Android学习——systemUIService 类分析

基于Android4.4 systemUIService.java  类分析

首先创建了并引用了一个类的数组mServices。数组类的成员均继承systemUI

    private final Class<?>[] SERVICES = new Class[] {            com.android.systemui.recent.Recents.class, // 最近应用            com.android.systemui.statusbar.SystemBars.class, // 系统状态栏            com.android.systemui.usb.StorageNotification.class, // storage存储通知            com.android.systemui.power.PowerUI.class, // 电量管理相关            com.android.systemui.media.RingtonePlayer.class, //铃声播放            com.android.systemui.settings.SettingsUI.class, // 设置相关        };    /**     * Hold a reference on the stuff we start.     */    private final SystemUI[] mServices = new SystemUI[SERVICES.length];

在onCreate() 中遍历数组中成员初始化并执行start()

  public void onCreate() {        HashMap<Class<?>, Object> components = new HashMap<Class<?>, Object>();        final int N = SERVICES.length;        for (int i=0; i<N; i++) {            Class<?> cl = SERVICES[i];            Log.d(TAG, "loading: " + cl);            try {                mServices[i] = (SystemUI)cl.newInstance();            } catch (IllegalAccessException ex) {                throw new RuntimeException(ex);            } catch (InstantiationException ex) {                throw new RuntimeException(ex);            }            mServices[i].mContext = this; //             mServices[i].mComponents = components;             Log.d(TAG, "running: " + mServices[i]);            mServices[i].start();        }    }

同时在该类中重写onConfigurationChanged()方法并调用mServices数组中所有成员的onConfigurationChanged（）方法，进而实现对 “相关事件改变” 执行对应的动作。

 public void onConfigurationChanged(Configuration newConfig) {        for (SystemUI ui: mServices) {            ui.onConfigurationChanged(newConfig);        }    }