Android 4.0 ICS SystemUI浅析——StatusBar加载流程分析
前面两篇文章《Android 4.0 ICS SystemUI浅析——SystemUI启动流程》、《Android 4.0 ICS SystemUI浅析——StatusBar结构分析》SystemUI和StatusBar的冰山一角，那么本文将从代码的角度来分析StatusBar的加载流程。
本文来自：http://blog.csdn.net/yihongyuelan 欢迎转载 请务必注明出处！
在《Android 4.0 ICS SystemUI浅析——SystemUI启动流程》中，我们提到了在Phone中，整个StatusBar和NavigationBar都是在/SourceCode/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java的start()方法中，完成初始化并显示到界面上的。因此，我们回到这段代码中查看：
@Override
public void start() {
mDisplay = ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE))
.getDefaultDisplay();
mWindowManager = IWindowManager.Stub.asInterface(
ServiceManager.getService(Context.WINDOW_SERVICE));
super.start(); // calls makeStatusBarView() 这里会调用父类StatusBar.java中的start()方法
addNavigationBar();//加载导航栏，本文因以StatusBar为主，因此暂不分析NavigationBar
//addIntruderView();
// Lastly, call to the icon policy to install/update all the icons.
mIconPolicy = new PhoneStatusBarPolicy(mContext);//用于初始化以及更新StatusBar上的icons
}我们继续跟踪super.start()方法，来到/SourceCode/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/StatusBar.java的start()方法中，如代码所示：
public void start() {
// First set up our views and stuff.首先准备我们需要显示的view以及原材料
//我们先跟踪这里的makeStatusBarView
View sb = makeStatusBarView();
// Connect in to the status bar manager service
StatusBarIconList iconList = new StatusBarIconList();
ArrayList notificationKeys = new ArrayList();
ArrayList notifications = new ArrayList();
... ...
} 通过Open Implementation跳转到makeStatusBarView的实现，因为我们是针对Phone来分析的，因此选择PhoneStatusBar，代码如下：
// ================================================================================
// Constructing the view
// ================================================================================
protected View makeStatusBarView() {
final Context context = mContext;
Resources res = context.getResources();
//获取ExpandedView的尺寸
updateDisplaySize(); // populates mDisplayMetrics
//定义icon的大小，缩放率和彼此间距
loadDimens();
mIconSize = res.getDimensionPixelSize(com.android.internal.R.dimen.status_bar_icon_size);
//设置ExpandedView的布局
ExpandedView expanded = (ExpandedView)View.inflate(context,
R.layout.status_bar_expanded, null);
if (DEBUG) {
expanded.setBackgroundColor(0x6000FF80);
}
expanded.mService = this;
//前面已注释，以下三段代码没有用到
mIntruderAlertView = View.inflate(context, R.layout.intruder_alert, null);
mIntruderAlertView.setVisibility(View.GONE);
mIntruderAlertView.setClickable(true);
PhoneStatusBarView sb;
//这里根据是否是双卡来加载不同的布局文件
if (TelephonyManager.getDefault().isMultiSimEnabled()) {
sb = (PhoneStatusBarView)View.inflate(context,
R.layout.msim_status_bar, null);
} else {
sb = (PhoneStatusBarView)View.inflate(context,
R.layout.status_bar, null);
}
sb.mService = this;
mStatusBarView = sb;
//是否显示NavigationBar
try {
boolean showNav = mWindowManager.hasNavigationBar();
if (showNav) {
mNavigationBarView =
(NavigationBarView) View.inflate(context, R.layout.navigation_bar, null);
mNavigationBarView.setDisabledFlags(mDisabled);
}
} catch (RemoteException ex) {
// no window manager? good luck with that
}
// figure out which pixel-format to use for the status bar.
mPixelFormat = PixelFormat.OPAQUE;
//系统状态图标布局初始化
mStatusIcons = (LinearLayout)sb.findViewById(R.id.statusIcons);
//通知图标布局初始化
mNotificationIcons = (IconMerger)sb.findViewById(R.id.notificationIcons);
mMoreIcon = sb.findViewById(R.id.moreIcon);
mNotificationIcons.setOverflowIndicator(mMoreIcon);
//icons布局初始化，该布局用于装载除开tiker外的所有控件
mIcons = (LinearLayout)sb.findViewById(R.id.icons);
//ticker布局初始化
mTickerView = sb.findViewById(R.id.ticker);
//以上几个重要布局的关系在上一篇文章有详细分析
//以下几段代码是在设置ExpandedView，ExpandedDialog通过加载ExpandedView显示，其中包括了ExpanedView上的清除按钮，
//设置按钮，滚动条，日期显示等等
mExpandedDialog = new ExpandedDialog(context);
mExpandedView = expanded;
mPile = (NotificationRowLayout)expanded.findViewById(R.id.latestItems);
mExpandedContents = mPile; // was: expanded.findViewById(R.id.notificationLinearLayout);
mNoNotificationsTitle = (TextView)expanded.findViewById(R.id.noNotificationsTitle);
mNoNotificationsTitle.setVisibility(View.GONE); // disabling for now
mClearButton = expanded.findViewById(R.id.clear_all_button);
mClearButton.setOnClickListener(mClearButtonListener);
mClearButton.setAlpha(0f);
mClearButton.setEnabled(false);
mDateView = (DateView)expanded.findViewById(R.id.date);
mSettingsButton = expanded.findViewById(R.id.settings_button);
mSettingsButton.setOnClickListener(mSettingsButtonListener);
mScrollView = (ScrollView)expanded.findViewById(R.id.scroll);
//tickerView的初始化
mTicker = new MyTicker(context, sb);
TickerView tickerView = (TickerView)sb.findViewById(R.id.tickerText);
tickerView.mTicker = mTicker;
//TrackingView初始化
mTrackingView = (TrackingView)View.inflate(context, R.layout.status_bar_tracking, null);
mTrackingView.mService = this;
mCloseView = (CloseDragHandle)mTrackingView.findViewById(R.id.close);
mCloseView.mService = this;
mEdgeBorder = res.getDimensionPixelSize(R.dimen.status_bar_edge_ignore);
// set the inital view visibility
setAreThereNotifications();
// Other icons
//以下是对其他icons的加载(信号及电量图标的加载)
mLocationController = new LocationController(mContext); // will post a notification
mBatteryController = new BatteryController(mContext);
mBatteryController.addIconView((ImageView)sb.findViewById(R.id.battery));
SignalClusterView signalCluster;
LinearLayout mSimSignalView;
//根据是否是双卡加载不同的布局文件
if (TelephonyManager.getDefault().isMultiSimEnabled()) {
mMSimNetworkController = new MSimNetworkController(mContext);
mSimSignalView = (LinearLayout) sb.findViewById(R.id.msim_signal_cluster);
if (FeatureQuery.FEATURE_ANNUCIATOR_NEW_STATUSBAR_STYLE) {
CUMSimSignalClusterView cuMSimSignalCluster = (CUMSimSignalClusterView)View.inflate(context, R.layout.msim_signal_cluster_view_cu, null);
mSimSignalView.addView(cuMSimSignalCluster);
for (int i=0; i < TelephonyManager.getDefault().getPhoneCount(); i++) {
mMSimNetworkController.addSignalCluster(cuMSimSignalCluster, i);
}
cuMSimSignalCluster.setNetworkController(mMSimNetworkController);
} else {
MSimSignalClusterView mSimSignalCluster = (MSimSignalClusterView)View.inflate(context, R.layout.msim_signal_cluster_view, null);
mSimSignalView.addView(mSimSignalCluster);
for (int i=0; i < TelephonyManager.getDefault().getPhoneCount(); i++) {
mMSimNetworkController.addSignalCluster(mSimSignalCluster, i);
}
mSimSignalCluster.setNetworkController(mMSimNetworkController);
}
} else {
mNetworkController = new NetworkController(mContext);
signalCluster = (SignalClusterView)sb.findViewById(R.id.signal_cluster);
mNetworkController.addSignalCluster(signalCluster);
signalCluster.setNetworkController(mNetworkController);
// final ImageView wimaxRSSI =
// (ImageView)sb.findViewById(R.id.wimax_signal);
// if (wimaxRSSI != null) {
// mNetworkController.addWimaxIconView(wimaxRSSI);
// }
}
// Recents Panel
//最近使用界面初始化
mRecentTasksLoader = new RecentTasksLoader(context);
updateRecentsPanel();
// receive broadcasts
//注册广播监听器
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED);
filter.addAction(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
filter.addAction(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
context.registerReceiver(mBroadcastReceiver, filter);
return sb;
}通过makeStatusBarView()我们可以看到，在该方法中整个StatusBar根据获取的设备配置信息进行了布局，就好比我们去吃饭，先要安排好座位和桌子，最后才上菜，我们需要加载的icons——就是菜！！:D
我们回到StatusBar.java的start()方法中继续分析，代码如下：
public void start() {
// First set up our views and stuff.首先准备我们需要显示的view以及原材料
//我们先跟踪这里的makeStatusBarView
View sb = makeStatusBarView();
// Connect in to the status bar manager service
//初始化各个存储器，用于存储各类信息，这些信息通过StatusBarManagerService获取
//iconsList用于存放icons
StatusBarIconList iconList = new StatusBarIconList();
//nodificationKeys保存以Binder为Key的notification
ArrayList notificationKeys = new ArrayList();
//保存StatusBarNotification类型的notifications
ArrayList notifications = new ArrayList();
//mCommandQueue是和IStatusBarService进行交互的IBinder
mCommandQueue = new CommandQueue(this, iconList);
//这里实际上获取的是StatusBarManagerService
mBarService = IStatusBarService.Stub.asInterface(
ServiceManager.getService(Context.STATUS_BAR_SERVICE));
int[] switches = new int[7];
ArrayList binders = new ArrayList();
try {
//通过StatusBarManagerService中的registerStatusBar来获取初始设置
mBarService.registerStatusBar(mCommandQueue, iconList, notificationKeys, notifications,
switches, binders);
} catch (RemoteException ex) {
// If the system process isn't there we're doomed anyway.
}
//对SystemUI上像Clock、ExpandedView、NavigationBar等进行初始化设置
disable(switches[0]);
setSystemUiVisibility(switches[1]);
topAppWindowChanged(switches[2] != 0);
// StatusBarManagerService has a back up of IME token and it's restored here.
setImeWindowStatus(binders.get(0), switches[3], switches[4]);
setHardKeyboardStatus(switches[5] != 0, switches[6] != 0);
// Set up the initial icon state
//icon加载(注：陷阱!!!一不注意就会迷失！！后文详将细分析)
int N = iconList.size();
int viewIndex = 0;
for (int i=0; i 可能大多数朋友都还是云里雾里的，先别急，我们只是把大致流程走完了，细节还没有去分析，接下来我们再来看看StatusBar到底是如何加载Icons的。
需要分析如何加载Icons，首先我们根据StatusBar.java中的start()方法可以看到，addIcon()方法完成了Icons的加载。那么通过Open Implementation跳转到PhoneStatusBar.java中的addIcon()方法中(因为我们之前传递的Context是PhoneStatusBar的)，代码如下：
public void addIcon(String slot, int index, int viewIndex, StatusBarIcon icon) {
if (SPEW) Slog.d(TAG, "addIcon slot=" + slot + " index=" + index + " viewIndex=" + viewIndex
+ " icon=" + icon);
//初始化StatusBarIconView
StatusBarIconView view = new StatusBarIconView(mContext, slot, null);
//加载icon
view.set(icon);
//这里的FEATURE_ANNUCIATOR_NEW_STATUSBAR_STYLE是高通自己定义的，默认为true
if (FeatureQuery.FEATURE_ANNUCIATOR_NEW_STATUSBAR_STYLE) {
//将设置好icon的StatusBarIconView加载到mStatusIcons布局中
mStatusIcons.addView(view, viewIndex, new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, mIconSize));
} else {
mStatusIcons.addView(view, viewIndex, new LinearLayout.LayoutParams(mIconSize, mIconSize));
}
}整个加载过程从表面上看来只有3步，但从本质上来讲远远不止3步。首先，我们先来看看addIcon(...)方法所传递的值；我将这里Slog中的内容打印出来，结果如下：
addIcon slot=tty index=6 viewIndex=0 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f02012b level=0 visible=false num=0 )
addIcon slot=cdma_eri index=11 viewIndex=1 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f0200d8 level=0 visible=false num=0 )
addIcon slot=bluetooth index=4 viewIndex=0 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f020073 level=0 visible=false num=0 )
addIcon slot=alarm_clock index=18 viewIndex=3 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f020060 level=0 visible=false num=0 )
addIcon slot=sync_active index=2 viewIndex=0 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f020129 level=0 visible=false num=0 )
addIcon slot=sync_failing index=1 viewIndex=0 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f02012a level=0 visible=false num=0 )
addIcon slot=volume index=9 viewIndex=4 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f0200d6 level=0 visible=false num=0 )
addIcon slot=headset index=16 viewIndex=6 icon=StatusBarIcon(pkg=com.android.systemui id=0x7f02000a level=0 visible=false num=0 ) public StatusBarIconView(Context context, String slot, Notification notification) {
super(context);
//获取资源
final Resources res = context.getResources();
mSlot = slot;
//画笔初始化
mNumberPain = new Paint();
mNumberPain.setTextAlign(Paint.Align.CENTER);
mNumberPain.setColor(res.getColor(R.drawable.notification_number_text_color));
mNumberPain.setAntiAlias(true);
mNotification = notification;
setContentDescription(notification);
// We do not resize and scale system icons (on the right), only notification icons (on the
// left).
if (notification != null) {
final int outerBounds = res.getDimensionPixelSize(R.dimen.status_bar_icon_size);
final int imageBounds = res.getDimensionPixelSize(R.dimen.status_bar_icon_drawing_size);
final float scale = (float)imageBounds / (float)outerBounds;
setScaleX(scale);
setScaleY(scale);
final float alpha = res.getFraction(R.dimen.status_bar_icon_drawing_alpha, 1, 1);
setAlpha(alpha);
}
//按图片原来的size居中显示
setScaleType(ImageView.ScaleType.CENTER);
}通过查看StatusBarIconView的继承关系我们可以发现public class StatusBarIconView extends AnimatedImageView ，继续跟踪可以看到public class AnimatedImageView extends ImageView，也就是说我们的StatusBarIconView其实就是一个封装过的ImageView，这样自然能够盛放我们的Icons了。继续查看StatusBarIconView的set()方法，代码如下：
/**
* Returns whether the set succeeded.
*/
public boolean set(StatusBarIcon icon) {
final boolean iconEquals = mIcon != null
&& streq(mIcon.iconPackage, icon.iconPackage)
&& mIcon.iconId == icon.iconId;
final boolean levelEquals = iconEquals
&& mIcon.iconLevel == icon.iconLevel;
final boolean visibilityEquals = mIcon != null
&& mIcon.visible == icon.visible;
final boolean numberEquals = mIcon != null
&& mIcon.number == icon.number;
//将icon的信息copy到mIcon中
mIcon = icon.clone();
setContentDescription(icon.contentDescription);
//获取icon图片并设置到StatusBarIconView中去
if (!iconEquals) {
Drawable drawable = getIcon(icon);
if (drawable == null) {
Slog.w(StatusBar.TAG, "No icon for slot " + mSlot);
return false;
}
setImageDrawable(drawable);
}
//设置需要显示的图片
if (!levelEquals) {
setImageLevel(icon.iconLevel);
}
//这个不太清楚具体是干嘛的
if (!numberEquals) {
if (icon.number > 0 && mContext.getResources().getBoolean(
R.bool.config_statusBarShowNumber)) {
if (mNumberBackground == null) {
mNumberBackground = getContext().getResources().getDrawable(
R.drawable.ic_notification_overlay);
}
placeNumber();
} else {
mNumberBackground = null;
mNumberText = null;
}
invalidate();
}
//设置是否可见
if (!visibilityEquals) {
setVisibility(icon.visible ? VISIBLE : GONE);
}
return true;
}到这一步时，我们已经将系统的Icons设置到了mStatusIcons这个mStatusIcons的LinearLayout上了。
但是，事实真的如此吗？这样就完成icons的初始化了吗？还是那句话，实践是检验真理是否正确的唯一标准！那么我们在PhoneStatusBar.java的addIcon()方法中，加入代码，将程序调用栈打印出来，结果一看便知(当然，也可以用Eclipse的远程调试)！加入代码如下：
StackTraceElement st[]= Thread.currentThread().getStackTrace();
for(int i=0;iI/System.out(420): 0:dalvik.system.VMStack.getThreadStackTrace(Native Method)
I/System.out(420): 1:java.lang.Thread.getStackTrace(Thread.java:591)
I/System.out(420): 2:com.android.systemui.statusbar.phone.PhoneStatusBar.addIcon(PhoneStatusBar.java:562)
I/System.out(420): 3:com.android.systemui.statusbar.CommandQueue$H.handleMessage(CommandQueue.java:212)
I/System.out(420): 4:android.os.Handler.dispatchMessage(Handler.java:99)
I/System.out(420): 5:android.os.Looper.loop(Looper.java:137)
I/System.out(420): 6:android.app.ActivityThread.main(ActivityThread.java:4450)
I/System.out(420): 7:java.lang.reflect.Method.invokeNative(Native Method)
I/System.out(420): 8:java.lang.reflect.Method.invoke(Method.java:511)
I/System.out(420): 9:com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
I/System.out(420): 10:com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
I/System.out(420): 11:dalvik.system.NativeStart.main(Native Method)
... ...
从打印出来的调用栈，我们可以发现，实际条用addIcon()方法的，并不是我们之前分析的StatusBar，而是来自CommandQueue中的handleMessage，这和我们之前的分析大相径庭啊！也就是说实际上addIcon()在CommandQueue中被调用了，那么我们就反过来分析，直接去CommandQueue.java中的handleMessage找到addIcon()。代码如下：
case OP_SET_ICON: {
StatusBarIcon icon = (StatusBarIcon)msg.obj;
StatusBarIcon old = mList.getIcon(index);
if (old == null) {
mList.setIcon(index, icon);
mCallbacks.addIcon(mList.getSlot(index), index, viewIndex, icon);
} else {
mList.setIcon(index, icon);
mCallbacks.updateIcon(mList.getSlot(index), index, viewIndex,
old, icon);
}
break;
}通过case OP_SET_ICON我们可以继续追查，我们可以查到是谁发送的这个message，代码如下：
public void setIcon(int index, StatusBarIcon icon) {
synchronized (mList) {
int what = MSG_ICON | index;
mHandler.removeMessages(what);
mHandler.obtainMessage(what, OP_SET_ICON, 0, icon.clone()).sendToTarget();
}
}图 1
其中第一个onTransact是一个IBinder，后两者是StatusBarManagerService中的方法。通过方法名称，我们可以大致猜测，setIcon是设置Icon，setIconVisibility是这是Icon是否可见，我们从逻辑上分析，如果是开机第一次调用我们应该先设置Icon然后再考虑设置其可见性(看完后文就会明白了:D)。我们直接跳转到StatusBarManagerService中的setIcon()方法，代码如下：
public void setIcon(String slot, String iconPackage, int iconId, int iconLevel,
String contentDescription) {
enforceStatusBar();
synchronized (mIcons) {
int index = mIcons.getSlotIndex(slot);//这里会检查是否是未定义的icon，如果是则抛出异常
if (index < 0) {
throw new SecurityException("invalid status bar icon slot: " + slot);
}
StatusBarIcon icon = new StatusBarIcon(iconPackage, iconId, iconLevel, 0,
contentDescription);
//Slog.d(TAG, "setIcon slot=" + slot + " index=" + index + " icon=" + icon);
mIcons.setIcon(index, icon);
if (mBar != null) {
try {
mBar.setIcon(index, icon);//这里调用的
} catch (RemoteException ex) {
}
}
}
}继续用Open Call Hierarchy查找哪里调用的setIcon方法，如图2：
图 2
这里一看就知道应该是StatusBarManager中的setIcon嘛，继续跟踪，代码如下：
public void setIcon(String slot, int iconId, int iconLevel, String contentDescription) {
try {
final IStatusBarService svc = getService();
if (svc != null) {
svc.setIcon(slot, mContext.getPackageName(), iconId, iconLevel,
contentDescription);//这里调用的
}
} catch (RemoteException ex) {
// system process is dead anyway.
throw new RuntimeException(ex);
}
}目前看来还不是很清晰，继续查找，如图3：
图 3
看到这里请不要头晕，因为真相就在眼前！那么这里应该是谁在调用呢？在本文的一开始，我们就分析了/SourceCode/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java的start()方法，在该方法中有如下代码：
mIconPolicy = new PhoneStatusBarPolicy(mContext);
public PhoneStatusBarPolicy(Context context) {
... ...
// listen for broadcasts
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_ALARM_CHANGED);
filter.addAction(Intent.ACTION_SYNC_STATE_CHANGED);
filter.addAction(AudioManager.RINGER_MODE_CHANGED_ACTION);
filter.addAction(AudioManager.VIBRATE_SETTING_CHANGED_ACTION);
filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
filter.addAction(Intent.ACTION_HEADSET_PLUG); // ted add 2021-4-24
filter.addAction(BluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED);
filter.addAction(TelephonyIntents.ACTION_SIM_STATE_CHANGED);
filter.addAction(TtyIntent.TTY_ENABLED_CHANGE_ACTION);
mContext.registerReceiver(mIntentReceiver, filter, null, mHandler);
... ...
// TTY status
mService.setIcon("tty", R.drawable.stat_sys_tty_mode, 0, null);//这里调用
mService.setIconVisibility("tty", false);
// Cdma Roaming Indicator, ERI
mService.setIcon("cdma_eri", R.drawable.stat_sys_roaming_cdma_0, 0, null);//这里调用
mService.setIconVisibility("cdma_eri", false);
... ...
mService.setIcon("bluetooth", bluetoothIcon, 0, null);//这里调用
mService.setIconVisibility("bluetooth", mBluetoothEnabled);
// Alarm clock
mService.setIcon("alarm_clock", R.drawable.stat_sys_alarm, 0, null);//这里调用
mService.setIconVisibility("alarm_clock", false);
// Sync state
mService.setIcon("sync_active", R.drawable.stat_sys_sync, 0, null);//这里调用
mService.setIcon("sync_failing", R.drawable.stat_sys_sync_error, 0, null);//这里调用
mService.setIconVisibility("sync_active", false);
mService.setIconVisibility("sync_failing", false);
// volume
mService.setIcon("volume", R.drawable.stat_sys_ringer_silent, 0, null);//这里调用
mService.setIconVisibility("volume", false);
updateVolume();
// headset
mService.setIcon("headset", R.drawable.ckt_headset_with_mic, 0, null);//这里调用
mService.setIconVisibility("headset", false);
}这里也同时验证了我们前面的猜想，即先设置Icon再设置其可见性。也许你会认为本文到这里已经完结了(太长了，一次看不完...o(╯□╰)o)，但有个别地方我还得再提一下，Android 启动之后，在SystemServer.java的run方法中，调用了StatusBarManagerService的构造方法，代码如下：
... ...
try {
Slog.i(TAG, "Status Bar");
statusBar = new StatusBarManagerService(context, wm);
ServiceManager.addService(Context.STATUS_BAR_SERVICE, statusBar);
} catch (Throwable e) {
reportWtf("starting StatusBarManagerService", e);
}
... ... public StatusBarManagerService(Context context, WindowManagerService windowManager) {
mContext = context;
mWindowManager = windowManager;
mWindowManager.setOnHardKeyboardStatusChangeListener(this);
final Resources res = context.getResources();
//这里加载了系统预置的所有icon，路径在：Sourcecode/framework/base/core/res/res/values/config.xml中
mIcons.defineSlots(res.getStringArray(com.android.internal.R.array.config_statusBarIcons));
}其中Sourcecode/framework/base/core/res/res/values/config.xml中的预置图标定义如下：
ime sync_failing sync_active gps bluetooth nfc tty speakerphone mute volume wifi cdma_eri phone_signal_second_sub data_connection phone_evdo_signal phone_signal headset battery alarm_clock secure clock 这些东西在后文判断时都会用到，在此记录用以备忘。
Update 20120810 时序图和UML图：
图 4
图 5
小结
本文主要是对StatusBar上面的Icons的加载进行了较为细致的分析，后面将继续分析各个部件的加载以及工作流程。其中自己也走了不少弯路，但还是想记录下载，毕竟没有谁从一开始就能做正确吧！将此总结分享出来希望能给各位一些帮助，同时也给自己一些激励，希望自己后面能做的更好。本文主要是枯燥的代码调用与追踪，但对于需要的朋友，我想还是很有帮助的，后面会将相关的时序图以及UML图贴出来，以供参考。