From 14299a2011285445062bea8bda0e0da6d2b08c95 Mon Sep 17 00:00:00 2001
From: neverland <chenjiahan@youzan.com>
Date: Tue, 7 Apr 2020 11:25:54 +0800
Subject: [PATCH] feat(Swipe): improve swipe threshold (#6003)

---
 src/swipe/index.js | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/swipe/index.js b/src/swipe/index.js
index d72b61b57..01873c39d 100644
--- a/src/swipe/index.js
+++ b/src/swipe/index.js
@@ -199,6 +199,7 @@ export default createComponent({
       if (!this.touchable) return;
 
       this.clear();
+      this.touchStartTime = Date.now();
       this.touchStart(event);
       this.correctPosition();
     },
@@ -217,23 +218,28 @@ export default createComponent({
     onTouchEnd() {
       if (!this.touchable || !this.swiping) return;
 
-      if (this.delta && this.isCorrectDirection) {
+      const { size, delta } = this;
+      const duration = Date.now() - this.touchStartTime;
+      const speed = delta / duration;
+      const shouldSwipe = Math.abs(speed) > 0.25 || Math.abs(delta) > size / 2;
+
+      if (shouldSwipe && this.isCorrectDirection) {
         const offset = this.vertical ? this.offsetY : this.offsetX;
 
         let pace = 0;
 
         if (this.loop) {
-          pace = offset > 0 ? (this.delta > 0 ? -1 : 1) : 0;
+          pace = offset > 0 ? (delta > 0 ? -1 : 1) : 0;
         } else {
-          pace = -Math[this.delta > 0 ? 'ceil' : 'floor'](
-            this.delta / this.size
-          );
+          pace = -Math[delta > 0 ? 'ceil' : 'floor'](delta / size);
         }
 
         this.move({
           pace,
           emitChange: true,
         });
+      } else if (delta) {
+        this.move({ pace: 0 });
       }
 
       this.swiping = false;
@@ -280,12 +286,12 @@ export default createComponent({
 
       // auto move first and last swipe in loop mode
       if (loop) {
-        if (children[0]) {
+        if (children[0] && targetOffset !== minOffset) {
           const outRightBound = targetOffset < minOffset;
           children[0].offset = outRightBound ? trackSize : 0;
         }
 
-        if (children[count - 1]) {
+        if (children[count - 1] && targetOffset !== 0) {
           const outLeftBound = targetOffset > 0;
           children[count - 1].offset = outLeftBound ? -trackSize : 0;
         }