json-joy
Version:
Collection of libraries for building collaborative editing apps.
39 lines (38 loc) • 964 B
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.MemoryUndo = void 0;
/**
* A Memory-based undo manager.
*/
class MemoryUndo {
constructor() {
/** Undo stack. */
this.uStack = [];
/** Redo stack. */
this.rStack = [];
}
// /** ------------------------------------------------------ {@link UndoRedo} */
push(undo) {
this.rStack = [];
this.uStack.push(undo);
}
undo() {
const undo = this.uStack.pop();
if (undo) {
const redo = undo[1](undo[0]);
this.rStack.push(redo);
}
}
redo() {
const redo = this.rStack.pop();
if (redo) {
const undo = redo[1](redo[0]);
this.uStack.push(undo);
}
}
/** -------------------------------------------------- {@link UiLifeCycles} */
start() {
return () => { };
}
}
exports.MemoryUndo = MemoryUndo;