背景

很多時(shí)候，因?yàn)楫a(chǎn)品都會(huì)要獲取用戶的行為，需要客戶端進(jìn)行相關(guān)的埋點(diǎn)。埋點(diǎn)主要分為兩種：

1. 侵入式埋點(diǎn)
   在每個(gè)需要埋點(diǎn)的地方手動(dòng)添加代碼

• 優(yōu)點(diǎn)：埋點(diǎn)準(zhǔn)確，可以精確描述不同組件之間的關(guān)聯(lián)
• 缺點(diǎn)：代碼耦合度高，后期難以維護(hù)，不需要的埋點(diǎn)需要手動(dòng)刪除

2. 無(wú)痕埋點(diǎn)
   通過(guò)全局監(jiān)聽(tīng)或AOP技術(shù)給所有的View添加埋點(diǎn)

• 優(yōu)點(diǎn)：代碼耦合度低，靈活度高，不同項(xiàng)目可復(fù)用
• 缺點(diǎn)：沒(méi)有侵入式埋點(diǎn)精準(zhǔn)，無(wú)法描述兩個(gè)組件之間的關(guān)聯(lián)

面試一句話

無(wú)痕埋點(diǎn)就是一種通過(guò)全局監(jiān)聽(tīng)或者AOP技術(shù)省去手動(dòng)埋點(diǎn)的技術(shù)，它和代碼耦合度低，靈活度高，適用于組件間關(guān)聯(lián)性不強(qiáng)的業(yè)務(wù)埋點(diǎn)

Code

完整代碼可見(jiàn) -- 代碼路徑

技術(shù)點(diǎn)

無(wú)痕埋點(diǎn)的技術(shù)路徑包括View操作的攔截，上報(bào)信息的設(shè)置與埋入，上報(bào)

1. 點(diǎn)擊監(jiān)聽(tīng)
2. 滑動(dòng)監(jiān)聽(tīng)
3. 埋點(diǎn)信息
4. ASpect監(jiān)聽(tīng)

點(diǎn)擊監(jiān)聽(tīng)

實(shí)現(xiàn)方法

通過(guò)給View設(shè)置setAccessibilityDelegate來(lái)獲取sendAccessibilityEvent回調(diào)監(jiān)聽(tīng)View的點(diǎn)擊事件

原理

1. 當(dāng)View被點(diǎn)擊時(shí)候，最后都會(huì)走到performClick()方法

   public boolean performClick() {
         // We still need to call this method to handle the cases where performClick() was called
         // externally, instead of through performClickInternal()
         notifyAutofillManagerOnClick();
   
         final boolean result;
         final ListenerInfo li = mListenerInfo;
         if (li != null && li.mOnClickListener != null) {
             playSoundEffect(SoundEffectConstants.CLICK);
             li.mOnClickListener.onClick(this);
             result = true;
         } else {
             result = false;
         }
         // 關(guān)鍵方法
         sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);
   
         notifyEnterOrExitForAutoFillIfNeeded(true);
   
         return result;
     }
   

2. 再看sendAccessibilityEvent（）方法,可以看到只要view的mAccessibilityDelegate為非空的，就會(huì)觸發(fā)sendAccessibilityEvent()回調(diào)

   public void sendAccessibilityEvent(int eventType) {
       if (mAccessibilityDelegate != null) {
           mAccessibilityDelegate.sendAccessibilityEvent(this, eventType);
       } else {
           sendAccessibilityEventInternal(eventType);
       }
   }
   

3. 所以我們只需要給View設(shè)置AccessibilityDelegate，就能對(duì)點(diǎn)擊事件進(jìn)行監(jiān)聽(tīng),host代表被監(jiān)聽(tīng)的View，eventType代表事件類(lèi)型，比如點(diǎn)擊、輸入

   view.setAccessibilityDelegate(new View.AccessibilityDelegate(){
       @Override
       public void sendAccessibilityEvent(View host, int eventType) {
           super.sendAccessibilityEvent(host, eventType);
           Log.d(TAG, "sendAccessibilityEvent: ");
       }
   });
   

4. 對(duì)于層級(jí)很深的ViewGroup，我們可以通過(guò)遍歷的方式，對(duì)他層級(jí)內(nèi)的View和ViewGroup添加監(jiān)聽(tīng)，為了避免動(dòng)態(tài)添加的View沒(méi)有添加監(jiān)聽(tīng)，我們需要給ViewGroup添加childView的監(jiān)聽(tīng)

   /**
    * 設(shè)置Activity頁(yè)面中View的事件監(jiān)聽(tīng)
    *
    * @param activity
    */
   public void setTracker(Activity activity) {
       // 找到根路徑的View
       View contentView = activity.findViewById(android.R.id.content);
       if (contentView != null) {
           setViewTracker(contentView, null);
       }
   }
   
   /**
    * 設(shè)置Fragment頁(yè)面中View的事件監(jiān)聽(tīng)
    *
    * @param fragment
    */
   public void setTracker(Fragment fragment) {
       View contentView = fragment.getView();
       if (contentView != null) {
           setViewTracker(contentView, fragment);
       }
   }
   
   
   /**
    * 設(shè)置View上的事件監(jiān)聽(tīng)
    *
    * @param view
    */
   public void setTracker(View view) {
       if (view != null) {
           setViewTracker(view, null);
       }
   }
   
   /**
    * 判斷view是否需要埋點(diǎn)，目前默認(rèn)只要可以點(diǎn)擊的都是true
    *
    * @param view
    * @return
    */
   private boolean needTracker(View view) {
       return true;
   }
   
   
   /**
    * 對(duì)每個(gè)View添加埋點(diǎn)的監(jiān)聽(tīng)
    *
    * @param view
    * @param fragment
    */
   private void setViewTracker(View view, Fragment fragment) {
       if (needTracker(view)) {
           if (fragment != null) {
               view.setTag(FRAGMENT_TAG_KEY, fragment);
           }
           view.setAccessibilityDelegate(this);
       }
       if (view instanceof ViewGroup) {
           int childCount = ((ViewGroup) view).getChildCount();
           for (int i = 0; i < childCount; i++) {
               setViewTracker(((ViewGroup) view).getChildAt(i), fragment);
           }
           ((ViewGroup) view).setOnHierarchyChangeListener(new ViewGroup.OnHierarchyChangeListener() {
               @Override
               public void onChildViewAdded(View parent, View child) {
                   setTracker(parent);
               }
   
               @Override
               public void onChildViewRemoved(View parent, View child) {
                   setTracker(parent);
               }
           });
           if (needTracker(view)) {
               view.setAccessibilityDelegate(this);
               viewScrollListener.setScrollListener(view);
           }
       }
   }