63 lines
1.7 KiB
TypeScript
63 lines
1.7 KiB
TypeScript
import { ExcalidrawElement } from "./element/types";
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import { newElementWith } from "./element/mutateElement";
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import { Box, getCommonBoundingBox } from "./element/bounds";
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import { getMaximumGroups } from "./groups";
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export interface Alignment {
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position: "start" | "center" | "end";
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axis: "x" | "y";
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}
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export const alignElements = (
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selectedElements: ExcalidrawElement[],
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alignment: Alignment,
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): ExcalidrawElement[] => {
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const groups: ExcalidrawElement[][] = getMaximumGroups(selectedElements);
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const selectionBoundingBox = getCommonBoundingBox(selectedElements);
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return groups.flatMap((group) => {
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const translation = calculateTranslation(
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group,
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selectionBoundingBox,
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alignment,
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);
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return group.map((element) =>
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newElementWith(element, {
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x: element.x + translation.x,
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y: element.y + translation.y,
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}),
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);
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});
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};
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const calculateTranslation = (
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group: ExcalidrawElement[],
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selectionBoundingBox: Box,
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{ axis, position }: Alignment,
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): { x: number; y: number } => {
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const groupBoundingBox = getCommonBoundingBox(group);
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const [min, max]: ["minX" | "minY", "maxX" | "maxY"] =
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axis === "x" ? ["minX", "maxX"] : ["minY", "maxY"];
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const noTranslation = { x: 0, y: 0 };
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if (position === "start") {
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return {
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...noTranslation,
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[axis]: selectionBoundingBox[min] - groupBoundingBox[min],
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};
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} else if (position === "end") {
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return {
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...noTranslation,
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[axis]: selectionBoundingBox[max] - groupBoundingBox[max],
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};
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} // else if (position === "center") {
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return {
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...noTranslation,
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[axis]:
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(selectionBoundingBox[min] + selectionBoundingBox[max]) / 2 -
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(groupBoundingBox[min] + groupBoundingBox[max]) / 2,
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};
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};
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