@TargetApi(Build.VERSION_CODES.JELLY_BEAN) private void handleWindowChange(AccessibilityNodeInfo nodeInfo) {  switch (Stage.getInstance().getCurrentStage()) {   case Stage.OPENING_STAGE:    // 調試信息，打印TTL    // Log.d("TTL", String.valueOf(ttl));     /* 如果打開紅包失敗且還沒到達最大嘗試次數，重試 */    if (openHongbao(nodeInfo) == -1 && ttl < MAX_TTL) return;     ttl = 0;    Stage.getInstance().entering(Stage.FETCHED_STAGE);    performMyGlobalAction(GLOBAL_ACTION_BACK);    if (nodesToFetch.size() == 0) handleWindowChange(nodeInfo);    break;   case Stage.OPENED_STAGE:    ListsuccessNodes = nodeInfo.findAccessibilityNodeInfosByText("紅包詳情");    if (successNodes.isEmpty() && ttl < MAX_TTL) {     ttl += 1;     return;    }    ttl = 0;    Stage.getInstance().entering(Stage.FETCHED_STAGE);    performMyGlobalAction(GLOBAL_ACTION_BACK);    break;   case Stage.FETCHED_STAGE:    /* 先消滅待搶紅包隊列中的紅包 */    if (nodesToFetch.size() > 0) {     /* 從最下面的紅包開始戳 */     AccessibilityNodeInfo node = nodesToFetch.remove(nodesToFetch.size() - 1);     if (node.getParent() != null) {      String id = getHongbaoHash(node);       if (id == null) return;       fetchedIdentifiers.add(id);       // 調試信息，在每次打開紅包后打印出已經獲取的紅包      // Log.d("fetched", Arrays.toString(fetchedIdentifiers.toArray()));       Stage.getInstance().entering(Stage.OPENING_STAGE);      node.getParent().performAction(AccessibilityNodeInfo.ACTION_CLICK);     }     return;    }     Stage.getInstance().entering(Stage.FETCHING_STAGE);    fetchHongbao(nodeInfo);    Stage.getInstance().entering(Stage.FETCHED_STAGE);    break;  } }