Jexer - Java Text User Interface library
========================================
-This library implements a text-based windowing system 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))
+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))
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 using UTF8 and SGR coordinates
- are supported. For the demo application, this is the default
- backend on non-Windows/non-Mac platforms.
+ 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.
* 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 socket. jexer.demos.Demo3 demonstrates how one might use a
- character encoding than the default UTF-8.
+ TCP (telnet) socket. jexer.demos.Demo3 demonstrates how one might
+ use a character encoding than the default UTF-8.
* Java Swing UI. The default window size for Swing is 80x25 and 20
point font; this can be changed in the TApplication(BackendType)
Additional backends can be created by subclassing
jexer.backend.Backend and passing it into the TApplication
-constructor.
+constructor. See Demo5 and Demo6 for examples of other backends.
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://github.com/klamonte/jexer .
+source code is hosted at: https://gitlab.com/klamonte/jexer .
addFileMenu();
addWindowMenu();
- // Add a custom window, see below for its code.
- addWindow(new MyWindow(this));
+ // 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) {
* 'java -cp jexer.jar jexer.demos.Demo5' . This demonstrates two
demo applications using different fonts in the same Swing frame.
- * 'java -cp jexer.jar jexer.demos.Demo6' . This demonstrates one
- application performing I/O to two screens: an xterm screen and a
- Swing screen.
+ * 'java -cp jexer.jar jexer.demos.Demo6' . This demonstrates two
+ applications performing I/O across three screens: an xterm screen
+ and Swing screen, monitored from a third Swing screen.
![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")
+
System Properties
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
obviously expected behavior did not happen or when a specification was
ambiguous. This section describes such issues.
- - The JVM needs some warmup time to exhibit the true performance
- behavior. Drag a window around for a bit to see this: the initial
- performance is slow, then the JIT compiler kicks in and Jexer can
- be visually competitive with C/C++ curses applications.
-
- See jexer.tterminal.ECMA48 for more specifics of terminal
emulation limitations.
input (see the ENABLE_LINE_INPUT flag for GetConsoleMode() and
SetConsoleMode()).
- - TTerminalWindow 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.
+ - 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
equivalent of cfmakeraw() when using System.in/out. System.out is
also (blindly!) put in 'stty sane cooked' mode when exiting.
+ - 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.
-Roadmap
--------
-Many tasks remain before calling this version 1.0. See docs/TODO.md
-for the complete list of tasks.
+See Also
+--------
+
+[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.