excalidraw/src/scene/scroll.ts
Jed Fox c6a0cfc2b1
Refactor (#862)
* Initial factoring out of parts of the LayerUI component

2360 → 2224 LOC

* Create a Section component

* Break up src/index.tsx

* Refactor actions to reduce duplication, fix CSS

Also consolidate icons

* Move scene/data.ts to its own directory

* Fix accidental reverts, banish further single-character variables

* ACTIVE_ELEM_COLOR → ACTIVE_ELEMENT_COLOR

* Further refactoring the icons file

* Log all errors

* Pointer Event polyfill to make the tests work

* add test hooks & fix tests

Co-authored-by: dwelle <luzar.david@gmail.com>
2020-03-07 16:20:38 +01:00

22 lines
640 B
TypeScript

import { FlooredNumber } from "../types";
import { ExcalidrawElement } from "../element/types";
import { getCommonBounds } from "../element";
export function normalizeScroll(pos: number) {
return Math.floor(pos) as FlooredNumber;
}
export function calculateScrollCenter(
elements: readonly ExcalidrawElement[],
): { scrollX: FlooredNumber; scrollY: FlooredNumber } {
const [x1, y1, x2, y2] = getCommonBounds(elements);
const centerX = (x1 + x2) / 2;
const centerY = (y1 + y2) / 2;
return {
scrollX: normalizeScroll(window.innerWidth / 2 - centerX),
scrollY: normalizeScroll(window.innerHeight / 2 - centerY),
};
}