lucky

lucky is an input daemon for Xorg configured with a lua script.

To get a quick overview of what can be done, see the examples.

build

Note: requires Zig master, you can download builds at https://ziglang.org/download

Dependencies:

• xcb
• xcb-keysyms

To install, run zig build -p <prefix> where <prefix> is the directory that contains the bin folder you want it to install to.

So to install it to the system you could do:

sudo zig build -p /usr/local

and to install it for just the current user you could do:

zig build -p ~/.local

You may also define a different build mode using -Doptimize=<mode>, the default is ReleaseFast

features

• Bind press and release functions to keys and mouse buttons
• Bind motion and window enter and exit functions to mouse buttons
  • motion_resolution option to determine how often to read motion events. Defaults to 5 so motion binds don't overwhelm your system (i.e. every 5th motion event will call the binding's motion callback).
• Optional filter function to make a binding only active in specific contexts, if the filter returns false the key will be passed through to other applications
• Various API functions to make complex, contextual bindings possible

cli flags

• -c, --config - file path to load for the config, defaults to XDG_CONFIG_HOME/lucky/config.lua

api

• lucky.bind(bind_string, { ... }) - bind a modifier+key/mouse button combination
• lucky.cmd(command, arg1, arg2, ...) - run a command directly, with function argument being a new argument to the command
• lucky.shell(command_string) - runs command_string under the system's shell, useful if you want to use subshells, pipelines, file redirects, etc. which are not available when running a command through cmd
• lucky.is_root(window_id) - returns true if window_id is the root window
• lucky.get_root() - returns the ID of the root window (based on the currently focused window)
• lucky.get_parent_window(window_id) - return the ID of the immediate non-root parent of window_id, if no parent exist return window_id
• lucky.get_top_level_window(window_id) - return the ID of the top level non-root parent of window_id, if no parents exist return window_id
• lucky.get_focused_window() - return the ID of the currently focused window
• lucky.get_geometry(window_id) - returns a table containing the x, y, width, height, and border_width of window_id
• lucky.get_title(window_id) - returns the title of window_id
• lucky.get_class(window_id) - returns the class of window_id
• lucky.get_instance(window_id) - returns the instance of window_id
• lucky.reload() - reload your config

examples

launch a terminal

lucky.bind('super Return', {
    press = function(window_id)
        lucky.cmd(os.getenv('TERMINAL') or 'xterm')
    end
})

bind super 1-9 to switch tag in dwm

for i=1,9 do
    lucky.bind('super ' .. tostring(i), {
        press = function()
            lucky.cmd('dwmc', 'viewex', tostring(i - 1))
        end,
    })
end

bind a key for a specific window

-- when Discord is focused, this keybinding will be active
lucky.bind('alt Return', {
    filter = function(wid)
        return lucky.get_class(wid) == "discord"
    end,
    press = function()
        lucky.cmd('notify-send', 'Discord is the current focused window')
    end
})

-- when Discord is not focused, this keybinding will be active
lucky.bind('alt Return', {
    press = function()
        lucky.cmd('notify-send', 'Discord is NOT the current focused window')
    end
})

reload config

lucky.bind('super minus', {
    press = function(window_id)
        lucky.reload()
    end
})

open clipboard in mpv

lucky.bind('super p', {
    press = function(window_id)
        lucky.shell('mpv --force-window=immediate "$(xclip -o -sel clip)"')
    end
})

horizontal mouse position as a tag switcher when holding super alt mouse_left

function pointer_to_tag(x, y, window_id)
    local max_x = lucky.get_geometry(lucky.get_root()).width - 1
    local percent = x / max_x
    local tag = math.floor(percent * 9) -- 9 tags
    lucky.cmd('dwmc', 'viewex', tostring(tag))
end

lucky.bind("super alt mouse_left", {
    press = pointer_to_tag,
    motion = pointer_to_tag
})

vertical mouse as a volume slider if you press the left mouse button on the left edge of the screen

function volume_slider(x, y, wid)
    local max_y = lucky.get_geometry(lucky.get_root()).height - 1
    local percent = math.floor(((max_y - y) / max_y) * 100)
    lucky.cmd('pactl', 'set-sink-volume', '@DEFAULT_SINK@', tostring(percent) .. '%')
end

lucky.bind("mouse_left", {
    filter = function(x, y, wid)
        return x == 0
    end,

    press = volume_slider,
    motion = volume_slider
})

future plans

• MAN PAGE!!!!!
• Pass arbitrary data on startup, so you can load thinsg dynamically in the config
  • For example, you could pass in the window manager for loading wm-specific keybinds, if you use multiple window managers
• Ability to send arbitrary inputs through the lua API, so keys can be rebound in certain contexts
• Make key repeat detectable
• Plan9-esque Mouse chording
  • I already know internally how to implement this, just need to work out the specifics of how it'll work for the user-side of things
• Expose more information to the binding callbacks, possibly shove it all in a table instead of individual function arguments
  • Mouse position for key presses
  • Mouse positions relative to the window, not just global position
  • Mouse movement relative to the last motion event for motion callback
• Look into what's possible with the X input extension
  • In particular, I'd like to implement things like touchpad and touchscreen gestures. Maybe stuff with drawing tablet input as well (pressure, for example).
  • I have a general idea of how to do stuff with this but I don't have devices to test with which makes it rather difficult to build support for these things
• Chording system
  • Could perhaps work by giving a table to a function instead, which has keys to functions or more tables for nested chords
  • Callback users can implement when updating the chord state, they could use this information to build their own whichkey-like system
• Allow users to replay a matched keybinding to other clients
  • Consider gutting the filter callback if this is implemented, since it lets you effectively do the same thing (the filter function might be a more comfortable for the common use case though, so maybe it'd still be worth keeping)
• Allow users to implement named labels for bindings. This would allow for things like enabling/disabling bindings via their label, or removing the binding entirely.