This library implements a text-based windowing system loosely reminiscent of Borland's Turbo Vision system. It looks like this:
...or this:
...or anything in between. Translucent windows -- including layered images -- are supported and generally look as one would expect in a modern graphical environment...but it's mostly text. Translucent windows were inspired in part by notcurses.
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 rendered as sixel, iTerm2, or Jexer images.
Support for pixel-based operations was introduced in version 1.5.0. If the terminal supports mouse mode 1016 (SGR-Pixel), one can now get smooth(er) mouse motion with custom bitmap overlaid mouse. Below is stock xterm, with a custom mouse icon, and SGR-Pixel mode active:
A new sixel encoder was introduced in version 1.6.0, and looks and performs much better. This encoder was inspired in part by chafa's high-performance principal component analysis based sixel encoder.
Jexer can be run inside its own terminal window, with support for all of its features including images and mouse, and more terminals:
Wondering how I did it? Here you go.
Jexer is available to all under the MIT License. See the file LICENSE for the full license text.
Jexer is available on Maven Central:
<dependency>
<groupId>com.gitlab.klamonte</groupId>
<artifactId>jexer</artifactId>
<version>1.6.0</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/AutumnMeowMeow/jexer
Why I Do Not Post My Projects Anymore
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Porting Guide - If you don't like writing Java, here is your map to where the key features are so that you can implement them in a different system/language.
See Xterm Window Manager for a more comprehensive demonstration of what Jexer can accomplish. Here one can see a floating terminal window over tiled terminals, two of which are showing images:
Jexer's examples/ folder currently contains:
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A prototype tiling window manager in less than 250 lines of code.
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A much slicker prototype tiling window manager in less than 200 lines of code.
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A prototype image thumbnail viewer in less than 350 lines of code.
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A prototype Xterm video player (using JavaCV to decode video frames) in less than 200 lines of code.
jexer.demos contains official demos showing all of the existing UI controls. The demos can be run as follows:
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'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.
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'java -Djexer.Swing=true -jar jexer.jar' . This will always use Swing on any platform.
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'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.
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'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; in this case, code page 437.
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'java -cp jexer.jar jexer.demos.Demo4' . This demonstrates hidden windows and a custom TDesktop.
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'java -cp jexer.jar jexer.demos.Demo5' . This demonstrates two demo applications using different fonts in the same Swing frame.
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'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.
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'java -cp jexer.jar jexer.demos.Demo7' . This demonstrates the BoxLayoutManager, achieving a similar result as the javax.swing.BoxLayout apidocs example.
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'java -cp jexer.jar jexer.demos.Demo8 PORT' (where PORT is a number to run the TCP daemon on). This will use the Xterm backend on a telnet server to share one screen to many terminals.
Most popular terminals can run Jexer, but only a few support all of Jexer's features. Jexer is actively developed against xterm and wezterm . The table below lists the terminals last tested against Jexer:
| Terminal | Environment | Mouse Click | Mouse Cursor | Images |
|---|---|---|---|---|
| xterm | X11 | yes | yes | yes |
| jexer | CLI, X11, Windows | yes | yes | yes |
| wezterm | X11, Windows | yes | yes | yes(7) |
| foot(3) | Wayland | yes | yes | yes |
| contour(3) | X11 | yes | yes | yes |
| mintty | Windows | yes | yes | yes |
| mlterm | X11 | yes | yes | yes |
| RLogin | Windows | yes | yes | yes |
| xterm.js(8) | Web | yes | yes | yes |
| alacritty(3b) | X11 | yes | yes | yes |
| gnome-terminal | X11 | yes | yes | no |
| iTerm2 | Mac | yes | yes | no(5) |
| kitty(3) | X11 | yes | yes | no(9) |
| lcxterm | CLI, Linux console | yes | yes | no |
| rxvt-unicode | X11 | yes | yes | no(2) |
| xfce4-terminal | X11 | yes | yes | no |
| Windows Terminal(6) | Windows | yes | yes | no |
| DomTerm(3) | Web | yes | no | yes |
| darktile | X11 | yes | no | no(5) |
| konsole | X11 | yes | no | no |
| yakuake | X11 | yes | no | no |
| screen | CLI | yes(1) | yes(1) | no(2) |
| tmux | CLI | yes(1) | yes(1) | no |
| putty | X11, Windows | yes | 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 |
| Linux | Linux console | no | no | no(2) |
| MacTerm | Mac | no | no | no(2) |
1 - Requires mouse support from host terminal.
2 - Also fails to filter out sixel data, leaving garbage on screen.
3 - Latest in repository.
3b - Latest in repository, using graphics PR branch.
4 - Requires TERM=xterm-1003 before starting.
5 - Sixel images can crash terminal.
6 - Version 1.4.3243.0, on Windows 10.0.19041.1. Tested against WSL-1 Debian instance.
7 - Both sixel and iTerm2 images.
8 - Using jerch's xterm-addon-image.
9 - Kitty image protocol support will never be in Jexer, as a matter of principle. Should that terminal adopt iTerm2 or sixel, then images could work. (Image support for kitty was removed on February 10, 2022.)
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Xterm Window Manager is a text-based window manager. It has virtual desktops, tiled terminals with draggable resizing, cascading terminal windows, and a plugin system for adding functionality. Add LCXterm and one can have a mouse-supporting X11-like text-based "GUI" on the raw Linux console.
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XtermDOOM is an effort to make MochaDoom run smoothly under Xterm. The game is not yet playable, but it can show off Jexer's multiplexing and multihead image capabilities. For ramblings about the game, terminal resources, etc. see /r/xtermdoom.
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LCXterm is a curses-based terminal emulator that allows one to use Jexer with full support on the raw Linux console.
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ptypipe is a small C utility that permits a Jexer TTerminalWindow to resize the running shell when its window is resized.
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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.
Jexer makes use of the Terminus TrueType font made available here .
Jexer incorporates some ideas done first, or better implemented, elsewhere. If you like what you see here, please take a look at these projects too:
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