pub struct Undoer<State> {
settings: Settings,
undos: VecDeque<State>,
redos: Vec<State>,
flux: Option<Flux<State>>,
}
Expand description
Automatic undo system.
Every frame you feed it the most recent state.
The Undoer
compares it with the latest undo point
and if there is a change it may create a new undo point.
Undoer
follows two simple rules:
- If the state has changed since the latest undo point, but has
remained stable for
stable_time
seconds, an new undo point is created. - If the state does not stabilize within
auto_save_interval
seconds, an undo point is created.
Rule 1) will make sure an undo point is not created until you stop dragging that slider. Rule 2) will make sure that you will get some undo points even if you are constantly changing the state.
Fields§
§settings: Settings
§undos: VecDeque<State>
New undoes are added to the back. Two adjacent undo points are never equal. The latest undo point may (often) be the current state.
redos: Vec<State>
Stores redos immediately after a sequence of undos.
Gets cleared every time the state changes.
Does not need to be a deque, because there can only be up to undos.len()
redos,
which is already limited to settings.max_undos
.
flux: Option<Flux<State>>
Implementations§
source§impl<State> Undoer<State>
impl<State> Undoer<State>
sourcepub fn with_settings(settings: Settings) -> Self
pub fn with_settings(settings: Settings) -> Self
sourcepub fn has_undo(&self, current_state: &State) -> bool
pub fn has_undo(&self, current_state: &State) -> bool
Do we have an undo point different from the given state?
pub fn has_redo(&self, current_state: &State) -> bool
sourcepub fn is_in_flux(&self) -> bool
pub fn is_in_flux(&self) -> bool
Return true if the state is currently changing
pub fn undo(&mut self, current_state: &State) -> Option<&State>
pub fn redo(&mut self, current_state: &State) -> Option<&State>
sourcepub fn add_undo(&mut self, current_state: &State)
pub fn add_undo(&mut self, current_state: &State)
Add an undo point if, and only if, there has been a change since the latest undo point.
sourcepub fn feed_state(&mut self, current_time: f64, current_state: &State)
pub fn feed_state(&mut self, current_time: f64, current_state: &State)
Call this as often as you want (e.g. every frame)
and Undoer
will determine if a new undo point should be created.
current_time
: current time in seconds.