Press n or j to go to the next uncovered block, b, p or k for the previous block.
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export interface UndoRedoOptions {
historyLimit?: number;
}
interface HistoryState<T> {
past: T[];
present: T;
future: T[];
}
export interface UseUndoRedoResult<T> {
state: T;
set: (
next: T | ((current: T) => T),
options?: {
mode?: "push" | "replace" | "pushFrom";
from?: T;
},
) => void;
undo: () => void;
redo: () => void;
reset: (nextState: T) => void;
canUndo: boolean;
canRedo: boolean;
history: {
past: T[];
future: T[];
};
}
export function useUndoRedo<T>(
initialState: T,
options: UndoRedoOptions = {},
): UseUndoRedoResult<T> {
const { historyLimit = 100 } = options;
const [historyState, setHistoryState] = useState<HistoryState<T>>({
past: [],
present: initialState,
future: [],
});
const set = useCallback(
(
next: T | ((current: T) => T),
options: { mode?: "push" | "replace" | "pushFrom"; from?: T } = {},
) => {
const mode = options.mode ?? "push";
setHistoryState((currentState) => {
const nextValue =
typeof next === "function" ? (next as (current: T) => T)(currentState.present) : next;
const historyFrom = options.from ?? currentState.present;
if (mode === "replace") {
Iif (Object.is(currentState.present, nextValue)) {
return currentState;
}
return {
past: currentState.past,
present: nextValue,
future: [],
};
}
if (mode === "pushFrom") {
Iif (Object.is(historyFrom, nextValue)) {
return currentState;
}
const nextPast = [...currentState.past, historyFrom];
return {
past:
nextPast.length > historyLimit
? nextPast.slice(nextPast.length - historyLimit)
: nextPast,
present: nextValue,
future: [],
};
}
if (Object.is(currentState.present, nextValue)) {
return currentState;
}
const nextPast = [...currentState.past, currentState.present];
return {
past:
nextPast.length > historyLimit
? nextPast.slice(nextPast.length - historyLimit)
: nextPast,
present: nextValue,
future: [],
};
});
},
[historyLimit],
);
const undo = useCallback(() => {
setHistoryState((currentState) => {
if (currentState.past.length === 0) {
return currentState;
}
const previous = currentState.past[currentState.past.length - 1];
return {
past: currentState.past.slice(0, -1),
present: previous,
future: [currentState.present, ...currentState.future],
};
});
}, []);
const redo = useCallback(() => {
setHistoryState((currentState) => {
if (currentState.future.length === 0) {
return currentState;
}
const [nextPresent, ...remainingFuture] = currentState.future;
return {
past: [...currentState.past, currentState.present],
present: nextPresent,
future: remainingFuture,
};
});
}, []);
const reset = useCallback((nextState: T) => {
setHistoryState({ past: [], present: nextState, future: [] });
}, []);
const canUndo = historyState.past.length > 0;
const canRedo = historyState.future.length > 0;
const history = useMemo(
() => ({
past: historyState.past,
future: historyState.future,
}),
[historyState.future, historyState.past],
);
return {
state: historyState.present,
set,
undo,
redo,
reset,
canUndo,
canRedo,
history,
};
}
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