lite-xl/doc/usage.md

lite

Overview

Lite is a lightweight text editor written mostly in Lua — it aims to provide something practical, pretty, small and fast, implemented as simply as possible; easy to modify and extend, or to use without doing either.

Lite XL is based on the Lite editor itself and provide some enhancements while remaining perfectly compatible with Lite.

Getting Started

Lite works using a project directory — this is the directory where your project's code and other data resides.

To open lite with a specific project directory the directory name can be passed as a command-line argument (. can be passed to use the current directory) or the directory can be dragged onto either the lite executable or a running instance of lite.

Once started the project directory can be changed using the command core:change-project-folder. The command will close all the documents currently opened and switch to the new project directory.

If you want to open a project directory in a new window the command core:open-project-folder will open a new editor window with the selected project directory.

The main way of opening files in lite is through the core:find-file command — this provides a fuzzy finder over all of the project's files and can be opened using the ctrl+p shortcut by default.

Commands can be run using keyboard shortcuts, or by using the core:find-command command bound to ctrl+shift+p by default. For example, pressing ctrl+shift+p and typing newdoc then pressing return would open a new document. The current keyboard shortcut for a command can be seen to the right of the command name on the command finder, thus to find the shortcut for a command ctrl+shift+p can be pressed and the command name typed.

User Module

lite can be configured through use of the user module. The user module can be used for changing options in the config module, adding additional key bindings, loading custom color themes, modifying the style or changing any other part of lite to your personal preference.

The user module is loaded by lite when the application starts, after the plugins have been loaded.

The user module can be modified by running the core:open-user-module command or otherwise directly opening the $HOME/.config/lite-xl/init.lua file.

On Windows, the variable $USERPROFILE will be used instead of $HOME.

Please note that Lite XL differs from the standard Lite editor for the location of the user's module.

Project Module

The project module is an optional module which is loaded from the current project's directory when lite is started. Project modules can be useful for things like adding custom commands for project-specific build systems, or loading project-specific plugins.

The project module is loaded by lite when the application starts, after both the plugins and user module have been loaded.

The project module can be edited by running the core:open-project-module command — if the module does not exist for the current project when the command is run it will be created.

Commands

Commands in lite are used both through the command finder (ctrl+shift+p) and by lite's keyboard shortcut system. Commands consist of 3 components:

• Name — The command name in the form of namespace:action-name, for example: doc:select-all
• Predicate — A function that returns true if the command can be ran, for example, for any document commands the predicate checks whether the active view is a document
• Function — The function which performs the command itself

Commands can be added using the command.add function provided by the core.command module:

local core = require "core"
local command = require "core.command"

command.add("core.docview", {
  ["doc:save"] = function()
    core.active_view.doc:save()
    core.log("Saved '%s', core.active_view.doc.filename)
  end
})

Commands can be performed programatically (eg. from another command or by your user module) by calling the command.perform function after requiring the command module:

local command = require "core.command"
command.perform "core:quit"

Keymap

All keyboard shortcuts in lite are handled by the core.keymap module. A key binding in lite maps a "stroke" (eg. ctrl+q) to one or more commands (eg. core:quit). When the shortcut is pressed lite will iterate each command assigned to that key and run the predicate function for that command — if the predicate passes it stops iterating and runs the command.

An example of where this used is the default binding of the tab key:

  ["tab"] = { "command:complete", "doc:indent" },

When tab is pressed the command:complete command is attempted which will only succeed if the command-input at the bottom of the window is active. Otherwise the doc:indent command is attempted which will only succeed if we have a document as our active view.

A new mapping can be added by your user module as follows:

local keymap = require "core.keymap"
keymap.add { ["ctrl+q"] = "core:quit" }

Plugins

Plugins in lite are normal lua modules and are treated as such — no complicated plugin manager is provided, and, once a plugin is loaded, it is never expected be to have to unload itself.

To install a plugin simply drop it in the plugins directory in the user module directory. When Lite XL starts it will first load the plugins included in the data directory and will then loads the plugins located in the user module directory.

To uninstall a plugin the plugin file can be deleted — any plugin (including those included with lite's default installation) can be deleted to remove its functionality.

If you want to load a plugin only under a certain circumstance (for example, only on a given project) the plugin can be placed somewhere other than the plugins directory so that it is not automatically loaded. The plugin can then be loaded manually as needed by using the require function.

Plugins can be downloaded from the plugins repository.

Restarting the editor

If you modifies the user configuration file or some of the Lua implementation files you may restart the editor using the command core:restart. All the application will be restarting by keeping the window that is already in use.

Color Themes

Colors themes in lite are lua modules which overwrite the color fields of lite's core.style module. Pre-defined color methods are located in the colors folder in the data directory. Additional color themes can be installed in the user's directory in a folder named colors.

A color theme can be set by requiring it in your user module:

core.reload_module "colors.winter"

In the Lite editor the function require is used instead of core.reload_module. In Lite XL core.reload_module should be used to ensure that the color module is actually reloaded when saving the user's configuration file.

Color themes can be downloaded from the color themes repository. They are included with Lite XL release packages.