chore: refactor virtual list

components/_util/BaseMixin.ts

@@ -2,7 +2,7 @@ import { getOptionProps } from './props-util';
 
 export default {
   methods: {
-    setState(state = {}, callback: () => any) {
+    setState(state = {}, callback: () => void) {
       let newState = typeof state === 'function' ? state(this.$data, this.$props) : state;
       if (this.getDerivedStateFromProps) {
         const s = this.getDerivedStateFromProps(getOptionProps(this), {

components/_util/createRef.js

@@ -1,8 +0,0 @@
-function createRef() {
-  const func = function setRef(node) {
-    func.current = node;
-  };
-  return func;
-}
-
-export default createRef;

components/_util/createRef.ts

@@ -0,0 +1,18 @@
+interface RefObject<T> {
+  readonly current: T | null;
+}
+function createRef<T>() {
+  // const refObject = {
+  //   current: null
+  // }
+
+  // Object.seal(refObject);
+
+  // return refObject;
+  function setRef(node: T) {
+    Object.assign(setRef, { current: node });
+  }
+  return setRef;
+}
+
+export default createRef;

components/_util/type.ts

@@ -1,4 +1,4 @@
-import { PropType } from 'vue';
+import { PropType, VNodeProps } from 'vue';
 
 export type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>;
 // https://stackoverflow.com/questions/46176165/ways-to-get-string-literal-type-of-array-values-without-enum-overhead
@@ -25,6 +25,8 @@ export type EventHandlers<E> = {
 
 export type Data = Record<string, unknown>;
 
+export type Key = string | number;
+
 export declare type DefaultFactory<T> = (props: Data) => T | null | undefined;
 export declare interface PropOptions<T = any, D = T> {
   type?: PropType<T> | true | null;

components/_util/vue-types/index.ts

@@ -16,7 +16,7 @@ const PropTypes = {
   get func() {
     return {
       type: Function,
-    } as BaseTypes;
+    };
   },
 
   get bool() {

components/vc-resize-observer/index.tsx

@@ -1,19 +1,24 @@
 // based on rc-resize-observer 0.1.3
+import { defineComponent, PropType } from 'vue';
 import ResizeObserver from 'resize-observer-polyfill';
 import BaseMixin from '../_util/BaseMixin';
 import { findDOMNode } from '../_util/props-util';
 
 // Still need to be compatible with React 15, we use class component here
-const VueResizeObserver = {
+const VueResizeObserver = defineComponent({
   name: 'ResizeObserver',
   mixins: [BaseMixin],
   props: {
     disabled: Boolean,
-    onResize: Function,
+    onResize: Function as PropType<
+      (size: { width: number; height: number; offsetWidth: number; offsetHeight: number }) => void
+    >,
   },
-  data() {
+  beforeCreate() {
     this.currentElement = null;
     this.resizeObserver = null;
+  },
+  data() {
     return {
       width: 0,
       height: 0,
@@ -54,7 +59,7 @@ const VueResizeObserver = {
       }
     },
 
-    handleResize(entries) {
+    handleResize(entries: ResizeObserverEntry[]) {
       const { target } = entries[0];
       const { width, height } = target.getBoundingClientRect();
       /**
@@ -82,8 +87,8 @@ const VueResizeObserver = {
   },
 
   render() {
-    return this.$slots.default && this.$slots.default()[0];
+    return this.$slots.default?.()[0];
   },
-};
+});
 
 export default VueResizeObserver;

components/vc-virtual-list/Filler.tsx

@@ -1,10 +1,23 @@
 import classNames from '../_util/classNames';
 import ResizeObserver from '../vc-resize-observer';
+import { CSSProperties, FunctionalComponent } from 'vue';
 
-const Filter = ({ height, offset, prefixCls, onInnerResize }, { slots }) => {
+interface FillerProps {
+  prefixCls?: string;
+  /** Virtual filler height. Should be `count * itemMinHeight` */
+  height: number;
+  /** Set offset of visible items. Should be the top of start item position */
+  offset?: number;
+  onInnerResize?: () => void;
+}
+
+const Filter: FunctionalComponent<FillerProps> = (
+  { height, offset, prefixCls, onInnerResize },
+  { slots },
+) => {
   let outerStyle = {};
 
-  let innerStyle = {
+  let innerStyle: CSSProperties = {
     display: 'flex',
     flexDirection: 'column',
   };
@@ -43,15 +56,8 @@ const Filter = ({ height, offset, prefixCls, onInnerResize }, { slots }) => {
     </div>
   );
 };
+
 Filter.displayName = 'Filter';
 Filter.inheritAttrs = false;
-Filter.props = {
-  prefixCls: String,
-  /** Virtual filler height. Should be `count * itemMinHeight` */
-  height: Number,
-  /** Set offset of visible items. Should be the top of start item position */
-  offset: Number,
-  onInnerResize: Function,
-};
 
 export default Filter;

components/vc-virtual-list/Item.jsx

@@ -1,17 +0,0 @@
-import { cloneVNode } from 'vue';
-
-function Item({ setRef }, { slots }) {
-  const children = slots?.default();
-  return children && children.length
-    ? cloneVNode(children[0], {
-        ref: setRef,
-      })
-    : children;
-}
-Item.props = {
-  setRef: {
-    type: Function,
-    default: () => {},
-  },
-};
-export default Item;

components/vc-virtual-list/Item.tsx

@@ -0,0 +1,17 @@
+import { cloneVNode, FunctionalComponent } from 'vue';
+
+export interface ItemProps {
+  setRef: (element: HTMLElement) => void;
+}
+
+const Item: FunctionalComponent<ItemProps> = ({ setRef }, { slots }) => {
+  const children = slots.default?.();
+
+  return children && children.length
+    ? cloneVNode(children[0], {
+        ref: setRef,
+      })
+    : children;
+};
+
+export default Item;

components/vc-virtual-list/List.tsx

@@ -1,3 +1,16 @@
+import {
+  ref,
+  defineComponent,
+  PropType,
+  watchEffect,
+  Component,
+  computed,
+  nextTick,
+  onBeforeUnmount,
+  reactive,
+  CSSProperties,
+} from 'vue';
+import { Key } from '../_util/type';
 import Filler from './Filler';
 import Item from './Item';
 import ScrollBar from './ScrollBar';
@@ -7,18 +20,24 @@ import useFrameWheel from './hooks/useFrameWheel';
 import useMobileTouchMove from './hooks/useMobileTouchMove';
 import useOriginScroll from './hooks/useOriginScroll';
 import PropTypes from '../_util/vue-types';
-import { computed, nextTick, onBeforeUnmount, reactive, watchEffect } from 'vue';
 import classNames from '../_util/classNames';
-import createRef from '../_util/createRef';
+import { RenderFunc, SharedConfig } from './interface';
 
 const EMPTY_DATA = [];
 
-const ScrollStyle = {
+const ScrollStyle: CSSProperties = {
   overflowY: 'auto',
   overflowAnchor: 'none',
 };
 
-function renderChildren(list, startIndex, endIndex, setNodeRef, renderFunc, { getKey }) {
+function renderChildren<T>(
+  list: T[],
+  startIndex: number,
+  endIndex: number,
+  setNodeRef: (item: T, element: HTMLElement) => void,
+  renderFunc: RenderFunc<T>,
+  { getKey }: SharedConfig<T>,
+) {
   return list.slice(startIndex, endIndex + 1).map((item, index) => {
     const eleIndex = startIndex + index;
     const node = renderFunc(item, eleIndex, {
@@ -33,43 +52,58 @@ function renderChildren(list, startIndex, endIndex, setNodeRef, renderFunc, { ge
   });
 }
 
-const ListProps = {
-  prefixCls: PropTypes.string,
-  data: PropTypes.array,
-  height: PropTypes.number,
-  itemHeight: PropTypes.number,
-  /** If not match virtual scroll condition, Set List still use height of container. */
-  fullHeight: PropTypes.bool.def(true),
-  itemKey: PropTypes.any,
-  component: PropTypes.any,
-  /** Set `false` will always use real scroll instead of virtual one */
-  virtual: PropTypes.bool,
-  children: PropTypes.func,
-  onScroll: PropTypes.func,
-};
+export interface ListState<T = object> {
+  scrollTop: number;
+  scrollMoving: boolean;
+  mergedData: T[];
+}
 
-const List = {
-  props: ListProps,
+const List = defineComponent({
   inheritAttrs: false,
   name: 'List',
+  props: {
+    prefixCls: PropTypes.string,
+    data: PropTypes.array,
+    height: PropTypes.number,
+    itemHeight: PropTypes.number,
+    /** If not match virtual scroll condition, Set List still use height of container. */
+    fullHeight: PropTypes.bool,
+    itemKey: {
+      type: [String, Number, Function] as PropType<Key | ((item: object) => Key)>,
+      required: true,
+    },
+    component: {
+      type: [String, Object] as PropType<string | Component>,
+    },
+    /** Set `false` will always use real scroll instead of virtual one */
+    virtual: PropTypes.bool,
+    children: PropTypes.func,
+    onScroll: PropTypes.func,
+  },
   setup(props) {
     // ================================= MISC =================================
 
     const inVirtual = computed(() => {
       const { height, itemHeight, data, virtual } = props;
-      return virtual !== false && height && itemHeight && data && itemHeight * data.length > height;
+      return !!(
+        virtual !== false &&
+        height &&
+        itemHeight &&
+        data &&
+        itemHeight * data.length > height
+      );
     });
 
-    const state = reactive({
+    const state = reactive<ListState>({
       scrollTop: 0,
       scrollMoving: false,
-      mergedData: computed(() => props.data || EMPTY_DATA),
+      mergedData: computed(() => props.data || EMPTY_DATA) as any,
     });
 
-    const componentRef = createRef();
+    const componentRef = ref<Element>();
 
     // =============================== Item Key ===============================
-    const getKey = item => {
+    const getKey = (item: Record<string, any>) => {
       if (typeof props.itemKey === 'function') {
         return props.itemKey(item);
       }
@@ -81,8 +115,8 @@ const List = {
     };
 
     // ================================ Scroll ================================
-    function syncScrollTop(newTop) {
-      let value;
+    function syncScrollTop(newTop: number | ((prev: number) => number)) {
+      let value: number;
       if (typeof newTop === 'function') {
         value = newTop(state.scrollTop);
       } else {
@@ -91,8 +125,8 @@ const List = {
 
       const alignedTop = keepInRange(value);
 
-      if (componentRef.current) {
-        componentRef.current.scrollTop = alignedTop;
+      if (componentRef.value) {
+        componentRef.value.scrollTop = alignedTop;
       }
 
       state.scrollTop = alignedTop;
@@ -112,9 +146,9 @@ const List = {
         };
       }
       let itemTop = 0;
-      let startIndex;
-      let startOffset;
-      let endIndex;
+      let startIndex: number | undefined;
+      let startOffset: number | undefined;
+      let endIndex: number | undefined;
       const dataLen = state.mergedData.length;
       for (let i = 0; i < dataLen; i += 1) {
         const item = state.mergedData[i];
@@ -122,7 +156,7 @@ const List = {
 
         const cacheHeight = heights[key];
         const currentItemBottom =
-          itemTop + (cacheHeight === undefined ? props.itemHeight : cacheHeight);
+          itemTop + (cacheHeight === undefined ? props.itemHeight! : cacheHeight);
 
         if (currentItemBottom >= state.scrollTop && startIndex === undefined) {
           startIndex = i;
@@ -130,7 +164,7 @@ const List = {
         }
 
         // Check item bottom in the range. We will render additional one item for motion usage
-        if (currentItemBottom > state.scrollTop + props.height && endIndex === undefined) {
+        if (currentItemBottom > state.scrollTop + props.height! && endIndex === undefined) {
           endIndex = i;
         }
 
@@ -157,9 +191,9 @@ const List = {
       };
     });
     // =============================== In Range ===============================
-    const maxScrollHeight = computed(() => calRes.value.scrollHeight - props.height);
+    const maxScrollHeight = computed(() => calRes.value.scrollHeight! - props.height!);
 
-    function keepInRange(newScrollTop) {
+    function keepInRange(newScrollTop: number) {
       let newTop = Math.max(newScrollTop, 0);
       if (!Number.isNaN(maxScrollHeight.value)) {
         newTop = Math.min(newTop, maxScrollHeight.value);
@@ -173,15 +207,15 @@ const List = {
     const originScroll = useOriginScroll(isScrollAtTop, isScrollAtBottom);
 
     // ================================ Scroll ================================
-    function onScrollBar(newScrollTop) {
+    function onScrollBar(newScrollTop: number) {
       const newTop = newScrollTop;
       syncScrollTop(newTop);
     }
 
     // This code may only trigger in test case.
     // But we still need a sync if some special escape
-    function onFallbackScroll(e) {
-      const { scrollTop: newScrollTop } = e.currentTarget;
+    function onFallbackScroll(e: UIEvent) {
+      const { scrollTop: newScrollTop } = e.currentTarget as Element;
       if (newScrollTop !== state.scrollTop) {
         syncScrollTop(newScrollTop);
       }
@@ -209,29 +243,29 @@ const List = {
         return false;
       }
 
-      onRawWheel({ preventDefault() {}, deltaY });
+      onRawWheel({ preventDefault() {}, deltaY } as WheelEvent);
       return true;
     });
     // Firefox only
-    function onMozMousePixelScroll(e) {
+    function onMozMousePixelScroll(e: MouseEvent) {
       if (inVirtual.value) {
         e.preventDefault();
       }
     }
     const removeEventListener = () => {
-      if (componentRef.current) {
-        componentRef.current.removeEventListener('wheel', onRawWheel);
-        componentRef.current.removeEventListener('DOMMouseScroll', onFireFoxScroll);
-        componentRef.current.removeEventListener('MozMousePixelScroll', onMozMousePixelScroll);
+      if (componentRef.value) {
+        componentRef.value.removeEventListener('wheel', onRawWheel);
+        componentRef.value.removeEventListener('DOMMouseScroll', onFireFoxScroll);
+        componentRef.value.removeEventListener('MozMousePixelScroll', onMozMousePixelScroll);
       }
     };
     watchEffect(() => {
       nextTick(() => {
-        if (componentRef.current) {
+        if (componentRef.value) {
           removeEventListener();
-          componentRef.current.addEventListener('wheel', onRawWheel);
-          componentRef.current.addEventListener('DOMMouseScroll', onFireFoxScroll);
-          componentRef.current.addEventListener('MozMousePixelScroll', onMozMousePixelScroll);
+          componentRef.value.addEventListener('wheel', onRawWheel);
+          componentRef.value.addEventListener('DOMMouseScroll', onFireFoxScroll);
+          componentRef.value.addEventListener('MozMousePixelScroll', onMozMousePixelScroll);
         }
       });
     });
@@ -252,15 +286,15 @@ const List = {
     );
 
     const componentStyle = computed(() => {
-      let cs = null;
+      let cs: CSSProperties | null = null;
       if (props.height) {
         cs = { [props.fullHeight ? 'height' : 'maxHeight']: props.height + 'px', ...ScrollStyle };
 
         if (inVirtual.value) {
-          cs.overflowY = 'hidden';
+          cs!.overflowY = 'hidden';
 
           if (state.scrollMoving) {
-            cs.pointerEvents = 'none';
+            cs!.pointerEvents = 'none';
           }
         }
       }
@@ -305,7 +339,6 @@ const List = {
       componentStyle,
       onFallbackScroll,
       onScrollBar,
-      componentRef,
       inVirtual,
       collectHeight,
       sharedConfig,
@@ -332,7 +365,7 @@ const List = {
         <Component
           class={`${prefixCls}-holder`}
           style={componentStyle}
-          ref={componentRef}
+          ref="componentRef"
           onScroll={onFallbackScroll}
         >
           <Filler
@@ -364,6 +397,6 @@ const List = {
       </div>
     );
   },
-};
+});
 
 export default List;

components/vc-virtual-list/ScrollBar.tsx

@@ -1,4 +1,4 @@
-import { reactive } from 'vue';
+import { defineComponent, PropType, reactive } from 'vue';
 import classNames from '../_util/classNames';
 import createRef from '../_util/createRef';
 import raf from '../_util/raf';
@@ -6,29 +6,18 @@ import PropTypes from '../_util/vue-types';
 
 const MIN_SIZE = 20;
 
-// export interface ScrollBarProps {
-//   prefixCls: string;
-//   scrollTop: number;
-//   scrollHeight: number;
-//   height: number;
-//   count: number;
-//   onScroll: (scrollTop: number) => void;
-//   onStartMove: () => void;
-//   onStopMove: () => void;
-// }
+interface ScrollBarState {
+  dragging: boolean;
+  pageY: number | null;
+  startTop: number | null;
+  visible: boolean;
+}
 
-// interface ScrollBarState {
-//   dragging: boolean;
-//   pageY: number;
-//   startTop: number;
-//   visible: boolean;
-// }
-
-function getPageY(e) {
+function getPageY(e: MouseEvent | TouchEvent) {
   return 'touches' in e ? e.touches[0].pageY : e.pageY;
 }
 
-export default {
+export default defineComponent({
   name: 'ScrollBar',
   inheritAttrs: false,
   props: {
@@ -37,9 +26,15 @@ export default {
     scrollHeight: PropTypes.number,
     height: PropTypes.number,
     count: PropTypes.number,
-    onScroll: PropTypes.func,
-    onStartMove: PropTypes.func,
-    onStopMove: PropTypes.func,
+    onScroll: {
+      type: Function as PropType<(scrollTop: number) => void>,
+    },
+    onStartMove: {
+      type: Function as PropType<() => void>,
+    },
+    onStopMove: {
+      type: Function as PropType<() => void>,
+    },
   },
   setup() {
     return {
@@ -47,7 +42,7 @@ export default {
       scrollbarRef: createRef(),
       thumbRef: createRef(),
       visibleTimeout: null,
-      state: reactive({
+      state: reactive<ScrollBarState>({
         dragging: false,
         pageY: null,
         startTop: null,
@@ -83,11 +78,11 @@ export default {
       }, 2000);
     },
 
-    onScrollbarTouchStart(e) {
+    onScrollbarTouchStart(e: TouchEvent) {
       e.preventDefault();
     },
 
-    onContainerMouseDown(e) {
+    onContainerMouseDown(e: MouseEvent) {
       e.stopPropagation();
       e.preventDefault();
     },
@@ -114,7 +109,7 @@ export default {
     },
 
     // ======================= Thumb =======================
-    onMouseDown(e) {
+    onMouseDown(e: MouseEvent | TouchEvent) {
       const { onStartMove } = this.$props;
 
       Object.assign(this.state, {
@@ -129,7 +124,7 @@ export default {
       e.preventDefault();
     },
 
-    onMouseMove(e) {
+    onMouseMove(e: MouseEvent | TouchEvent) {
       const { dragging, pageY, startTop } = this.state;
       const { onScroll } = this.$props;
 
@@ -203,7 +198,7 @@ export default {
           bottom: 0,
           right: 0,
           position: 'absolute',
-          display: visible ? null : 'none',
+          display: visible ? undefined : 'none',
         }}
         onMousedown={this.onContainerMouseDown}
         onMousemove={this.delayHidden}
@@ -229,4 +224,4 @@ export default {
       </div>
     );
   },
-};
+});

components/vc-virtual-list/hooks/useFrameWheel.ts

@@ -1,22 +1,33 @@
+import { Ref } from 'vue';
 import raf from '../../_util/raf';
 import isFF from '../utils/isFirefox';
 import useOriginScroll from './useOriginScroll';
 
-export default function useFrameWheel(inVirtual, isScrollAtTop, isScrollAtBottom, onWheelDelta) {
+interface FireFoxDOMMouseScrollEvent {
+  detail: number;
+  preventDefault: Function;
+}
+
+export default function useFrameWheel(
+  inVirtual: Ref<boolean>,
+  isScrollAtTop: Ref<boolean>,
+  isScrollAtBottom: Ref<boolean>,
+  onWheelDelta: (offset: number) => void,
+): [(e: WheelEvent) => void, (e: FireFoxDOMMouseScrollEvent) => void] {
   let offsetRef = 0;
-  let nextFrame = null;
+  let nextFrame: number | null | undefined = null;
 
   // Firefox patch
-  let wheelValue = null;
+  let wheelValue: null = null;
   let isMouseScroll = false;
 
   // Scroll status sync
   const originScroll = useOriginScroll(isScrollAtTop, isScrollAtBottom);
 
-  function onWheel(event) {
+  function onWheel(event: { preventDefault?: any; deltaY?: any }) {
     if (!inVirtual.value) return;
 
-    raf.cancel(nextFrame);
+    raf.cancel(nextFrame!);
 
     const { deltaY } = event;
     offsetRef += deltaY;
@@ -40,7 +51,7 @@ export default function useFrameWheel(inVirtual, isScrollAtTop, isScrollAtBottom
   }
 
   // A patch for firefox
-  function onFireFoxScroll(event) {
+  function onFireFoxScroll(event: { detail: any }) {
     if (!inVirtual.value) return;
 
     isMouseScroll = event.detail === wheelValue;

components/vc-virtual-list/hooks/useHeights.tsx

@@ -1,9 +1,15 @@
-import { reactive, ref } from 'vue';
-import { findDOMNode } from '../../_util/props-util';
+import { reactive, Ref, ref, VNodeProps } from 'vue';
+import { GetKey } from '../interface';
 
-export default function useHeights(getKey, onItemAdd, onItemRemove) {
-  const instance = new Map();
-  const heights = reactive({});
+type CacheMap = Record<string, number>;
+
+export default function useHeights<T>(
+  getKey: GetKey<T>,
+  onItemAdd?: ((item: T) => void) | null,
+  onItemRemove?: ((item: T) => void) | null,
+): [(item: T, instance: HTMLElement) => void, () => void, CacheMap, Ref<number>] {
+  const instance = new Map<VNodeProps['key'], HTMLElement>();
+  const heights = reactive<CacheMap>({});
   let updatedMark = ref(0);
   let heightUpdateId = 0;
   function collectHeight() {
@@ -15,11 +21,10 @@ export default function useHeights(getKey, onItemAdd, onItemRemove) {
       let changed = false;
       instance.forEach((element, key) => {
         if (element && element.offsetParent) {
-          const htmlElement = findDOMNode(element);
-          const { offsetHeight } = htmlElement;
-          if (heights[key] !== offsetHeight) {
+          const { offsetHeight } = element;
+          if (heights[key!] !== offsetHeight) {
             changed = true;
-            heights[key] = htmlElement.offsetHeight;
+            heights[key!] = element.offsetHeight;
           }
         }
       });
@@ -29,7 +34,7 @@ export default function useHeights(getKey, onItemAdd, onItemRemove) {
     });
   }
 
-  function setInstance(item, ins) {
+  function setInstance(item: T, ins: HTMLElement) {
     const key = getKey(item);
     const origin = instance.get(key);
 

components/vc-virtual-list/hooks/useMobileTouchMove.ts

@@ -1,19 +1,28 @@
-import { watch } from 'vue';
+import { watch, Ref } from 'vue';
 
 const SMOOTH_PTG = 14 / 15;
 
-export default function useMobileTouchMove(inVirtual, listRef, callback) {
+export default function useMobileTouchMove(
+  inVirtual: Ref<boolean>,
+  listRef: Ref<Element | undefined>,
+  callback: (offsetY: number, smoothOffset?: boolean) => boolean,
+) {
   let touched = false;
   let touchY = 0;
 
-  let element = null;
+  let element: HTMLElement | null = null;
 
   // Smooth scroll
-  let interval = null;
+  let interval: any = null;
 
-  let cleanUpEvents;
+  const cleanUpEvents = () => {
+    if (element) {
+      element.removeEventListener('touchmove', onTouchMove);
+      element.removeEventListener('touchend', onTouchEnd);
+    }
+  };
 
-  const onTouchMove = e => {
+  const onTouchMove = (e: TouchEvent) => {
     if (touched) {
       const currentY = Math.ceil(e.touches[0].pageY);
       let offsetY = touchY - currentY;
@@ -41,31 +50,25 @@ export default function useMobileTouchMove(inVirtual, listRef, callback) {
     cleanUpEvents();
   };
 
-  const onTouchStart = e => {
+  const onTouchStart = (e: TouchEvent) => {
     cleanUpEvents();
 
     if (e.touches.length === 1 && !touched) {
       touched = true;
       touchY = Math.ceil(e.touches[0].pageY);
 
-      element = e.target;
-      element.addEventListener('touchmove', onTouchMove);
-      element.addEventListener('touchend', onTouchEnd);
+      element = e.target as HTMLElement;
+      element!.addEventListener('touchmove', onTouchMove);
+      element!.addEventListener('touchend', onTouchEnd);
     }
   };
 
-  cleanUpEvents = () => {
-    if (element) {
-      element.removeEventListener('touchmove', onTouchMove);
-      element.removeEventListener('touchend', onTouchEnd);
-    }
-  };
   watch(inVirtual, val => {
-    listRef.current.removeEventListener('touchstart', onTouchStart);
+    listRef.value.removeEventListener('touchstart', onTouchStart);
     cleanUpEvents();
     clearInterval(interval);
-    if (val.value) {
-      listRef.current.addEventListener('touchstart', onTouchStart);
+    if (val) {
+      listRef.value.addEventListener('touchstart', onTouchStart);
     }
   });
 }

components/vc-virtual-list/hooks/useOriginScroll.ts

@@ -1,7 +1,9 @@
-export default (isScrollAtTop, isScrollAtBottom) => {
+import { Ref } from 'vue';
+
+export default (isScrollAtTop: Ref<boolean>, isScrollAtBottom: Ref<boolean>) => {
   // Do lock for a wheel when scrolling
   let lock = false;
-  let lockTimeout = null;
+  let lockTimeout: any = null;
   function lockScroll() {
     clearTimeout(lockTimeout);
 
@@ -11,7 +13,7 @@ export default (isScrollAtTop, isScrollAtBottom) => {
       lock = false;
     }, 50);
   }
-  return (deltaY, smoothOffset = false) => {
+  return (deltaY: number, smoothOffset = false) => {
     const originScroll =
       // Pass origin wheel when on the top
       (deltaY < 0 && isScrollAtTop.value) ||

components/vc-virtual-list/hooks/useScrollTo.tsx

@@ -1,41 +1,43 @@
-/* eslint-disable no-param-reassign */
-
+import { Data } from '../../_util/type';
+import { Ref } from 'vue';
 import raf from '../../_util/raf';
+import { GetKey } from '../interface';
+import { ListState } from '../List';
 
 export default function useScrollTo(
-  containerRef,
-  state,
-  heights,
+  containerRef: Ref<Element | undefined>,
+  state: ListState,
+  heights: Data,
   props,
-  getKey,
-  collectHeight,
-  syncScrollTop,
+  getKey: GetKey,
+  collectHeight: () => void,
+  syncScrollTop: (newTop: number) => void,
 ) {
-  let scroll = null;
+  let scroll: number | null = null;
 
   return arg => {
-    raf.cancel(scroll);
+    raf.cancel(scroll!);
     const data = state.mergedData;
     const itemHeight = props.itemHeight;
     if (typeof arg === 'number') {
       syncScrollTop(arg);
     } else if (arg && typeof arg === 'object') {
-      let index;
+      let index: number;
       const { align } = arg;
 
       if ('index' in arg) {
         ({ index } = arg);
       } else {
-        index = data.findIndex(item => getKey(item) === arg.key);
+        index = data.findIndex((item: object) => getKey(item) === arg.key);
       }
 
       const { offset = 0 } = arg;
 
       // We will retry 3 times in case dynamic height shaking
-      const syncScroll = (times, targetAlign) => {
-        if (times < 0 || !containerRef.current) return;
+      const syncScroll = (times: number, targetAlign?: 'top' | 'bottom') => {
+        if (times < 0 || !containerRef.value) return;
 
-        const height = containerRef.current.clientHeight;
+        const height = containerRef.value.clientHeight;
         let needCollectHeight = false;
         let newTargetAlign = targetAlign;
 
@@ -51,7 +53,7 @@ export default function useScrollTo(
           for (let i = 0; i <= index; i += 1) {
             const key = getKey(data[i]);
             itemTop = stackTop;
-            const cacheHeight = heights[key];
+            const cacheHeight = heights[key!];
             itemBottom = itemTop + (cacheHeight === undefined ? itemHeight : cacheHeight);
 
             stackTop = itemBottom;
@@ -62,7 +64,7 @@ export default function useScrollTo(
           }
 
           // Scroll to
-          let targetTop = null;
+          let targetTop: number | null = null;
 
           switch (mergedAlign) {
             case 'top':
@@ -73,7 +75,7 @@ export default function useScrollTo(
               break;
 
             default: {
-              const { scrollTop } = containerRef.current;
+              const { scrollTop } = containerRef.value;
               const scrollBottom = scrollTop + height;
               if (itemTop < scrollTop) {
                 newTargetAlign = 'top';
@@ -83,7 +85,7 @@ export default function useScrollTo(
             }
           }
 
-          if (targetTop !== null && targetTop !== containerRef.current.scrollTop) {
+          if (targetTop !== null && targetTop !== containerRef.value.scrollTop) {
             syncScrollTop(targetTop);
           }
         }

components/vc-virtual-list/interface.ts

@@ -0,0 +1,14 @@
+import { CSSProperties, VNodeTypes } from 'vue';
+import { Key } from '../_util/type';
+
+export type RenderFunc<T> = (
+  item: T,
+  index: number,
+  props: { style?: CSSProperties },
+) => VNodeTypes;
+
+export interface SharedConfig<T> {
+  getKey: (item: T) => Key;
+}
+
+export type GetKey<T = object> = (item: T) => Key;