android源码浅析--notification

在上一篇文章中，用到了Notification，准备好好的看下notification的源码。

类概述：  

一个表示如何使用NotificationManager把一个持久的通知呈现给用户的类。
The 

Notification.Builder

 has been added to make it easier to construct Notifications.
添加Notification.Builder使构建Notification更容易。

        静态变量：

/**
* Use all default values (where applicable).
*/
public static final int DEFAULT_ALL = ~0;

/**
* Use the default notification sound. This will ignore any given
* {@link #sound}.
*
* @see #defaults
*/
public static final int DEFAULT_SOUND = 1;

/**
* Use the default notification vibrate. This will ignore any given
* {@link #vibrate}. Using phone vibration requires the
* {@link android.Manifest.permission#VIBRATE VIBRATE} permission.
*
* @see #defaults
*/
public static final int DEFAULT_VIBRATE = 2;

/**
* Use the default notification lights. This will ignore the
* {@link #FLAG_SHOW_LIGHTS} bit, and {@link #ledARGB}, {@link #ledOffMS}, or
* {@link #ledOnMS}.
*
* @see #defaults
*/
public static final int DEFAULT_LIGHTS = 4;
        定义了默认的灯、震动、声音和全部属性。震动的话需要添加android.permission.VIBRATE权限。
/**
* Use this constant as the value for audioStreamType to request that
* the default stream type for notifications be used. Currently the
* default stream type is STREAM_RING.
*/
public static final int STREAM_DEFAULT = -1;
        notification默认的音频类型。
/**
* Bit to be bitwise-ored into the {@link #flags} field that should be
* set if you want the LED on for this notification.
* <ul>
* <li>To turn the LED off, pass 0 in the alpha channel for colorARGB
* or 0 for both ledOnMS and ledOffMS.</li>
* <li>To turn the LED on, pass 1 for ledOnMS and 0 for ledOffMS.</li>
* <li>To flash the LED, pass the number of milliseconds that it should
* be on and off to ledOnMS and ledOffMS.</li>
* </ul>
* <p>
* Since hardware varies, you are not guaranteed that any of the values
* you pass are honored exactly. Use the system defaults (TODO) if possible
* because they will be set to values that work on any given hardware.
* <p>
* The alpha channel must be set for forward compatibility.
*
*/
public static final int FLAG_SHOW_LIGHTS = 0x00000001;

/**
* Bit to be bitwise-ored into the {@link #flags} field that should be
* set if this notification is in reference to something that is ongoing,
* like a phone call. It should not be set if this notification is in
* reference to something that happened at a particular point in time,
* like a missed phone call.
*/
public static final int FLAG_ONGOING_EVENT = 0x00000002;

/**
* Bit to be bitwise-ored into the {@link #flags} field that if set,
* the audio will be repeated until the notification is
* cancelled or the notification window is opened.
*/
public static final int FLAG_INSISTENT = 0x00000004;

/**
* Bit to be bitwise-ored into the {@link #flags} field that should be
* set if you want the sound and/or vibration play each time the
* notification is sent, even if it has not been canceled before that.
*/
public static final int FLAG_ONLY_ALERT_ONCE = 0x00000008;

/**
* Bit to be bitwise-ored into the {@link #flags} field that should be
* set if the notification should be canceled when it is clicked by the
* user. On tablets, the
*/
public static final int FLAG_AUTO_CANCEL = 0x00000010;

/**
* Bit to be bitwise-ored into the {@link #flags} field that should be
* set if the notification should not be canceled when the user clicks
* the Clear all button.
*/
public static final int FLAG_NO_CLEAR = 0x00000020;

/**
* Bit to be bitwise-ored into the {@link #flags} field that should be
* set if this notification represents a currently running service. This
* will normally be set for you by {@link Service#startForeground}.
*/
public static final int FLAG_FOREGROUND_SERVICE = 0x00000040;

/**
* Bit to be bitwise-ored into the {@link #flags} field that should be set if this notification
* represents a high-priority event that may be shown to the user even if notifications are
* otherwise unavailable (that is, when the status bar is hidden). This flag is ideally used
* in conjunction with {@link #fullScreenIntent}.
*/
public static final int FLAG_HIGH_PRIORITY = 0x00000080;
FLAG_SHOW_LIGHTS:
如果想为Notification添加LED灯提示，需要在Flag属性中添加FLAG_SHOW_LIGHT标志位。 LED关闭状态下，0表示颜色或者LED灯开关 LED开启状态下，1代表LED开，0代表LED关。 LED闪烁状态下，ledOnMS表示灯亮时间，ledOffMS表示灯灭时间。 因为硬件不一，所以不能保证在各种硬件上都能够奏效，应尽可能使用系统给定的默认值(TODO)，它能够适配各种硬件。 alpha通道必须设置为向前兼容性 FLAG_ONGOING_EVENT：
如果需要notification常驻状态栏，引用正在进行的活动，如一个打进的电话，需要在Flag属性中添加FLAG_ONGOING_EVENT标志位。但是其不能引用一个过去已经发生的活动，如一个未接电话。（设置其Flag，notification将被放入“正在进行”组）
        FLAG_INSISTENT：
设置此Flag，在通知取消或通知窗口打开之前，音频会一直重复。
FLAG_ONLY_ALERT_ONCE：
设置此Flag，震动和声音只执行一次。 FLAG_AUTO_CANCEL：

设置此Flag，当用户点击时，通知会被清除。 FLAG_NO_CLEAR：
设置此Flag，当用户点击清除所有按钮时，该通知不被清除。 FLAG_FOREGROUND_SERVICE：
设置此Flag，表示该通知为正运行的服务（当你退出手机QQ时，在状态栏会看到一个QQ图标） FLAG_HIGH_PRIORITY：
一个过时的Flag，现在已使用优先级字段代替。设置该Flag表示一高优先级事件，当通知不可以使用（状态栏被隐藏时）也可通知用户，应配合fullScreenIntent使用。

常量

/**
* The timestamp for the notification.  The icons and expanded views
* are sorted by this key.
*/
public long when;

/**
* The resource id of a drawable to use as the icon in the status bar.
* This is required; notifications with an invalid icon resource will not be shown.
*/
public int icon;

/**
* If the icon in the status bar is to have more than one level, you can set this.  Otherwise,
* leave it at its default value of 0.
*
* @see android.widget.ImageView#setImageLevel
* @see android.graphics.drawable#setLevel
*/
public int iconLevel;

/**
* The number of events that this notification represents.  For example, in a new mail
* notification, this could be the number of unread messages.  This number is superimposed over
* the icon in the status bar.  If the number is 0 or negative, it is not shown in the status
* bar.
*/
public int number;

/**
* The intent to execute when the expanded status entry is clicked.  If
* this is an activity, it must include the
* {@link android.content.Intent#FLAG_ACTIVITY_NEW_TASK} flag, which requires
* that you take care of task management as described in the
* <a href="{@docRoot}guide/topics/fundamentals/tasks-and-back-stack.html">Tasks and Back
* Stack</a> document.  In particular, make sure to read the notification section
* <a href="{@docRoot}guide/topics/ui/notifiers/notifications.html#HandlingNotifications">Handling
* Notifications</a> for the correct ways to launch an application from a
* notification.
*/
public PendingIntent contentIntent;

/**
* The intent to execute when the status entry is deleted by the user
* with the "Clear All Notifications" button. This probably shouldn't
* be launching an activity since several of those will be sent at the
* same time.
*/
public PendingIntent deleteIntent;

/**
* An intent to launch instead of posting the notification to the status bar.
*
* @see Notification.Builder#setFullScreenIntent
*/
public PendingIntent fullScreenIntent;

/**
* Text to scroll across the screen when this item is added to
* the status bar on large and smaller devices.
*
* <p>This field is provided separately from the other ticker fields
* both for compatibility and to allow an application to choose different
* text for when the text scrolls in and when it is displayed all at once
* in conjunction with one or more icons.
*
* @see #tickerView
*/
public CharSequence tickerText;

/**
* The view to show as the ticker in the status bar when the notification
* is posted.
*/
public RemoteViews tickerView;

/**
* The view that will represent this notification in the expanded status bar.
*/
public RemoteViews contentView;

/**
* The bitmap that may escape the bounds of the panel and bar.
*/
public Bitmap largeIcon;

/**
* The sound to play.
*
* <p>
* To play the default notification sound, see {@link #defaults}.
* </p>
*/
public Uri sound;

when：
通知的时间戳，通知图标会根据该时间戳在状态栏进行排序。icon：

在状态栏中显示的图标，如果是无效资源，不予显示。iconLevel：

如果状态栏中的icon有等级之分，可以设置此参数，默认情况下，一般为0.number：

通知事件发生的次数，比如一个邮件通知，这个参数表示未读邮件数。这个数字会叠加到状态栏中通知图标上，如果为0或者负，则不显示。contentIntent：

The intent to execute when the expanded status entry is clicked.当扩展状态内容被点击时触发该intent（expanded status entry不知道该如何翻译是好了

）如果是要跳转到一个Activity，一定要包含FLAG_ACTIVITY_NEW_TASK这个标志位，用于调整堆栈中的Task。能够确保正确的从一个通知进入一个应用。deleteIntent：

当用户点击“clean all button"或者滑动取消通知时触发该Intent，不能启动一个activity或者server（因为会在同一时间发送）。fullScreenIntent：
全屏状态下代替状态栏中intent功能tickerText：

当通知发送时像股票一样提示文本。contentView：
在状态栏中代表Notification的View。largeIcon：

可以脱离状态栏的图片sound：
通知声音audioStreamType：

视频播放流类型vibrate：

震动类型ledARGB：

LED灯颜色ledOnMS：

LED灯闪烁时，灯亮时间。ledOffMS：

LED灯闪烁时，灯灭时间。defaults：

LED默认值。

构造函数

默认构造函数：

/**
* Constructs a Notification object with everything set to 0.
* You might want to consider using {@link Builder} instead.
*/
public Notification()
{
this.when = System.currentTimeMillis();
}

可以用Notification.Builder来替代构造一个Notification（关于Builder建造者模式 http://blog.csdn.net/aomandeshangxiao/article/details/8214646）。

/**
* @hide
*/
public Notification(Context context, int icon, CharSequence tickerText, long when,
CharSequence contentTitle, CharSequence contentText, Intent contentIntent)
{
this.when = when;
this.icon = icon;
this.tickerText = tickerText;
setLatestEventInfo(context, contentTitle, contentText,
PendingIntent.getActivity(context, 0, contentIntent, 0));
}

这个构造函数被hide，setLatestEventInfo方法也被deprecate，不建议使用，使用Notification.Builder即可。

/**
* Constructs a Notification object with the information needed to
* have a status bar icon without the standard expanded view.
*
* @param icon          The resource id of the icon to put in the status bar.
* @param tickerText    The text that flows by in the status bar when the notification first
*                      activates.
* @param when          The time to show in the time field.  In the System.currentTimeMillis
*                      timebase.
*
* @deprecated Use {@link Builder} instead.
*/
@Deprecated
public Notification(int icon, CharSequence tickerText, long when)
{
this.icon = icon;
this.tickerText = tickerText;
this.when = when;
}

这个构造函数是deprecated（弃用）的。

/**
* Unflatten the notification from a parcel.
*/
public Notification(Parcel parcel)
{
int version = parcel.readInt();

when = parcel.readLong();
icon = parcel.readInt();
number = parcel.readInt();
if (parcel.readInt() != 0) {
contentIntent = PendingIntent.CREATOR.createFromParcel(parcel);
}
if (parcel.readInt() != 0) {
deleteIntent = PendingIntent.CREATOR.createFromParcel(parcel);
}
if (parcel.readInt() != 0) {
tickerText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel);
}
if (parcel.readInt() != 0) {
tickerView = RemoteViews.CREATOR.createFromParcel(parcel);
}
if (parcel.readInt() != 0) {
contentView = RemoteViews.CREATOR.createFromParcel(parcel);
}
if (parcel.readInt() != 0) {
largeIcon = Bitmap.CREATOR.createFromParcel(parcel);
}
defaults = parcel.readInt();
flags = parcel.readInt();
if (parcel.readInt() != 0) {
sound = Uri.CREATOR.createFromParcel(parcel);
}

audioStreamType = parcel.readInt();
vibrate = parcel.createLongArray();
ledARGB = parcel.readInt();
ledOnMS = parcel.readInt();
ledOffMS = parcel.readInt();
iconLevel = parcel.readInt();

if (parcel.readInt() != 0) {
fullScreenIntent = PendingIntent.CREATOR.createFromParcel(parcel);
}
}

通过一个Parcel参数来构造一个Notification。

其他方法

@Override
public Notification clone() {
Notification that = new Notification();

that.when = this.when;
that.icon = this.icon;
that.number = this.number;

// PendingIntents are global, so there's no reason (or way) to clone them.
that.contentIntent = this.contentIntent;
that.deleteIntent = this.deleteIntent;
that.fullScreenIntent = this.fullScreenIntent;

if (this.tickerText != null) {
that.tickerText = this.tickerText.toString();
}
if (this.tickerView != null) {
that.tickerView = this.tickerView.clone();
}
if (this.contentView != null) {
that.contentView = this.contentView.clone();
}
if (this.largeIcon != null) {
that.largeIcon = Bitmap.createBitmap(this.largeIcon);
}
that.iconLevel = this.iconLevel;
that.sound = this.sound; // android.net.Uri is immutable
that.audioStreamType = this.audioStreamType;

final long[] vibrate = this.vibrate;
if (vibrate != null) {
final int N = vibrate.length;
final long[] vib = that.vibrate = new long
;
System.arraycopy(vibrate, 0, vib, 0, N);
}

that.ledARGB = this.ledARGB;
that.ledOnMS = this.ledOnMS;
that.ledOffMS = this.ledOffMS;
that.defaults = this.defaults;

that.flags = this.flags;

return that;
}

官网解释：

Creates and returns a copy of this Object. The default implementation returns a so-called "shallow" copy: It creates a new instance of the same class and then copies the field values (including object references) from this instance to the new instance. A "deep" copy, in contrast, would also recursively clone nested objects. A subclass that needs to implement this kind of cloning should call super.clone() to create the new instance and then create deep copies of the nested, mutable objects.

创建并返回这个对象的一个拷贝。默认的实现返回一个所谓的“浅“复制:它创建一个新的实例相同的类,然后从这个实例复制字段值(包括对象引用)生成新实例。相对应的“深度”拷贝,也会递归地复制嵌套对象。一个子类,实现这种克隆需要调用super.clone()方法来创建一个深层嵌套的、可变的实例。

public int describeContents() {
return 0;
}

描述了在Parcelable中包含的各种特殊对象的编组表示。在代码中直接返回0。

/**
* Flatten this notification from a parcel.
*/
public void writeToParcel(Parcel parcel, int flags)
{
parcel.writeInt(1);

parcel.writeLong(when);
parcel.writeInt(icon);
parcel.writeInt(number);
if (contentIntent != null) {
parcel.writeInt(1);
contentIntent.writeToParcel(parcel, 0);
} else {
parcel.writeInt(0);
}
if (deleteIntent != null) {
parcel.writeInt(1);
deleteIntent.writeToParcel(parcel, 0);
} else {
parcel.writeInt(0);
}
if (tickerText != null) {
parcel.writeInt(1);
TextUtils.writeToParcel(tickerText, parcel, flags);
} else {
parcel.writeInt(0);
}
if (tickerView != null) {
parcel.writeInt(1);
tickerView.writeToParcel(parcel, 0);
} else {
parcel.writeInt(0);
}
if (contentView != null) {
parcel.writeInt(1);
contentView.writeToParcel(parcel, 0);
} else {
parcel.writeInt(0);
}
if (largeIcon != null) {
parcel.writeInt(1);
largeIcon.writeToParcel(parcel, 0);
} else {
parcel.writeInt(0);
}

parcel.writeInt(defaults);
parcel.writeInt(this.flags);

if (sound != null) {
parcel.writeInt(1);
sound.writeToParcel(parcel, 0);
} else {
parcel.writeInt(0);
}
parcel.writeInt(audioStreamType);
parcel.writeLongArray(vibrate);
parcel.writeInt(ledARGB);
parcel.writeInt(ledOnMS);
parcel.writeInt(ledOffMS);
parcel.writeInt(iconLevel);

if (fullScreenIntent != null) {
parcel.writeInt(1);
fullScreenIntent.writeToParcel(parcel, 0);
} else {
parcel.writeInt(0);
}
}

用Notification填充Parcel。

/**
* Parcelable.Creator that instantiates Notification objects
*/
public static final Parcelable.Creator<Notification> CREATOR
= new Parcelable.Creator<Notification>()
{
public Notification createFromParcel(Parcel parcel)
{
return new Notification(parcel);
}

public Notification[] newArray(int size)
{
return new Notification[size];
}
};

通过Parcelable.Creator来实例化Notification。

/**
* Sets the {@link #contentView} field to be a view with the standard "Latest Event"
* layout.
*
* <p>Uses the {@link #icon} and {@link #when} fields to set the icon and time fields
* in the view.</p>
* @param context       The context for your application / activity.
* @param contentTitle The title that goes in the expanded entry.
* @param contentText  The text that goes in the expanded entry.
* @param contentIntent The intent to launch when the user clicks the expanded notification.
* If this is an activity, it must include the
* {@link android.content.Intent#FLAG_ACTIVITY_NEW_TASK} flag, which requires
* that you take care of task management as described in the
* <a href="{@docRoot}guide/topics/fundamentals/tasks-and-back-stack.html">Tasks and Back
* Stack</a> document.
*
* @deprecated Use {@link Builder} instead.
*/
@Deprecated
public void setLatestEventInfo(Context context,
CharSequence contentTitle, CharSequence contentText, PendingIntent contentIntent) {
RemoteViews contentView = new RemoteViews(context.getPackageName(),
R.layout.status_bar_latest_event_content);
if (this.icon != 0) {
contentView.setImageViewResource(R.id.icon, this.icon);
}
if (contentTitle != null) {
contentView.setTextViewText(R.id.title, contentTitle);
}
if (contentText != null) {
contentView.setTextViewText(R.id.text, contentText);
}
if (this.when != 0) {
contentView.setLong(R.id.time, "setTime", when);
}

this.contentView = contentView;
this.contentIntent = contentIntent;
}

上面提到的setLatestEventInfo方法，被弃用，使用Notification.Builder替代。 设置最新点击的内容视图，通过设置图标，时间等参数。

@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("Notification(contentView=");
if (contentView != null) {
sb.append(contentView.getPackage());
sb.append("/0x");
sb.append(Integer.toHexString(contentView.getLayoutId()));
} else {
sb.append("null");
}
sb.append(" vibrate=");
if (this.vibrate != null) {
int N = this.vibrate.length-1;
sb.append("[");
for (int i=0; i<N; i++) {
sb.append(this.vibrate[i]);
sb.append(',');
}
if (N != -1) {
sb.append(this.vibrate
);
}
sb.append("]");
} else if ((this.defaults & DEFAULT_VIBRATE) != 0) {
sb.append("default");
} else {
sb.append("null");
}
sb.append(",sound=");
if (this.sound != null) {
sb.append(this.sound.toString());
} else if ((this.defaults & DEFAULT_SOUND) != 0) {
sb.append("default");
} else {
sb.append("null");
}
sb.append(",defaults=0x");
sb.append(Integer.toHexString(this.defaults));
sb.append(",flags=0x");
sb.append(Integer.toHexString(this.flags));
if ((this.flags & FLAG_HIGH_PRIORITY) != 0) {
sb.append("!!!1!one!");
}
sb.append(")");
return sb.toString();
}

toString()方法。

建造者（Builder）

首先，Builder类是一个静态内部类：

public static class Builder {

里面使用到的全局变量：

private Context mContext;

private long mWhen;
private int mSmallIcon;
private int mSmallIconLevel;
private int mNumber;
private CharSequence mContentTitle;
private CharSequence mContentText;
private CharSequence mContentInfo;
private PendingIntent mContentIntent;
private RemoteViews mContentView;
private PendingIntent mDeleteIntent;
private PendingIntent mFullScreenIntent;
private CharSequence mTickerText;
private RemoteViews mTickerView;
private Bitmap mLargeIcon;
private Uri mSound;
private int mAudioStreamType;
private long[] mVibrate;
private int mLedArgb;
private int mLedOnMs;
private int mLedOffMs;
private int mDefaults;
private int mFlags;
private int mProgressMax;
private int mProgress;
private boolean mProgressIndeterminate;

参考上面Notification的全局变量。 构造函数：

/**
* Constructor.
*
* Automatically sets the when field to {@link System#currentTimeMillis()
* System.currentTimeMllis()} and the audio stream to the {@link #STREAM_DEFAULT}.
*
* @param context A {@link Context} that will be used to construct the
*      RemoteViews. The Context will not be held past the lifetime of this
*      Builder object.
*/
public Builder(Context context) {
mContext = context;

// Set defaults to match the defaults of a Notification
mWhen = System.currentTimeMillis();
mAudioStreamType = STREAM_DEFAULT;
}

需要传入一个Context，然后获取下当前时间，设置下视频流类型。 设置当前事件时间：系统会根据这个时间在状态栏上为Notification排序。

/**
* Set the time that the event occurred.  Notifications in the panel are
* sorted by this time.
*/
public Builder setWhen(long when) {
mWhen = when;
return this;
}

设置图标：

       /**
         * Set the small icon to use in the notification layouts.  Different classes of devices
         * may return different sizes.  See the UX guidelines for more information on how to
         * design these icons.
         *
         * @param icon A resource ID in the application's package of the drawble to use.
         */
        public Builder setSmallIcon(int icon) {
            mSmallIcon = icon;
            return this;
        }

        /**
         * A variant of {@link #setSmallIcon(int) setSmallIcon(int)} that takes an additional
         * level parameter for when the icon is a {@link android.graphics.drawable.LevelListDrawable
         * LevelListDrawable}.
         *
         * @param icon A resource ID in the application's package of the drawble to use.
         * @param level The level to use for the icon.
         *
         * @see android.graphics.drawable.LevelListDrawable
         */
        public Builder setSmallIcon(int icon, int level) {
            mSmallIcon = icon;
            mSmallIconLevel = level;
            return this;
        }

设置Notification布局的小图标，不同的硬件设备会显示不同的尺寸。可以查看UX文档获取更多如何设计图标的信息。 设置内容标题：

/**
* Set the title (first row) of the notification, in a standard notification.
*/
public Builder setContentTitle(CharSequence title) {
mContentTitle = title;
return this;
}

设置Notification的第一行标题。
设置内容：

/**
* Set the text (second row) of the notification, in a standard notification.
*/
public Builder setContentText(CharSequence text) {
mContentText = text;
return this;
}

设置Notification的第二行内容。
设置Notification右侧数字：

/**
* Set the large number at the right-hand side of the notification.  This is
* equivalent to setContentInfo, although it might show the number in a different
* font size for readability.
*/
public Builder setNumber(int number) {
mNumber = number;
return this;
}

设置在状态栏右侧显示的数字，等同于setContentInfo，也可以显示数字。 设置Notification右侧显示的文本：

/**
* Set the large text at the right-hand side of the notification.
*/
public Builder setContentInfo(CharSequence info) {
mContentInfo = info;
return this;
}

设置进度：

/**
* Set the progress this notification represents, which may be
* represented as a {@link ProgressBar}.
*/
public Builder setProgress(int max, int progress, boolean indeterminate) {
mProgressMax = max;
mProgress = progress;
mProgressIndeterminate = indeterminate;
return this;
}

Notification就相当于一个ProgrssBar。
设置内容视图：

**
* Supply a custom RemoteViews to use instead of the standard one.
*/
public Builder setContent(RemoteViews views) {
mContentView = views;
return this;
}

使用自定义视图替代标准视图。
设置PendingIntent：

/**
* Supply a {@link PendingIntent} to send when the notification is clicked.
* If you do not supply an intent, you can now add PendingIntents to individual
* views to be launched when clicked by calling {@link RemoteViews#setOnClickPendingIntent
* RemoteViews.setOnClickPendingIntent(int,PendingIntent)}.  Be sure to
* read {@link Notification#contentIntent Notification.contentIntent} for
* how to correctly use this.
*/
public Builder setContentIntent(PendingIntent intent) {
mContentIntent = intent;
return this;
}

当Notification被点击时提供一个PendingIntent，如果没有提供这个intent，可以在点击时调用RemoteViews.setOnclickPendingIntent(int,PendingIntent)去设置一个PendingIntent.
设置DeleteIntent：

/**
* Supply a {@link PendingIntent} to send when the notification is cleared by the user
* directly from the notification panel.  For example, this intent is sent when the user
* clicks the "Clear all" button, or the individual "X" buttons on notifications.  This
* intent is not sent when the application calls {@link NotificationManager#cancel
* NotificationManager.cancel(int)}.
*/
public Builder setDeleteIntent(PendingIntent intent) {
mDeleteIntent = intent;
return this;
}

设置一个当用户清除状态栏中的Notification是触发的PendingIntent。
设置FullScreenIntent：

/**
* An intent to launch instead of posting the notification to the status bar.
* Only for use with extremely high-priority notifications demanding the user's
* <strong>immediate</strong> attention, such as an incoming phone call or
* alarm clock that the user has explicitly set to a particular time.
* If this facility is used for something else, please give the user an option
* to turn it off and use a normal notification, as this can be extremely
* disruptive.
*
* @param intent The pending intent to launch.
* @param highPriority Passing true will cause this notification to be sent
*          even if other notifications are suppressed.
*/
public Builder setFullScreenIntent(PendingIntent intent, boolean highPriority) {
mFullScreenIntent = intent;
setFlag(FLAG_HIGH_PRIORITY, highPriority);
return this;
}

一个全屏状态下替代状态栏上的Notification的intent，仅适用于使用非常高的优先级通知，会引起用户的即时关注，如用户已显式设置为一个特定的时间，一个来电或闹钟。
设置TickerText：

/**
         * Set the text that is displayed in the status bar when the notification first
         * arrives.
         */
        public Builder setTicker(CharSequence tickerText) {
            mTickerText = tickerText;
            return this;
        }

        /**
         * Set the text that is displayed in the status bar when the notification first
         * arrives, and also a RemoteViews object that may be displayed instead on some
         * devices.
         */
        public Builder setTicker(CharSequence tickerText, RemoteViews views) {
            mTickerText = tickerText;
            mTickerView = views;
            return this;
        }

设置Notification第一次到达时在status Bar 上面显示的文本，第二个方法里面还可以设置一个自定义视图。

设置大图标：

/**
* Set the large icon that is shown in the ticker and notification.
*/
public Builder setLargeIcon(Bitmap icon) {
mLargeIcon = icon;
return this;
}

设置声音：

 /**
         * Set the sound to play.  It will play on the default stream.
         */
        public Builder setSound(Uri sound) {
            mSound = sound;
            mAudioStreamType = STREAM_DEFAULT;
            return this;
        }

        /**
         * Set the sound to play.  It will play on the stream you supply.
         *
         * @see #STREAM_DEFAULT
         * @see AudioManager for the <code>STREAM_</code> constants.
         */
        public Builder setSound(Uri sound, int streamType) {
            mSound = sound;
            mAudioStreamType = streamType;
            return this;
        }

设置震动：

/**
* Set the vibration pattern to use.
*
* @see android.os.Vibrator for a discussion of the <code>pattern</code>
* parameter.
*/
public Builder setVibrate(long[] pattern) {
mVibrate = pattern;
return this;
}

设置LED灯光：

/**
* Set the argb value that you would like the LED on the device to blnk, as well as the
* rate.  The rate is specified in terms of the number of milliseconds to be on
* and then the number of milliseconds to be off.
*/
public Builder setLights(int argb, int onMs, int offMs) {
mLedArgb = argb;
mLedOnMs = onMs;
mLedOffMs = offMs;
return this;
}

设置Ongoing：

/**
* Set whether this is an ongoing notification.
*
* <p>Ongoing notifications differ from regular notifications in the following ways:
* <ul>
*   <li>Ongoing notifications are sorted above the regular notifications in the
*   notification panel.</li>
*   <li>Ongoing notifications do not have an 'X' close button, and are not affected
*   by the "Clear all" button.
* </ul>
*/
public Builder setOngoing(boolean ongoing) {
setFlag(FLAG_ONGOING_EVENT, ongoing);
return this;
}

设置Notification是否是正在进行。 设置是否只提示一次：

/**
* Set this flag if you would only like the sound, vibrate
* and ticker to be played if the notification is not already showing.
*/
public Builder setOnlyAlertOnce(boolean onlyAlertOnce) {
setFlag(FLAG_ONLY_ALERT_ONCE, onlyAlertOnce);
return this;
}

设置是否自动取消：

/**
* Setting this flag will make it so the notification is automatically
* canceled when the user clicks it in the panel.  The PendingIntent
* set with {@link #setDeleteIntent} will be broadcast when the notification
* is canceled.
*/
public Builder setAutoCancel(boolean autoCancel) {
setFlag(FLAG_AUTO_CANCEL, autoCancel);
return this;
}

里面都用的私有setFlag方法：

private void setFlag(int mask, boolean value) {
if (value) {
mFlags |= mask;
} else {
mFlags &= ~mask;
}
}

使用默认设置：

/**
* Set the default notification options that will be used.
* <p>
* The value should be one or more of the following fields combined with
* bitwise-or:
* {@link #DEFAULT_SOUND}, {@link #DEFAULT_VIBRATE}, {@link #DEFAULT_LIGHTS}.
* <p>
* For all default values, use {@link #DEFAULT_ALL}.
*/
public Builder setDefaults(int defaults) {
mDefaults = defaults;
return this;
}

通过ID获取notification视图：

private RemoteViews makeRemoteViews(int resId) {
RemoteViews contentView = new RemoteViews(mContext.getPackageName(), resId);
boolean hasLine3 = false;
if (mSmallIcon != 0) {
contentView.setImageViewResource(R.id.icon, mSmallIcon);
contentView.setViewVisibility(R.id.icon, View.VISIBLE);
} else {
contentView.setViewVisibility(R.id.icon, View.GONE);
}
if (mContentTitle != null) {
contentView.setTextViewText(R.id.title, mContentTitle);
}
if (mContentText != null) {
contentView.setTextViewText(R.id.text, mContentText);
hasLine3 = true;
}
if (mContentInfo != null) {
contentView.setTextViewText(R.id.info, mContentInfo);
contentView.setViewVisibility(R.id.info, View.VISIBLE);
hasLine3 = true;
} else if (mNumber > 0) {
final int tooBig = mContext.getResources().getInteger(
R.integer.status_bar_notification_info_maxnum);
if (mNumber > tooBig) {
contentView.setTextViewText(R.id.info, mContext.getResources().getString(
R.string.status_bar_notification_info_overflow));
} else {
NumberFormat f = NumberFormat.getIntegerInstance();
contentView.setTextViewText(R.id.info, f.format(mNumber));
}
contentView.setViewVisibility(R.id.info, View.VISIBLE);
hasLine3 = true;
} else {
contentView.setViewVisibility(R.id.info, View.GONE);
}
if (mProgressMax != 0 || mProgressIndeterminate) {
contentView.setProgressBar(
R.id.progress, mProgressMax, mProgress, mProgressIndeterminate);
contentView.setViewVisibility(R.id.progress, View.VISIBLE);
} else {
contentView.setViewVisibility(R.id.progress, View.GONE);
}
if (mWhen != 0) {
contentView.setLong(R.id.time, "setTime", mWhen);
}
contentView.setViewVisibility(R.id.line3, hasLine3 ? View.VISIBLE : View.GONE);
return contentView;
}

获取默认视图：

private RemoteViews makeContentView() {
if (mContentView != null) {
return mContentView;
} else {
return makeRemoteViews(mLargeIcon == null
? R.layout.status_bar_latest_event_content
: R.layout.status_bar_latest_event_content_large_icon);
}
}

获取TickerView：

private RemoteViews makeTickerView() {
if (mTickerView != null) {
return mTickerView;
} else {
if (mContentView == null) {
return makeRemoteViews(mLargeIcon == null
? R.layout.status_bar_latest_event_ticker
: R.layout.status_bar_latest_event_ticker_large_icon);
} else {
return null;
}
}
}

注意上面三个方法均是私有方法，在外部不能访问，在下面的方法中调用到了这些方法

通过Builder最后获取一个Notification：

/**
* Combine all of the options that have been set and return a new {@link Notification}
* object.
*/
public Notification getNotification() {
Notification n = new Notification();
n.when = mWhen;
n.icon = mSmallIcon;
n.iconLevel = mSmallIconLevel;
n.number = mNumber;
n.contentView = makeContentView();
n.contentIntent = mContentIntent;
n.deleteIntent = mDeleteIntent;
n.fullScreenIntent = mFullScreenIntent;
n.tickerText = mTickerText;
n.tickerView = makeTickerView();
n.largeIcon = mLargeIcon;
n.sound = mSound;
n.audioStreamType = mAudioStreamType;
n.vibrate = mVibrate;
n.ledARGB = mLedArgb;
n.ledOnMS = mLedOnMs;
n.ledOffMS = mLedOffMs;
n.defaults = mDefaults;
n.flags = mFlags;
if (mLedOnMs != 0 && mLedOffMs != 0) {
n.flags |= FLAG_SHOW_LIGHTS;
}
if ((mDefaults & DEFAULT_LIGHTS) != 0) {
n.flags |= FLAG_SHOW_LIGHTS;
}
return n;
}

Builder的最后，提供一个完整的产品出来。

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