[new feature] ImagePreview: add max-zoom、min-zoom prop (#3133)

packages/image-preview/ImagePreview.js

@@ -5,8 +5,6 @@ import Swipe from '../swipe';
 import SwipeItem from '../swipe-item';
 
 const [sfc, bem] = use('image-preview');
-const MAX_ZOOM = 3;
-const MIN_ZOOM = 1 / 3;
 
 function getDistance(touches) {
   return Math.sqrt(
@@ -36,6 +34,14 @@ export default sfc({
       type: Boolean,
       default: true
     },
+    minZoom: {
+      type: Number,
+      default: 1 / 3
+    },
+    maxZoom: {
+      type: Number,
+      default: 3
+    },
     overlayClass: {
       type: String,
       default: 'van-image-preview__overlay'
@@ -160,7 +166,7 @@ export default sfc({
       if (this.zooming && touches.length === 2) {
         const distance = getDistance(touches);
         const scale = (this.startScale * distance) / this.startDistance;
-        this.scale = range(scale, MIN_ZOOM, MAX_ZOOM);
+        this.scale = range(scale, this.minZoom, this.maxZoom);
       }
     },
 

packages/image-preview/en-US.md

@@ -61,6 +61,8 @@ setTimeout(() => {
 | asyncClose | Whether to enable async close | `Boolean` | `false` |
 | className | Custom className | `String | Array | Object` | - |
 | lazyLoad | Whether to enable thumb lazy load，should register [Lazyload](#/en-US/lazyload) component | `Boolean` | `false` |
+| maxZoom | Max zoom | `Number` | `3` |
+| minZoom | Min zoom | `Number` | `1/3` |
 
 ### onClose Parematers
 

packages/image-preview/index.js

@@ -8,6 +8,8 @@ const defaultConfig = {
   images: [],
   loop: true,
   value: true,
+  minZoom: 1 / 3,
+  maxZoom: 3,
   className: '',
   lazyLoad: false,
   showIndex: true,

packages/image-preview/zh-CN.md

@@ -69,6 +69,8 @@ setTimeout(() => {
 | asyncClose | 是否开启异步关闭 | `Boolean` | `false` | 1.4.8 |
 | className | 自定义类名 | `String | Array | Object` | - | 1.5.2 |
 | lazyLoad | 是否开启图片懒加载，须配合 [Lazyload](#/zh-CN/lazyload) 组件使用 | `Boolean` | `false` | 1.5.3 |
+| maxZoom | 手势缩放时，最大缩放比例 | `Number` | `3` | 1.6.14 |
+| minZoom | 手势缩放时，最小缩放比例 | `Number` | `1/3` | 1.6.14 |
 
 ### onClose 回调参数
 

types/image-preview.d.ts

@@ -3,6 +3,8 @@ import { VanPopupMixin } from './mixins/popup';
 export type ImagePreviewOptions = string[] | {
   loop?: boolean;
   images: string[];
+  maxZoom?: number;
+  minZoom?: number;
   className?: any;
   startPosition?: number;
   lazyLoad?: boolean;