View a locked point with mafs

.changeset/shaggy-parrots-provide.md

@@ -0,0 +1,5 @@
+---
+"@khanacademy/perseus": minor
+---
+
+Can pass a point into `lockedFigures` into MafsGraph and a point will be displayed.

packages/perseus/src/widgets/__stories__/interactive-graph.stories.tsx

@@ -11,6 +11,7 @@ import {
     polygonQuestion,
     rayQuestion,
     segmentQuestion,
+    segmentWithLockedPointsQuestion,
     sinusoidQuestion,
 } from "../__testdata__/interactive-graph.testdata";
 
@@ -56,6 +57,21 @@ export const Segment = (args: StoryArgs): React.ReactElement => (
     <RendererWithDebugUI question={segmentQuestion} />
 );
 
+export const SegmentWithMafsAndLockedPoints = (
+    args: StoryArgs,
+): React.ReactElement => (
+    <RendererWithDebugUI
+        apiOptions={{
+            flags: {
+                mafs: {
+                    segment: true,
+                },
+            },
+        }}
+        question={segmentWithLockedPointsQuestion}
+    />
+);
+
 export const Sinusoid = (args: StoryArgs): React.ReactElement => (
     <RendererWithDebugUI question={sinusoidQuestion} />
 );

packages/perseus/src/widgets/__testdata__/interactive-graph.testdata.ts

@@ -1,3 +1,5 @@
+import {color} from "@khanacademy/wonder-blocks-tokens";
+
 import type {Coord} from "../../interactive2/types";
 import type {PerseusRenderer} from "../../perseus-types";
 
@@ -480,6 +482,61 @@ export const segmentQuestion: PerseusRenderer = {
     },
 };
 
+export const segmentWithLockedPointsQuestion: PerseusRenderer = {
+    content:
+        "Line segment $\\overline{OG}$ is rotated $180^\\circ$ about the point $(-2,4)$.  \n\n**Draw the image of this rotation using the interactive graph.**\n\n*The direction of a rotation by a positive angle is counter-clockwise.* \n\n[[☃ interactive-graph 1]]\n\n",
+    images: {},
+    widgets: {
+        "interactive-graph 1": {
+            graded: true,
+            options: {
+                correct: {
+                    coords: [
+                        [
+                            [-7, -7],
+                            [2, -5],
+                        ],
+                    ],
+                    type: "segment",
+                },
+                graph: {
+                    type: "segment",
+                },
+                gridStep: [1, 1],
+                labels: ["x", "y"],
+                markings: "graph",
+                range: [
+                    [-10, 10],
+                    [-10, 10],
+                ],
+                rulerLabel: "",
+                rulerTicks: 10,
+                showProtractor: false,
+                showRuler: false,
+                snapStep: [0.5, 0.5],
+                step: [1, 1],
+                lockedFigures: [
+                    {
+                        type: "point",
+                        coord: [-7, -7],
+                        style: {stroke: color.red, fill: color.red},
+                    },
+                    {
+                        type: "point",
+                        coord: [2, -5],
+                        style: {stroke: color.red, fill: color.red},
+                    },
+                ],
+            },
+            type: "interactive-graph",
+            version: {
+                major: 0,
+                minor: 0,
+            },
+        },
+    },
+};
+
 export const segmentQuestionDefaultCorrect: PerseusRenderer = {
     content:
         "Line segment $\\overline{OG}$ is rotated $180^\\circ$ about the point $(-2,4)$.  \n\n**Draw the image of this rotation using the interactive graph.**\n\n*The direction of a rotation by a positive angle is counter-clockwise.* \n\n[[☃ interactive-graph 1]]\n\n",

packages/perseus/src/widgets/interactive-graphs/mafs-graph.tsx

@@ -7,6 +7,7 @@
 import {interactiveGraphReducer} from "./interactive-graph-reducer";
 import {initializeGraphState} from "./interactive-graph-state";
 import {getLegacyGrid} from "./legacy-grid";
+import MafsLockedLayer from "./mafs-locked-layer";
 
 import type {InteractiveGraphAction} from "./interactive-graph-action";
 import type {InteractiveGraphState} from "./interactive-graph-state";
@@ -94,7 +95,19 @@
                     width={width}
                     height={height}
                 >
+                    {/* Background layer */}
                     {!legacyGrid && <Grid {...props} />}
+
+                    {/* Locked layer */}
+                    {props.lockedFigures && (
+                        <MafsLockedLayer
+                            // Make a copy of lockedFigures since the prop
+                            // type is readonly.
+                            lockedFigures={[...props.lockedFigures]}
+                        />
+                    )}
+
+                    {/* Interactive layer */}
                     {renderGraph({
                         state,
                         dispatch,

packages/perseus/src/widgets/interactive-graphs/mafs-locked-layer.tsx

@@ -0,0 +1,41 @@
+import {Point} from "mafs";
+import * as React from "react";
+
+import type {LockedFigure} from "../../perseus-types";
+
+type Props = {
+    lockedFigures: Array<LockedFigure>;
+};
+
+const MafsLockedLayer = (props: Props) => {
+    const {lockedFigures} = props;
+    return (
+        <>
+            {lockedFigures.map((figure, index) => {
+                if (figure.type === "point") {
+                    const [x, y] = figure.coord;
+                    return (
+                        <Point
+                            key={`${figure.type}-${index}`}
+                            x={x}
+                            y={y}
+                            svgCircleProps={{style: figure.style}}
+                        />
+                    );
+                }
+
+                /**
+                 * Devlopment-time future-proofing: This `never` should
+                 * fail during type-checking if we add a new locked
+                 * shape type and forget to handle it in any other
+                 * switch case here.
+                 */
+                // eslint-disable-next-line @typescript-eslint/no-unused-vars
+                const exhaustiveCheck: never = figure.type;
+                throw new Error(`Unknown locked shape type: ${figure.type}`);
+            })}
+        </>
+    );
+};
+
+export default MafsLockedLayer;