snapshot of https://github.com/excalidraw/excalidraw.git (master, 2026-09-16; blobs > 131072B omitted)

packages/excalidraw/components/canvases/InteractiveCanvas.tsx

@@ -0,0 +1,307 @@
+import React, { useEffect, useRef } from "react";
+
+import {
+  isShallowEqual,
+  sceneCoordsToViewportCoords,
+  type EditorInterface,
+} from "@excalidraw/common";
+
+import type {
+  InteractiveCanvasRenderConfig,
+  InteractiveSceneRenderAnimationState,
+  InteractiveSceneRenderConfig,
+  RenderableElementsMap,
+  RenderInteractiveSceneCallback,
+} from "@excalidraw/excalidraw/scene/types";
+
+import type {
+  NonDeletedExcalidrawElement,
+  NonDeletedSceneElementsMap,
+} from "@excalidraw/element/types";
+
+import { t } from "../../i18n";
+import { getSelectionColor } from "../../renderer/helpers";
+import { renderInteractiveScene } from "../../renderer/interactiveScene";
+
+import { AnimationController } from "../../renderer/animation";
+
+import type {
+  AppClassProperties,
+  AppState,
+  InteractiveCanvasAppState,
+} from "../../types";
+import type { DOMAttributes } from "react";
+
+type InteractiveCanvasProps = {
+  containerRef: React.RefObject<HTMLDivElement | null>;
+  canvas: HTMLCanvasElement | null;
+  elementsMap: RenderableElementsMap;
+  visibleElements: readonly NonDeletedExcalidrawElement[];
+  selectedElements: readonly NonDeletedExcalidrawElement[];
+  allElementsMap: NonDeletedSceneElementsMap;
+  canvasNonce: string;
+  selectionNonce: number | undefined;
+  scale: number;
+  appState: InteractiveCanvasAppState;
+  renderScrollbars: boolean;
+  editorInterface: EditorInterface;
+  app: AppClassProperties;
+  interactionEnabled: boolean;
+  navigationEnabled: boolean;
+  renderInteractiveSceneCallback: (
+    data: RenderInteractiveSceneCallback,
+  ) => void;
+  handleCanvasRef: (canvas: HTMLCanvasElement | null) => void;
+  onContextMenu: Exclude<
+    DOMAttributes<HTMLCanvasElement | HTMLDivElement>["onContextMenu"],
+    undefined
+  >;
+  onClick: Exclude<DOMAttributes<HTMLCanvasElement>["onClick"], undefined>;
+  onPointerMove: Exclude<
+    DOMAttributes<HTMLCanvasElement>["onPointerMove"],
+    undefined
+  >;
+  onPointerUp: Exclude<
+    DOMAttributes<HTMLCanvasElement>["onPointerUp"],
+    undefined
+  >;
+  onPointerCancel: Exclude<
+    DOMAttributes<HTMLCanvasElement>["onPointerCancel"],
+    undefined
+  >;
+  onTouchMove: Exclude<
+    DOMAttributes<HTMLCanvasElement>["onTouchMove"],
+    undefined
+  >;
+  onPointerDown: Exclude<
+    DOMAttributes<HTMLCanvasElement>["onPointerDown"],
+    undefined
+  >;
+  onDoubleClick: Exclude<
+    DOMAttributes<HTMLCanvasElement>["onDoubleClick"],
+    undefined
+  >;
+};
+
+export const INTERACTIVE_SCENE_ANIMATION_KEY = "animateInteractiveScene";
+
+const InteractiveCanvas = (props: InteractiveCanvasProps) => {
+  const isComponentMounted = useRef(false);
+  const rendererParams = useRef(null as InteractiveSceneRenderConfig | null);
+
+  useEffect(() => {
+    if (!isComponentMounted.current) {
+      isComponentMounted.current = true;
+      return;
+    }
+
+    const remotePointerButton: InteractiveCanvasRenderConfig["remotePointerButton"] =
+      new Map();
+    const remotePointerViewportCoords: InteractiveCanvasRenderConfig["remotePointerViewportCoords"] =
+      new Map();
+    const remoteSelectedElementIds: InteractiveCanvasRenderConfig["remoteSelectedElementIds"] =
+      new Map();
+    const remotePointerUsernames: InteractiveCanvasRenderConfig["remotePointerUsernames"] =
+      new Map();
+    const remotePointerUserStates: InteractiveCanvasRenderConfig["remotePointerUserStates"] =
+      new Map();
+
+    props.appState.collaborators.forEach((user, socketId) => {
+      if (user.selectedElementIds) {
+        for (const id of Object.keys(user.selectedElementIds)) {
+          if (!remoteSelectedElementIds.has(id)) {
+            remoteSelectedElementIds.set(id, []);
+          }
+          remoteSelectedElementIds.get(id)!.push(socketId);
+        }
+      }
+      if (!user.pointer || user.pointer.renderCursor === false) {
+        return;
+      }
+      if (user.username) {
+        remotePointerUsernames.set(socketId, user.username);
+      }
+      if (user.userState) {
+        remotePointerUserStates.set(socketId, user.userState);
+      }
+      remotePointerViewportCoords.set(
+        socketId,
+        sceneCoordsToViewportCoords(
+          {
+            sceneX: user.pointer.x,
+            sceneY: user.pointer.y,
+          },
+          props.appState,
+        ),
+      );
+      remotePointerButton.set(socketId, user.button);
+    });
+
+    const selectionColor = getSelectionColor(props.containerRef?.current);
+
+    rendererParams.current = {
+      app: props.app,
+      canvas: props.canvas,
+      elementsMap: props.elementsMap,
+      visibleElements: props.visibleElements,
+      selectedElements: props.selectedElements,
+      allElementsMap: props.allElementsMap,
+      scale: window.devicePixelRatio,
+      appState: props.appState,
+      renderConfig: {
+        remotePointerViewportCoords,
+        remotePointerButton,
+        remoteSelectedElementIds,
+        remotePointerUsernames,
+        remotePointerUserStates,
+        selectionColor,
+        renderScrollbars: props.renderScrollbars,
+        // NOTE not memoized on so we don't rerender on cursor move
+        lastViewportPosition: props.app.viewport.lastPosition,
+      },
+      editorInterface: props.editorInterface,
+      callback: props.renderInteractiveSceneCallback,
+      animationState: {
+        bindingHighlight: undefined,
+      },
+      deltaTime: 0,
+    };
+
+    if (!AnimationController.running(INTERACTIVE_SCENE_ANIMATION_KEY)) {
+      AnimationController.start<InteractiveSceneRenderAnimationState>(
+        INTERACTIVE_SCENE_ANIMATION_KEY,
+        ({ deltaTime, state }) => {
+          const nextAnimationState = renderInteractiveScene({
+            ...rendererParams.current!,
+            deltaTime,
+            animationState: state,
+          }).animationState;
+
+          if (nextAnimationState) {
+            for (const key in nextAnimationState) {
+              if (
+                nextAnimationState[
+                  key as keyof InteractiveSceneRenderAnimationState
+                ] !== undefined
+              ) {
+                return nextAnimationState;
+              }
+            }
+          }
+
+          return undefined;
+        },
+      );
+    }
+  });
+
+  return (
+    <canvas
+      className="excalidraw__canvas interactive"
+      // NOTE no `cursor` style here — the cursor is managed imperatively
+      // (see `AppCursor`); an inline style would clobber it whenever its
+      // computed value changes across rerenders
+      style={{
+        width: props.appState.width,
+        height: props.appState.height,
+      }}
+      width={props.appState.width * props.scale}
+      height={props.appState.height * props.scale}
+      ref={props.handleCanvasRef}
+      // NOTE all the handlers early-exit in App when the editor is
+      // non-interactive (running only a restricted, link-only code path if
+      // `interaction.allowed.links` is enabled), so they're safe to bind
+      // unconditionally
+      onContextMenu={props.onContextMenu}
+      onClick={props.onClick}
+      onPointerMove={props.onPointerMove}
+      onPointerUp={props.onPointerUp}
+      onPointerCancel={props.onPointerCancel}
+      onTouchMove={props.onTouchMove}
+      onPointerDown={props.onPointerDown}
+      onDoubleClick={
+        props.appState.viewModeEnabled ? undefined : props.onDoubleClick
+      }
+    >
+      {t("labels.drawingCanvas")}
+    </canvas>
+  );
+};
+
+const getRelevantAppStateProps = (
+  appState: AppState,
+): InteractiveCanvasAppState => ({
+  zoom: appState.zoom,
+  scrollX: appState.scrollX,
+  scrollY: appState.scrollY,
+  width: appState.width,
+  height: appState.height,
+  viewModeEnabled: appState.viewModeEnabled,
+  activeTool: appState.activeTool,
+  openDialog: appState.openDialog,
+  editingGroupId: appState.editingGroupId,
+  selectedElementIds: appState.selectedElementIds,
+  frameToHighlight: appState.frameToHighlight,
+  offsetLeft: appState.offsetLeft,
+  offsetTop: appState.offsetTop,
+  theme: appState.theme,
+  selectionElement: appState.selectionElement,
+  selectedGroupIds: appState.selectedGroupIds,
+  selectedLinearElement: appState.selectedLinearElement,
+  multiElement: appState.multiElement,
+  newElement: appState.newElement,
+  isBindingEnabled: appState.isBindingEnabled,
+  isMidpointSnappingEnabled: appState.isMidpointSnappingEnabled,
+  gridModeEnabled: appState.gridModeEnabled,
+  suggestedBinding: appState.suggestedBinding,
+  hoveredArrowTextAnchor: appState.hoveredArrowTextAnchor,
+  isRotating: appState.isRotating,
+  elementsToHighlight: appState.elementsToHighlight,
+  collaborators: appState.collaborators, // Necessary for collab. sessions
+  activeEmbeddable: appState.activeEmbeddable,
+  snapLines: appState.snapLines,
+  zenModeEnabled: appState.zenModeEnabled,
+  editingTextElement: appState.editingTextElement,
+  isCropping: appState.isCropping,
+  croppingElementId: appState.croppingElementId,
+  searchMatches: appState.searchMatches,
+  activeLockedId: appState.activeLockedId,
+  hoveredElementIds: appState.hoveredElementIds,
+  frameRendering: appState.frameRendering,
+  shouldCacheIgnoreZoom: appState.shouldCacheIgnoreZoom,
+  exportScale: appState.exportScale,
+  currentItemArrowType: appState.currentItemArrowType,
+});
+
+const areEqual = (
+  prevProps: InteractiveCanvasProps,
+  nextProps: InteractiveCanvasProps,
+) => {
+  // This could be further optimised if needed, as we don't have to render interactive canvas on each scene mutation
+  if (
+    prevProps.selectionNonce !== nextProps.selectionNonce ||
+    prevProps.canvasNonce !== nextProps.canvasNonce ||
+    prevProps.scale !== nextProps.scale ||
+    // we need to memoize on elementsMap because they may have renewed
+    // even if canvasNonce didn't change (e.g. we filter elements out based
+    // on appState)
+    prevProps.elementsMap !== nextProps.elementsMap ||
+    prevProps.visibleElements !== nextProps.visibleElements ||
+    prevProps.selectedElements !== nextProps.selectedElements ||
+    prevProps.renderScrollbars !== nextProps.renderScrollbars ||
+    prevProps.interactionEnabled !== nextProps.interactionEnabled ||
+    prevProps.navigationEnabled !== nextProps.navigationEnabled
+  ) {
+    return false;
+  }
+
+  // Comparing the interactive appState for changes in case of some edge cases
+  return isShallowEqual(
+    // asserting AppState because we're being passed the whole AppState
+    // but resolve to only the InteractiveCanvas-relevant props
+    getRelevantAppStateProps(prevProps.appState as AppState),
+    getRelevantAppStateProps(nextProps.appState as AppState),
+  );
+};
+
+export default React.memo(InteractiveCanvas, areEqual);