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Emit signal when index changes
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@evenorog
evenorog committed Apr 18, 2023
1 parent 1c14144 commit 9b90228
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Showing 2 changed files with 32 additions and 14 deletions.
36 changes: 25 additions & 11 deletions src/record.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -162,6 +162,13 @@ impl<E, S> Record<E, S> {
pub fn checkpoint(&mut self) -> Checkpoint<E, S> {
Checkpoint::from(self)
}

/// Remove all elements after the index.
fn rm_tail(&mut self) -> VecDeque<Entry<E>> {
// Check if the saved edit will be removed.
self.saved = self.saved.filter(|&saved| saved <= self.index);
self.entries.split_off(self.index)
}
}

impl<E: Edit, S: Slot> Record<E, S> {
Expand All @@ -178,14 +185,12 @@ impl<E: Edit, S: Slot> Record<E, S> {
) -> (E::Output, bool, VecDeque<Entry<E>>) {
let output = edit.edit(target);
// We store the state of the stack before adding the entry.
let index = self.index;
let old_index = self.index;
let could_undo = self.can_undo();
let could_redo = self.can_redo();
let was_saved = self.is_saved();
// Pop off all elements after len from entries.
let tail = self.entries.split_off(index);
// Check if the saved state was popped off.
self.saved = self.saved.filter(|&saved| saved <= index);

let tail = self.rm_tail();
// Try to merge edits unless the target is in a saved state.
let merged = match self.entries.back_mut() {
Some(last) if !was_saved => last.edit.merge(edit),
Expand Down Expand Up @@ -216,23 +221,26 @@ impl<E: Edit, S: Slot> Record<E, S> {
self.socket.emit_if(could_redo, || Signal::Redo(false));
self.socket.emit_if(!could_undo, || Signal::Undo(true));
self.socket.emit_if(was_saved, || Signal::Saved(false));
self.socket
.emit_if(old_index != self.index, || Signal::Index(self.index));
(output, merged_or_annulled, tail)
}

/// Calls the [`Edit::undo`] method for the active edit and sets
/// the previous one as the new active one.
pub fn undo(&mut self, target: &mut E::Target) -> Option<E::Output> {
self.can_undo().then(|| {
let old_index = self.index;
let was_saved = self.is_saved();
let old = self.index;
let output = self.entries[self.index - 1].undo(target);
self.index -= 1;
let is_saved = self.is_saved();
self.socket.emit_if(old == 1, || Signal::Undo(false));
self.socket.emit_if(old_index == 1, || Signal::Undo(false));
self.socket
.emit_if(old == self.entries.len(), || Signal::Redo(true));
.emit_if(old_index == self.entries.len(), || Signal::Redo(true));
self.socket
.emit_if(was_saved != is_saved, || Signal::Saved(is_saved));
self.socket.emit(|| Signal::Index(self.index));
output
})
}
Expand All @@ -241,16 +249,17 @@ impl<E: Edit, S: Slot> Record<E, S> {
/// the next one as the new active one.
pub fn redo(&mut self, target: &mut E::Target) -> Option<E::Output> {
self.can_redo().then(|| {
let old_index = self.index;
let was_saved = self.is_saved();
let old = self.index;
let output = self.entries[self.index].redo(target);
self.index += 1;
let is_saved = self.is_saved();
self.socket.emit_if(old == 0, || Signal::Undo(true));
self.socket.emit_if(old_index == 0, || Signal::Undo(true));
self.socket
.emit_if(old == self.len() - 1, || Signal::Redo(false));
.emit_if(old_index == self.len() - 1, || Signal::Redo(false));
self.socket
.emit_if(was_saved != is_saved, || Signal::Saved(is_saved));
self.socket.emit(|| Signal::Index(self.index));
output
})
}
Expand All @@ -269,13 +278,15 @@ impl<E: Edit, S: Slot> Record<E, S> {

/// Removes all edits from the record without undoing them.
pub fn clear(&mut self) {
let old_index = self.index;
let could_undo = self.can_undo();
let could_redo = self.can_redo();
self.entries.clear();
self.saved = self.is_saved().then_some(0);
self.index = 0;
self.socket.emit_if(could_undo, || Signal::Undo(false));
self.socket.emit_if(could_redo, || Signal::Redo(false));
self.socket.emit_if(old_index != 0, || Signal::Index(0));
}

/// Revert the changes done to the target since the saved state.
Expand All @@ -290,6 +301,7 @@ impl<E: Edit, S: Slot> Record<E, S> {
return Vec::new();
}

let old_index = self.index();
let could_undo = self.can_undo();
let could_redo = self.can_redo();
let was_saved = self.is_saved();
Expand Down Expand Up @@ -319,6 +331,8 @@ impl<E: Edit, S: Slot> Record<E, S> {
.emit_if(could_redo != can_redo, || Signal::Redo(can_redo));
self.socket
.emit_if(was_saved != is_saved, || Signal::Saved(is_saved));
self.socket
.emit_if(old_index != self.index, || Signal::Index(self.index));

outputs
}
Expand Down
10 changes: 7 additions & 3 deletions src/socket.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,12 +51,14 @@ impl<S: Slot> Socket<S> {
#[derive(Clone, Debug, PartialEq)]
#[non_exhaustive]
pub enum Signal {
/// Says if the structures can undo.
/// Emitted when the structures ability to undo has changed.
Undo(bool),
/// Says if the structures can redo.
/// Emitted when the structures ability to redo has changed.
Redo(bool),
/// Says if the target is in a saved state.
/// Emitted when the saved state has changed.
Saved(bool),
/// Emitted when the index has changed.
Index(usize),
}

/// Use this to handle signals emitted.
Expand All @@ -80,12 +82,14 @@ pub enum Signal {
/// record.edit(&mut target, Add('a'));
/// assert_eq!(iter.next(), Some(Signal::Undo(true)));
/// assert_eq!(iter.next(), Some(Signal::Saved(false)));
/// assert_eq!(iter.next(), Some(Signal::Index(1)));
/// assert_eq!(iter.next(), None);
///
/// record.undo(&mut target);
/// assert_eq!(iter.next(), Some(Signal::Undo(false)));
/// assert_eq!(iter.next(), Some(Signal::Redo(true)));
/// assert_eq!(iter.next(), Some(Signal::Saved(true)));
/// assert_eq!(iter.next(), Some(Signal::Index(0)));
/// assert_eq!(iter.next(), None);
/// # }
/// ```
Expand Down

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