From e0dd29aa3652f687900ffc37b1226b8cf21e851c Mon Sep 17 00:00:00 2001
From: Mark Tolmacs <mark@lazycat.hu>
Date: Wed, 17 Sep 2025 18:37:56 +0200
Subject: [PATCH] fix:Refactored and fixed highlight animation

---
 .../components/canvases/InteractiveCanvas.tsx | 64 +++++++++++++++++++
 .../excalidraw/renderer/interactiveScene.ts   | 53 +++++++--------
 packages/excalidraw/scene/types.ts            |  6 ++
 3 files changed, 98 insertions(+), 25 deletions(-)

diff --git a/packages/excalidraw/components/canvases/InteractiveCanvas.tsx b/packages/excalidraw/components/canvases/InteractiveCanvas.tsx
index efca26e4c6..cae51e5b2d 100644
--- a/packages/excalidraw/components/canvases/InteractiveCanvas.tsx
+++ b/packages/excalidraw/components/canvases/InteractiveCanvas.tsx
@@ -5,8 +5,10 @@ import {
   isShallowEqual,
   sceneCoordsToViewportCoords,
 } from "@excalidraw/common";
+import { AnimationController } from "@excalidraw/excalidraw/renderer/animation";
 
 import type {
+  ExcalidrawBindableElement,
   NonDeletedExcalidrawElement,
   NonDeletedSceneElementsMap,
 } from "@excalidraw/element/types";
@@ -17,6 +19,7 @@ import { renderInteractiveScene } from "../../renderer/interactiveScene";
 
 import type {
   InteractiveCanvasRenderConfig,
+  InteractiveSceneRenderAnimationState,
   RenderableElementsMap,
   RenderInteractiveSceneCallback,
 } from "../../scene/types";
@@ -78,6 +81,7 @@ type InteractiveCanvasProps = {
 
 const InteractiveCanvas = (props: InteractiveCanvasProps) => {
   const isComponentMounted = useRef(false);
+  const lastSuggestedBinding = useRef<ExcalidrawBindableElement | null>(null);
 
   useEffect(() => {
     if (!isComponentMounted.current) {
@@ -156,9 +160,69 @@ const InteractiveCanvas = (props: InteractiveCanvasProps) => {
         },
         device: props.device,
         callback: props.renderInteractiveSceneCallback,
+        deltaTime: 0,
       },
       isRenderThrottlingEnabled(),
     );
+
+    if (lastSuggestedBinding.current !== props.appState.suggestedBinding) {
+      lastSuggestedBinding.current = props.appState.suggestedBinding;
+      if (props.appState.suggestedBinding) {
+        AnimationController.cancel("bindingHighlight");
+        AnimationController.start<InteractiveSceneRenderAnimationState>(
+          "bindingHighlight",
+          ({ deltaTime, state }) => {
+            if (
+              lastSuggestedBinding.current !== props.appState.suggestedBinding
+            ) {
+              return null;
+            }
+
+            const nextAnimationState = renderInteractiveScene(
+              {
+                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.lastViewportPosition,
+                },
+                device: props.device,
+                callback: props.renderInteractiveSceneCallback,
+                animationState: state,
+                deltaTime,
+              },
+              false,
+            ).animationState;
+
+            if (nextAnimationState) {
+              for (const key in nextAnimationState) {
+                if (
+                  nextAnimationState[
+                    key as keyof InteractiveSceneRenderAnimationState
+                  ] !== undefined
+                ) {
+                  return nextAnimationState;
+                }
+              }
+
+              return undefined;
+            }
+          },
+        );
+      }
+    }
   });
 
   return (
diff --git a/packages/excalidraw/renderer/interactiveScene.ts b/packages/excalidraw/renderer/interactiveScene.ts
index 269a174dd1..f42a91cb99 100644
--- a/packages/excalidraw/renderer/interactiveScene.ts
+++ b/packages/excalidraw/renderer/interactiveScene.ts
@@ -87,8 +87,6 @@ import {
   strokeRectWithRotation,
 } from "./helpers";
 
-import { AnimationController } from "./animation";
-
 import type {
   InteractiveCanvasRenderConfig,
   InteractiveSceneRenderConfig,
@@ -198,7 +196,8 @@ const renderBindingHighlightForBindableElement = (
   deltaTime: number,
   state?: { runtime: number },
 ) => {
-  const remainingTime = BIND_MODE_TIMEOUT - (state?.runtime ?? 0);
+  const remainingTime =
+    BIND_MODE_TIMEOUT - (state?.runtime ?? BIND_MODE_TIMEOUT);
   const opacity = clamp((1 / BIND_MODE_TIMEOUT) * remainingTime, 0.0001, 1);
   const offset = element.strokeWidth / 2;
 
@@ -206,7 +205,6 @@ const renderBindingHighlightForBindableElement = (
     case "magicframe":
     case "frame":
       context.save();
-      context.clearRect(0, 0, context.canvas.width, context.canvas.height);
 
       context.translate(
         element.x + appState.scrollX,
@@ -243,7 +241,6 @@ const renderBindingHighlightForBindableElement = (
       const cx = center[0] + appState.scrollX;
       const cy = center[1] + appState.scrollY;
 
-      context.clearRect(0, 0, context.canvas.width, context.canvas.height);
       context.translate(cx, cy);
       context.rotate(element.angle as Radians);
       context.translate(-cx, -cy);
@@ -401,7 +398,7 @@ const renderBindingHighlightForBindableElement = (
   }
 
   if ((state?.runtime ?? 0) > BIND_MODE_TIMEOUT) {
-    return null;
+    return;
   }
 
   return {
@@ -860,7 +857,14 @@ const _renderInteractiveScene = ({
   appState,
   renderConfig,
   device,
-}: InteractiveSceneRenderConfig) => {
+  animationState,
+  deltaTime,
+}: InteractiveSceneRenderConfig): {
+  scrollBars?: ReturnType<typeof getScrollBars>;
+  atLeastOneVisibleElement: boolean;
+  elementsMap: RenderableElementsMap;
+  animationState?: typeof animationState;
+} => {
   if (canvas === null) {
     return { atLeastOneVisibleElement: false, elementsMap };
   }
@@ -869,6 +873,7 @@ const _renderInteractiveScene = ({
     canvas,
     scale,
   );
+  let nextAnimationState = animationState;
 
   const context = bootstrapCanvas({
     canvas,
@@ -939,25 +944,22 @@ const _renderInteractiveScene = ({
   }
 
   if (appState.isBindingEnabled && appState.suggestedBinding) {
-    AnimationController.start<{ runtime: number }>(
-      "bindingHighlight",
-      ({ deltaTime, state }) => {
-        if (!appState.suggestedBinding) {
-          return null; // Stop the animation
-        }
-
-        return renderBindingHighlightForBindableElement(
-          context,
-          appState.suggestedBinding,
-          allElementsMap,
-          appState,
-          deltaTime,
-          state,
-        );
-      },
-    );
+    nextAnimationState = {
+      ...animationState,
+      bindingHighlight: renderBindingHighlightForBindableElement(
+        context,
+        appState.suggestedBinding,
+        allElementsMap,
+        appState,
+        deltaTime,
+        animationState?.bindingHighlight,
+      ),
+    };
   } else {
-    AnimationController.cancel("bindingHighlight");
+    nextAnimationState = {
+      ...animationState,
+      bindingHighlight: undefined,
+    };
   }
 
   if (appState.frameToHighlight) {
@@ -1329,6 +1331,7 @@ const _renderInteractiveScene = ({
     scrollBars,
     atLeastOneVisibleElement: visibleElements.length > 0,
     elementsMap,
+    animationState: nextAnimationState,
   };
 };
 
diff --git a/packages/excalidraw/scene/types.ts b/packages/excalidraw/scene/types.ts
index 35775f089e..c36ee2dbed 100644
--- a/packages/excalidraw/scene/types.ts
+++ b/packages/excalidraw/scene/types.ts
@@ -89,6 +89,10 @@ export type StaticSceneRenderConfig = {
   renderConfig: StaticCanvasRenderConfig;
 };
 
+export type InteractiveSceneRenderAnimationState = {
+  bindingHighlight: { runtime: number } | undefined;
+};
+
 export type InteractiveSceneRenderConfig = {
   canvas: HTMLCanvasElement | null;
   elementsMap: RenderableElementsMap;
@@ -100,6 +104,8 @@ export type InteractiveSceneRenderConfig = {
   renderConfig: InteractiveCanvasRenderConfig;
   device: Device;
   callback: (data: RenderInteractiveSceneCallback) => void;
+  animationState?: InteractiveSceneRenderAnimationState;
+  deltaTime: number;
 };
 
 export type NewElementSceneRenderConfig = {