Krabby

Installation | Configuration | Documentation | Supported platforms | Browser compatibility | Troubleshooting | Contributing

<img src="https://www.iconfinder.com/icons/877852/download/svg/512" height="168" align="right">

Krabby is a browser extension (for Chrome and Firefox) for keyboard-based navigation, inspired by Kakoune.

The main differences with existing extensions are: multiple selections, keyboard layout agnostic, SOV (subject–object–verb) constructs and simple interaction with external programs. It is also quite usable with the mouse.

See YouTube · Krabby and krabby-resources for all available demos.

TL;DR

WebExtension — Keyboard interface — Subject–object–verb order — Multiple selections — Kakoune-inspired

Run the following in your terminal, then follow the onscreen instructions.

git clone https://github.com/alexherbo2/krabby
cd krabby
make install [static=no] [interactive=yes]

After installing, try to accomplish the following examples:

<details> <summary>Opening links in a paragraph</summary>

Navigate to https://tuppervim.org and type:

f{hint}s[alt+a][alt+I][ctrl+enter][alt+x]

Explanation

• <kbd>f</kbd> enters hint mode,
• {hint} is a placeholder for you to select a link,
• <kbd>s</kbd> creates a selection out of the active element,
• <kbd>Alt</kbd> + <kbd>a</kbd> expands the region,
• <kbd>Alt</kbd> + <kbd>I</kbd> selects all links,
• <kbd>Control</kbd> + <kbd>Enter</kbd> opens selected links in the background.
• Optionally, <kbd>Alt</kbd> + <kbd>x</kbd> will undo the operation (closing right tabs).

</details> <details> <summary>Play videos with mpv</summary>

Navigate to https://youtube.com/results?search_query=Berserk+AMV and type:

F{hint}{hint}<page-down>{hint}<escape>m

Explanation

• <kbd>F</kbd> enters hint mode (lock),
• {hint} is a placeholder for you to select 2 links,
• <kbd>Page Down</kbd> scrolls one page down,
• {hint} is a placeholder for you to select another link,
• <kbd>Escape</kbd> leaves hint mode.
• Finally, <kbd>m</kbd> opens the selection with mpv.

</details>

If you want to play around without installing, a live demo is available here.

Features

• Subject–object–verb order. Learn more at Differences with Vi(m).
• Keyboard layout agnostic. Maps to physical keys, but displays with the US layout.
• Multiple selections as a central way of interacting
• Powerful selection manipulation primitives
• Link hints
• External editor support. Open your favorite editor on text inputs.
• Tab search
• Contextual commands
• Contextual help
• Simple interaction with external programs
• Usable with the mouse. You can for example create a selection by grabbing a link with the mouse and <kbd>s</kbd> to create the selection. Or create multiple selections by clicking on hints with <kbd>F</kbd>. If you hold <kbd>Control</kbd> or <kbd>Command</kbd>, you can even make selections with the mouse selection area.
• Limited scope. Krabby is not Vim, nor Kakoune. Krabby is trying to be a navigation tool and some concepts from code editors don’t translate well. For example, there is no concept of mode in Krabby, but a system of contexts.
• Composability. Composability is better than extensibility. Krabby tries hard to provide features that interact well with each other. For example, <kbd>f</kbd> and <kbd>y</kbd> are two building blocks to focus a link and yank its URL. Depending on the context, <kbd>y</kbd> will yank the page or a link URL.
• Modular (think Emacs). Krabby is divided into multiple small projects. At its core Krabby just holds the configuration and grabs its functionalities from other projects.
• Chrome and Firefox support. It has also been tested on Opera, Vivaldi and Brave.

Dependencies

• Crystal
• jq
• wl-clipboard for Wayland or xclip for X11 (Optional, for plumbing)
• mpv (Optional, for playing videos)
• dmenu (Optional, for tab search and plumbing)
• Pandoc (Optional, for HTML filtering)

Extensions

• Commands (WebExtension API to perform browser actions)
• Shell (WebExtension API to execute external commands)
• [Editor] (Open an external editor to edit text inputs)
• [dmenu][webextension-dmenu] (Tab search, selection and beyond with a dmenu filter program)

Installation

Run the following in your terminal, then follow the onscreen instructions.

make install [static=no] [extensions=yes] [interactive=yes]

Supported platforms

• Linux
• FreeBSD
• OpenBSD
• macOS

Browser compatibility

| Web browser | Support | Engine | Notes | | ----------- |:-------:|:-------------------------------:| ------------------------------------------------------------------------ | | Chrome | ✓ | | | | Chromium | ✓ | | | | Firefox | ✓ | | Only developer or unbranded version | | Edge | ? | | | | Opera | ✓ | | | | Safari | ✗ | | | | Vivaldi | ✓ | | | | Brave | ✓ | | |

Credits

• Kakoune ([@mawww]) for [ideas][Why Kakoune] and [selection.cc].
• [Saka Key] ([@eejdoowad]) was a reference, for implementation and its code quality.
• [@ul], for his advice and proofreading, especially in the early stages.
• [@GeoGavilanes] for the Krabby icon.
• [@occivink], for his work on [phantom selections][kakoune-phantom-selection], from which the “save and restore selections” feature is inspired.
• mpv and Kakoune for their website, from which Krabby is inspired.
• [@AdamWagner] for his work to unify scrolling mechanisms.

References

• [Create a keyboard interface to the web]