perf(collapse): use animate to improve performance (#3826)

fix #3820

packages/collapse-item/animate.ts

@@ -0,0 +1,94 @@
+import { canIUseAnimate } from '../common/version';
+import { getRect } from '../common/utils';
+
+function useAnimate(
+  context: WechatMiniprogram.Component.TrivialInstance,
+  expanded: boolean,
+  mounted: boolean,
+  height: number
+) {
+  const selector = '.van-collapse-item__wrapper';
+  if (expanded) {
+    context.animate(
+      selector,
+      [
+        { height: 0, ease: 'ease-in-out', offset: 0 },
+        { height: `${height}px`, ease: 'ease-in-out', offset: 1 },
+        { height: `auto`, ease: 'ease-in-out', offset: 1 },
+      ],
+      mounted ? 300 : 0,
+      () => {
+        context.clearAnimation(selector);
+      }
+    );
+
+    return;
+  }
+
+  context.animate(
+    selector,
+    [
+      { height: `${height}px`, ease: 'ease-in-out', offset: 0 },
+      { height: 0, ease: 'ease-in-out', offset: 1 },
+    ],
+    300,
+    () => {
+      context.clearAnimation(selector);
+    }
+  );
+}
+
+function useAnimation(
+  context: WechatMiniprogram.Component.TrivialInstance,
+  expanded: boolean,
+  mounted: boolean,
+  height: number
+) {
+  const animation = wx.createAnimation({
+    duration: 0,
+    timingFunction: 'ease-in-out',
+  });
+
+  if (expanded) {
+    if (height === 0) {
+      animation.height('auto').top(1).step();
+    } else {
+      animation
+        .height(height)
+        .top(1)
+        .step({
+          duration: mounted ? 300 : 1,
+        })
+        .height('auto')
+        .step();
+    }
+
+    context.setData({
+      animation: animation.export(),
+    });
+    return;
+  }
+
+  animation.height(height).top(0).step({ duration: 1 }).height(0).step({
+    duration: 300,
+  });
+
+  context.setData({
+    animation: animation.export(),
+  });
+}
+
+export function setContentAnimate(
+  context: WechatMiniprogram.Component.TrivialInstance,
+  expanded: boolean,
+  mounted: boolean
+) {
+  getRect
+    .call(context, '.van-collapse-item__content')
+    .then((rect) => rect.height)
+    .then((height: number) => {
+      canIUseAnimate()
+        ? useAnimate(context, expanded, mounted, height)
+        : useAnimation(context, expanded, mounted, height);
+    });
+}

packages/collapse-item/index.ts

@@ -1,5 +1,5 @@
-import { getRect } from '../common/utils';
 import { VantComponent } from '../common/component';
+import { setContentAnimate } from './animate';
 
 VantComponent({
   classes: ['title-class', 'content-class'],
@@ -32,23 +32,15 @@ VantComponent({
     expanded: false,
   },
 
-  created() {
-    this.animation = wx.createAnimation({
-      duration: 0,
-      timingFunction: 'ease-in-out',
-    });
-  },
-
   mounted() {
     this.updateExpanded();
-
-    this.inited = true;
+    this.mounted = true;
   },
 
   methods: {
     updateExpanded() {
       if (!this.parent) {
-        return Promise.resolve();
+        return;
       }
 
       const { value, accordion } = this.parent.data;
@@ -63,50 +55,12 @@ VantComponent({
         : (value || []).some((name: string | number) => name === currentName);
 
       if (expanded !== this.data.expanded) {
-        this.updateStyle(expanded);
+        setContentAnimate(this, expanded, this.mounted);
       }
 
       this.setData({ index, expanded });
     },
 
-    updateStyle(expanded: boolean) {
-      const { inited } = this;
-      getRect
-        .call(this, '.van-collapse-item__content')
-        .then((rect) => rect.height)
-        .then((height: number) => {
-          const { animation } = this;
-
-          if (expanded) {
-            if (height === 0) {
-              animation.height('auto').top(1).step();
-            } else {
-              animation
-                .height(height)
-                .top(1)
-                .step({
-                  duration: inited ? 300 : 1,
-                })
-                .height('auto')
-                .step();
-            }
-
-            this.setData({
-              animation: animation.export(),
-            });
-            return;
-          }
-
-          animation.height(height).top(0).step({ duration: 1 }).height(0).step({
-            duration: 300,
-          });
-
-          this.setData({
-            animation: animation.export(),
-          });
-        });
-    },
-
     onClick() {
       if (this.data.disabled) {
         return;

packages/collapse/index.ts

@@ -1,34 +1,34 @@
 import { VantComponent } from '../common/component';
 
-type TrivialInstance = WechatMiniprogram.Component.TrivialInstance;
-
 VantComponent({
   relation: {
     name: 'collapse-item',
     type: 'descendant',
-    current: 'collapse'
+    current: 'collapse',
   },
 
   props: {
     value: {
       type: null,
-      observer: 'updateExpanded'
+      observer: 'updateExpanded',
     },
     accordion: {
       type: Boolean,
-      observer: 'updateExpanded'
+      observer: 'updateExpanded',
     },
     border: {
       type: Boolean,
-      value: true
-    }
+      value: true,
+    },
   },
 
   methods: {
     updateExpanded() {
-      this.children.forEach((child: TrivialInstance) => {
-        child.updateExpanded();
-      });
+      this.children.forEach(
+        (child: WechatMiniprogram.Component.TrivialInstance) => {
+          child.updateExpanded();
+        }
+      );
     },
 
     switch(name: string | number, expanded: boolean) {
@@ -38,8 +38,8 @@ VantComponent({
         name = expanded
           ? (value || []).concat(name)
           : (value || []).filter(
-            (activeName: string | number) => activeName !== name
-          );
+              (activeName: string | number) => activeName !== name
+            );
       } else {
         name = expanded ? name : '';
       }
@@ -52,6 +52,6 @@ VantComponent({
 
       this.$emit('change', name);
       this.$emit('input', name);
-    }
-  }
+    },
+  },
 });

packages/common/version.ts

@@ -36,3 +36,8 @@ export function canIUseFormFieldButton() {
   const system = getSystemInfoSync();
   return compareVersion(system.SDKVersion, '2.10.3') >= 0;
 }
+
+export function canIUseAnimate() {
+  const system = getSystemInfoSync();
+  return compareVersion(system.SDKVersion, '2.9.0') >= 0;
+}