excalidraw/src/element/mutateElement.ts

import { ExcalidrawElement, ExcalidrawTextElement } from "./types";
import { randomSeed } from "roughjs/bin/math";

type ElementUpdate<TElement extends ExcalidrawElement> = Omit<
  Partial<TElement>,
  "id" | "seed"
>;

// This function tracks updates of text elements for the purposes for collaboration.
// The version is used to compare updates when more than one user is working in
// the same drawing.
export function mutateElement(
  element: ExcalidrawElement,
  updates?: ElementUpdate<ExcalidrawElement>,
) {
  if (updates) {
    Object.assign(element, updates);
  }
  (element as any).version++;
  (element as any).versionNonce = randomSeed();
}

export function newElementWith(
  element: ExcalidrawElement,
  updates: ElementUpdate<ExcalidrawElement>,
): ExcalidrawElement {
  return {
    ...element,
    ...updates,
    version: element.version + 1,
    versionNonce: randomSeed(),
  };
}

// This function tracks updates of text elements for the purposes for collaboration.
// The version is used to compare updates when more than one user is working in
// the same document.
export function mutateTextElement(
  element: ExcalidrawTextElement,
  updates: ElementUpdate<ExcalidrawTextElement>,
): void {
  Object.assign(element, updates);
  (element as any).version++;
  (element as any).versionNonce = randomSeed();
}

export function newTextElementWith(
  element: ExcalidrawTextElement,
  updates: ElementUpdate<ExcalidrawTextElement>,
): ExcalidrawTextElement {
  return {
    ...element,
    ...updates,
    version: element.version + 1,
    versionNonce: randomSeed(),
  };
}