1. 介绍
Android中的Statusbar包含导航栏(NavigationBar, 位于左侧、右侧或者底部)和状态栏(StatusBar, 位于顶部, 可下拉)两个部分, 位于SystemUI(frameworks/base/packages/SystemUI)模块
2. 初始化
SystemServer::startOtherServices()
SystemServer::startSystemUi("com.android.systemui.SystemUIService")
SystemUIService::onCreate()
/*
* 加载并启动config_systemUIServiceComponents定义的服务列表
* frameworks/base/packages/SystemUI/res/values/config.xml
* <!-- SystemUI Services: The classes of the stuff to start. -->
* <string-array name="config_systemUIServiceComponents" translatable="false">
* <item>com.android.systemui.Dependency</item>
* <item>com.android.systemui.statusbar.CommandQueue$CommandQueueStart</item>
* ......
* <item>com.android.systemui.SystemBars</item>
* ......
* <item>com.android.systemui.keyboard.KeyboardUI</item>
* ......
* </string-array>
*/
SystemUIApplication::startServicesIfNeeded()
com.android.systemui.SystemBars::start()
/*
* 启动config_statusBarComponent定义的服务
* frameworks/base/packages/SystemUI/res/values/config.xml
* <string name="config_statusBarComponent" translatable="false">
* com.android.systemui.statusbar.phone.StatusBar
* </string>
*
* 在Automotive中被overlay, CarStatusBar继承自StatusBar
* <string name="config_statusBarComponent" translatable="false">
* com.android.systemui.statusbar.car.CarStatusBar
* </string>
*/
SystemBars::createStatusBarFromConfig()
CarStatusBar::start()
StatusBar::start()
StatusBar::createAndAddWindows()
StatusBar::addStatusBarWindow()
CarStatusBar::makeStatusBarView()
StatusBar::makeStatusBarView()
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+++ NavigationBar +++
----------------------------------------------------------------------------
WindowManagerService::hasNavigationBar()
/*
* frameworks/base/core/res/res/values/config.xml
* <bool name="config_showNavigationBar">false</bool>
*
* 在Automotive中被overlay
* <bool name="config_showNavigationBar">true</bool>
*/
PhoneWindowManager::hasNavigationBar()
CarStatusBar::createNavigationBar()
/*
* frameworks/base/packages/SystemUI/res/values/config.xml
* 根据如下配置决定是导航栏的位置，Automotive中会被overlay
* config_enableBottomNavigationBar
* config_enableLeftNavigationBar
* config_enableRightNavigationBar
* 然后通过WindowManager::addView()添加创建窗口
* WindowManager.LayoutParams.TYPE_NAVIGATION_BAR
* WindowManager.LayoutParams.TYPE_NAVIGATION_BAR_PANEL
*/
CarStatusBar::buildNavBarWindows()
CarStatusBar::buildNavBarContent()
CarStatusBar::attachNavBarWindows()
----------------------------------------------------------------------------
+++ StatusBar +++
----------------------------------------------------------------------------
/* 加载super_status_bar.xml实例化为状态栏的根控件 */
StatusBar::inflateStatusBarWindow()
/*
* 通过WindowManager::addView()添加窗口, 类型如下
* WindowManager.LayoutParams.TYPE_STATUS_BAR
*/
StatusBarWindowManager::add()
3. 显示和隐藏
3.1 应用实例
应用可以通过如下的方式隐藏状态栏和导航栏
// Android < 4:
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
// 4 =< Android < 11:
int uiFlags = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_FULLSCREEN
| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION;
getWindow().getDecorView().setSystemUiVisibility(uiFlags);
// Android >= 11
/*
* systemBars包含statusBars和navigationBars
*/
controller.hide(WindowInsetsCompat.Type.systemBars())
controller.show(WindowInsetsCompat.Type.systemBars())
3.2 调用流程
View::setSystemUiVisibility()
ViewRootImpl::recomputeViewAttributes()
ViewRootImpl::scheduleTraversals()
ViewRootImpl::doTraversal()
ViewRootImpl::performTraversals()
ViewRootImpl::collectViewAttributes()
View::dispatchCollectViewAttributes()
View::performCollectViewAttributes()
// Do Something
View::dispatchWindowSystemUiVisiblityChanged()
ViewRootImpl::relayoutWindow()
IWindowSession::relayout()
com.android.server.wm.Session::relayout()
WindowManagerService::relayoutWindow()
PhoneWindowManager::adjustWindowParamsLw()
----------------------------------------------------------------------------
+++ How to get here +++
----------------------------------------------------------------------------
PhoneWindowManager::updateSystemUiVisibilityLw()
StatusBarManagerService::setSystemUiVisibility()
IStatusBar::setSystemUiVisibility()
CommandQueue::setSystemUiVisibility()
StatusBar::setSystemUiVisibility()
StatusBar::notifyUiVisibilityChanged()
WindowManagerService::statusBarVisibilityChanged()
PhoneWindowManager::adjustSystemUiVisibilityLw()
WindowManagerService::updateStatusBarVisibilityLocked()
InputManagerService::setSystemUiVisibility()
DisplayContent::updateSystemUiVisibility()
ViewRootImpl::W::dispatchSystemUiVisibilityChanged()
ViewRootImpl::dispatchSystemUiVisibilityChanged()
ViewRootImpl::handleDispatchSystemUiVisibilityChanged()
View::updateLocalSystemUiVisibility()
View::dispatchSystemUiVisibilityChanged()
OnSystemUiVisibilityChangeListener::onSystemUiVisibilityChange()
参考:
<Android 9.0 SystemUI分析>
<StatusBar状态栏部分功能记录>
<Android 显示、隐藏状态栏和导航栏>
<Android SystemUI(一):图文并茂的介绍>
<API 30新特性：WindowInsetsController>