@tldraw/store
Version:
tldraw infinite canvas SDK (store).
105 lines (104 loc) • 2.64 kB
JavaScript
class IncrementalSetConstructor {
constructor(previousValue) {
this.previousValue = previousValue;
}
/**
* The next value of the set.
*
* @internal
*/
nextValue;
/**
* The diff of the set.
*
* @internal
*/
diff;
/**
* Get the next value of the set.
*
* @public
*/
get() {
const numRemoved = this.diff?.removed?.size ?? 0;
const numAdded = this.diff?.added?.size ?? 0;
if (numRemoved === 0 && numAdded === 0) {
return void 0;
}
return { value: this.nextValue, diff: this.diff };
}
/**
* Add an item to the set.
*
* @param item - The item to add.
* @param wasAlreadyPresent - Whether the item was already present in the set.
* @internal
*/
_add(item, wasAlreadyPresent) {
this.nextValue ??= new Set(this.previousValue);
this.nextValue.add(item);
this.diff ??= {};
if (wasAlreadyPresent) {
this.diff.removed?.delete(item);
} else {
this.diff.added ??= /* @__PURE__ */ new Set();
this.diff.added.add(item);
}
}
/**
* Add an item to the set.
*
* @param item - The item to add.
* @public
*/
add(item) {
const wasAlreadyPresent = this.previousValue.has(item);
if (wasAlreadyPresent) {
const wasRemoved = this.diff?.removed?.has(item);
if (!wasRemoved) return;
return this._add(item, wasAlreadyPresent);
}
const isCurrentlyPresent = this.nextValue?.has(item);
if (isCurrentlyPresent) return;
this._add(item, wasAlreadyPresent);
}
/**
* Remove an item from the set.
*
* @param item - The item to remove.
* @param wasAlreadyPresent - Whether the item was already present in the set.
* @internal
*/
_remove(item, wasAlreadyPresent) {
this.nextValue ??= new Set(this.previousValue);
this.nextValue.delete(item);
this.diff ??= {};
if (wasAlreadyPresent) {
this.diff.removed ??= /* @__PURE__ */ new Set();
this.diff.removed.add(item);
} else {
this.diff.added?.delete(item);
}
}
/**
* Remove an item from the set.
*
* @param item - The item to remove.
* @public
*/
remove(item) {
const wasAlreadyPresent = this.previousValue.has(item);
if (!wasAlreadyPresent) {
const wasAdded = this.diff?.added?.has(item);
if (!wasAdded) return;
return this._remove(item, wasAlreadyPresent);
}
const hasAlreadyBeenRemoved = this.diff?.removed?.has(item);
if (hasAlreadyBeenRemoved) return;
this._remove(item, wasAlreadyPresent);
}
}
export {
IncrementalSetConstructor
};
//# sourceMappingURL=IncrementalSetConstructor.mjs.map