[adapters] 增加小游戏适配部分源码

adapters/platforms/taobao-minigame/wrapper/builtin/EventTarget.js

@@ -0,0 +1,57 @@
+const _events = new WeakMap()
+
+export default class EventTarget {
+  constructor() {
+    _events.set(this, {})
+  }
+
+  addEventListener(type, listener, options = {}) {
+    let events = _events.get(this)
+
+    if (!events) {
+      events = {}
+      _events.set(this, events)
+    }
+    if (!events[type]) {
+      events[type] = []
+    }
+    events[type].push(listener)
+
+    if (options.capture) {
+      // console.warn('EventTarget.addEventListener: options.capture is not implemented.')
+    }
+    if (options.once) {
+      // console.warn('EventTarget.addEventListener: options.once is not implemented.')
+    }
+    if (options.passive) {
+      // console.warn('EventTarget.addEventListener: options.passive is not implemented.')
+    }
+  }
+
+  removeEventListener(type, listener) {
+    const events = _events.get(this)
+
+    if (events) {
+      const listeners = events[type]
+
+      if (listeners && listeners.length > 0) {
+          for (let i = listeners.length; i--; i > 0) {
+              if (listeners[i] === listener) {
+                  listeners.splice(i, 1)
+                  break
+              }
+          }
+      }
+    }
+  }
+
+  dispatchEvent(event = {}) {
+    const listeners = _events.get(this)[event.type]
+
+    if (listeners) {
+      for (let i = 0; i < listeners.length; i++) {
+        listeners[i](event)
+      }
+    }
+  }
+}