Reflex.Data.ActionStack

A dynamic structure intended for modelling action stacks for undo/redo. Internally, it is represented as two stacks: "done" and "undone". Redo/undo moves the top element from one stack to another. New do events add elements to the "done" stack and clears the "undone" stack.

Documentation

data ActionStack t a

Constructors

ActionStack

Fields

• _actionStack_do :: Event t a

  fires when element is added to do stack

• _actionStack_undo :: Event t a

  fires when element is added to undo stack

actionStack_makeDoSelector :: (GCompare k, Reflex t) => ActionStack t (DSum k Identity) -> k a -> Event t a

helper method for ActionStacks that use DSum to represent actions

actionStack_makeUndoSelector :: (GCompare k, Reflex t) => ActionStack t (DSum k Identity) -> k a -> Event t a

helper method for ActionStacks that use DSum to represent actions

data ActionStackConfig t a

Constructors

ActionStackConfig

Fields

• _actionStackConfig_do :: Event t a

  event to add an element to the stack

• _actionStackConfig_undo :: Event t ()

  event to undo top action of do stack

• _actionStackConfig_redo :: Event t ()

  event to redo top action of undo stack

• _actionStackConfig_clear :: Event t ()

  clears both doundo stack without firing any doundo events

holdActionStack :: forall t m a. (Reflex t, MonadHold t m, MonadFix m) => ActionStackConfig t a -> m (ActionStack t a)