excalidraw/src/element/mutateElement.ts
2020-07-30 20:14:38 +02:00

96 lines
2.8 KiB
TypeScript

import { ExcalidrawElement } from "./types";
import { invalidateShapeForElement } from "../renderer/renderElement";
import Scene from "../scene/Scene";
import { getSizeFromPoints } from "../points";
import { randomInteger } from "../random";
import { Point } from "../types";
type ElementUpdate<TElement extends ExcalidrawElement> = Omit<
Partial<TElement>,
"id" | "version" | "versionNonce"
>;
// 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. Note: this will trigger the component to update. Make sure you
// are calling it either from a React event handler or within unstable_batchedUpdates().
export const mutateElement = <TElement extends Mutable<ExcalidrawElement>>(
element: TElement,
updates: ElementUpdate<TElement>,
) => {
let didChange = false;
// casting to any because can't use `in` operator
// (see https://github.com/microsoft/TypeScript/issues/21732)
const { points } = updates as any;
if (typeof points !== "undefined") {
updates = { ...getSizeFromPoints(points), ...updates };
}
for (const key in updates) {
const value = (updates as any)[key];
if (typeof value !== "undefined") {
if (
(element as any)[key] === value &&
// if object, always update in case its deep prop was mutated
(typeof value !== "object" || value === null || key === "groupIds")
) {
continue;
}
if (key === "points") {
const prevPoints = (element as any)[key];
const nextPoints = value;
if (prevPoints.length === nextPoints.length) {
let didChangePoints = false;
let i = prevPoints.length;
while (--i) {
const prevPoint: Point = prevPoints[i];
const nextPoint: Point = nextPoints[i];
if (
prevPoint[0] !== nextPoint[0] ||
prevPoint[1] !== nextPoint[1]
) {
didChangePoints = true;
break;
}
}
if (!didChangePoints) {
continue;
}
}
}
(element as any)[key] = value;
didChange = true;
}
}
if (!didChange) {
return;
}
if (
typeof updates.height !== "undefined" ||
typeof updates.width !== "undefined" ||
typeof points !== "undefined"
) {
invalidateShapeForElement(element);
}
element.version++;
element.versionNonce = randomInteger();
Scene.getScene(element)?.informMutation();
};
export const newElementWith = <TElement extends ExcalidrawElement>(
element: TElement,
updates: ElementUpdate<TElement>,
): TElement => ({
...element,
...updates,
version: element.version + 1,
versionNonce: randomInteger(),
});