android sevice系列之 StatusBarService

2011/3/21  23:56

 

Android状态栏管理
android的状态栏：

 

在android中，状态栏不属于某个应用程序，而是系统的一部分，是通过StatusBarService来管理的。

Android通过StatusBarPolicy及StatusBarService来管理状态栏。
一．    StatusBarPolicy 负责状态栏显示的策略管理
Android中状态栏上有很多图标，这些图标什么时候显示什么时候不显示？这些都是 StatusBarPolicy来管理的。
StatusBarPolicy的构造函数里初始化了好几个图标，如时间icon，闹钟icon，信号栏icon等。默认时有很多图标是不显示的，需要显示时再进行更新。StatusBarPolicy调用 registerReceiver注册了感兴趣的intent,当感兴趣的intent发生时，对图标进行更新。例如，设置一个闹钟后，闹钟模块会发出一个叫做Intent.ACTION_ALARM_CHANGED的intent，然后StatusBarPolicy接收到此intent，继而更新状态栏上的闹钟图标。
见如下的代码：

private StatusBarPolicy(Context context, StatusBarService service) { mContext = context; mService = service; // clock mCalendar = Calendar.getInstance(TimeZone.getDefault()); mClockData = IconData.makeText("clock", ""); mClockIcon = service.addIcon(mClockData, null); updateClock(); // battery mBatteryData = IconData.makeIcon("battery", null, com.android.internal.R.drawable.stat_sys_battery_unknown, 0, 0); mBatteryIcon = service.addIcon(mBatteryData, null); // phone_signal mPhone = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE); mPhoneData = IconData.makeIcon("phone_signal", null, com.android.internal.R.drawable.stat_sys_signal_null, 0, 0); mPhoneIcon = service.addIcon(mPhoneData, null); // register for phone state notifications. ((TelephonyManager)mContext.getSystemService(Context.TELEPHONY_SERVICE)) .listen(mPhoneStateListener, PhoneStateListener.LISTEN_SERVICE_STATE | PhoneStateListener.LISTEN_SIGNAL_STRENGTH | PhoneStateListener.LISTEN_CALL_STATE | PhoneStateListener.LISTEN_DATA_CONNECTION_STATE | PhoneStateListener.LISTEN_DATA_ACTIVITY); // data_connection mDataData = IconData.makeIcon("data_connection", null, com.android.internal.R.drawable.stat_sys_data_connected_g, 0, 0); mDataIcon = service.addIcon(mDataData, null); service.setIconVisibility(mDataIcon, false); // wifi mWifiData = IconData.makeIcon("wifi", null, sWifiSignalImages[0], 0, 0); mWifiIcon = service.addIcon(mWifiData, null); service.setIconVisibility(mWifiIcon, false); // wifi will get updated by the sticky intents // bluetooth status mBluetoothData = IconData.makeIcon("bluetooth", null, com.android.internal.R.drawable.stat_sys_data_bluetooth, 0, 0); mBluetoothIcon = service.addIcon(mBluetoothData, null); updateBluetooth(null); // Gps status mGpsEnabledIconData = IconData.makeIcon("gps", null, com.android.internal.R.drawable.stat_sys_gps_acquiring_anim, 0, 0); mGpsFixIconData = IconData.makeIcon("gps", null, com.android.internal.R.drawable.stat_sys_gps_on, 0, 0); mGpsIcon = service.addIcon(mGpsEnabledIconData, null); service.setIconVisibility(mGpsIcon, false); // Alarm clock mAlarmClockIconData = IconData.makeIcon( "alarm_clock", null, com.android.internal.R.drawable.stat_notify_alarm, 0, 0); mAlarmClockIcon = service.addIcon(mAlarmClockIconData, null); service.setIconVisibility(mAlarmClockIcon, false); // Sync state mSyncActiveIcon = service.addIcon(IconData.makeIcon("sync_active", null, R.drawable.stat_notify_sync_anim0, 0, 0), null); mSyncFailingIcon = service.addIcon(IconData.makeIcon("sync_failing", null, R.drawable.stat_notify_sync_error, 0, 0), null); service.setIconVisibility(mSyncActiveIcon, false); service.setIconVisibility(mSyncFailingIcon, false); // volume mVolumeData = IconData.makeIcon("volume", null, com.android.internal.R.drawable.stat_sys_ringer_silent, 0, 0); mVolumeIcon = service.addIcon(mVolumeData, null); service.setIconVisibility(mVolumeIcon, false); IntentFilter filter = new IntentFilter(); // Register for Intent broadcasts for... filter.addAction(Intent.ACTION_TIME_TICK); filter.addAction(Intent.ACTION_TIME_CHANGED); filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED); filter.addAction(Intent.ACTION_BATTERY_CHANGED); filter.addAction(Intent.ACTION_TIMEZONE_CHANGED); 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(BluetoothIntent.ENABLED_ACTION); filter.addAction(BluetoothIntent.DISABLED_ACTION); filter.addAction(BluetoothIntent.HEADSET_STATE_CHANGED_ACTION); filter.addAction(BluetoothA2dp.SINK_STATE_CHANGED_ACTION); filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION); filter.addAction(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION); filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION); filter.addAction(WifiManager.RSSI_CHANGED_ACTION); filter.addAction(GpsLocationProvider.GPS_ENABLED_CHANGE_ACTION); filter.addAction(GpsLocationProvider.GPS_FIX_CHANGE_ACTION); filter.addAction(TelephonyIntents.ACTION_SIM_STATE_CHANGED); mContext.registerReceiver(mIntentReceiver, filter, null, mHandler); } 

二．    StatusBarService
正如上面看到的，StatusBarPolicy只是一个策略管理，实际的功能是StatusBarService来实现的。StatusBarService初始化时初始化了一个用于显示statusbar 的StatusBarView。StatusBarView里面定义了icon名字，的显示顺序，对应的png图等。代码如下：

public StatusBarService(Context context) { mContext = context; mDisplay = ((WindowManager)context.getSystemService( Context.WINDOW_SERVICE)).getDefaultDisplay(); makeStatusBarView(context); mUninstallReceiver = new UninstallReceiver(); } private void makeStatusBarView(Context context) { Resources res = context.getResources(); mRightIconSlots = res.getStringArray(com.android.internal.R.array.status_bar_icon_order); mRightIcons = new StatusBarIcon[mRightIconSlots.length]; ExpandedView expanded = (ExpandedView)View.inflate(context, com.android.internal.R.layout.status_bar_expanded, null); expanded.mService = this; StatusBarView sb = (StatusBarView)View.inflate(context, com.android.internal.R.layout.status_bar, null); sb.mService = this; …… } 

 

mRightIconSlots 是一个String型数组，里面记录了状态栏上各个图标的名字。StatusBarPolicy就是根据这个名字找到相应的icon，调用setIcon设置其图标。mRightIconSlots的值从/frameworks/base/core/res/res/values/arrays.xml 中获得，现摘取片段如下：

<string-array name="status_bar_icon_order"> <item>clock</item> <item>alarm_clock</item> <item>battery</item> <item>phone_signal</item> <item>data_connection</item> <item>volume</item> <item>mute</item> <item>speakerphone</item> <item>wifi</item> <item>bluetooth</item> <item>gps</item> <item>sync_active</item> <item>sync_failing</item> <item>ime</item> </string-array> 

由此已经可以看出要增加一个系统级图标，应该在此xml中增加相应的item，然后在StatusBarPolicy中做相应修改即可。