Android4.4 状态栏WiFi图标显示流程

1. 状态栏信号图标

1.1 WIFI信号显示

WIFI信号在状态栏的显示如下图所示

当WiFi状态为关闭时，状态栏不会有任何显示。当WiFi状态打开时，会如上图所示，左侧表示有可用WiFi，右侧表示当前WiFi打开但未连接。

当WiFi状态连接时，会如上图所示，显示信号连接强度和数据连接状态。

1.2 图标更新流程框架

如图所示，WiFi图标的显示流程主要是通过监听系统的WiFi状态，然后通知UI去事实的刷新图标资源。NetworkController.java 继承 BroadcastReceiver 监听系统WiFi状态的变化。

2. WIFI图标更新流介绍

2.1 重要类

frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/policy/NetworkController.java
定义相关函数，继承BroadcastReceiver监听系统广播，动态注册广播接收器。是状态栏WiFi图标更新的核心类。
frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/policy/WifiIcons.java
定义了 Wifi 信号更新所需的图标资源。
frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java
与signal_cluster_view.xml文件相对应，定义了状态上信号簇以及图片资源更新的相关方法。

2.2 WIFI图标更新流程

（1）NetworkController实例化，在PhoneStatusBar.java进行实例化

 protected PhoneStatusBarView makeStatusBarView() {final Context context = mContext;//此处省略部分代码//...mNetworkController = new NetworkController(mContext);mBluetoothController = new BluetoothController(mContext);mRotationLockController = new RotationLockController(mContext);final SignalClusterView signalCluster =(SignalClusterView)mStatusBarView.findViewById(R.id.signal_cluster);mNetworkController.addSignalCluster(signalCluster);signalCluster.setNetworkController(mNetworkController);//此处省略部分代码//...
}

(2) 初次更新WIFI图标

NetworkController.java

/*** Construct this controller object and register for updates.*/
public NetworkController(Context context) {mContext = context;//此处省略部分代码...//...// broadcastsIntentFilter filter = new IntentFilter();filter.addAction(WifiManager.RSSI_CHANGED_ACTION);filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);filter.addAction(TelephonyIntents.SPN_STRINGS_UPDATED_ACTION);filter.addAction(SimManager.INSERT_SIMS_CHANGED_ACTION);//此处省略部分代码...//.../* @} */context.registerReceiver(this, filter);//此处省略部分代码...//...
}public void addSignalCluster(SignalCluster cluster) {mSignalClusters.add(cluster);refreshSignalCluster(cluster);
}public void refreshSignalCluster(SignalCluster cluster) {if (mDemoMode) {return;}cluster.setWifiIndicators(// only show wifi in the cluster if connected or if wifi-onlymWifiEnabled, mWifiConnected,mWifiIconId,mWifiActivityIconId,mContentDescriptionWifi);//此处省略部分代码...//...
}

SignalClusterView.java

@Override
public void setWifiIndicators(boolean visible,boolean connected, int strengthIcon, int activityIcon,String contentDescription) {mWifiVisible = visible;mWifiConnected = connected;mWifiStrengthId = strengthIcon;mWifiActivityId = activityIcon;mWifiDescription = contentDescription;apply(0);
}// Run after each indicator change.
private void apply(int phoneId) {//此处省略部分代码...//...if (mWifiVisible && !mVoWifiVisible) {mWifiGroup.setVisibility(View.VISIBLE);mWifiSignal.setImageResource(mWifiStrengthId);mWifiActivity.setImageResource(mWifiActivityId);mWifiGroup.setContentDescription(mWifiDescription);} else {mWifiGroup.setVisibility(View.GONE);}//此处省略部分代码...//...
}

(3)WiFi状态变化时更新状态栏图标

当WiFi状态变化时会收到状态变化的广播

NetworkController.java

@Override
public void onReceive(Context context, Intent intent) {final String action = intent.getAction();/* SPRD: for multi-sim @{ */Log.d(TAG, "action: "+intent.getAction());mDDS = TelephonyManager.getDefault().getDefaultDataPhoneId(context);if (action.equals(WifiManager.RSSI_CHANGED_ACTION)|| action.equals(WifiManager.WIFI_STATE_CHANGED_ACTION)|| action.equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)) {updateWifiState(intent);refreshViews(mDDS);}//此处省略部分代码...//...
}

从intent中获取WiFi参数，是否连接，信号强度等

private void updateWifiState(Intent intent) {final String action = intent.getAction();if (action.equals(WifiManager.WIFI_STATE_CHANGED_ACTION)) {mWifiEnabled = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE,WifiManager.WIFI_STATE_UNKNOWN) == WifiManager.WIFI_STATE_ENABLED;} else if (action.equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)) {final NetworkInfo networkInfo = (NetworkInfo) intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);boolean wasConnected = mWifiConnected;mWifiConnected = networkInfo != null && networkInfo.isConnected();// If we just connected, grab the inintial signal strength and ssidif (mWifiConnected && !wasConnected) {// try getting it out of the intent firstWifiInfo info = (WifiInfo) intent.getParcelableExtra(WifiManager.EXTRA_WIFI_INFO);if (info == null) {info = mWifiManager.getConnectionInfo();}if (info != null) {mWifiSsid = huntForSsid(info);} else {mWifiSsid = null;}} else if (!mWifiConnected) {mWifiSsid = null;}} else if (action.equals(WifiManager.RSSI_CHANGED_ACTION)) {mWifiRssi = intent.getIntExtra(WifiManager.EXTRA_NEW_RSSI, -200);mWifiLevel = WifiManager.calculateSignalLevel(mWifiRssi,WifiIcons.WIFI_LEVEL_COUNT - 1) + 1;}updateWifiIcons();
}

根据数据匹配对应的图标id

private void updateWifiIcons() {if (mWifiConnected) {mWifiIconId = WifiIcons.WIFI_SIGNAL_STRENGTH[mInetCondition][mWifiLevel];mQSWifiIconId = WifiIcons.QS_WIFI_SIGNAL_STRENGTH[mInetCondition][mWifiLevel];mContentDescriptionWifi = mContext.getString(AccessibilityContentDescriptions.WIFI_CONNECTION_STRENGTH[mWifiLevel]);/* SPRD: Add for VoWifi in bug 629758. @{ */int length = mSignalClusters.size();for (int i = 0; i < length; i++) {mSignalClusters.get(i).setWifiLevel(mWifiLevel);}/* @} */} else {if (mDataAndWifiStacked) {mWifiIconId = 0;mQSWifiIconId = 0;} else {mWifiIconId = mWifiEnabled ? R.drawable.stat_sys_wifi_signal_null: 0;mQSWifiIconId = mWifiEnabled ? R.drawable.ic_qs_wifi_no_network: 0;}mContentDescriptionWifi = mContext.getString(R.string.accessibility_no_wifi);}
}

根据匹配好的图标id通过refreshSignalCluster(cluster)进行状态栏刷新

void refreshViews(int phoneId) {//此处省略部分代码...//...if (mLastPhoneSignalIconId[phoneId] != mPhoneSignalIconId[phoneId]|| mLastDataDirectionOverlayIconId[phoneId] != combinedActivityIconId|| mLastWifiIconId != mWifiIconId|| mLastWimaxIconId != mWimaxIconId|| mLastDataTypeIconId[phoneId] != mDataTypeIconId[phoneId]|| mLastAirplaneMode != mAirplaneMode || mLastLocale != mLocale|| mLastWifiActivityIconId != mWifiActivityIconId// SPRD: modify for bug328207: refresh roaming icon immediately if changed|| mLastMobileDataRoamingId[phoneId] != mMobileDataRoamingId[phoneId]// SPRD: Reliance UI spec 1.8. See bug #622109.|| mLastMobileVoLTEId[phoneId] != mMobileVoLTEId[phoneId]/* SPRD: to fix bug 255331: icon dont't update timely {@ */|| mLastDataSignalIconId[phoneId] != mDataSignalIconId[phoneId]|| mLastMobileActivityIconId[phoneId] != mMobileActivityIconId[phoneId]|| (isSupportLTE && (mLastPhoneSignalIconId[mLTEId] != mPhoneSignalIconId[mLTEId]))) {/* @} */// NB: the mLast*s will be updated laterfor (SignalCluster cluster : mSignalClusters) {refreshSignalCluster(cluster);}for (NetworkSignalChangedCallback cb : mSignalsChangedCallbacks) {notifySignalsChangedCallbacks(cb);}}//此处省略部分代码...//...
}

WifiIcons.java代码如下：

class WifiIcons {static final int[][] WIFI_SIGNAL_STRENGTH = {{R.drawable.stat_sys_wifi_signal_0,R.drawable.stat_sys_wifi_signal_1_fully,R.drawable.stat_sys_wifi_signal_2_fully,R.drawable.stat_sys_wifi_signal_3_fully,R.drawable.stat_sys_wifi_signal_4_fully },{R.drawable.stat_sys_wifi_signal_0,R.drawable.stat_sys_wifi_signal_1_fully,R.drawable.stat_sys_wifi_signal_2_fully,R.drawable.stat_sys_wifi_signal_3_fully,R.drawable.stat_sys_wifi_signal_4_fully }};static final int[][] QS_WIFI_SIGNAL_STRENGTH = {{ R.drawable.ic_qs_wifi_0,R.drawable.ic_qs_wifi_1,R.drawable.ic_qs_wifi_2,R.drawable.ic_qs_wifi_3,R.drawable.ic_qs_wifi_4 },{ R.drawable.ic_qs_wifi_0,R.drawable.ic_qs_wifi_full_1,R.drawable.ic_qs_wifi_full_2,R.drawable.ic_qs_wifi_full_3,R.drawable.ic_qs_wifi_full_4 }};static final int WIFI_LEVEL_COUNT = WIFI_SIGNAL_STRENGTH[0].length;
}