Android 2.3 StatusBar 分析（二）

1，Status Bar 上的icon 的配置
android 预定义需要在status bar上显示的icon.其在framework/base/core/res/res/values/config.xml

<!-- Component to be used as the status bar service.  Must implement the IStatusBar
         interface.  This name is in the ComponentName flattened format (package/class)  -->
    <string name="config_statusBarComponent">com.android.systemui/com.android.systemui.statusbar.StatusBarService</string>

    <!-- Do not translate. Defines the slots for the right-hand side icons.  That is to say, the
         icons in the status bar that are not notifications. -->
    <string-array name="config_statusBarIcons">
       <item><xliff:g id="id">ime</xliff:g></item>
       <item><xliff:g id="id">sync_failing</xliff:g></item>
       <item><xliff:g id="id">sync_active</xliff:g></item>
       <item><xliff:g id="id">gps</xliff:g></item>
       <item><xliff:g id="id">bluetooth</xliff:g></item>
       <item><xliff:g id="id">nfc</xliff:g></item>
       <item><xliff:g id="id">tty</xliff:g></item>
       <item><xliff:g id="id">speakerphone</xliff:g></item>
       <item><xliff:g id="id">mute</xliff:g></item>
       <item><xliff:g id="id">volume</xliff:g></item>
       <item><xliff:g id="id">wifi</xliff:g></item>
       <item><xliff:g id="id">cdma_eri</xliff:g></item>
       <item><xliff:g id="id">data_connection</xliff:g></item>
       <item><xliff:g id="id">phone_evdo_signal</xliff:g></item>
       <item><xliff:g id="id">phone_signal</xliff:g></item>
       <item><xliff:g id="id">battery</xliff:g></item>
       <item><xliff:g id="id">alarm_clock</xliff:g></item>
       <item><xliff:g id="id">headset</xliff:g></item>
       <item><xliff:g id="id">secure</xliff:g></item>
       <item><xliff:g id="id">clock</xliff:g></item>
    </string-array>

这些icon在这个string array的位置就决定了其在status bar 上显示的位置了。我们可以从code里面得出该结论。所以当你要调换icon的顺序时，改动这个config.xml就可以了。下面我们来看如何得到该结论：
1,在StatusBarManagerService 初始化的时候就会读取config.xml下icons 的String array.
1)StatusBarManagerService.java

StatusBarIconList mIcons = new StatusBarIconList();
public StatusBarManagerService(Context context) {
        mContext = context;

        final Resources res = context.getResources();
        mIcons.defineSlots(res.getStringArray(com.android.internal.R.array.config_statusBarIcons));
    }

2)StatusBarIconList.java

    
public void defineSlots(String[] slots) {
        final int N = slots.length;
        String[] s = mSlots = new String[N];
        for (int i=0; i<N; i++) {
            s[i] = slots[i];
            Slog.i("", "StatusBarIconList "+i+" : "+ slots[i]);
        }
        mIcons = new StatusBarIcon[N];
    }

这里的mSlots这个string array就是保存了刚才config.xml中读出来的,并new 对应数目的StatusBarIcon。

3)StatusBarPolicy.java

// battery
        mService.setIcon("battery", com.android.internal.R.drawable.stat_sys_battery_unknown, 0);
....
mService.setIcon("data_connection", R.drawable.stat_sys_data_connected_g, 0);
....

4)StatusBarManager.java

 public void setIcon(String slot, int iconId, int iconLevel) {
    	 
        try {
            mService.setIcon(slot, mContext.getPackageName(), iconId, iconLevel);
            Slog.i("StatusBarManager", "setIcon: slot"+slot+" packageName:"+ mContext.getPackageName());
        } catch (RemoteException ex) {
            // system process is dead anyway.
            throw new RuntimeException(ex);
        }
    }

5)StatusBarManagerService.java

 public void setIcon(String slot, String iconPackage, int iconId, int iconLevel) {
        enforceStatusBar();

        synchronized (mIcons) {
            int index = mIcons.getSlotIndex(slot);
            if (index < 0) {
                throw new SecurityException("invalid status bar icon slot: " + slot);
            }

            StatusBarIcon icon = new StatusBarIcon(iconPackage, iconId, iconLevel);
            Slog.d(TAG, "setIcon slot=" + slot + " index=" + index + " icon=" + icon);
            mIcons.setIcon(index, icon);

            if (mBar != null) {
                try {
                    mBar.setIcon(index, icon);
                } catch (RemoteException ex) {
                }
            }
        }
    }

 // ================================================================================
    // Callbacks from the status bar service.
    // ================================================================================
    public void registerStatusBar(IStatusBar bar, StatusBarIconList iconList,
            List<IBinder> notificationKeys, List<StatusBarNotification> notifications) {
        enforceStatusBarService();

        Slog.i(TAG, "registerStatusBar bar=" + bar);
        mBar = bar;
        synchronized (mIcons) {
            iconList.copyFrom(mIcons);
        }
        synchronized (mNotifications) {
        	Slog.i(TAG, "mNotifications=" + mNotifications.);
            for (Map.Entry<IBinder,StatusBarNotification> e: mNotifications.entrySet()) {
                notificationKeys.add(e.getKey());
                notifications.add(e.getValue());
            }
        }
    }

这里的registerStatusBar会在StatusBarService的onCreate的时候调用：

StatusBarIconList iconList = new StatusBarIconList();
        ArrayList<IBinder> notificationKeys = new ArrayList<IBinder>();
        ArrayList<StatusBarNotification> notifications = new ArrayList<StatusBarNotification>();
        mCommandQueue = new CommandQueue(this, iconList);
        mBarService = IStatusBarService.Stub.asInterface(
                ServiceManager.getService(Context.STATUS_BAR_SERVICE));
        hardware = IHardwareService.Stub.asInterface(ServiceManager.getService("hardware")); // helen
        try {
            mBarService.registerStatusBar(mCommandQueue, iconList, notificationKeys, notifications);
        } catch (RemoteException ex) {
            // If the system process isn't there we're doomed anyway.
        }

6）CommandQueue。java

  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();
        }
    }


 case MSG_ICON: {
                    final int index = msg.what & INDEX_MASK;
                    final int viewIndex = mList.getViewIndex(index);
                    switch (msg.arg1) {
                        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;
                        }
                        case OP_REMOVE_ICON:
                            if (mList.getIcon(index) != null) {
                                mList.removeIcon(index);
                                mCallbacks.removeIcon(mList.getSlot(index), index, viewIndex);
                            }
                            break;
                    }
                    break;
                }

7)StatusBarService.java

    public void addIcon(String slot, int index, int viewIndex, StatusBarIcon icon) {
        if (SPEW_ICONS) {
            Slog.d(TAG, "addIcon slot=" + slot + " index=" + index + " viewIndex=" + viewIndex
                    + " icon=" + icon);
        }
        StatusBarIconView view = new StatusBarIconView(this, slot);
        view.set(icon);
        mStatusIcons.addView(view, viewIndex, new LinearLayout.LayoutParams(mIconSize, mIconSize));
    }