Carousel: Fix autoplay and enable callback on autoplay index change

change/@fluentui-react-carousel-806c25e9-e23b-4c65-b072-007f894a236a.json

@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: Add autoplay index change callback and fix autoplay pause on interaction",
+  "packageName": "@fluentui/react-carousel",
+  "email": "[email protected]",
+  "dependentChangeType": "patch"
+}

package.json

@@ -218,9 +218,9 @@
     "doctrine": "3.0.0",
     "dotparser": "1.1.1",
     "ejs": "3.1.10",
-    "embla-carousel": "8.3.0",
-    "embla-carousel-autoplay": "8.3.0",
-    "embla-carousel-fade": "8.3.0",
+    "embla-carousel": "8.4.0",
+    "embla-carousel-autoplay": "8.4.0",
+    "embla-carousel-fade": "8.4.0",
     "enquirer": "2.3.6",
     "enzyme": "3.10.0",
     "enzyme-to-json": "3.6.2",

packages/react-components/react-carousel/library/etc/react-carousel.api.md

@@ -209,6 +209,7 @@ export type CarouselProps = ComponentProps<CarouselSlots> & {
     align?: 'center' | 'start' | 'end';
     activeIndex?: number;
     onActiveIndexChange?: EventHandler<CarouselIndexChangeData>;
+    onAutoplayIndexChange?: (ev: null, data: CarouselAutoplayIndexChangeData) => void;
     circular?: boolean;
     groupSize?: number | 'auto';
     draggable?: boolean;

packages/react-components/react-carousel/library/package.json

@@ -36,9 +36,9 @@
     "@fluentui/react-utilities": "^9.18.17",
     "@griffel/react": "^1.5.22",
     "@swc/helpers": "^0.5.1",
-    "embla-carousel": "^8.3.0",
-    "embla-carousel-autoplay": "^8.3.0",
-    "embla-carousel-fade": "^8.3.0"
+    "embla-carousel": "^8.4.0",
+    "embla-carousel-autoplay": "^8.4.0",
+    "embla-carousel-fade": "^8.4.0"
   },
   "peerDependencies": {
     "@types/react": ">=16.14.0 <19.0.0",

packages/react-components/react-carousel/library/src/components/Carousel/Carousel.types.ts

@@ -1,5 +1,9 @@
 import type { ComponentProps, ComponentState, EventHandler, Slot } from '@fluentui/react-utilities';
-import type { CarouselContextValue, CarouselIndexChangeData } from '../CarouselContext.types';
+import type {
+  CarouselAutoplayIndexChangeData,
+  CarouselContextValue,
+  CarouselIndexChangeData,
+} from '../CarouselContext.types';
 
 export type CarouselSlots = {
   root: Slot<'div'>;
@@ -39,6 +43,12 @@ export type CarouselProps = ComponentProps<CarouselSlots> & {
    */
   onActiveIndexChange?: EventHandler<CarouselIndexChangeData>;
 
+  /**
+   * Callback to notify a page change.
+   */
+  // eslint-disable-next-line @nx/workspace-consistent-callback-type -- EventHandler<T> does not support "null"
+  onAutoplayIndexChange?: (ev: null, data: CarouselAutoplayIndexChangeData) => void;
+
   /**
    * Circular enables the carousel to loop back around on navigation past trailing index.
    */

packages/react-components/react-carousel/library/src/components/Carousel/useCarousel.ts

@@ -34,6 +34,7 @@ export function useCarousel_unstable(props: CarouselProps, ref: React.Ref<HTMLDi
     whitespace = false,
     announcement,
     motion = 'slide',
+    onAutoplayIndexChange,
   } = props;
 
   const { dir } = useFluent();
@@ -49,6 +50,7 @@ export function useCarousel_unstable(props: CarouselProps, ref: React.Ref<HTMLDi
       containScroll: whitespace ? false : 'keepSnaps',
       motion,
       onDragIndexChange: onActiveIndexChange,
+      onAutoplayIndexChange,
     });
 
   const selectPageByElement: CarouselContextValue['selectPageByElement'] = useEventCallback((event, element, jump) => {

packages/react-components/react-carousel/library/src/components/CarouselAutoplayButton/useCarouselAutoplayButton.tsx

@@ -1,13 +1,7 @@
 import type { ARIAButtonElement } from '@fluentui/react-aria';
 import { useToggleButton_unstable } from '@fluentui/react-button';
 import { PlayCircleRegular, PauseCircleRegular } from '@fluentui/react-icons';
-import {
-  mergeCallbacks,
-  slot,
-  useControllableState,
-  useEventCallback,
-  useIsomorphicLayoutEffect,
-} from '@fluentui/react-utilities';
+import { mergeCallbacks, slot, useControllableState, useEventCallback } from '@fluentui/react-utilities';
 import * as React from 'react';
 
 import type { CarouselAutoplayButtonProps, CarouselAutoplayButtonState } from './CarouselAutoplayButton.types';
@@ -36,15 +30,13 @@ export const useCarouselAutoplayButton_unstable = (
   const enableAutoplay = useCarouselContext(ctx => ctx.enableAutoplay);
 
   React.useEffect(() => {
+    // Update carousel autoplay based on button state
+    enableAutoplay(autoplay);
+
     return () => {
       // We disable autoplay if the button gets unmounted.
       enableAutoplay(false);
     };
-  }, [enableAutoplay]);
-
-  useIsomorphicLayoutEffect(() => {
-    // Enable/disable autoplay on state change
-    enableAutoplay(autoplay);
   }, [autoplay, enableAutoplay]);
 
   const handleClick = (event: React.MouseEvent<HTMLButtonElement & HTMLAnchorElement>) => {

packages/react-components/react-carousel/library/src/components/CarouselContext.types.ts

@@ -14,6 +14,13 @@ export type CarouselIndexChangeData = (
   index: number;
 };
 
+export type CarouselAutoplayIndexChangeData = EventData<'autoplay', null> & {
+  /**
+   * The index to be set after event has occurred.
+   */
+  index: number;
+};
+
 export type CarouselContextValue = {
   activeIndex: number;
   circular: boolean;

packages/react-components/react-carousel/library/src/components/useEmblaCarousel.ts

@@ -4,7 +4,7 @@ import * as React from 'react';
 
 import { carouselCardClassNames } from './CarouselCard/useCarouselCardStyles.styles';
 import { carouselSliderClassNames } from './CarouselSlider/useCarouselSliderStyles.styles';
-import { CarouselMotion, CarouselUpdateData, CarouselVisibilityEventDetail } from '../Carousel';
+import { CarouselMotion, CarouselProps, CarouselUpdateData, CarouselVisibilityEventDetail } from '../Carousel';
 import Autoplay from 'embla-carousel-autoplay';
 import Fade from 'embla-carousel-fade';
 import { pointerEventPlugin } from './pointerEvents';
@@ -43,9 +43,20 @@ export function useEmblaCarousel(
     activeIndex: number | undefined;
     motion?: CarouselMotion;
     onDragIndexChange?: EventHandler<CarouselIndexChangeData>;
+    onAutoplayIndexChange?: CarouselProps['onAutoplayIndexChange'];
   },
 ) {
-  const { align, direction, loop, slidesToScroll, watchDrag, containScroll, motion, onDragIndexChange } = options;
+  const {
+    align,
+    direction,
+    loop,
+    slidesToScroll,
+    watchDrag,
+    containScroll,
+    motion,
+    onDragIndexChange,
+    onAutoplayIndexChange,
+  } = options;
   const [activeIndex, setActiveIndex] = useControllableState({
     defaultState: options.defaultActiveIndex,
     state: options.activeIndex,
@@ -67,36 +78,27 @@ export function useEmblaCarousel(
   });
 
   const emblaApi = React.useRef<EmblaCarouselType | null>(null);
-  const autoplayRef = React.useRef<boolean>(false);
+  const autoplay = React.useRef<boolean>(false);
 
   const resetAutoplay = React.useCallback(() => {
-    emblaApi.current?.plugins().autoplay.reset();
+    emblaApi.current?.plugins().autoplay?.reset();
   }, []);
 
-  /* Our autoplay button, which is required by standards for autoplay to be enabled, will handle controlled state */
-  const enableAutoplay = React.useCallback(
-    (autoplay: boolean) => {
-      autoplayRef.current = autoplay;
-      if (autoplay) {
-        emblaApi.current?.plugins().autoplay.play();
-        // Reset after play to ensure timing and any focus/mouse pause state is reset.
-        resetAutoplay();
-      } else {
-        emblaApi.current?.plugins().autoplay.stop();
-      }
-    },
-    [resetAutoplay],
-  );
-
   const getPlugins = React.useCallback(() => {
-    const plugins: EmblaPluginType[] = [
-      Autoplay({
-        playOnInit: autoplayRef.current,
-        stopOnInteraction: !autoplayRef.current,
-        stopOnMouseEnter: true,
-        stopOnFocusIn: true,
-      }),
-    ];
+    const plugins: EmblaPluginType[] = [];
+
+    if (autoplay.current) {
+      plugins.push(
+        Autoplay({
+          playOnInit: true,
+          /* stopOnInteraction: false causes autoplay to restart on interaction end*/
+          /* we must remove/re-add plugin on autoplay state change*/
+          stopOnInteraction: false,
+          stopOnMouseEnter: true,
+          stopOnFocusIn: true,
+        }),
+      );
+    }
 
     // Optionally add Fade plugin
     if (motion === 'fade') {
@@ -114,6 +116,49 @@ export function useEmblaCarousel(
     return plugins;
   }, [motion, onDragEvent, watchDrag]);
 
+  const reinitializeCarousel = React.useCallback(() => {
+    const plugins = getPlugins();
+
+    emblaOptions.current = {
+      startIndex: emblaOptions.current.startIndex,
+      align,
+      direction,
+      loop,
+      slidesToScroll,
+      watchDrag,
+      containScroll,
+    };
+
+    emblaApi.current?.reInit(
+      {
+        ...DEFAULT_EMBLA_OPTIONS,
+        ...emblaOptions.current,
+      },
+      plugins,
+    );
+  }, [align, containScroll, direction, getPlugins, loop, slidesToScroll, watchDrag]);
+
+  React.useEffect(() => {
+    reinitializeCarousel();
+  }, [reinitializeCarousel]);
+
+  /* Our autoplay button, which is required by standards for autoplay to be enabled, will handle controlled state */
+  const enableAutoplay = React.useCallback(
+    (_autoplay: boolean) => {
+      autoplay.current = _autoplay;
+      reinitializeCarousel();
+
+      if (_autoplay) {
+        emblaApi.current?.plugins().autoplay?.play();
+        // Reset after play to ensure timing and any focus/mouse pause state is reset.
+        resetAutoplay();
+      } else {
+        emblaApi.current?.plugins().autoplay?.stop();
+      }
+    },
+    [reinitializeCarousel, resetAutoplay],
+  );
+
   // Listeners contains callbacks for UI elements that may require state update based on embla changes
   const listeners = React.useRef(new Set<(data: CarouselUpdateData) => void>());
   const subscribeForValues = React.useCallback((listener: (data: CarouselUpdateData) => void) => {
@@ -142,22 +187,27 @@ export function useEmblaCarousel(
     }
   });
 
+  const handleIndexChange = React.useCallback(() => {
+    const newIndex = emblaApi.current?.selectedScrollSnap() ?? 0;
+    const slides = emblaApi.current?.slideNodes();
+    const actualIndex = emblaApi.current?.internalEngine().slideRegistry[newIndex][0] ?? 0;
+
+    // We set the active or first index of group on-screen as the selected tabster index
+    slides?.forEach((slide, slideIndex) => {
+      setTabsterDefault(slide, slideIndex === actualIndex);
+    });
+    setActiveIndex(newIndex);
+  }, [setActiveIndex]);
+
+  const handleAutoplayIndexChange = useEventCallback(() => {
+    handleIndexChange();
+    const newIndex = emblaApi.current?.selectedScrollSnap() ?? 0;
+    onAutoplayIndexChange?.(null, { event: null, type: 'autoplay', index: newIndex });
+  });
+
   const viewportRef: React.RefObject<HTMLDivElement> = React.useRef(null);
+  const currentElementRef = React.useRef<HTMLDivElement | null>();
   const containerRef: React.RefObject<HTMLDivElement> = React.useMemo(() => {
-    let currentElement: HTMLDivElement | null = null;
-
-    const handleIndexChange = () => {
-      const newIndex = emblaApi.current?.selectedScrollSnap() ?? 0;
-      const slides = emblaApi.current?.slideNodes();
-      const actualIndex = emblaApi.current?.internalEngine().slideRegistry[newIndex][0] ?? 0;
-
-      // We set the active or first index of group on-screen as the selected tabster index
-      slides?.forEach((slide, slideIndex) => {
-        setTabsterDefault(slide, slideIndex === actualIndex);
-      });
-      setActiveIndex(newIndex);
-    };
-
     const handleVisibilityChange = () => {
       const cardElements = emblaApi.current?.slideNodes();
       const visibleIndexes = emblaApi.current?.slidesInView() ?? [];
@@ -172,21 +222,23 @@ export function useEmblaCarousel(
       });
     };
 
+    // Get plugins using autoplayRef to prevent state change recreating EmblaCarousel
     const plugins = getPlugins();
 
     return {
       set current(newElement: HTMLDivElement | null) {
-        if (currentElement) {
+        if (currentElementRef.current) {
           emblaApi.current?.off('slidesInView', handleVisibilityChange);
           emblaApi.current?.off('select', handleIndexChange);
           emblaApi.current?.off('reInit', handleReinit);
+          emblaApi.current?.off('autoplay:select', handleAutoplayIndexChange);
           emblaApi.current?.destroy();
         }
 
         // Use direct viewport if available, else fallback to container (includes Carousel controls).
         const wrapperElement = viewportRef.current ?? newElement;
+        currentElementRef.current = wrapperElement;
         if (wrapperElement) {
-          currentElement = wrapperElement;
           emblaApi.current = EmblaCarousel(
             wrapperElement,
             {
@@ -199,10 +251,11 @@ export function useEmblaCarousel(
           emblaApi.current?.on('reInit', handleReinit);
           emblaApi.current?.on('slidesInView', handleVisibilityChange);
           emblaApi.current?.on('select', handleIndexChange);
+          emblaApi.current?.on('autoplay:select', handleAutoplayIndexChange);
         }
       },
     };
-  }, [getPlugins, setActiveIndex, handleReinit]);
+  }, [getPlugins, handleAutoplayIndexChange, handleIndexChange, handleReinit]);
 
   const carouselApi = React.useMemo(
     () => ({
@@ -245,27 +298,6 @@ export function useEmblaCarousel(
     }
   }, [activeIndex]);
 
-  React.useEffect(() => {
-    const plugins = getPlugins();
-
-    emblaOptions.current = {
-      startIndex: emblaOptions.current.startIndex,
-      align,
-      direction,
-      loop,
-      slidesToScroll,
-      watchDrag,
-      containScroll,
-    };
-    emblaApi.current?.reInit(
-      {
-        ...DEFAULT_EMBLA_OPTIONS,
-        ...emblaOptions.current,
-      },
-      plugins,
-    );
-  }, [align, direction, loop, slidesToScroll, watchDrag, containScroll, getPlugins]);
-
   return {
     activeIndex,
     carouselApi,