Brick.Widgets.List

This module provides a scrollable list type and functions for manipulating and rendering it.

Documentation

data List e

List state. Lists have an element type e that is the data stored by the list. Lists handle the following events by default:

• Up/down arrow keys: move cursor of selected item
• Page up / page down keys: move cursor of selected item by one page at a time (based on the number of items shown)
• Home/end keys: move cursor of selected item to beginning or end of list

Instances

Functor List

Foldable List

Traversable List

HandleEvent (List e)

Constructing a list

list

Arguments

:: Name

The list name (must be unique)

-> Vector e

The initial list contents

-> Int

The list item height in rows (all list item widgets must be this high)

-> List e

Construct a list in terms of an element type e.

Rendering a list

renderList

Arguments

:: List e

The List to be rendered

-> (Bool -> e -> Widget)

Rendering function, True for the selected element

-> Widget

rendered widget

Turn a list state value into a widget given an item drawing function.

Lenses

listElementsL :: forall e e. Lens (List e) (List e) (Vector e) (Vector e)

listSelectedL :: forall e. Lens' (List e) (Maybe Int)

listNameL :: forall e. Lens' (List e) Name

listItemHeightL :: forall e. Lens' (List e) Int

Manipulating a list

listMoveBy :: Int -> List e -> List e

Move the list selected index by the specified amount, subject to validation.

listMoveTo :: Int -> List e -> List e

Set the selected index for a list to the specified index, subject to validation.

listMoveUp :: List e -> List e

Move the list selected index up by one. (Moves the cursor up, subtracts one from the index.)

listMoveDown :: List e -> List e

Move the list selected index down by one. (Moves the cursor down, adds one to the index.)

listInsert

Arguments

:: Int

The position at which to insert (0 <= i <= size)

-> e

The element to insert

-> List e

-> List e

Insert an item into a list at the specified position.

listRemove

Arguments

:: Int

The position at which to remove an element (0 <= i < size)

-> List e

-> List e

Remove an element from a list at the specified position.

listReplace :: Eq e => Vector e -> Maybe Int -> List e -> List e

Replace the contents of a list with a new set of elements and update the new selected index. If the specified selected index (via Just) is not in the list bounds, zero is used instead.

listSelectedElement :: List e -> Maybe (Int, e)

Return a list's selected element, if any.

listClear :: List e -> List e

Remove all elements from the list and clear the selection.

listReverse :: List e -> List e

Reverse the list. The element selected before the reversal will again be the selected one.

Attributes

listAttr :: AttrName

The top-level attribute used for the entire list.

listSelectedAttr :: AttrName

The attribute used only for the currently-selected list item. Extends listAttr.