========================================
This library implements a text-based windowing system loosely
-reminiscient of Borland's [Turbo
-Vision](http://en.wikipedia.org/wiki/Turbo_Vision) system. (For those
-wishing to use the actual C++ Turbo Vision library, see [Sergio
-Sigala's C++ version based on the sources released by
-Borland,](http://tvision.sourceforge.net/) or consider Free Pascal's
-[Free Vision library.](http://wiki.freepascal.org/Free_Vision))
+reminiscent of Borland's [Turbo
+Vision](http://en.wikipedia.org/wiki/Turbo_Vision) system. It looks
+like this:
-Jexer currently supports three backends:
-
-* System.in/out to a command-line ECMA-48 / ANSI X3.64 type terminal
- (tested on Linux + xterm). I/O is handled through terminal escape
- sequences generated by the library itself: ncurses is not required
- or linked to. xterm mouse tracking is supported using both UTF8 and
- SGR coordinates. Images are optionally rendered via sixel graphics
- (see jexer.ECMA48.sixel). For the demo application, this is the
- default backend on non-Windows/non-Mac platforms.
+![Several Windows Open Including A Terminal](/screenshots/screenshot1.png?raw=true "Several Windows Open Including A Terminal")
-* The same command-line ECMA-48 / ANSI X3.64 type terminal as above,
- but to any general InputStream/OutputStream or Reader/Writer. See
- the file jexer.demos.Demo2 for an example of running the demo over a
- TCP (telnet) socket. jexer.demos.Demo3 demonstrates how one might
- use a character encoding than the default UTF-8.
+Jexer works on both Xterm-like terminals and Swing, and supports
+images in both Xterm and Swing. On Swing, images are true color:
-* Java Swing UI. The default window size for Swing is 80x25 and 20
- point font; this can be changed in the TApplication(BackendType)
- constructor. For the demo applications, this is the default backend
- on Windows and Mac platforms. This backend can be explicitly
- selected for the demo applications by setting jexer.Swing=true.
+![Swing Snake Image](/screenshots/snake_swing.png?raw=true "Swing Snake Image")
-Additional backends can be created by subclassing
-jexer.backend.Backend and passing it into the TApplication
-constructor. See Demo5 and Demo6 for examples of other backends.
+On Xterm, images are dithered to a common palette:
-The Jexer homepage, which includes additional information and binary
-release downloads, is at: https://jexer.sourceforge.io . The Jexer
-source code is hosted at: https://gitlab.com/klamonte/jexer .
+![Xterm Snake Image](/screenshots/snake_xterm.png?raw=true "Xterm Snake Image")
License
-------
-This project is licensed under the MIT License. See the file LICENSE
+Jexer is available to all under the MIT License. See the file LICENSE
for the full license text.
-Maven
------
+
+Obtaining Jexer
+---------------
Jexer is available on Maven Central:
</dependency>
```
+Binary releases are available on SourceForge:
+https://sourceforge.net/projects/jexer/files/jexer/
+The Jexer source code is hosted at: https://gitlab.com/klamonte/jexer
-Acknowledgements
-----------------
-
-Jexer makes use of the Terminus TrueType font [made available
-here](http://files.ax86.net/terminus-ttf/) .
-
-
-
-Usage
------
-
-Simply subclass TApplication and then run it in a new thread:
-
-```Java
-import jexer.*;
-
-class MyApplication extends TApplication {
-
- public MyApplication() throws Exception {
- super(BackendType.SWING); // Could also use BackendType.XTERM
- // Create standard menus for File and Window
- addFileMenu();
- addWindowMenu();
- // Add a custom window, see below for its code. The TWindow
- // constructor will add it to this application.
- new MyWindow(this);
- }
-
- public static void main(String [] args) throws Exception {
- MyApplication app = new MyApplication();
- (new Thread(app)).start();
- }
-}
-```
-
-Similarly, subclass TWindow and add some widgets:
-
-```Java
-class MyWindow extends TWindow {
-
- public MyWindow(TApplication application) {
- // See TWindow's API for several constructors. This one uses the
- // application, title, width, and height. Note that the window width
- // and height include the borders. The widgets inside the window
- // will see (0, 0) as the top-left corner inside the borders,
- // i.e. what the window would see as (1, 1).
- super(application, "My Window", 30, 20);
-
- // See TWidget's API for convenience methods to add various kinds of
- // widgets. Note that ANY widget can be a container for other
- // widgets: TRadioGroup for example has TRadioButtons as child
- // widgets.
-
- // We will add a basic label, text entry field, and button.
- addLabel("This is a label", 5, 3);
- addField(5, 5, 20, false, "enter text here");
- // For the button, we will pop up a message box if the user presses
- // it.
- addButton("Press &Me!", 5, 8, new TAction() {
- public void DO() {
- MyWindow.this.messageBox("Box Title", "You pressed me, yay!");
- }
- } );
- }
-}
-```
+Documentation
+-------------
-Put these into a file, compile it with jexer.jar in the classpath, run
-it and you'll see an application like this:
+* [Java API Docs](https://jexer.sourceforge.io/apidocs/api/index.html)
-![The Example Code Above](/screenshots/readme_application.png?raw=true "The application in the text of README.md")
+* [Wiki](https://gitlab.com/klamonte/jexer/wikis/home)
-More Examples
--------------
+Programming Examples
+--------------------
The examples/ folder currently contains:
controls. The demos can be run as follows:
* 'java -jar jexer.jar' . This will use System.in/out with
- xterm-like sequences on non-Windows non-Mac platforms. On Windows
+ Xterm-like sequences on non-Windows non-Mac platforms. On Windows
and Mac it will use a Swing JFrame.
* 'java -Djexer.Swing=true -jar jexer.jar' . This will always use
Swing on any platform.
* 'java -cp jexer.jar jexer.demos.Demo2 PORT' (where PORT is a
- number to run the TCP daemon on). This will use the telnet
- protocol to establish an 8-bit clean channel and be aware of
- screen size changes.
+ number to run the TCP daemon on). This will use the Xterm backend
+ on a telnet server that will update with screen size changes.
* 'java -cp jexer.jar jexer.demos.Demo3' . This will use
- System.in/out with xterm-like sequences. One can see in the code
+ System.in/out with Xterm-like sequences. One can see in the code
how to pass a different InputReader and OutputReader to
TApplication, permitting a different encoding than UTF-8.
demo applications using different fonts in the same Swing frame.
* 'java -cp jexer.jar jexer.demos.Demo6' . This demonstrates two
- applications performing I/O across three screens: an xterm screen
+ applications performing I/O across three screens: an Xterm screen
and Swing screen, monitored from a third Swing screen.
More Screenshots
----------------
-![Several Windows Open Including A Terminal](/screenshots/screenshot1.png?raw=true "Several Windows Open Including A Terminal")
-
![Yo Dawg...](/screenshots/yodawg.png?raw=true "Yo Dawg, I heard you like text windowing systems, so I ran a text windowing system inside your text windowing system so you can have a terminal in your terminal.")
![Sixel Pictures Of Cliffs Of Moher And Buoy](/screenshots/sixel_images.png?raw=true "Sixel Pictures Of Cliffs Of Moher And Buoy")
![Sixel Color Wheel](/screenshots/sixel_color_wheel.png?raw=true "Sixel Color Wheel")
+
Terminal Support
----------------
-The table below lists terminals tested against Jexer's ECMA48/Xterm
-backend.
+The table below lists terminals tested against Jexer's Xterm backend:
| Terminal | Environment | Mouse Click | Mouse Cursor | Images |
| -------------- | ------------------ | ----------- | ------------ | ------ |
-System Properties
------------------
-
-The following properties control features of Jexer:
-
- jexer.Swing
- -----------
-
- Used only by jexer.demos.Demo1 and jexer.demos.Demo4. If true, use
- the Swing interface for the demo application. Default: true on
- Windows (os.name starts with "Windows") and Mac (os.name starts with
- "Mac"), false on non-Windows and non-Mac platforms.
-
- jexer.Swing.cursorStyle
- -----------------------
-
- Used by jexer.backend.SwingTerminal. Selects the cursor style to
- draw. Valid values are: underline, block, outline. Default:
- underline.
-
- jexer.Swing.tripleBuffer
- ------------------------
-
- Used by jexer.backend.SwingTerminal. If true, use triple-buffering
- which reduces screen tearing but may also be slower to draw on
- slower systems. If false, use naive Swing thread drawing, which may
- be faster on slower systems but also more likely to have screen
- tearing. Default: true.
-
- jexer.TTerminal.ptypipe
- -----------------------
-
- Used by jexer.TTerminalWindow. If true, spawn shell using the
- 'ptypipe' utility rather than 'script'. This permits terminals to
- resize with the window. ptypipe is a separate C language utility,
- available at https://gitlab.com/klamonte/ptypipe. Default: false.
-
- jexer.TTerminal.closeOnExit
- ---------------------------
-
- Used by jexer.TTerminalWindow. If true, close the window when the
- spawned shell exits. Default: false.
-
- jexer.ECMA48.rgbColor
- ---------------------
-
- Used by jexer.backend.ECMA48Terminal. If true, emit T.416-style RGB
- colors for normal system colors. This is expensive in bandwidth,
- and potentially terrible looking for non-xterms. Default: false.
-
- jexer.ECMA48.sixel
- ------------------
-
- Used by jexer.backend.ECMA48Terminal. If true, emit image data
- using sixel, otherwise show blank cells where images could be. This
- is expensive in bandwidth, very expensive in CPU (especially for
- large images), and will leave artifacts on the screen if the
- terminal does not support sixel. Default: true.
-
-
-
-Known Issues / Arbitrary Decisions
-----------------------------------
-
-Some arbitrary design decisions had to be made when either the
-obviously expected behavior did not happen or when a specification was
-ambiguous. This section describes such issues.
-
- - See jexer.tterminal.ECMA48 for more specifics of terminal
- emulation limitations.
-
- - TTerminalWindow uses cmd.exe on Windows. Output will not be seen
- until enter is pressed, due to cmd.exe's use of line-oriented
- input (see the ENABLE_LINE_INPUT flag for GetConsoleMode() and
- SetConsoleMode()).
-
- - TTerminalWindow by default launches 'script -fqe /dev/null' or
- 'script -q -F /dev/null' on non-Windows platforms. This is a
- workaround for the C library behavior of checking for a tty:
- script launches $SHELL in a pseudo-tty. This works on Linux and
- Mac but might not on other Posix-y platforms.
-
- - Closing a TTerminalWindow without exiting the process inside it
- may result in a zombie 'script' process.
-
- - When using the Swing backend, and not using 'ptypipe', closing a
- TTerminalWindow without exiting the process inside it may result
- in a SIGTERM to the JVM causing it to crash. The root cause is
- currently unknown, but is potentially a bug in more recent
- releases of the 'script' utility from the util-linux package.
-
- - TTerminalWindow can only notify the child process of changes in
- window size if using the 'ptypipe' utility, due to Java's lack of
- support for forkpty() and similar. ptypipe is available at
- https://gitlab.com/klamonte/ptypipe.
-
- - Java's InputStreamReader as used by the ECMA48 backend requires a
- valid UTF-8 stream. The default X10 encoding for mouse
- coordinates outside (160,94) can corrupt that stream, at best
- putting garbage keyboard events in the input queue but at worst
- causing the backend reader thread to throw an Exception and exit
- and make the entire UI unusable. Mouse support therefore requires
- a terminal that can deliver either UTF-8 coordinates (1005 mode)
- or SGR coordinates (1006 mode). Most modern terminals can do
- this.
+See Also
+--------
- - jexer.session.TTYSession calls 'stty size' once every second to
- check the current window size, performing the same function as
- ioctl(TIOCGWINSZ) but without requiring a native library.
+* [Tranquil Java IDE](https://tjide.sourceforge.io) is a TUI-based
+ integrated development environment for the Java language that was
+ built using a very lightly modified GPL version of Jexer. TJ
+ provided a real-world use case to shake out numerous bugs and
+ limitations of Jexer.
- - jexer.backend.ECMA48Terminal calls 'stty' to perform the
- equivalent of cfmakeraw() when using System.in/out. System.out is
- also (blindly!) put in 'stty sane cooked' mode when exiting.
+* [LCXterm](https://lcxterm.sourceforge.io) is a curses-based terminal
+ emulator that allows one to use Jexer with full support on the raw
+ Linux console.
- - jexer.backend.ECMA48Terminal uses a single palette containing
- MAX_COLOR_REGISTERS colors for all sixel images. These colors are
- generated in the SixelPalette.makePalette() method with bits for
- hue, saturation, and luminance, and the two extremes set to pure
- black and pure white. This provides a reasonable general-purpose
- palette light on CPU, but at a cost that individual images do not
- look as good as the terminal is actually capable of.
+* [ptypipe](https://gitlab.com/klamonte/ptypipe) is a small C utility
+ that permits a Jexer TTerminalWindow to resize the running shell
+ when its window is resized.
-See Also
---------
+Acknowledgements
+----------------
-[Tranquil Java IDE](https://tjide.sourceforge.io) is a TUI-based
-integrated development environment for the Java language that was
-built using a very lightly modified GPL version of Jexer. TJ provided
-a real-world use case to shake out numerous bugs and limitations of
-Jexer.
-
-
-
-Maintainers Wanted
-------------------
-
-Both Jexer and TJIDE are seeking additional maintainers. I am not in
-a position in life to take on significant off-hours programming work,
-and am willing to hand these projects over to one or more persons with
-time and interest.
-
-My personal code design philosophy for TJIDE/Jexer is outlined at
-https://gitlab.com/klamonte/tjide/blob/master/java/docs/code_design.txt
-. I realize that some of the features listed below may require
-deviations from this philosophy, but this is what I have built so far.
-
-Some of the areas that will likely require significant efforts are:
-
- * Editor improvements. The editor is currently very minimalistic,
- much closer to MS-DOS edit.com than a real programmer's editor.
- Users will probably desire many more features: drag-and-drop, real
- syntax or at least regexp highlighting (not just keywords), paren
- matching, paragraph/comment reflow, and dozens more. The
- underlying Document/Line/Word model is not going to be sufficient
- to meet these features.
-
- * Better Windows and OSX support. It would be nice to ship a
- jlink'ed JVM on these platforms with the JRE, JDK, and JPDA
- modules all together. For Windows, it might be preferable to
- consider doing any of the following: ship a third-party terminal,
- use PowerShell, or use the newer ConPTY for TTerminalWindow.
-
- * Bug fixes. The Jexer codebase is quite large despite my best
- efforts. Bugs are typically very small to fix, but can take some
- time to find: a simple NPE or AssertionError can sometimes take
- 4-8 hours to squash. Fortunately, fixing issues in one place has
- not often led to breakages elsewhere.
-
- * New Jexer applications. So far as I know, Jexer is the only
- mouse-supporting full TUI windowing framework with sixel image
- support in existence. I cannot predict what kinds of applications
- could be built out of it, and how those needs will push back to
- the framework.
-
-These are what I can clearly see right now. Obviously users are
-capable of finding many more.
-
-I intend to continue poking on Jexer and TJIDE, and will maintain a
-branch to be "the fastest and simplest Java language IDE available",
-which will deliberately remain small.
-
-I hope that other languages choose to transliterate Jexer to provide
-TUIs to their own platforms. I will be happy to help them understand
-the code to support those efforts.
+Jexer makes use of the Terminus TrueType font [made available
+here](http://files.ax86.net/terminus-ttf/) .