Jexer - Java Text User Interface library
========================================
-This library is currently in design, but when finished it is intended
-to implement a text-based windowing system loosely reminiscient of
-Borland's [Turbo Vision](http://en.wikipedia.org/wiki/Turbo_Vision)
-library. For those wishing to use the actual C++ Turbo Vision
-library, see [Sergio Sigala's updated
-version](http://tvision.sourceforge.net/) that runs on many more
-platforms.
+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 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 (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)
+ 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.
+
+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.
+
+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 .
+
License
-------
-This library is licensed LGPL ("GNU Lesser General Public License")
-version 3 or greater. See the file LICENSE for the full license text,
-which includes both the GPL v3 and the LGPL supplemental terms.
+This project is licensed under the MIT License. See the file LICENSE
+for the full license text.
+
+
+Maven
+-----
+
+Jexer is available on Maven Central:
+
+```xml
+<dependency>
+ <groupId>com.gitlab.klamonte</groupId>
+ <artifactId>jexer</artifactId>
+ <version>0.3.0</version>
+</dependency>
+```
+
+
+
+Acknowledgements
+----------------
+
+Jexer makes use of the Terminus TrueType font [made available
+here](http://files.ax86.net/terminus-ttf/) .
+
Usage
-----
-The library is currently under initial development, usage patterns are
-still being worked on. Generally the goal will be to build
-applications somewhat as follows:
+Simply subclass TApplication and then run it in a new thread:
```Java
import jexer.*;
-public class MyApplication extends TApplication {
+class MyApplication extends TApplication {
- public MyApplication() {
- super();
-
- // Create an editor window that has support for
- // copy/paste, search text, arrow keys, horizontal
- // and vertical scrollbar, etc.
- addEditor();
+ 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) {
+ public static void main(String [] args) throws Exception {
MyApplication app = new MyApplication();
- app.run();
+ (new Thread(app)).start();
}
}
```
+Similarly, subclass TWindow and add some widgets:
-Roadmap
--------
+```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!");
+ }
+ } );
+ }
+}
+```
+
+Put these into a file, compile it with jexer.jar in the classpath, run
+it and you'll see an application like this:
+
+![The Example Code Above](/screenshots/readme_application.png?raw=true "The application in the text of README.md")
+
+
+
+More Examples
+-------------
+
+The examples/ folder currently contains:
+
+ * A [prototype tiling window
+ manager](/examples/JexerTilingWindowManager.java) in less than 250
+ lines of code.
+
+ * A [prototype image thumbnail
+ viewer](/examples/JexerImageViewer.java) 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 telnet
+ protocol to establish an 8-bit clean channel and be aware of
+ 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.
+
+
+
+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.
+
+| Terminal | Environment | Mouse Click | Mouse Cursor | Images |
+| -------------- | ------------------ | ----------- | ------------ | ------ |
+| xterm | X11 | yes | yes | yes |
+| lcxterm(3) | CLI, Linux console | yes | yes | no |
+| rxvt-unicode | X11 | yes | yes | no(2) |
+| alacritty(3) | X11 | yes | yes | no |
+| gnome-terminal | X11 | yes | yes | no |
+| xfce4-terminal | X11 | yes | yes | no |
+| mlterm | X11 | yes | yes | no(5) |
+| aminal(3) | X11 | yes | no | no |
+| 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) |
+| Linux | Linux console | no | no | no(2) |
+| qodem(3) | CLI, Linux console | yes | yes(4) | no |
+| qodem-x11(3) | X11 | yes | no | no |
+
+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 - Opening image crashes terminal.
+
+
+
+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.
+
+ - 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.
+
+ - 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.
+
+ - 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.
+
+
+
+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.
-This is a work in progress. Many tasks remain before calling this
-version 1.0:
-
-0.0.1:
-
-- Base classes:
- - Events
- - Codepage
- - TApplication loop
-
-0.0.2:
-
-- Get modal messagebox running without fibers
-- Port remaining d-tui functionality over
- - All widgets
-
-0.0.3:
-
-- ECMATerminal
- - Mouse 1006 mode parsing
- - Win32 support (used for reading/writing sockets)
-- Bugs
- - TDirectoryList cannot be navigated only with keyboard
- - TTreeView cannot be navigated only with keyboard
- - RangeViolation after dragging scrollbar up/down
-
-Wishlist features (2.0):
-
-- TTerminal
- - Handle resize events (pass to child process)
- - xterm mouse handling
-- TWindow
- - "Smart placement" for new windows
-- Screen
- - Allow complex characters in putCharXY() and detect them in putStrXY().
-- TComboBox
-- TListBox
-- TSpinner
-- TCalendar widget
-- TColorPicker widget
-- Drag and drop
- - TEditor
- - TField
- - TText
- - TTerminal
- - TComboBox
-- AWTBackend
-- ECMABackend
- - libgpm support
+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.