This library implements a text-based windowing system loosely reminiscent of Borland’s Turbo Vision system. It looks like this:
Jexer works on both Xterm-like terminals and Swing, and supports images in both Xterm and Swing. On Swing, images are true color:
On Xterm, images are dithered to a common palette:
Jexer is available to all under the MIT License. See the file LICENSE for the full license text.
Jexer is available on Maven Central:
xml
<dependency>
<groupId>com.gitlab.klamonte</groupId>
<artifactId>jexer</artifactId>
<version>0.3.2</version>
</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
Jexer’s original list of features for its 1.0.0 release are undergoing final testing. If you know of a bug or key feature missing, please consider opening an issue here.
The examples/ folder currently contains:
A prototype tiling window manager in less than 250 lines of code.
A much slicker prototype tiling window manager in less than 200 lines of code.
A prototype image thumbnail viewer in less than 350 lines of code.
jexer.demos contains official demos showing all of the existing UI 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 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 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 how to pass a different InputReader and OutputReader to TApplication, permitting a different encoding than UTF-8.
‘java -cp jexer.jar jexer.demos.Demo4’ . This demonstrates hidden windows and a custom TDesktop.
‘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 two applications performing I/O across three screens: an Xterm screen and Swing screen, monitored from a third Swing screen.
‘java -cp jexer.jar jexer.demos.Demo7’ . This demonstrates the BoxLayoutManager, achieving a similar result as the javax.swing.BoxLayout apidocs example.
Jexer can be run inside its own terminal window, with support for all of its features including images and mouse, and more terminals:
Sixel output uses a single palette which works OK for a variety of real-world images:
The color wheel with that palette is shown below:
The table below lists terminals tested against Jexer’s Xterm backend:
Terminal | Environment | Mouse Click | Mouse Cursor | Images |
---|---|---|---|---|
xterm | X11 | yes | yes | yes |
jexer | CLI, X11, Windows | yes | yes | yes |
mlterm | X11 | yes | yes | yes |
RLogin | Windows | yes | yes | yes |
alacritty(3) | X11 | yes | yes | no |
gnome-terminal | X11 | yes | yes | no |
iTerm2 | Mac | yes | yes | no(5) |
kitty(3) | X11 | yes | yes | no |
lcxterm(3) | CLI, Linux console | yes | yes | no |
mintty | Windows | yes | yes | no(5) |
rxvt-unicode | X11 | yes | yes | no(2) |
xfce4-terminal | X11 | yes | yes | no |
aminal(3) | X11 | yes | no | no |
konsole | X11 | yes | no | no |
yakuake | X11 | yes | no | no |
Windows Terminal(6) | Windows | no | no | no(2) |
screen | CLI | yes(1) | yes(1) | no(2) |
tmux | CLI | yes(1) | yes(1) | no |
putty | X11, Windows | yes | no | no(2) |
Linux | Linux console | no | no | no(2) |
qodem(3) | CLI, Linux console | yes | yes(4) | no |
qodem-x11(3) | X11 | yes | no | no |
yaft | Linux console (FB) | no | no | yes |
1 - Requires mouse support from host terminal.
2 - Also fails to filter out sixel data, leaving garbage on screen.
3 - Latest in repository.
4 - Requires TERM=xterm-1003 before starting.
5 - Sixel images can crash terminal.
6 - Version 0.7.3291.0, on Windows 10.0.18362.30. Tested against WSL-1 Debian instance.
Tranquil Java IDE 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.
LCXterm is a curses-based terminal emulator that allows one to use Jexer with full support on the raw Linux console.
ptypipe is a small C utility that permits a Jexer TTerminalWindow to resize the running shell when its window is resized.
Jexer makes use of the Terminus TrueType font made available here .