feat: 增加 uni.createIntersectionObserver 接口

package.json

@@ -38,6 +38,7 @@
         "eslint-plugin-promise": "^4.0.0",
         "eslint-plugin-standard": "^4.0.0",
         "eslint-plugin-vue": "^4.7.1",
+        "intersection-observer": "^0.7.0",
         "jsdom": "^13.0.0",
         "jsdom-global": "^3.0.2",
         "rollup": "^0.67.4",

src/core/service/api/create-intersection-observer.js

+import Vue from 'vue'
+import 'intersection-observer'
+
+const defaultOptions = {
+  thresholds: [0],
+  initialRatio: 0,
+  observeAll: false
+}
+
+class MPIntersectionObserver {
+  _intersectionObserver
+  _el
+  _options
+  _root = null
+  _rootMargin = '0'
+  constructor (context, options) {
+    this._el = context.$el
+    this._options = Object.assign({}, defaultOptions, options)
+  }
+  _makeRootMargin (margins = {}) {
+    this._rootMargin = ['top', 'right', 'bottom', 'left'].map(name => `${Number(margins[name]) || 0}px`).join(' ')
+  }
+  relativeTo (selector, margins) {
+    this._root = this._el.querySelector(selector)
+    this._makeRootMargin(margins)
+  }
+  relativeToViewport (margins) {
+    this._root = null
+    this._makeRootMargin(margins)
+  }
+  observe (selector, callback) {
+    if (typeof callback !== 'function') {
+      return
+    }
+    let options = {
+      root: this._root,
+      rootMargin: this._rootMargin,
+      threshold: this._options.thresholds
+    }
+    let intersectionObserver = this._intersectionObserver = new IntersectionObserver((entries, observer) => {
+      entries.forEach(entrie => {
+        callback({
+          intersectionRatio: entrie.intersectionRatio,
+          intersectionRect: entrie.intersectionRect,
+          boundingClientRect: entrie.boundingClientRect,
+          relativeRect: entrie.rootBounds,
+          time: entrie.time,
+          dataset: entrie.target.dataset,
+          id: entrie.target.id
+        })
+      })
+    }, options)
+    if (this._options.observeAll) {
+      intersectionObserver.USE_MUTATION_OBSERVER = true
+      Array.prototype.map.call(this._el.querySelectorAll(selector), el => {
+        intersectionObserver.observe(el)
+      })
+    } else {
+      intersectionObserver.USE_MUTATION_OBSERVER = false
+      intersectionObserver.observe(this._el.querySelector(selector))
+    }
+  }
+  disconnect () {
+    this._intersectionObserver && this._intersectionObserver.disconnect()
+  }
+}
+
+export function createIntersectionObserver (context, options) {
+  if (!(context instanceof Vue)) {
+    options = context
+    context = null
+  }
+  if (context) {
+    return new MPIntersectionObserver(context, options)
+  }
+  const pages = getCurrentPages()
+  if (pages.length) {
+    context = pages[pages.length - 1]
+    return new MPIntersectionObserver(context, options)
+  } else {
+    UniServiceJSBridge.emit('onError', 'createIntersectionObserver:fail')
+  }
+}

src/platforms/h5/helpers/todo-api.js

@@ -49,7 +49,6 @@ export default [
   'setBackgroundTextStyle',
   'createAnimation',
   'loadFontFace',
-  'createIntersectionObserver',
   'getProvider',
   'login',
   'checkSession',

yarn.lock

@@ -3977,6 +3977,10 @@ interpret@^1.0.1:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/interpret/-/interpret-1.2.0.tgz#d5061a6224be58e8083985f5014d844359576296"
 
+intersection-observer@^0.7.0:
+  version "0.7.0"
+  resolved "https://registry.yarnpkg.com/intersection-observer/-/intersection-observer-0.7.0.tgz#ee16bee978db53516ead2f0a8154b09b400bbdc9"
+
 invariant@^2.2.2:
   version "2.2.4"
   resolved "https://registry.yarnpkg.com/invariant/-/invariant-2.2.4.tgz#610f3c92c9359ce1db616e538008d23ff35158e6"