273 lines
12 KiB
Plaintext
273 lines
12 KiB
Plaintext
|
= tcell
|
||
|
|
||
|
|
||
|
image:https://img.shields.io/travis/gdamore/tcell.svg?label=linux[Linux Status,link="https://travis-ci.org/gdamore/tcell"]
|
||
|
image:https://img.shields.io/appveyor/ci/gdamore/tcell.svg?label=windows[Windows Status,link="https://ci.appveyor.com/project/gdamore/tcell"]
|
||
|
image:https://img.shields.io/badge/license-APACHE2-blue.svg[Apache License,link="https://github.com/gdamore/tcell/blob/master/LICENSE"]
|
||
|
image:https://img.shields.io/badge/gitter-join-brightgreen.svg[Gitter,link="https://gitter.im/gdamore/tcell"]
|
||
|
image:https://img.shields.io/badge/godoc-reference-blue.svg[GoDoc,link="https://godoc.org/github.com/gdamore/tcell"]
|
||
|
image:http://goreportcard.com/badge/gdamore/tcell[Go Report Card,link="http://goreportcard.com/report/gdamore/tcell"]
|
||
|
image:https://codecov.io/gh/gdamore/tcell/branch/master/graph/badge.svg[codecov,link="https://codecov.io/gh/gdamore/tcell"]
|
||
|
image:https://tidelift.com/badges/github/gdamore/tcell?style=flat[Dependencies]
|
||
|
|
||
|
[cols="2",grid="none"]
|
||
|
|===
|
||
|
|_Tcell_ is a _Go_ package that provides a cell based view for text terminals, like _xterm_.
|
||
|
It was inspired by _termbox_, but includes many additional improvements.
|
||
|
a|[.right]
|
||
|
image::logos/tcell.png[float="right"]
|
||
|
|===
|
||
|
|
||
|
## Examples
|
||
|
|
||
|
* https://github.com/gdamore/proxima5[proxima5] - space shooter (https://youtu.be/jNxKTCmY_bQ[video])
|
||
|
* https://github.com/gdamore/govisor[govisor] - service management UI (http://2.bp.blogspot.com/--OsvnfzSNow/Vf7aqMw3zXI/AAAAAAAAARo/uOMtOvw4Sbg/s1600/Screen%2BShot%2B2015-09-20%2Bat%2B9.08.41%2BAM.png[screenshot])
|
||
|
* mouse demo - included mouse test (http://2.bp.blogspot.com/-fWvW5opT0es/VhIdItdKqJI/AAAAAAAAATE/7Ojc0L1SpB0/s1600/Screen%2BShot%2B2015-10-04%2Bat%2B11.47.13%2BPM.png[screenshot])
|
||
|
* https://github.com/gdamore/gomatrix[gomatrix] - converted from Termbox
|
||
|
* https://github.com/zyedidia/micro/[micro] - lightweight text editor with syntax-highlighting and themes
|
||
|
* https://github.com/viktomas/godu[godu] - simple golang utility helping to discover large files/folders.
|
||
|
* https://github.com/rivo/tview[tview] - rich interactive widgets for terminal UIs
|
||
|
* https://github.com/marcusolsson/tui-go[tui-go] - UI library for terminal apps
|
||
|
* https://github.com/rgm3/gomandelbrot[gomandelbrot] - Mandelbrot!
|
||
|
* https://github.com/senorprogrammer/wtf[WTF]- Personal information dashboard for your terminal
|
||
|
* https://github.com/browsh-org/browsh[browsh] - A fully-modern text-based browser, rendering to TTY and browsers (https://www.youtube.com/watch?v=HZq86XfBoRo[video])
|
||
|
* https://github.com/sachaos/go-life[go-life] - Conway's Game of Life.
|
||
|
* https://github.com/gcla/gowid[gowid] - compositional widgets for terminal UIs, inspired by urwid
|
||
|
* https://termshark.io[termshark] - a terminal UI for tshark, inspired by Wireshark, built on gowid
|
||
|
|
||
|
## Pure Go Terminfo Database
|
||
|
|
||
|
_Tcell_ includes a full parser and expander for terminfo capability strings,
|
||
|
so that it can avoid hard coding escape strings for formatting. It also favors
|
||
|
portability, and includes support for all POSIX systems.
|
||
|
|
||
|
The database is also flexible & extensible, and can modified by either running
|
||
|
a program to build the entire database, or an entry for just a single terminal.
|
||
|
|
||
|
## More Portable
|
||
|
|
||
|
_Tcell_ is portable to a wide variety of systems.
|
||
|
_Tcell_ is believed
|
||
|
to work with all of the systems officially supported by golang with
|
||
|
the exception of nacl (which lacks any kind of a terminal interface).
|
||
|
(Plan9 is not supported by _Tcell_, but it is experimental status only
|
||
|
in golang.) For all of these systems *except Solaris/illumos*, _Tcell_
|
||
|
is pure Go, with no need for CGO.
|
||
|
|
||
|
## No Async IO
|
||
|
|
||
|
_Tcell_ is able to operate without requiring `SIGIO` signals (unlike _termbox_),
|
||
|
or asynchronous I/O, and can instead use standard Go file
|
||
|
objects and Go routines.
|
||
|
This means it should be safe, especially for
|
||
|
use with programs that use exec, or otherwise need to manipulate the
|
||
|
tty streams.
|
||
|
This model is also much closer to idiomatic Go, leading
|
||
|
to fewer surprises.
|
||
|
|
||
|
## Rich Unicode & non-Unicode support
|
||
|
|
||
|
_Tcell_ includes enhanced support for Unicode, including wide characters and
|
||
|
combining characters, provided your terminal can support them.
|
||
|
Note that
|
||
|
Windows terminals generally don't support the full Unicode repertoire.
|
||
|
|
||
|
It will also convert to and from Unicode locales, so that the program
|
||
|
can work with UTF-8 internally, and get reasonable output in other locales.
|
||
|
_Tcell_ tries hard to convert to native characters on both input and output, and
|
||
|
on output _Tcell_ even makes use of the alternate character set to facilitate
|
||
|
drawing certain characters.
|
||
|
|
||
|
## More Function Keys
|
||
|
|
||
|
_Tcell_ also has richer support for a larger number of special keys that some terminals can send.
|
||
|
|
||
|
## Better Color Handling
|
||
|
|
||
|
_Tcell_ will respect your terminal's color space as specified within your terminfo
|
||
|
entries, so that for example attempts to emit color sequences on VT100 terminals
|
||
|
won't result in unintended consequences.
|
||
|
|
||
|
In Windows mode, _Tcell_ supports 16 colors, bold, dim, and reverse,
|
||
|
instead of just termbox's 8 colors with reverse. (Note that there is some
|
||
|
conflation with bold/dim and colors.)
|
||
|
|
||
|
_Tcell_ maps 16 colors down to 8, for terminals that need it.
|
||
|
(The upper 8 colors are just brighter versions of the lower 8.)
|
||
|
|
||
|
## Better Mouse Support
|
||
|
|
||
|
_Tcell_ supports enhanced mouse tracking mode, so your application can receive
|
||
|
regular mouse motion events, and wheel events, if your terminal supports it.
|
||
|
|
||
|
## _Termbox_ Compatibility
|
||
|
|
||
|
A compatibility layer for _termbox_ is provided in the `compat` directory.
|
||
|
To use it, try importing `github.com/gdamore/tcell/termbox`
|
||
|
instead. Most _termbox-go_ programs will probably work without further
|
||
|
modification.
|
||
|
|
||
|
## Working With Unicode
|
||
|
|
||
|
Internally Tcell uses UTF-8, just like Go.
|
||
|
However, Tcell understands how to
|
||
|
convert to and from other character sets, using the capabilities of
|
||
|
the `golang.org/x/text/encoding packages`.
|
||
|
Your application must supply
|
||
|
them, as the full set of the most common ones bloats the program by about 2MB.
|
||
|
If you're lazy, and want them all anyway, see the `encoding` sub-directory.
|
||
|
|
||
|
## Wide & Combining Characters
|
||
|
|
||
|
The `SetContent()` API takes a primary rune, and an optional list of combining runes.
|
||
|
If any of the runes is a wide (East Asian) rune occupying two cells,
|
||
|
then the library will skip output from the following cell, but care must be
|
||
|
taken in the application to avoid explicitly attempting to set content in the
|
||
|
next cell, otherwise the results are undefined. (Normally wide character
|
||
|
is displayed, and the other character is not; do not depend on that behavior.)
|
||
|
|
||
|
Experience has shown that the vanilla Windows 8 console application does not
|
||
|
support any of these characters properly, but at least some options like
|
||
|
_ConEmu_ do support Wide characters.
|
||
|
|
||
|
## Colors
|
||
|
|
||
|
_Tcell_ assumes the ANSI/XTerm color model, including the 256 color map that
|
||
|
XTerm uses when it supports 256 colors. The terminfo guidance will be
|
||
|
honored, with respect to the number of colors supported. Also, only
|
||
|
terminals which expose ANSI style `setaf` and `setab` will support color;
|
||
|
if you have a color terminal that only has `setf` and `setb`, please let me
|
||
|
know; it wouldn't be hard to add that if there is need.
|
||
|
|
||
|
## 24-bit Color
|
||
|
|
||
|
_Tcell_ _supports true color_! (That is, if your terminal can support it,
|
||
|
_Tcell_ can accurately display 24-bit color.)
|
||
|
|
||
|
To use 24-bit color, you need to use a terminal that supports it. Modern
|
||
|
xterm and similar teminal emulators can support this. As terminfo lacks any
|
||
|
way to describe this capability, we fabricate the capability for
|
||
|
terminals with names ending in `*-truecolor`. The stock distribution ships
|
||
|
with a database that defines `xterm-truecolor`.
|
||
|
To try it out, set your
|
||
|
`TERM` variable to `xterm-truecolor`.
|
||
|
|
||
|
When using TrueColor, programs will display the colors that the programmer
|
||
|
intended, overriding any "`themes`" you may have set in your terminal
|
||
|
emulator. (For some cases, accurate color fidelity is more important
|
||
|
than respecting themes. For other cases, such as typical text apps that
|
||
|
only use a few colors, its more desirable to respect the themes that
|
||
|
the user has established.)
|
||
|
|
||
|
If you find this undesirable, you can either use a `TERM` variable
|
||
|
that lacks the `TRUECOLOR` setting, or set `TCELL_TRUECOLOR=disable` in your
|
||
|
environment.
|
||
|
|
||
|
## Performance
|
||
|
|
||
|
Reasonable attempts have been made to minimize sending data to terminals,
|
||
|
avoiding repeated sequences or drawing the same cell on refresh updates.
|
||
|
|
||
|
## Terminfo
|
||
|
|
||
|
(Not relevent for Windows users.)
|
||
|
|
||
|
The Terminfo implementation operates with two forms of database. The first
|
||
|
is the built-in go database, which contains a number of real database entries
|
||
|
that are compiled into the program directly. This should minimize calling
|
||
|
out to database file searches.
|
||
|
|
||
|
The second is in the form of JSON files, that contain the same information,
|
||
|
which can be located either by the `$TCELLDB` environment file, `$HOME/.tcelldb`,
|
||
|
or is located in the Go source directory as `database.json`.
|
||
|
|
||
|
These files (both the Go and the JSON files) can be generated using the
|
||
|
mkinfo.go program. If you need to regnerate the entire set for some reason,
|
||
|
run the mkdatabase.sh file. The generation uses the infocmp(1) program on
|
||
|
the system to collect the necessary information.
|
||
|
|
||
|
The `mkinfo.go` program can also be used to generate specific database entries
|
||
|
for named terminals, in case your favorite terminal is missing. (If you
|
||
|
find that this is the case, please let me know and I'll try to add it!)
|
||
|
|
||
|
_Tcell_ requires that the terminal support the `cup` mode of cursor addressing.
|
||
|
Terminals without absolute cursor addressability are not supported.
|
||
|
This is unlikely to be a problem; such terminals have not been mass produced
|
||
|
since the early 1970s.
|
||
|
|
||
|
## Mouse Support
|
||
|
|
||
|
Mouse support is detected via the `kmous` terminfo variable, however,
|
||
|
enablement/disablement and decoding mouse events is done using hard coded
|
||
|
sequences based on the XTerm X11 model. As of this writing all popular
|
||
|
terminals with mouse tracking support this model. (Full terminfo support
|
||
|
is not possible as terminfo sequences are not defined.)
|
||
|
|
||
|
On Windows, the mouse works normally.
|
||
|
|
||
|
Mouse wheel buttons on various terminals are known to work, but the support
|
||
|
in terminal emulators, as well as support for various buttons and
|
||
|
live mouse tracking, varies widely. Modern _xterm_, macOS _Terminal_, and _iTerm_ all work well.
|
||
|
|
||
|
## Testablity
|
||
|
|
||
|
There is a `SimulationScreen`, that can be used to simulate a real screen
|
||
|
for automated testing. The supplied tests do this. The simulation contains
|
||
|
event delivery, screen resizing support, and capabilities to inject events
|
||
|
and examine "`physical`" screen contents.
|
||
|
|
||
|
## Platforms
|
||
|
|
||
|
### POSIX (Linux, FreeBSD, macOS, Solaris, etc.)
|
||
|
|
||
|
For mainstream systems with a suitably well defined system call interface
|
||
|
to tty settings, everything works using pure Go.
|
||
|
|
||
|
For the remainder (right now means only Solaris/illumos) we use POSIX function
|
||
|
calls to manage termios, which implies that CGO is required on those platforms.
|
||
|
|
||
|
### Windows
|
||
|
|
||
|
Windows console mode applications are supported. Unfortunately _mintty_
|
||
|
and other _cygwin_ style applications are not supported.
|
||
|
|
||
|
Modern console applications like ConEmu, as well as the Windows 10
|
||
|
console itself, support all the good features (resize, mouse tracking, etc.)
|
||
|
|
||
|
I haven't figured out how to cleanly resolve the dichotomy between cygwin
|
||
|
style termios and the Windows Console API; it seems that perhaps nobody else
|
||
|
has either. If anyone has suggestions, let me know! Really, if you're
|
||
|
using a Windows application, you should use the native Windows console or a
|
||
|
fully compatible console implementation.
|
||
|
|
||
|
### Plan9 and Native Client (Nacl)
|
||
|
|
||
|
The nacl and plan9 platforms won't work, but compilation stubs are supplied
|
||
|
for folks that want to include parts of this in software targetting those
|
||
|
platforms. The Simulation screen works, but as Tcell doesn't know how to
|
||
|
allocate a real screen object on those platforms, `NewScreen()` will fail.
|
||
|
|
||
|
If anyone has wisdom about how to improve support for either of these,
|
||
|
please let me know. PRs are especially welcome.
|
||
|
|
||
|
### Commercial Support
|
||
|
|
||
|
_Tcell_ is absolutely free, but if you want to obtain commercial, professional support, there are options.
|
||
|
|
||
|
[cols="2",align="center",frame="none", grid="none"]
|
||
|
|===
|
||
|
^.^|
|
||
|
image:logos/tidelift.png[100,100]
|
||
|
a|
|
||
|
https://tidelift.com/[Tidelift] subscriptions include support for _Tcell_, as well as many other open source packages.
|
||
|
|
||
|
^.^|
|
||
|
image:logos/staysail.png[100,100]
|
||
|
a|
|
||
|
mailto:info@staysail.tech[Staysail Systems, Inc.] offers direct support, and custom development around _Tcell_ on an hourly basis.
|
||
|
|
||
|
^.^|
|
||
|
image:logos/patreon.png[100,100]
|
||
|
a|I also welcome donations at https://www.patreon.com/gedamore/[Patreon], if you just want to make a contribution.
|
||
|
|===
|