excalidraw/src/element/sizeHelpers.ts
fujimoto kyosuke b1ed5b4cdc
Support negative resize for multiple points line/arrow (#1237)
* Support negative resize for multiple points line

* prettier

* Fix an issue with width or height becoming zero
2020-04-09 11:53:12 +02:00

106 lines
2.7 KiB
TypeScript

import { ExcalidrawElement } from "./types";
import { mutateElement } from "./mutateElement";
import { isLinearElement } from "./typeChecks";
import { SHIFT_LOCKING_ANGLE } from "../constants";
export function isInvisiblySmallElement(element: ExcalidrawElement): boolean {
if (isLinearElement(element)) {
return element.points.length < 2;
}
return element.width === 0 && element.height === 0;
}
/**
* Makes a perfect shape or diagonal/horizontal/vertical line
*/
export function getPerfectElementSize(
elementType: string,
width: number,
height: number,
): { width: number; height: number } {
const absWidth = Math.abs(width);
const absHeight = Math.abs(height);
if (elementType === "line" || elementType === "arrow") {
const lockedAngle =
Math.round(Math.atan(absHeight / absWidth) / SHIFT_LOCKING_ANGLE) *
SHIFT_LOCKING_ANGLE;
if (lockedAngle === 0) {
height = 0;
} else if (lockedAngle === Math.PI / 2) {
width = 0;
} else {
height =
Math.round(absWidth * Math.tan(lockedAngle)) * Math.sign(height) ||
height;
}
} else if (elementType !== "selection") {
height = absWidth * Math.sign(height);
}
return { width, height };
}
export function resizePerfectLineForNWHandler(
element: ExcalidrawElement,
x: number,
y: number,
) {
const anchorX = element.x + element.width;
const anchorY = element.y + element.height;
const distanceToAnchorX = x - anchorX;
const distanceToAnchorY = y - anchorY;
if (Math.abs(distanceToAnchorX) < Math.abs(distanceToAnchorY) / 2) {
mutateElement(element, {
x: anchorX,
width: 0,
y,
height: -distanceToAnchorY,
});
} else if (Math.abs(distanceToAnchorY) < Math.abs(element.width) / 2) {
mutateElement(element, {
y: anchorY,
height: 0,
});
} else {
const nextHeight =
Math.sign(distanceToAnchorY) *
Math.sign(distanceToAnchorX) *
element.width;
mutateElement(element, {
x,
y: anchorY - nextHeight,
width: -distanceToAnchorX,
height: nextHeight,
});
}
}
/**
* @returns {boolean} whether element was normalized
*/
export function normalizeDimensions(
element: ExcalidrawElement | null,
): element is ExcalidrawElement {
if (!element || (element.width >= 0 && element.height >= 0)) {
return false;
}
if (element.width < 0) {
const nextWidth = Math.abs(element.width);
mutateElement(element, {
width: nextWidth,
x: element.x - nextWidth,
});
}
if (element.height < 0) {
const nextHeight = Math.abs(element.height);
mutateElement(element, {
height: nextHeight,
y: element.y - nextHeight,
});
}
return true;
}