to "Enable".
-
---> "Share desktop"
-
- Values: "Yes", "No".
- Default: "Yes".
-
- Share the connection with other clients on the same VNC server. The exact
- behaviour in each case depends on the server configuration.
-
---> "Open new window" (no GUI equivalent, applicable only in the applet mode)
-
- Values: "Yes", "No".
- Default: "No".
-
- Operate in a separate window. This makes possible resizing the desktop,
- and adds scroll bars when necessary. If the server supports variable
- desktop size, the window will resize automatically when remote desktop
- size changes.
-
---> "Scaling factor" (no GUI equivalent)
-
- Value: an integer in the range of [1..1000], or the string "auto".
- Default: "100".
-
- Scale local representation of the remote desktop. The value is
- interpreted as scaling factor in percents. The default value of 100%
- corresponds to the original framebuffer size. Values below 100 reduce
- image size, values above 100 enlarge the image proportionally. If the
- parameter is set to "auto", automatic scaling is performed. Auto-scaling
- tries to choose scaling factor such way that the whole remote framebuffer
- will fit on the local screen. Currently, auto-scaling is supported only
- when the remote desktop is shown in a separate frame (always true in the
- application mode, and also in the applet mode with "Open new window"
- parameter set to "yes").
-
---> "Show controls" (no GUI equivalent)
-
- Values: "Yes", "No".
- Default: "Yes".
-
- Set to "No" if you want to get rid of that button panel at the top.
-
---> "Offer relogin" (no GUI equivalent, applicable only in the applet mode)
-
- Values: "Yes", "No".
- Default: "Yes".
-
- If set to "No", the buttons "Login again" and "Close window" won't be
- shown on disconnects or after an error has occured.
-
---> "Show offline desktop" (no GUI equivalent)
-
- Values: "Yes", "No".
- Default: "No".
-
- If set to "Yes", the viewer would continue to display desktop even
- if the remote side has closed the connection. In this case, if the
- button panel is enabled, then the "Disconnect" button would be
- changed to "Hide desktop" after the connection is lost.
-
---> "Defer screen updates" (no GUI equivalent)
-
- Value: time in milliseconds.
- Default: "20".
-
- When updating the desktop contents after receiving an update from server,
- schedule repaint within the specified number of milliseconds. Small delay
- helps to coalesce several small updates into one drawing operation,
- improving CPU usage. Set this parameter to 0 to disable deferred updates.
-
---> "Defer cursor updates" (no GUI equivalent)
-
- Value: time in milliseconds.
- Default: "10".
-
- When updating the desktop after moving the mouse, schedule repaint within
- the specified number of milliseconds. This setting makes sense only when
- "Cursor shape updates" parameter is set to "Enable". Small delay helps to
- coalesce several small updates into one drawing operation, improving CPU
- usage. Set this parameter to 0 to disable deferred cursor updates.
-
---> "Defer update requests" (no GUI equivalent)
-
- Value: time in milliseconds.
- Default: "0".
-
- After processing an update received from server, wait for the specified
- number of milliseconds before requesting next screen update. Such delay
- will end immediately on every mouse or keyboard event if not in the "view
- only" mode. Small delay helps the server to coalesce several small
- updates into one framebuffer update, improving both bandwidth and CPU
- usage. Increasing the parameter value does not affect responsiveness on
- mouse and keyboard events, but causes delays in updating the screen when
- there is no mouse and keyboard activity on the client side.
-
---> "SocketFactory" (no GUI equivalent)
-
- Value: name of the class.
- Default: none.
+ 2. When run as a standalone application, the TigerVNC Java Viewer reads
+ parameters from the command line. Example:
- This option provides the way to define an alternate I/O implementation.
- The dynamically referenced class must implement a SocketFactory
- interface, and create a Socket, as configured by this parameter. See the
- source in SocketFactory.java.
-
---> "DEBUG_XU" (no GUI equivalent)
-
- Value: non-negative integer.
- Default: 0.
-
- Debugging option that causes update statistics reset after the specified
- number of first framebuffer updates. This option was added to measure the
- performance of a VNC server. First few updates (especially the very first
- one) may be notably slower than others, and the viewer can exclude such
- updates from statistics.
-
---> "DEBUG_CU" (no GUI equivalent)
-
- Value: non-negative integer.
- Default: 0.
-
- Debugging option that causes the viewer disconnect after the specified
- number of framebuffer updates. When used with the "DEBUG_XU" parameter,
- the number of updates specified in "DEBUG_XU" is not counted as part of
- this parameter's value. E.g. if "DEBUG_XU"=2 and "DEBUG_CU"=10, then the
- viewer will disconnect after 12 framebuffer updates: update statistics
- will be reset after first two updates, then collected for next 10
- updates, then the viewer will disconnect automatically. If the value is
- 0, the viewer will not disconnect automatically. This option was added to
- measure the performance of a VNC server.
+ java -jar VncViewer.jar Port=5901 ScalingFactor=50
+Both parameter names and their values are case-insensitive.
-RECORDING VNC SESSIONS
-======================
+For a complete list of parameters and their descriptions, run:
-Current version of the TigerVNC Java viewer is able to record VNC (RFB)
-sessions in files for later playback. The data format in saved session files
-is compatible with the rfbproxy program written by Tim Waugh. Most important
-thing about session recording is that it's supported only if Java security
-manager allows access to local filesystem. Typically, it would not work for
-unsigned applets. To use this feature, either use TigerVNC Java viewer as a
-standalone application (Java Runtime Environment or Java Development Kit
-should be installed), or as a signed applet. The code checks if it's possible
-to support session recording, and if everything's fine, the new "Record"
-button should appear in the button panel. Pressing this button opens new
-window which controls session recording. The GUI is pretty self-explained.
-
-Other important facts about session recording:
-
---> All sessions are recorded in the 24-bit color format. If you use
- restricted colors (8-bit format), it will be temporarly switched to
- 24-bit mode during session recording.
-
---> All sessions are recorded with cursor shape updates turned off. This is
- necessary to represent remote cursor movements in recorded sessions.
-
---> Closing and re-opening the recording control window does not affect the
- recording. It's not necessary to keep that window open during recording a
- session.
-
---> Avoid using Zlib and ZRLE encodings when recording sessions. If you have
- started recording BEFORE opening a VNC session, then you are ok. But
- otherwise, all Zlib-encoded updates will be saved Raw-encoded (that is,
- without compression at all). The case with ZRLE is even worse -- ZRLE
- updates will not be saved at all, so the resulting session file may be
- corrupted. Zlib decoding depends on the pixel data received earlier, thus
- saving the data received from the server at an arbitrary moment is not
- sufficient to decompress it correctly. And there is no way to tell Zlib
- or ZRLE decoder to reset decompressor's state -- that's a limitation of
- these encoders. The viewer could re-compress raw pixel data again before
- saving Zlib-encoded sessions, but unfortunately Java API does not allow
- to flush zlib data streams making it impossible to save Zlib-encoded RFB
- pixel data without using native code.
-
---> Usually, Tight encoding is the most suitable one for session recording,
- but some of the issues described above for the Zlib encoding affect the
- Tight encoding as well. Unlike Zlib sessions, Tight-encoded sessions are
- always saved Tight-encoded, but the viewer has to re-compress parts of
- data to synchronize encoder's and decoder's zlib streams. And, due to
- Java zlib API limitations, zlib streams' states have to be reset on each
- compressed rectangle, causing compression ratios to be lower than in the
- original VNC session. If you want to achieve the best possible
- performance, turn recording on BEFORE connecting to the VNC server,
- otherwise CPU usage and compression ratios may be notably less efficient.
+ java -jar VncViewer.jar -?
HINTS
=====
---> To refresh remote desktop in the view-only mode, press "r" or "R"
+--> To refresh the remote desktop in the view-only mode, press "r" or "R"
on the keyboard.
projects / tigervnc.git / commitdiff