Enum redo::Signal

pub enum Signal {
    Undo(bool),
    Redo(bool),
    Saved(bool),
    Cursor {
        old: usize,
        new: usize,
    },
    Root {
        old: usize,
        new: usize,
    },
}

The signal sent when the record, the history, or the receiver changes.

When one of these states changes, they will send a corresponding signal to the user. For example, if the record can no longer redo any commands, it sends a Redo(false) signal to tell the user.

Examples

let history = History::builder()
    .connect(|signal| match signal {
        Signal::Undo(on) => println!("undo: {}", on),
        Signal::Redo(on) => println!("redo: {}", on),
        Signal::Saved(on) => println!("saved: {}", on),
        Signal::Cursor { old, new } => println!("cursor: {} -> {}", old, new),
        Signal::Root { old, new } => println!("root: {} -> {}", old, new),
    })
    .default();

Variants

Undo(bool)

Says if the record can undo.

This signal will be emitted when the records ability to undo changes.

Redo(bool)

Says if the record can redo.

This signal will be emitted when the records ability to redo changes.

Saved(bool)

Says if the receiver is in a saved state.

This signal will be emitted when the record enters or leaves its receivers saved state.

Cursor

Says if the current command has changed.

This signal will be emitted when the cursor has changed. This includes when two commands have been merged, in which case old == new.

Fields of Cursor

old: usize

The old cursor.

new: usize

The new cursor.

Root

Says if the current branch, or root, has changed.

This is only emitted from History.

Fields of Root

old: usize

The old root.

new: usize

The new root.

Trait Implementations

impl Eq for Signal

impl PartialOrd<Signal> for Signal

fn partial_cmp(&self, other: &Signal) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Signal) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Signal) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Signal) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Signal) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for Signal

impl PartialEq<Signal> for Signal

fn eq(&self, other: &Signal) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Signal) -> bool

This method tests for !=.

impl Clone for Signal

fn clone(&self) -> Signal

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Ord for Signal

fn cmp(&self, other: &Signal) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl Debug for Signal

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

Formats the value using the given formatter.

impl Hash for Signal

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where     H: Hasher,

Feeds a slice of this type into the given [Hasher].