Struct UndoStack 

pub struct UndoStack {
    pub group_window: Duration,
    pub max_depth: usize,
    /* private fields */
}

Per-editable undo stack (W3.3).

Stores entries in chronological order. head is the next-undo index - entries at index 0..head are undoable; entries at head..len are redoable (post-undo). Any new edit truncates the redo side.

Fields

group_window: Duration

Typing-coalesce window. Consecutive single-char inserts within this duration of each other collapse into one entry.

max_depth: usize

Maximum stack depth. Older entries dropped from the front.

Implementations

impl UndoStack

pub fn len(&self) -> usize

Number of stored entries (undo + redo halves).

pub fn is_empty(&self) -> bool

true when empty.

pub fn can_undo(&self) -> bool

true when there’s something to undo.

pub fn can_redo(&self) -> bool

true when there’s something to redo.

pub fn clear(&mut self)

Clear all entries (external buffer rewrite - recorded offsets no longer describe the live rope). Mirrors QLineEdit::setText.

pub fn record_insert( &mut self, position: usize, inserted: &str, cursor_before: TextPos, )

Record a pure-insertion edit.

pub fn record_delete( &mut self, position: usize, removed: &str, cursor_before: TextPos, )

Record a pure-deletion edit.

pub fn record_replace( &mut self, position: usize, removed: &str, inserted: &str, cursor_before: TextPos, )

Record a replace edit (removed + inserted).

pub fn undo(&mut self, buf: &mut TextBuffer, cur: &mut TextCursor) -> bool

Pop one undo entry. Returns true when an entry was applied.

pub fn redo(&mut self, buf: &mut TextBuffer, cur: &mut TextCursor) -> bool

Re-apply the next redo entry. Returns true when an entry was applied.

Trait Implementations

impl Clone for UndoStack

fn clone(&self) -> UndoStack

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Component for UndoStack

where Self: Send + Sync + 'static,

const STORAGE_TYPE: StorageType = bevy_ecs::component::StorageType::Table

A constant indicating the storage type used for this component.

type Mutability = Mutable

A marker type to assist Bevy with determining if this component is mutable, or immutable. Mutable components will have [Component<Mutability = Mutable>], while immutable components will instead have [Component<Mutability = Immutable>].

fn register_required_components( _requiree: ComponentId, required_components: &mut RequiredComponentsRegistrator<'_, '_>, )

Registers required components.

fn clone_behavior() -> ComponentCloneBehavior

Called when registering this component, allowing to override clone function (or disable cloning altogether) for this component.

fn relationship_accessor() -> Option<ComponentRelationshipAccessor<Self>>

Returns [ComponentRelationshipAccessor] required for working with relationships in dynamic contexts.

fn on_add() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_add [ComponentHook] for this [Component] if one is defined.

fn on_insert() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_insert [ComponentHook] for this [Component] if one is defined.

fn on_discard() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_discard [ComponentHook] for this [Component] if one is defined.

fn on_remove() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_remove [ComponentHook] for this [Component] if one is defined.

fn on_despawn() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_despawn [ComponentHook] for this [Component] if one is defined.

fn map_entities<E>(_this: &mut Self, _mapper: &mut E)

where E: EntityMapper,

Maps the entities on this component using the given [EntityMapper]. This is used to remap entities in contexts like scenes and entity cloning. When deriving [Component], this is populated by annotating fields containing entities with #[entities]

impl Debug for UndoStack

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

Formats the value using the given formatter.

impl Default for UndoStack

fn default() -> Self

Returns the “default value” for a type.