Brick.Keybindings.KeyConfig

This module provides KeyConfig and associated functions. A KeyConfig is the basis for the custom keybinding system in this library.

To get started, see newKeyConfig. Once a KeyConfig has been constructed, see keyDispatcher.

Since a key configuration can have keys bound to multiple events, it is the application author's responsibility to check for collisions since the nature of the collisions will depend on how the application is implemented. To check for collisions, use the result of keyEventMappings.

Documentation

data KeyConfig k

A configuration of custom key bindings. A KeyConfig stores everything needed to resolve a key event into one or more key bindings. Make a KeyConfig with newKeyConfig, then use it to dispatch to KeyEventHandlers with keyDispatcher.

Make a new KeyConfig with newKeyConfig.

A KeyConfig stores:

• A collection of named key events, mapping the event type k to Text labels.
• For each event k, optionally store a list of default key bindings for that event.
• An optional customized binding list for each event, setting the event to either Unbound or providing explicit overridden bindings with BindingList.

Instances

Show k => Show (KeyConfig k)

Defined in Brick.Keybindings.KeyConfig

Methods

showsPrec :: Int -> KeyConfig k -> ShowS

show :: KeyConfig k -> String

showList :: [KeyConfig k] -> ShowS

Eq k => Eq (KeyConfig k)

Defined in Brick.Keybindings.KeyConfig

Methods

(==) :: KeyConfig k -> KeyConfig k -> Bool

(/=) :: KeyConfig k -> KeyConfig k -> Bool

newKeyConfig

Arguments

:: Ord k

=> KeyEvents k

The base mapping of key events and names to use.

-> [(k, [Binding])]

Default bindings by key event, such as from a configuration file or embedded code. Optional on a per-event basis.

-> [(k, BindingState)]

Custom bindings by key event, such as from a configuration file. Explicitly setting an event to Unbound here has the effect of disabling its default bindings. Optional on a per-event basis. Note that this function does not check for collisions since it is up to the application to determine whether a key bound to more than one event constitutes a collision!

-> KeyConfig k

Build a KeyConfig with the specified KeyEvents event-to-name mapping, list of default bindings by event, and list of custom bindings by event.

data BindingState

An explicit configuration of key bindings for a key event.

Constructors

BindingList [Binding]

Bind the event to the specified list of bindings.

Unbound

Disable all bindings for the event, including default bindings.

Instances

Show BindingState

Defined in Brick.Keybindings.KeyConfig

Methods

showsPrec :: Int -> BindingState -> ShowS

show :: BindingState -> String

showList :: [BindingState] -> ShowS

Eq BindingState

Defined in Brick.Keybindings.KeyConfig

Methods

(==) :: BindingState -> BindingState -> Bool

(/=) :: BindingState -> BindingState -> Bool

Ord BindingState

Defined in Brick.Keybindings.KeyConfig

Methods

compare :: BindingState -> BindingState -> Ordering

(<) :: BindingState -> BindingState -> Bool

(<=) :: BindingState -> BindingState -> Bool

(>) :: BindingState -> BindingState -> Bool

(>=) :: BindingState -> BindingState -> Bool

max :: BindingState -> BindingState -> BindingState

min :: BindingState -> BindingState -> BindingState

Specifying bindings

data Binding

A key binding.

The easiest way to express Bindings is to use the helper functions in this module that work with instances of ToBinding, e.g.

let ctrlB = ctrl 'b'
    shiftX = shift 'x'
    ctrlMetaK = ctrl $ meta 'k'
    -- Or with Vty keys directly:
    ctrlDown = ctrl KDown

Constructors

Binding

Fields

• kbKey :: Key

  The key itself.

• kbMods :: Set Modifier

  The set of modifiers.

Instances

Show Binding

Defined in Brick.Keybindings.KeyConfig

Methods

showsPrec :: Int -> Binding -> ShowS

show :: Binding -> String

showList :: [Binding] -> ShowS

ToBinding Binding

Defined in Brick.Keybindings.KeyConfig

Methods

bind :: Binding -> Binding

Eq Binding

Defined in Brick.Keybindings.KeyConfig

Methods

(==) :: Binding -> Binding -> Bool

(/=) :: Binding -> Binding -> Bool

Ord Binding

Defined in Brick.Keybindings.KeyConfig

Methods

compare :: Binding -> Binding -> Ordering

(<) :: Binding -> Binding -> Bool

(<=) :: Binding -> Binding -> Bool

(>) :: Binding -> Binding -> Bool

(>=) :: Binding -> Binding -> Bool

max :: Binding -> Binding -> Binding

min :: Binding -> Binding -> Binding

class ToBinding a where

The class of types that can form the basis of Bindings.

This is provided to make it easy to write and modify bindings in less verbose ways.

Methods

bind :: a -> Binding

Binding constructor.

Instances

ToBinding Binding

Defined in Brick.Keybindings.KeyConfig

Methods

bind :: Binding -> Binding

ToBinding Key

Defined in Brick.Keybindings.KeyConfig

Methods

bind :: Key -> Binding

ToBinding Char

Defined in Brick.Keybindings.KeyConfig

Methods

bind :: Char -> Binding

binding :: Key -> [Modifier] -> Binding

Construct a Binding. Modifier order is ignored.

fn :: Int -> Binding

Function key binding.

meta :: ToBinding a => a -> Binding

Add Meta to a binding.

ctrl :: ToBinding a => a -> Binding

Add Ctrl to a binding.

shift :: ToBinding a => a -> Binding

Add Shift to a binding.

Querying KeyConfigs

firstDefaultBinding :: (Show k, Ord k) => KeyConfig k -> k -> Maybe Binding

A convenience function to return the first result of allDefaultBindings, if any.

firstActiveBinding :: (Show k, Ord k) => KeyConfig k -> k -> Maybe Binding

A convenience function to return the first result of allActiveBindings, if any.

allDefaultBindings :: Ord k => KeyConfig k -> k -> [Binding]

Returns the list of default bindings for the specified event, irrespective of whether the event has been explicitly configured with other bindings or set to Unbound.

allActiveBindings :: (Show k, Ord k) => KeyConfig k -> k -> [Binding]

Return all active key bindings for the specified event. This returns customized bindings if any have been set in the KeyConfig, no bindings if the event has been explicitly set to Unbound, or the default bindings if the event is absent from the customized bindings.

keyEventMappings :: (Ord k, Eq k) => KeyConfig k -> [(Binding, Set k)]

Return a list of mappings including each key bound to any event combined with the list of events to which it is bound. This is useful for identifying problematic key binding collisions. Since key binding collisions cannot be determined in general, we leave it up to the application author to determine which key-to-event bindings are problematic.

Misc

keyConfigEvents :: KeyConfig k -> KeyEvents k

The base mapping of events and their names that is used in this configuration.

lookupKeyConfigBindings :: Ord k => KeyConfig k -> k -> Maybe BindingState

Look up the binding state for the specified event. This returns Nothing when the event has no explicitly configured custom BindingState.