PendingIntent
Intent是一个意图，一个描述了想要启动一个Activity、Broadcast或是Service的意图。它主要持有的信息是它想要启动的组件（Activity、Broadcast或是Service）。
PendingIntent可以看作是对Intent的包装。供当前App之外的其他App调用。有点“被动”或是“Callback”的意思，但不是严格意义上的“被动”或是“Callback”。总之，当前App不能用它马上启动它所包裹的Intent。而是在外部App执行这个PendingIntent时，间接地、实际地调用里面的Intent。PendingIntent主要持有的信息是它所包装的Intent和当前App的Context。正由于PendingIntent中保存有当前App的Context，使它赋予外部App一种能力，使得外部App可以如同当前App一样的执行PendingIntent里的Intent，就算在执行时当前App已经不存在了，也能通过存在PendingIntent里的Context照样执行Intent。
参考：
NotificationManager
源码位置：framework/base/core/java/android/app/NotificationManager.java
enuqunotificationwithtag
功能：
负责“发出”与“取消” Notification。
方法：
notify()；
cancel()；
INotificationManager.Java
frameworks/base/services/java/com/android/server/ NotificationManagerService.java
Notification
SystemServer.java
StatusBarManagerService.java(初始化)
NotificationManagerService.java（statusBarManagerService.setNotificationCallBack）
[systemreadly]
SystemUIService.java----onCreate(); --- for( SystemUI.start() )
StatusBar.java --- start() -- registerStatusBar();
mandQueue.java 通过handler更新ui
./base/packages/SystemUI/src/com/android/systemui/statusbar/CommandQueue.java()
nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
n = new Notification();
n.flags = Notification.FLAG_ONGOING_EVENT;
n.icon = R.drawable.notify;
n.tickerText = "一个通知";
n.when = System.currentTimeMillis();
nm.notify(id,n);
|
开机 |
| SystemServer |
| StatusBarManagerService |
| NotificationManagerService |
| SystemUIService |
| PhoneStatusBar |
| CommandQueue |
| NotificationManager |
|
发起Notification |
| 开机 启动过程 |
| 通知更新 |
| 绑定Statusbar |
| 通知有Notification需要更新
|
| 通知更新ui |
StatusBar分为两个部分：一是通常在手机界面最上端的未下拉的statusbar；二是下拉状态栏，也就是扩展状态栏。
通过在实际应用中，我们可以发现，statusbar就是一个activity，那么，它的使用自然少不了和service之间的交互。
PhoneStatusBar 通过IStatusBarService来访问StatusBarManagerService，而
StatusBarManagerService通过CommandQueue来和PhoneStatusBar进行交互。
一、StatusBar.java
通过class StatusBar的声明，我们可以看出，它或者其子类实现和StatusBarManagerService进行交互的CommandQueue的回调方法。
public abstract class StatusBar extends SystemUI implements CommandQueue.Callbacks {
public void start() {
View sb = makeStatusBarView();
//创建包括在config.xml中定义要在statusbar上显示的所有icons，那么它包含icons个数在何处初始化？
StatusBarIconList iconList = new StatusBarIconList();
（frameworks\base\core\java\com\android\internal\statusbar）
//保存Notification是以Binder为key的
ArrayList<IBinder> notificationKeys = new ArrayList<IBinder>();
//保存在statusbar上显示的StatusBarNotification
ArrayList<StatusBarNotification> notifications = new ArrayList<StatusBarNotification>();
//和IStatusBarService进行交互的IBinder
mCommandQueue = new CommandQueue(this, iconList);
//获取StatusBarManagerService的本地实现
mBarService = IStatusBarService.Stub.asInterface(
ServiceManager.getService(Context.STATUS_BAR_SERVICE));
int[] switches = new int[7];
ArrayList<IBinder> binders = new ArrayList<IBinder>();
try {
//这一步实际上就是将PhoneStatusBar的实现的CommandQueue其中包含
//callbacks传递给StatusbarManagerService使用
mBarService.registerStatusBar(mCommandQueue,
iconList, notificationKeys, notifications,
switches, binders);
} catch (RemoteException ex) {
// If the system process isn't there we're doomed anyway.
}
for (int i=0; i<N; i++) {
//这里第一次使用时icon仅仅是开辟一个存储空间，i代表的是数组的index，而viewIndex和i对应
StatusBarIcon icon = iconList.getIcon(i);
if (icon != null) {
addIcon(iconList.getSlot(i), i, viewIndex, icon);
viewIndex++;
}
}
N = notificationKeys.size();
if (N == notifications.size()) {
for (int i=0; i<N; i++) {
addNotification②(notificationKeys.get(i), notifications.get(i));
}
} else {
}
//xml文件中定义的statusbar的height
(frameworks\base\core\res\res\values)
final int height = getStatusBarHeight();
}
//这里将所有的状态栏上的view先初始化
WindowManagerImpl.getDefault().addView(sb, lp);
}
二、PhoneStatusBar.java
public class PhoneStatusBar extends StatusBar {
}
PhoneStatusBar 是StatusBar(extends SystemUI)的子类，真正和StatusBarManagerService交互的实际上就是它。
对于SystemUI，首先启动的是Start();
public void start() {
……
//调用StatusBar的start方法，建立和StatusbarManagerService之间的联系
super.start();//在StatusBar的start中实现makeStatusBarView然后初始化statusbar icon状态
//启动更新Icon的方法
mIconPolicy = new PhoneStatusBarPolicy(mContext);
}
super.start()中我们看到，StatusBar是一个abstract类，真正要建立View是不能够的，必须在子类中创建。
实际上，StatusBar中也这样定义protected abstract View makeStatusBarView()
PhoneStatusBar 中：
protected View makeStatusBarView() {
final Context context = mContext;
Resources res = context.getResources();
//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);
//状态栏下拉时的view
ExpandedView expanded = (ExpandedView)View.inflate(context,
R.layout.status_bar_expanded, null);
//真正显示的statusbar是根据是否是双卡来选择xml文件
PhoneStatusBarView sb;
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);
}
//获取statusbar的实例
sb.mService = this;
mStatusBarView = sb;
//显示statusbar icon的view
mStatusIcons = (LinearLayout)sb.findViewById(R.id.statusIcons);
//显示notification的view
mNotificationIcons = (IconMerger)sb.findViewById(R.id.notificationIcons);
mMoreIcon = sb.findViewById(R.id.moreIcon);
//定义下拉状态栏，显示Notifications
mExpandedDialog = new ExpandedDialog(context);
/*这个expanded就是指layout下的status_bar_expanded.xml解析所得下拉状态栏*/
mExpandedView = expanded;
//显示Notification的控件，NotificationRowLayout是处理函数，
mPile = (NotificationRowLayout)expanded.findViewById(R.id.latestItems);
mExpandedContents = mPile; // was: expanded.findViewById(R.id.notificationLinearLayout);
//Android2.3中显示onGoing等信息的textview，android4.0已经不用了
mNoNotificationsTitle = (TextView)expanded.findViewById(R.id.noNotificationsTitle);
mNoNotificationsTitle.setVisibility(View.GONE);
……
}
在步骤一的函数start()中的标识①处调用的是PhoneStatusBar的函数，在那里初始化status bar icon，
前面说了，在registerStatusBar时获得的iconList是没有icon的
public void addIcon(String slot, int index, int viewIndex, StatusBarIcon icon) {
//依据config.xml中的config_statusBarIcons定义的字符串创建StatusBarIconView,注意
//mContext是PhoneStatusBar的mContext
StatusBarIconView view = new StatusBarIconView(mContext, slot, null);
//设置显示的icon
view.set(icon);
//添加到msim_status_bar.xml的保存icon的view中去
if (FeatureQuery.FEATURE_ANNUCIATOR_NEW_STATUSBAR_STYLE) {
mStatusIcons.addView(view, viewIndex,
new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, mIconSize));
} else {
mStatusIcons.addView(view, viewIndex,
new LinearLayout.LayoutParams(mIconSize, mIconSize));
}
}
在PhoneStatusBar.java中用到下面这两个类
StatusBarIconsView.java
public class StatusBarIconView extends AnimatedImageView
public StatusBarIconView(Context context, String slot, Notification notification) {
final Resources res = context.getResources();
mSlot = slot;
mNumberPain = new Paint();
mNumberPain.setTextAlign(Paint.Align.CENTER);
mNumberPain.setColor(res.getColor(R.drawable.notification_number_text_color));
mNumberPain.setAntiAlias(true);
mNotification = notification;
……
setScaleType(ImageView.ScaleType.CENTER);
}
}
由class的声明可以看出，StatusBarIconView是一个AnimatedImageView，因此，可以显示icon
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信息拷贝给mIcon
mIcon = icon.clone();
if (!iconEquals) {
Drawable drawable = getIcon(icon);
if (drawable == null) {
return false;
}
//下面两步就是获取drawable，然后设置到view中去
setImageDrawable(drawable);
}
}
private Drawable getIcon(StatusBarIcon icon) {
//我们在PhoneStatusBar中创建StatusBarIconView时传了mContext，因此这里getContext()
//也是PhoneStatusBar的
return getIcon(getContext(), icon);
}
public static Drawable getIcon(Context context, StatusBarIcon icon) {
……
try {
//获取icon
return r.getDrawable(icon.iconId);
} catch (RuntimeException e) {
}
return null;
}
只有在下面这个类中才正式显示icon在statusbar上
PhoneStatusBarPolicy.java
Context是PhoneStatusBar的mContext
public PhoneStatusBarPolicy(Context context) {
//StatusBarManagerService
mService = (StatusBarManager)context.getSystemService(Context.STATUS_BAR_SERVICE);
mStorageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
mStorageManager.registerListener(
new com.Android.systemui.usb.StorageNotification(context));
// TTY status
mService.setIcon("tty", R.drawable.stat_sys_tty_mode, 0, null);
// Alarm clock
mService.setIcon("alarm_clock", R.drawable.stat_sys_alarm, 0, null);
mService.setIconVisibility("alarm_clock", false);
// volume
mService.setIcon("volume", R.drawable.stat_sys_ringer_silent, 0, null);
mService.setIconVisibility("volume", false);
updateVolume();
//headset
mService.setIcon("headset", com.Android.internal.R.drawable.stat_sys_headset, 0, null);
mService.setIconVisibility("headset", false);
}
上面的mService是StatusBarManager，那么setIcon是操作如下：
StatusBarManager.java
public void setIcon(String slot, int iconId, int iconLevel, String contentDescription) {
try {
//StatusBarManagerService的本地代理service
final IStatusBarService svc = getService();
if (svc != null) {
svc.setIcon(slot, mContext.getPackageName(), iconId, iconLevel,
contentDescription);
}
} catch (RemoteException ex) {
// system process is dead anyway.
throw new RuntimeException(ex);
}
}
三、StatusBarManagerService.java
前面，我们启动PhoneStatusBar时会调用StatusBar的start函数，在这里和StatusbarManagerService
建立联系。
StatusBar.java中
mBarService.registerStatusBar(mCommandQueue, iconList, notificationKeys, notifications,
switches, binders);
public class StatusBarManagerService extends IStatusBarService.Stub
implements WindowManagerService.OnHardKeyboardStatusChangeListener
{
public StatusBarManagerService(Context context, WindowManagerService windowManager) {
mContext = context;
mWindowManager = windowManager;
mWindowManager.setOnHardKeyboardStatusChangeListener(this);
final Resources res = context.getResources();
//这里，获取config_statusBarIcons.xm中定义的显示icon的数组
mIcons.defineSlots(res.
getStringArray(com.Android.internal.R.array.config_statusBarIcons));
}
}
public void registerStatusBar(IStatusBar bar, StatusBarIconList iconList,
List<IBinder> notificationKeys, List<StatusBarNotification> notifications,
int switches[], List<IBinder> binders) {
//这个bar就是CommandQueue在PhoneStatusbar中的实现callbacks
mBar = bar;
synchronized (mIcons) {
//将初始化这个service时获取的config_statusBarIcons数组中字符串保存到iconList，
//也就是传递给PhoneStatusBar使用了
iconList.copyFrom(mIcons);
}
synchronized (mNotifications) {
for (Map.Entry<IBinder,StatusBarNotification> e: mNotifications.entrySet()) {
notificationKeys.add(e.getKey());
notifications.add(e.getValue());
}
}
……
}
public void setIcon(String slot, String iconPackage, int iconId, int iconLevel,
String contentDescription) {
enforceStatusBar();
synchronized (mIcons) {
//也就是当前这个slot在数组中的index
int index = mIcons.getSlotIndex(slot);
//如果没有定义的slot，就报异常
if (index < 0) {
throw new SecurityException("invalid status bar icon slot: " + slot);
}
//这才正式创建StatusBarIcon，iconPackage是PhoneStatusBar的，iconId就是我们设置的
StatusBarIcon icon = new StatusBarIcon(iconPackage, iconId, iconLevel, 0,
contentDescription);
//数组中对应的index设置了icon
mIcons.setIcon(index, icon);
if (mBar != null) {
try {
mBar.setIcon(index, icon);
} catch (RemoteException ex) {
}
}
}
}
CommandQueue.java
public void setIcon(int index, StatusBarIcon icon) {
synchronized (mList) {
//mList用的也是StatusBarManagerService中初始化的iconList
int what = MSG_ICON | index;
mHandler.removeMessages(what);
mHandler.obtainMessage(what, OP_SET_ICON, 0, icon.clone()).sendToTarget();
}
}
private final class H extends Handler {
public void handleMessage(Message msg) {
final int what = msg.what & MSG_MASK;
switch (what) {
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;
//mList
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;
}
}
}
最后就是调用PhoneStatusBar的addIcon。至此，就用StatusBar显示了icon