JEXER HAS MOVED TO GITLAB

Hello GitHub users. Jexer's official home is over at GitLab: https://gitlab.com/klamonte/jexer .

Jexer - Java Text User Interface library

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:

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:

License

Jexer is available to all under the MIT License. See the file LICENSE for the full license text.

Obtaining Jexer

Jexer is available on Maven Central:

<dependency>
  <groupId>com.gitlab.klamonte</groupId>
  <artifactId>jexer</artifactId>
  <version>1.5.0</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/klamonte/jexer

Documentation

• Java API Docs

• Wiki

• Jexer web page

• Development Standards

Programming Examples

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:

• 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.

More Screenshots

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:

There is now support for rendering the text underneath images (jexer.ECMA48.imagesOverText and jexer.Swing.imagesOverText). This is readily visible in terminal windows with sixel and PNG images. (If you like this, then you need to go check out notcurses poste haste.)

On the ECMA48 backend the internal font is used for rendering if jexer.ECMA48.imagesOverText=true because terminals are extremely finicky when putting text over sixel images, and this was the most simple way to get something going. The default is jexer.ECMA48.imagesOverText=false; in this mode images that would overlap text in the same cell are rendered against the (assumed) background color, omitting the text glyph. Here is an example of multihead, and the xterm windows on the right is covering up partially-obscured text cells, and it is still quite usable:

Terminal Support

The table below lists terminals tested against Jexer's Xterm backend:

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.

See Also

• 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.

• 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.

• 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.

Acknowledgements

Jexer makes use of the Terminus TrueType font made available here .