Android 7.0 SystemUI 之啓動和狀態欄和導航欄簡介
一、SystemUI 是什麼
首先SystemUI 是一個系統應用,apk路徑位於/system/priv-app
源碼路徑位於:/framework/base/packages/SystemUI
它負責的功能如下:
- 狀態欄信息的展示:比如電量信息,時間,wifi狀態等
- 通知欄消息
- 壁紙管理
- 截圖功能
- 近期任務欄顯示,比如長按home鍵顯示最近使用的app
- 錄製屏幕功能
- 截圖服務
以下是7.0 SystemUI 的代碼截圖
二、SystemUI 的啓動
SystemUI 是在SystemServer裏的AMS實例的systemReady方法裏調用startSystemUi方法啓動
SystemServer路徑:/base/services/java/com/android/server/SystemServer.java
mActivityManagerService.systemReady(new Runnable() {
......
static final void startSystemUi(Context context) {
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.android.systemui",
"com.android.systemui.SystemUIService"));
intent.addFlags(Intent.FLAG_DEBUG_TRIAGED_MISSING);
//Slog.d(TAG, "Starting service: " + intent);
context.startServiceAsUser(intent, UserHandle.SYSTEM);
}
......
在這個方法裏啓動一個SystemUIService服務.
public class SystemUIService extends Service {
@Override
public void onCreate() {
super.onCreate();
((SystemUIApplication) getApplication()).startServicesIfNeeded();
}
......
在onCreate方法中會調用SystemUIApplication的startServicesIfNeeded方法,這個方法會調用 startServicesIfNeeded(SERVICES)方法啓動一系列服務(並不是真正的服務,都繼承自SystemUI),可以這麼說SystemUI就是一個容器,裏面裝有負責不同功能的模塊。
public class SystemUIApplication extends Application {
......
private final Class<?>[] SERVICES = new Class[] {
com.android.systemui.tuner.TunerService.class,
com.android.systemui.keyguard.KeyguardViewMediator.class,
com.android.systemui.recents.Recents.class,
com.android.systemui.volume.VolumeUI.class,
Divider.class,
com.android.systemui.statusbar.SystemBars.class,
com.android.systemui.usb.StorageNotification.class,
com.android.systemui.power.PowerUI.class,
com.android.systemui.media.RingtonePlayer.class,
com.android.systemui.keyboard.KeyboardUI.class,
com.android.systemui.tv.pip.PipUI.class,
com.android.systemui.shortcut.ShortcutKeyDispatcher.class
};
public void startServicesIfNeeded() {
startServicesIfNeeded(SERVICES);
}
......
startServicesIfNeeded方法會遍歷services這個數組,依次調用service的start方法啓動服務
private void startServicesIfNeeded(Class<?>[] services) {
//如果已經啓動了就返回
if (mServicesStarted) {
return;
}
//如果沒啓動完成完成
if (!mBootCompleted) {
if ("1".equals(SystemProperties.get("sys.boot_completed"))) {
mBootCompleted = true;
if (DEBUG) Log.v(TAG, "BOOT_COMPLETED was already sent");
}
}
final int N = services.length;
for (int i=0; i<N; i++) {
Class<?> cl = services[i];
if (DEBUG) Log.d(TAG, "loading: " + cl);
try {
Object newService = SystemUIFactory.getInstance().createInstance(cl);
mServices[i] = (SystemUI) ((newService == null) ? cl.newInstance() : newService);
} catch (IllegalAccessException ex) {
throw new RuntimeException(ex);
} catch (InstantiationException ex) {
throw new RuntimeException(ex);
}
//啓動服務
mServices[i].start();
//如果啓動完成了
if (mBootCompleted) {
mServices[i].onBootCompleted();
}
}
mServicesStarted = true;
}
這裏以com.android.systemui.statusbar.SystemBars.class爲例,講解一下
三、狀態欄和導航欄 的啓動
SystemBars的start方法會創建一個ServiceMonitor(服務監聽者),會進入到ServiceMonitor的start方法
public class SystemBars extends SystemUI implements ServiceMonitor.Callbacks {
......
public void start() {
// ServiceMonitor是服務監聽者
mServiceMonitor = new ServiceMonitor(TAG, DEBUG, mContext, Settings.Secure.BAR_SERVICE_COMPONENT, this);
mServiceMonitor.start(); // will call onNoService if no remote service is found
}
......
}
在ServiceMonitor的start方法啓動
public class ServiceMonitor {
......
public void start() {
......
mHandler.sendEmptyMessage(MSG_START_SERVICE);
}
......
}
在Handler裏處理這個MSG_START_SERVICE
public class ServiceMonitor {
......
private final Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
switch(msg.what) {
case MSG_START_SERVICE:
//啓動服務
startService();
break;
case MSG_CONTINUE_START_SERVICE:
continueStartService();
break;
case MSG_STOP_SERVICE:
stopService();
break;
case MSG_PACKAGE_INTENT:
packageIntent((Intent)msg.obj);
break;
case MSG_CHECK_BOUND:
checkBound();
break;
case MSG_SERVICE_DISCONNECTED:
serviceDisconnected((ComponentName)msg.obj);
break;
}
}
};
......
}
startService方法如下
public class ServiceMonitor {
......
private void startService() {
//獲取服務組件名稱
mServiceName = getComponentNameFromSetting();
//如果爲空,回調服務的onNoService方法
if (mServiceName == null) {
mBound = false;
mCallbacks.onNoService();
} else {
//不爲空,回調服務的的onServiceStartAttempt方法
long delay = mCallbacks.onServiceStartAttempt();
mHandler.sendEmptyMessageDelayed(MSG_CONTINUE_START_SERVICE, delay);
}
}
......
}
這裏對mServiceName是否爲空進行判斷,總之無論如何它最終都會啓動這個服務。
回調SystemBars的onNoService裏創建StatusBar
public class SystemBars extends SystemUI implements ServiceMonitor.Callbacks {
......
@Override
public void onNoService() {
if (DEBUG) Log.d(TAG, "onNoService");
//創建StatusBar
createStatusBarFromConfig(); // fallback to using an in-process implementation
}
......
private void createStatusBarFromConfig() {
//config_statusBarComponent就是PhoneStatusBar
final String clsName = mContext.getString(R.string.config_statusBarComponent);
Class<?> cls = null;
try {
cls = mContext.getClassLoader().loadClass(clsName);
} catch (Throwable t) {
throw andLog("Error loading status bar component: " + clsName, t);
}
try {
//創建BaseStatusBar實例
mStatusBar = (BaseStatusBar) cls.newInstance();
} catch (Throwable t) {
throw andLog("Error creating status bar component: " + clsName, t);
}
mStatusBar.mContext = mContext;
mStatusBar.mComponents = mComponents;
//啓動
mStatusBar.start();
}
在createStatusBarFromConfig方法裏會獲取一個config_statusBarComponent的字符串值,這個值就是PhoneStatusBar的clasName
所以這裏的mStatusBar是PhoneStatusBar實例,啓動了PhoneStatusBar
PhoneStatusBar的start方法
public class PhoneStatusBar extends BaseStatusBar implements DemoMode, DragDownHelper.DragDownCallback, ActivityStarter, OnUnlockMethodChangedListener,HeadsUpManager.OnHeadsUpChangedListener {
......
public void start() {
......
//調用父類的start方法,在父類BaseStatusBar裏調用createAndAddWindows方法
// 3.1
super.start(); // calls createAndAddWindows()
......
//添加導航欄
// 3.2
addNavigationBar();
......
}
它會回調父類BaseStatusBar 的start方法
3.1、 super.start()
public abstract class BaseStatusBar extends SystemUI implements
CommandQueue.Callbacks, ActivatableNotificationView.OnActivatedListener,
ExpandableNotificationRow.ExpansionLogger, NotificationData.Environment,
ExpandableNotificationRow.OnExpandClickListener,
OnGutsClosedListener {
......
public void start() {
......
/*實例化IStatusBarService,
隨後BaseStatusBar將自己註冊到IStatusBarService之中。以此聲明本實例纔是狀態欄的真正
實現者,IStatusBarService會將其所接受到的請求轉發給本實例。
IStatusBarService會保存SystemUi的狀態信息,避免SystemUi崩潰而造成信息的丟失
*/
mBarService = IStatusBarService.Stub.asInterface(
ServiceManager.getService(Context.STATUS_BAR_SERVICE));
......
//IStatusBarService與BaseStatusBar進行通信的橋樑。
mCommandQueue = new CommandQueue(this);
/*switches則存儲了一些雜項:禁用功能列表,SystemUIVisiblity,是否在導航欄中顯示虛擬的
菜單鍵,輸入法窗口是否可見、輸入法窗口是否消費BACK鍵、是否接入了實體鍵盤、實體鍵盤是否被啓用。
*/
int[] switches = new int[9];
ArrayList<IBinder> binders = new ArrayList<IBinder>();
/*它保存了用於顯示在狀態欄的系統狀態
區中的狀態圖標列表。在完成註冊之後,IStatusBarService將會在其中填充兩個數組,一個字符串
數組用於表示狀態的名稱,一個StatusBarIcon類型的數組用於存儲需要顯示的圖標資源。
*/
ArrayList<String> iconSlots = new ArrayList<>();
ArrayList<StatusBarIcon> icons = new ArrayList<>();
Rect fullscreenStackBounds = new Rect();
Rect dockedStackBounds = new Rect();
//IStatusBarService註冊一些信息
try {
mBarService.registerStatusBar(mCommandQueue, iconSlots, icons, switches, binders,
fullscreenStackBounds, dockedStackBounds);
} catch (RemoteException ex) {
}
//創建狀態欄窗口
createAndAddWindows();
......
}
......
}
BaseStatusBar進行一些設置,獲取了IStatusBarService實例並註冊一些信息到IStatusBarService中,IStatusBarService是一個系統服務,BaseStatusBar將自己註冊到IStatusBarService之中,IStatusBarService會把操作狀態欄和導航欄的請求轉發給BaseStatusBar
爲了保證SystemUI意外退出後不會發生信息丟失,IStatusBarService保存了所有需要狀態欄與導航欄進行顯示或處理的信息副本。 在註冊時將一個繼承自IStatusBar.Stub的CommandQueue的實例註冊到IStatusBarService以建立通信,並將信息副本取回。
public class CommandQueue extends IStatusBar.Stub {
IStatusBarService的真身是StatusBarManagerService
路徑:./services/core/java/com/android/server/statusbar/StatusBarManagerService.java
它的註冊方法做一些數據的初始化
public class StatusBarManagerService extends IStatusBarService.Stub {
......
public void registerStatusBar(IStatusBar bar, List<String> iconSlots,
List<StatusBarIcon> iconList, int switches[], List<IBinder> binders,
Rect fullscreenStackBounds, Rect dockedStackBounds) {
//檢查權限
enforceStatusBarService();
mBar = bar;
synchronized (mIcons) {
for (String slot : mIcons.keySet()) {
iconSlots.add(slot);
iconList.add(mIcons.get(slot));
}
}
synchronized (mLock) {
switches[0] = gatherDisableActionsLocked(mCurrentUserId, 1);
switches[1] = mSystemUiVisibility;
switches[2] = mMenuVisible ? 1 : 0;
switches[3] = mImeWindowVis;
switches[4] = mImeBackDisposition;
switches[5] = mShowImeSwitcher ? 1 : 0;
switches[6] = gatherDisableActionsLocked(mCurrentUserId, 2);
switches[7] = mFullscreenStackSysUiVisibility;
switches[8] = mDockedStackSysUiVisibility;
binders.add(mImeToken);
fullscreenStackBounds.set(mFullscreenStackBounds);
dockedStackBounds.set(mDockedStackBounds);
}
}
......
}
這幾者的關係如下
回到PhoneStatusBar中, 父類BaseStatusBar中的createAndAddWindows爲抽象方法,由子類實現,看下PhoneStatusBar的
createAndAddWindows
@Override
public void createAndAddWindows() {
//添加狀態欄窗口
addStatusBarWindow();
}
方法實現如下
private void addStatusBarWindow() {
//創建控件
makeStatusBarView();
//創建StatusBarWindowManager實例
mStatusBarWindowManager = new StatusBarWindowManager(mContext);
//創建遠程輸入控制實例
mRemoteInputController = new RemoteInputController(mStatusBarWindowManager,
mHeadsUpManager);
//添加狀態欄窗口
mStatusBarWindowManager.add(mStatusBarWindow, getStatusBarHeight());
}
看下makeStatusBarView方法
makeStatusBarView的方法裏調用 inflateStatusBarWindow(context)加載佈局
protected void inflateStatusBarWindow(Context context) {
mStatusBarWindow = (StatusBarWindowView) View.inflate(context, R.layout.super_status_bar, null);
}
這裏介紹下佈局
狀態欄佈局介紹
整個狀態欄的父佈局是R.layout.super_status_bar,對應的是StatusBarWindowView這個自定義佈局.
<com.android.systemui.statusbar.phone.StatusBarWindowView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:sysui="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
......
<!--正常狀態欄下的佈局 -->
<include layout="@layout/status_bar"
android:layout_width="match_parent"
android:layout_height="@dimen/status_bar_height" />
<!--狀態欄圖標下的SeekBar佈局 -->
<include layout="@layout/brightness_mirror" />
<!--車載模式的佈局 -->
<ViewStub android:id="@+id/fullscreen_user_switcher_stub"
android:layout="@layout/car_fullscreen_user_switcher"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<!--狀態欄下拉的佈局 -->
<include layout="@layout/status_bar_expanded"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone" />
</com.android.systemui.statusbar.phone.StatusBarWindowView>
我這裏以主要的佈局層次做介紹,結合圖片分析會更加清楚
StatusBarWindowView裏有幾個主要的佈局
- layout/status_bar
- layout/brightness_mirror
- layout/status_bar_expanded
如下圖
1.layout/status_bar
這個是正常狀態下(未下拉的狀態欄圖標區域)
這個佈局對應的是PhoneStatusBarView
<com.android.systemui.statusbar.phone.PhoneStatusBarView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:systemui="http://schemas.android.com/apk/res/com.android.systemui"
android:id="@+id/status_bar"
android:background="@drawable/system_bar_background"
android:orientation="vertical"
android:focusable="false"
android:descendantFocusability="afterDescendants"
>
......
<!--狀態欄 -->
<LinearLayout android:id="@+id/status_bar_contents"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingStart="6dp"
android:paddingEnd="8dp"
android:orientation="horizontal"
>
<!-- The alpha of this area is controlled from both PhoneStatusBarTransitions and
PhoneStatusBar (DISABLE_NOTIFICATION_ICONS). -->
<!-- 通知圖標區域-->
<com.android.systemui.statusbar.AlphaOptimizedFrameLayout
android:id="@+id/notification_icon_area"
android:layout_width="0dip"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal" />
<!-- 系統圖標區域 -->
<com.android.keyguard.AlphaOptimizedLinearLayout android:id="@+id/system_icon_area"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal"
>
<!-- 系統圖標 -->
<include layout="@layout/system_icons" />
<!-- 時鐘信息 -->
<com.android.systemui.statusbar.policy.Clock
android:id="@+id/clock"
android:textAppearance="@style/TextAppearance.StatusBar.Clock"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:singleLine="true"
android:paddingStart="@dimen/status_bar_clock_starting_padding"
android:paddingEnd="@dimen/status_bar_clock_end_padding"
android:gravity="center_vertical|start"
/>
</com.android.keyguard.AlphaOptimizedLinearLayout>
</LinearLayout>
</com.android.systemui.statusbar.phone.PhoneStatusBarView>
以下是細節圖,連線表示層次結構
其中,狀態欄的區域分爲以下幾種
- 通知欄圖標,在狀態欄的最左側顯示通知信息,比如來了一個短信,那麼就會彈出一個短信圖標
- 時間信息,顯示一個時間,比如上午9:58
- 信號圖標,顯示手機信號,wifi信號等
- 電量圖標,顯示當前電量狀態
- 狀態圖標,wifi,藍牙等開關狀態
2.@layout/brightness_mirror
這個佈局就是中間那個調整亮度的seekBar.沒啥好介紹的.
3.@layout/status_bar_expanded
這個佈局是下拉時的狀態欄的佈局
<com.android.systemui.statusbar.phone.NotificationPanelView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:systemui="http://schemas.android.com/apk/res/com.android.systemui"
android:id="@+id/notification_panel"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/transparent"
>
<!--鎖屏時的時鐘佈局 -->
<include
layout="@layout/keyguard_status_view"
android:layout_height="wrap_content"
android:visibility="gone" />
<com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="@integer/notification_panel_layout_gravity"
android:id="@+id/notification_container_parent"
android:clipToPadding="false"
android:clipChildren="false">
<!--quciksetting區域 -->
<com.android.systemui.AutoReinflateContainer
android:id="@+id/qs_auto_reinflate_container"
android:layout="@layout/qs_panel"
android:layout_width="@dimen/notification_panel_width"
android:layout_height="match_parent"
android:layout_gravity="@integer/notification_panel_layout_gravity"
android:clipToPadding="false"
android:clipChildren="false" />
<!-- 通知欄區域 -->
<com.android.systemui.statusbar.stack.NotificationStackScrollLayout
android:id="@+id/notification_stack_scroller"
android:layout_width="@dimen/notification_panel_width"
android:layout_height="match_parent"
android:layout_gravity="@integer/notification_panel_layout_gravity"
android:layout_marginBottom="@dimen/close_handle_underlap" />
<!--鎖屏切換 -->
<ViewStub
android:id="@+id/keyguard_user_switcher"
android:layout="@layout/keyguard_user_switcher"
android:layout_height="match_parent"
android:layout_width="match_parent" />
<!--鎖屏下的狀態欄 -->
<include
layout="@layout/keyguard_status_bar"
android:visibility="invisible" />
</com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer>
<!--鎖屏界面底部的圖標 -->
<include
layout="@layout/keyguard_bottom_area"
android:visibility="gone" />
</com.android.systemui.statusbar.phone.NotificationPanelView><!-- end of sliding panel -->
細節圖
創建完佈局後,就會添加窗口到WindowManager裏,這樣狀態欄就創建完成了.接下來會回到3.2 addNavigationBar()的步驟中.
3.2、addNavigationBar
這個方法是添加底部的導航欄的,就是那些home鍵,back鍵所在的區域.
public class PhoneStatusBar extends BaseStatusBar implements DemoMode, DragDownHelper.DragDownCallback, ActivityStarter, OnUnlockMethodChangedListener,HeadsUpManager.OnHeadsUpChangedListener {
......
protected void addNavigationBar() {
if (mNavigationBarView == null) return;
//初始化導航欄
prepareNavigationBarView();
//添加到WindowManager中
mWindowManager.addView(mNavigationBarView, getNavigationBarLayoutParams());
}
......
}
在這個方法裏先初始化導航欄,然後把導航欄添加到窗口中.
prepareNavigationBarView()
public class PhoneStatusBar extends BaseStatusBar implements DemoMode, DragDownHelper.DragDownCallback, ActivityStarter, OnUnlockMethodChangedListener,HeadsUpManager.OnHeadsUpChangedListener {
......
private void prepareNavigationBarView() {
//重新初始化
mNavigationBarView.reorient();
//最近應用鍵
ButtonDispatcher recentsButton = mNavigationBarView.getRecentsButton();
recentsButton.setOnClickListener(mRecentsClickListener);
recentsButton.setOnTouchListener(mRecentsPreloadOnTouchListener);
recentsButton.setLongClickable(true);
recentsButton.setOnLongClickListener(mRecentsLongClickListener);
//後退鍵
ButtonDispatcher backButton = mNavigationBarView.getBackButton();
backButton.setLongClickable(true);
backButton.setOnLongClickListener(mLongPressBackListener);
//home鍵
ButtonDispatcher homeButton = mNavigationBarView.getHomeButton();
homeButton.setOnTouchListener(mHomeActionListener);
homeButton.setOnLongClickListener(mLongPressHomeListener);
//監聽配置改變
mAssistManager.onConfigurationChanged();
}
......
}
四、結束
關於SystemUI的狀態欄和導航欄就介紹完了,講的很淺顯,只是從整體上梳理了下流程.