feat: flip arrowheads if only arrow(s) selected (#8525)

Co-authored-by: Mark Tolmacs <mark@lazycat.hu>

packages/excalidraw/actions/actionFlip.test.tsx

@@ -3,87 +3,209 @@ import { Excalidraw } from "../index";
 import { render } from "../tests/test-utils";
 import { API } from "../tests/helpers/api";
 import { point } from "../../math";
-import { actionFlipHorizontal } from "./actionFlip";
+import { actionFlipHorizontal, actionFlipVertical } from "./actionFlip";
 
 const { h } = window;
 
-const testElements = [
+describe("flipping re-centers selection", () => {
+  it("elbow arrow touches group selection side yet it remains in place after multiple moves", async () => {
+    const elements = [
       API.createElement({
         type: "rectangle",
         id: "rec1",
-    x: 1046,
-    y: 541,
+        x: 100,
+        y: 100,
         width: 100,
         height: 100,
-    boundElements: [
-      {
-        id: "arr",
-        type: "arrow",
-      },
-    ],
+        boundElements: [{ id: "arr", type: "arrow" }],
       }),
       API.createElement({
         type: "rectangle",
         id: "rec2",
-    x: 1169,
-    y: 777,
-    width: 102,
-    height: 115,
-    boundElements: [
-      {
-        id: "arr",
-        type: "arrow",
-      },
-    ],
+        x: 220,
+        y: 250,
+        width: 100,
+        height: 100,
+        boundElements: [{ id: "arr", type: "arrow" }],
       }),
       API.createElement({
         type: "arrow",
-    id: "arrow",
-    x: 1103.0717787616313,
-    y: 536.8531862198708,
-    width: 159.68539325842903,
-    height: 333.0396003698186,
+        id: "arr",
+        x: 149.9,
+        y: 95,
+        width: 156,
+        height: 239.9,
         startBinding: {
           elementId: "rec1",
-      focus: 0.1366906474820229,
-      gap: 5.000000000000057,
-      fixedPoint: [0.5683453237410123, -0.05014327585315258],
+          focus: 0,
+          gap: 5,
+          fixedPoint: [0.49, -0.05],
         },
         endBinding: {
           elementId: "rec2",
-      focus: 0.0014925373134265828,
+          focus: 0,
           gap: 5,
-      fixedPoint: [-0.04862325174825108, 0.4992537313432874],
+          fixedPoint: [-0.05, 0.49],
         },
+        startArrowhead: null,
+        endArrowhead: "arrow",
         points: [
           point(0, 0),
           point(0, -35),
-      point(-97.80898876404626, -35),
-      point(-97.80898876404626, 298.0396003698186),
-      point(61.87640449438277, 298.0396003698186),
+          point(-90.9, -35),
+          point(-90.9, 204.9),
+          point(65.1, 204.9),
         ],
         elbowed: true,
       }),
     ];
+    await render(<Excalidraw initialData={{ elements }} />);
 
-describe("flipping action", () => {
-  it("flip re-centers the selection even after multiple flip actions", async () => {
-    await render(<Excalidraw initialData={{ elements: testElements }} />);
-
-    API.setSelectedElements(testElements);
+    API.setSelectedElements(elements);
 
     expect(Object.keys(h.state.selectedElementIds).length).toBe(3);
 
     API.executeAction(actionFlipHorizontal);
     API.executeAction(actionFlipHorizontal);
     API.executeAction(actionFlipHorizontal);
+    API.executeAction(actionFlipHorizontal);
 
     const rec1 = h.elements.find((el) => el.id === "rec1");
-    expect(rec1?.x).toBeCloseTo(1113.78, 0);
-    expect(rec1?.y).toBeCloseTo(541, 0);
+    expect(rec1?.x).toBeCloseTo(100);
+    expect(rec1?.y).toBeCloseTo(100);
 
     const rec2 = h.elements.find((el) => el.id === "rec2");
-    expect(rec2?.x).toBeCloseTo(988.72, 0);
-    expect(rec2?.y).toBeCloseTo(777, 0);
+    expect(rec2?.x).toBeCloseTo(220);
+    expect(rec2?.y).toBeCloseTo(250);
+  });
+});
+
+describe("flipping arrowheads", () => {
+  beforeEach(async () => {
+    await render(<Excalidraw />);
+  });
+
+  it("flipping bound arrow should flip arrowheads only", () => {
+    const rect = API.createElement({
+      type: "rectangle",
+      boundElements: [{ type: "arrow", id: "arrow1" }],
+    });
+    const arrow = API.createElement({
+      type: "arrow",
+      id: "arrow1",
+      startArrowhead: "arrow",
+      endArrowhead: null,
+      endBinding: {
+        elementId: rect.id,
+        focus: 0.5,
+        gap: 5,
+      },
+    });
+
+    API.setElements([rect, arrow]);
+    API.setSelectedElements([arrow]);
+
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe(null);
+
+    API.executeAction(actionFlipHorizontal);
+    expect(API.getElement(arrow).startArrowhead).toBe(null);
+    expect(API.getElement(arrow).endArrowhead).toBe("arrow");
+
+    API.executeAction(actionFlipHorizontal);
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe(null);
+
+    API.executeAction(actionFlipVertical);
+    expect(API.getElement(arrow).startArrowhead).toBe(null);
+    expect(API.getElement(arrow).endArrowhead).toBe("arrow");
+  });
+
+  it("flipping bound arrow should flip arrowheads only 2", () => {
+    const rect = API.createElement({
+      type: "rectangle",
+      boundElements: [{ type: "arrow", id: "arrow1" }],
+    });
+    const rect2 = API.createElement({
+      type: "rectangle",
+      boundElements: [{ type: "arrow", id: "arrow1" }],
+    });
+    const arrow = API.createElement({
+      type: "arrow",
+      id: "arrow1",
+      startArrowhead: "arrow",
+      endArrowhead: "circle",
+      startBinding: {
+        elementId: rect.id,
+        focus: 0.5,
+        gap: 5,
+      },
+      endBinding: {
+        elementId: rect2.id,
+        focus: 0.5,
+        gap: 5,
+      },
+    });
+
+    API.setElements([rect, rect2, arrow]);
+    API.setSelectedElements([arrow]);
+
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe("circle");
+
+    API.executeAction(actionFlipHorizontal);
+    expect(API.getElement(arrow).startArrowhead).toBe("circle");
+    expect(API.getElement(arrow).endArrowhead).toBe("arrow");
+
+    API.executeAction(actionFlipVertical);
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe("circle");
+  });
+
+  it("flipping unbound arrow shouldn't flip arrowheads", () => {
+    const arrow = API.createElement({
+      type: "arrow",
+      id: "arrow1",
+      startArrowhead: "arrow",
+      endArrowhead: "circle",
+    });
+
+    API.setElements([arrow]);
+    API.setSelectedElements([arrow]);
+
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe("circle");
+
+    API.executeAction(actionFlipHorizontal);
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe("circle");
+  });
+
+  it("flipping bound arrow shouldn't flip arrowheads if selected alongside non-arrow eleemnt", () => {
+    const rect = API.createElement({
+      type: "rectangle",
+      boundElements: [{ type: "arrow", id: "arrow1" }],
+    });
+    const arrow = API.createElement({
+      type: "arrow",
+      id: "arrow1",
+      startArrowhead: "arrow",
+      endArrowhead: null,
+      endBinding: {
+        elementId: rect.id,
+        focus: 0.5,
+        gap: 5,
+      },
+    });
+
+    API.setElements([rect, arrow]);
+    API.setSelectedElements([rect, arrow]);
+
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe(null);
+
+    API.executeAction(actionFlipHorizontal);
+    expect(API.getElement(arrow).startArrowhead).toBe("arrow");
+    expect(API.getElement(arrow).endArrowhead).toBe(null);
   });
 });

packages/excalidraw/actions/actionFlip.ts

@@ -2,6 +2,7 @@ import { register } from "./register";
 import { getSelectedElements } from "../scene";
 import { getNonDeletedElements } from "../element";
 import type {
+  ExcalidrawArrowElement,
   ExcalidrawElbowArrowElement,
   ExcalidrawElement,
   NonDeleted,
@@ -19,9 +20,13 @@ import {
 import { updateFrameMembershipOfSelectedElements } from "../frame";
 import { flipHorizontal, flipVertical } from "../components/icons";
 import { StoreAction } from "../store";
-import { isElbowArrow, isLinearElement } from "../element/typeChecks";
+import {
+  isArrowElement,
+  isElbowArrow,
+  isLinearElement,
+} from "../element/typeChecks";
 import { mutateElbowArrow } from "../element/routing";
-import { mutateElement } from "../element/mutateElement";
+import { mutateElement, newElementWith } from "../element/mutateElement";
 
 export const actionFlipHorizontal = register({
   name: "flipHorizontal",
@@ -112,6 +117,21 @@ const flipElements = (
   flipDirection: "horizontal" | "vertical",
   app: AppClassProperties,
 ): ExcalidrawElement[] => {
+  if (
+    selectedElements.every(
+      (element) =>
+        isArrowElement(element) && (element.startBinding || element.endBinding),
+    )
+  ) {
+    return selectedElements.map((element) => {
+      const _element = element as ExcalidrawArrowElement;
+      return newElementWith(_element, {
+        startArrowhead: _element.endArrowhead,
+        endArrowhead: _element.startArrowhead,
+      });
+    });
+  }
+
   const { minX, minY, maxX, maxY, midX, midY } =
     getCommonBoundingBox(selectedElements);
 

packages/excalidraw/tests/helpers/api.ts

@@ -129,6 +129,10 @@ export class API {
     expect(API.getSelectedElements().length).toBe(0);
   };
 
+  static getElement = <T extends ExcalidrawElement>(element: T): T => {
+    return h.app.scene.getElementsMapIncludingDeleted().get(element.id) as T || element;
+  }
+
   static createElement = <
     T extends Exclude<ExcalidrawElementType, "selection"> = "rectangle",
   >({
@@ -186,6 +190,12 @@ export class API {
     endBinding?: T extends "arrow"
       ? ExcalidrawArrowElement["endBinding"] | ExcalidrawElbowArrowElement["endBinding"]
       : never;
+    startArrowhead?: T extends "arrow"
+      ? ExcalidrawArrowElement["startArrowhead"] | ExcalidrawElbowArrowElement["startArrowhead"]
+      : never;
+    endArrowhead?: T extends "arrow"
+      ? ExcalidrawArrowElement["endArrowhead"] | ExcalidrawElbowArrowElement["endArrowhead"]
+      : never;
     elbowed?: boolean;
   }): T extends "arrow" | "line"
     ? ExcalidrawLinearElement
@@ -342,6 +352,8 @@ export class API {
     if (element.type === "arrow") {
       element.startBinding = rest.startBinding ?? null;
       element.endBinding = rest.endBinding ?? null;
+      element.startArrowhead = rest.startArrowhead ?? null;
+      element.endArrowhead = rest.endArrowhead ?? null;
     }
     if (id) {
       element.id = id;