Struct undo::history::History

pub struct History<A, F = Box<dyn FnMut(Signal)>> { /* fields omitted */ }

A history of actions.

Unlike Record which maintains a linear undo history, History maintains an undo tree containing every edit made to the target.

Examples

let mut target = String::new();
let mut history = History::new();
history.apply(&mut target, Add('a'))?;
history.apply(&mut target, Add('b'))?;
history.apply(&mut target, Add('c'))?;
let abc = history.branch();
history.go_to(&mut target, abc, 1).unwrap()?;
history.apply(&mut target, Add('f'))?;
history.apply(&mut target, Add('g'))?;
assert_eq!(target, "afg");
history.go_to(&mut target, abc, 3).unwrap()?;
assert_eq!(target, "abc");

Implementations

impl<A> History<A>

pub fn new() -> History<A>

Returns a new history.

impl<A, F> History<A, F>

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more actions.

Panics

Panics if the new capacity overflows usize.

pub fn capacity(&self) -> usize

Returns the capacity of the history.

pub fn shrink_to_fit(&mut self)

Shrinks the capacity of the history as much as possible.

pub fn len(&self) -> usize

Returns the number of actions in the current branch of the history.

pub fn is_empty(&self) -> bool

Returns true if the current branch of the history is empty.

pub fn limit(&self) -> usize

Returns the limit of the history.

pub fn connect(&mut self, slot: F) -> Option<F>

Sets how the signal should be handled when the state changes.

The previous slot is returned if it exists.

pub fn disconnect(&mut self) -> Option<F>

Removes and returns the slot if it exists.

pub fn is_saved(&self) -> bool

Returns true if the target is in a saved state, false otherwise.

pub fn can_undo(&self) -> bool

Returns true if the history can undo.

pub fn can_redo(&self) -> bool

Returns true if the history can redo.

pub fn branch(&self) -> usize

Returns the current branch.

pub fn current(&self) -> usize

Returns the position of the current action.

pub fn queue(&mut self) -> Queue<'_, A, F>

Returns a queue.

pub fn checkpoint(&mut self) -> Checkpoint<'_, A, F>

Returns a checkpoint.

pub fn display(&self) -> Display<'_, A, F>

Returns a structure for configurable formatting of the history.

impl<A: Action, F: FnMut(Signal)> History<A, F>

pub fn apply(&mut self, target: &mut A::Target, action: A) -> Result<A>

Pushes the action to the top of the history and executes its apply method.

Errors

If an error occur when executing apply the error is returned.

pub fn undo(&mut self, target: &mut A::Target) -> Result<A>

Calls the undo method for the active action and sets the previous one as the new active one.

Errors

If an error occur when executing undo the error is returned.

pub fn redo(&mut self, target: &mut A::Target) -> Result<A>

Calls the redo method for the active action and sets the next one as the new active one.

Errors

If an error occur when executing redo the error is returned.

pub fn go_to(
    &mut self,
    target: &mut A::Target,
    branch: usize,
    current: usize
) -> Option<Result<A>>

Repeatedly calls undo or redo until the action in branch at current is reached.

Errors

If an error occur when executing undo or redo the error is returned.

pub fn time_travel(
    &mut self,
    target: &mut A::Target,
    to: &DateTime<impl TimeZone>
) -> Option<Result<A>>

Go back or forward in the history to the action that was made closest to the datetime provided.

This method does not jump across branches.

pub fn set_saved(&mut self, saved: bool)

Marks the target as currently being in a saved or unsaved state.

pub fn clear(&mut self)

Removes all actions from the history without undoing them.

impl<A: ToString, F> History<A, F>

pub fn undo_text(&self) -> Option<String>

Returns the string of the action which will be undone in the next call to undo.

pub fn redo_text(&self) -> Option<String>

Returns the string of the action which will be redone in the next call to redo.

Trait Implementations

impl<A: Clone, F: Clone> Clone for History<A, F>

fn clone(&self) -> History<A, F>

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<A: Debug, F> Debug for History<A, F>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<A> Default for History<A>

fn default() -> History<A>

Returns the “default value” for a type.

impl<'de, A, F> Deserialize<'de> for History<A, F> where
    A: Deserialize<'de>, 

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<'a, A, F> From<&'a History<A, F>> for Display<'a, A, F>

fn from(history: &'a History<A, F>) -> Self

Performs the conversion.

impl<'a, A, F> From<&'a mut History<A, F>> for Queue<'a, A, F>

fn from(history: &'a mut History<A, F>) -> Self

Performs the conversion.

impl<'a, A, F> From<&'a mut History<A, F>> for Checkpoint<'a, A, F>

fn from(history: &'a mut History<A, F>) -> Self

Performs the conversion.

impl<A, F> From<History<A, F>> for Record<A, F>

fn from(history: History<A, F>) -> Record<A, F>

Performs the conversion.

impl<A, F> From<Record<A, F>> for History<A, F>

fn from(record: Record<A, F>) -> Self

Performs the conversion.

impl<A, F> Serialize for History<A, F> where
    A: Serialize, 

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.