127 lines
3.2 KiB
Rust
127 lines
3.2 KiB
Rust
// Copyright: Ankitects Pty Ltd and contributors
|
|
// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
|
|
|
|
use crate::{
|
|
collection::{Collection, CollectionOp},
|
|
err::Result,
|
|
};
|
|
use std::fmt;
|
|
|
|
pub(crate) trait Undoable: fmt::Debug + Send {
|
|
fn apply(&self, ctx: &mut Collection) -> Result<()>;
|
|
}
|
|
|
|
#[derive(Debug)]
|
|
struct UndoStep {
|
|
kind: CollectionOp,
|
|
changes: Vec<Box<dyn Undoable>>,
|
|
}
|
|
|
|
#[derive(Debug, PartialEq)]
|
|
enum UndoMode {
|
|
NormalOp,
|
|
Undoing,
|
|
Redoing,
|
|
}
|
|
|
|
impl Default for UndoMode {
|
|
fn default() -> Self {
|
|
Self::NormalOp
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Default)]
|
|
pub(crate) struct UndoManager {
|
|
undo_steps: Vec<UndoStep>,
|
|
redo_steps: Vec<UndoStep>,
|
|
mode: UndoMode,
|
|
current_step: Option<UndoStep>,
|
|
}
|
|
|
|
impl UndoManager {
|
|
pub(crate) fn save_undoable(&mut self, item: Box<dyn Undoable>) {
|
|
if let Some(step) = self.current_step.as_mut() {
|
|
step.changes.push(item)
|
|
}
|
|
}
|
|
|
|
pub(crate) fn begin_step(&mut self, op: Option<CollectionOp>) {
|
|
if op.is_none() {
|
|
// action doesn't support undoing; clear the queue
|
|
self.undo_steps.clear();
|
|
self.redo_steps.clear();
|
|
} else if self.mode == UndoMode::NormalOp {
|
|
// a normal op clears the redo queue
|
|
self.redo_steps.clear();
|
|
}
|
|
self.current_step = op.map(|op| UndoStep {
|
|
kind: op,
|
|
changes: vec![],
|
|
});
|
|
}
|
|
|
|
pub(crate) fn end_step(&mut self) {
|
|
if let Some(step) = self.current_step.take() {
|
|
if self.mode == UndoMode::Undoing {
|
|
self.redo_steps.push(step);
|
|
} else {
|
|
self.undo_steps.push(step);
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(crate) fn discard_step(&mut self) {
|
|
self.begin_step(None)
|
|
}
|
|
|
|
fn can_undo(&self) -> Option<CollectionOp> {
|
|
self.undo_steps.last().map(|s| s.kind.clone())
|
|
}
|
|
|
|
fn can_redo(&self) -> Option<CollectionOp> {
|
|
self.redo_steps.last().map(|s| s.kind.clone())
|
|
}
|
|
}
|
|
|
|
impl Collection {
|
|
pub fn can_undo(&self) -> Option<CollectionOp> {
|
|
self.state.undo.can_undo()
|
|
}
|
|
|
|
pub fn can_redo(&self) -> Option<CollectionOp> {
|
|
self.state.undo.can_redo()
|
|
}
|
|
|
|
pub fn undo(&mut self) -> Result<()> {
|
|
if let Some(step) = self.state.undo.undo_steps.pop() {
|
|
let changes = step.changes;
|
|
self.state.undo.mode = UndoMode::Undoing;
|
|
let res = self.transact(Some(step.kind), |col| {
|
|
for change in changes.iter().rev() {
|
|
change.apply(col)?;
|
|
}
|
|
Ok(())
|
|
});
|
|
self.state.undo.mode = UndoMode::NormalOp;
|
|
res?;
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
pub fn redo(&mut self) -> Result<()> {
|
|
if let Some(step) = self.state.undo.redo_steps.pop() {
|
|
let changes = step.changes;
|
|
self.state.undo.mode = UndoMode::Redoing;
|
|
let res = self.transact(Some(step.kind), |col| {
|
|
for change in changes.iter().rev() {
|
|
change.apply(col)?;
|
|
}
|
|
Ok(())
|
|
});
|
|
self.state.undo.mode = UndoMode::NormalOp;
|
|
res?;
|
|
}
|
|
Ok(())
|
|
}
|
|
}
|