概述
http://blog.csdn.net/lewif/article/details/50827430
目录(?)[+]
- 涉及的java类
- DisplayManagerService
- DisplayAdapter
- DisplayDevice
- DisplayManagerGlobal
- DisplayManager
- LogicalDisplay
- Display
- DisplayContent
- DisplayInfo
- 类之间的关系
- 默认屏幕的上层初始化分析
涉及的java类
DisplayManagerService
Manages attached displays.
The DisplayManagerService manages theglobal lifecycle of displays,
decides how to configure logicaldisplays based on the physical display devices currently
attached, sends notifications to thesystem and to applications when the state
changes, and so on.
The display manager service relies on acollection of DisplayAdapter components,
for discovering and configuring physicaldisplay devices attached to the system.
There are separate display adapters foreach manner that devices are attached:
one display adapter for built-in localdisplays, one for simulated non-functional
displays when the system is headless,one for simulated overlay displays used for
development, one for wifi displays, etc.
Display adapters are only weakly coupledto the display manager service.
Display adapters communicate changes indisplay device state to the display manager
service asynchronously via aDisplayAdapter.Listener registered
by the display manager service. This separation of concerns is important for
two main reasons. First, it neatly encapsulates theresponsibilities of these
two classes: display adapters handleindividual display devices whereas
the display manager service handles theglobal state. Second, it eliminates
the potential for deadlocks resultingfrom asynchronous display device discovery.
DisplayAdapter
A display adapter makes zero or moredisplay devices available to the system
and provides facilities for discoveringwhen displays are connected or disconnected.
For now, all display adapters areregistered in the system server but
in principle it could be done from otherprocesses.
现在支持的4种Adapter，分别对应不同类型的display。
1.LocalDisplayAdapter
A display adapter for the local displaysmanaged by Surface Flinger
2.WifiDisplayAdapter
Connects to Wifi displays that implementthe Miracast protocol.
This class is responsible for connectingto Wifi displays and mediating
the interactions between Media Server,Surface Flinger and the Display Manager Service.
3.VirtualDisplayAdapter
4.OverlayDisplayAdapter
DisplayDevice
Represents a physical display device such asthe built-in display an external monitor, or a WiFi display.
WifiDisplayDevice
VirtualDisplayDevice
OverlayDisplayDevice
LocalDisplayDevice
DisplayManagerGlobal
Manager communication with the displaymanager service on behalf of an application process.
DisplayManager
Manages the properties of attacheddisplays.
LogicalDisplay
Describes how a logical display isconfigured.
At this time, we only support logicaldisplays that are coupled to a particular
primary display device from which thelogical display derives its basic properties
such as its size, density and refreshrate.
A logical display may be mirrored ontomultiple display devices in addition to its
primary display device. Note that the contents of a logical displaymay not
always be visible, even on its primarydisplay device, such as in the case where
the primary display device is currentlymirroring content from a different
logical display.
Note: The display manager architecturedoes not actually require logical displays
to be associated with any individualdisplay device. Logical displays and
display devices are orthogonalconcepts. Some mapping will existbetween
logical displays and display devices butit can be many-to-many and
and some might have no relation at all.
Display
Provides information about the size anddensity of a logical display.
DisplayContent
Utility class for keeping track of theWindowStates and other pertinent contents of a particular Display.
DisplayInfo
Describes the characteristics of aparticular logical display.
类之间的关系
以添加系统built in display为例，下面是各个类之间的关系图，
其中，LocalDisplayDevice中的mPhys是向surface flinger获取的display的硬件相关属性，而mDisplayToken是surfacefinger中为display创建的new BBinder对应的代理对象。
默认屏幕的上层初始化分析
1.
systemserver.Java
/*--------------systemserver.java---------------------------*/
// 专门为window manager创建了一个handler thread
// Create a handler thread just for the window manager to enjoy.
HandlerThread wmHandlerThread = new HandlerThread("WindowManager");
wmHandlerThread.start();
//创建一个window manager的Handler(looper是wmHandlerThread线程的)
Handler wmHandler = new Handler(wmHandlerThread.getLooper());
wmHandler.post(new Runnable(){
@Override
public void run() {
//Looper.myLooper().setMessageLogging(new LogPrinter(
// android.util.Log.DEBUG, TAG, android.util.Log.LOG_ID_SYSTEM));
android.os.Process.setThreadPriority(
android.os.Process.THREAD_PRIORITY_DISPLAY);
android.os.Process.setCanSelfBackground(false);
// For debug builds, log eventloop stalls to dropbox for analysis.
if (StrictMode.conditionallyEnableDebugLogging()) {
Slog.i(TAG, "Enabled StrictMode logging for WM Looper");
}
}
});
/*--------------systemserver.java---------------------------*/
// DisplayManagerService display = null;
// 新建DisplayManagerService服务
Slog.i(TAG, "Display Manager");
display =new DisplayManagerService(context,wmHandler);
ServiceManager.addService(Context.DISPLAY_SERVICE,display, true);
//需要等待第一个display初始化完成后，才继续进行，否则一直循环
if (!display.waitForDefaultDisplay()) {
reportWtf("Timeoutwaiting for default display to be initialized.",
new Throwable());
}
/*--------------DisplayManagerService.java---------------------------*/
// 在mSyncRoot wait，直到mLogicalDisplays.get(Display.DEFAULT_DISPLAY)不为null
// 即有地方添加了默认display的LogicalDisplay
/**
* Pauses theboot process to wait for the first display to be initialized.
*/
publicbooleanwaitForDefaultDisplay() {
synchronized (mSyncRoot) {
long timeout = SystemClock.uptimeMillis() + WAIT_FOR_DEFAULT_DISPLAY_TIMEOUT;
while (mLogicalDisplays.get(Display.DEFAULT_DISPLAY) == null) {
long delay = timeout - SystemClock.uptimeMillis();
if (delay <= 0) {
returnfalse;
}
if (DEBUG) {
Slog.d(TAG, "waitForDefaultDisplay:waiting, timeout=" + delay);
}
try {
mSyncRoot.wait(delay);
} catch (InterruptedException ex) {
}
}
}
returntrue;
}
/*--------------DisplayManagerService.java---------------------------*/
publicDisplayManagerService(Context context, Handler mainHandler) {
mContext = context;
mHeadless = SystemProperties.get(SYSTEM_HEADLESS).equals("1");
//新建个DisplayManagerHandler
mHandler = newDisplayManagerHandler(mainHandler.getLooper());
mUiHandler = UiThread.getHandler();
//新建个DisplayAdapterListener
mDisplayAdapterListener = new DisplayAdapterListener();
//persist.demo.singledisplay是只创建默认display的logical display
mSingleDisplayDemoMode = SystemProperties.getBoolean("persist.demo.singledisplay", false);
mHandler.sendEmptyMessage(MSG_REGISTER_DEFAULT_DISPLAY_ADAPTER);
}
DisplayManagerHandler的消息处理函数，
/*--------------DisplayManagerService.java---------------------------*/
privatefinalclassDisplayManagerHandlerextendsHandler {
publicDisplayManagerHandler(Looper looper) {
super(looper, null, true/*async*/);
}
@Override
publicvoidhandleMessage(Message msg) {
switch (msg.what) {
case MSG_REGISTER_DEFAULT_DISPLAY_ADAPTER:
registerDefaultDisplayAdapter();
break;
case MSG_REGISTER_ADDITIONAL_DISPLAY_ADAPTERS:
registerAdditionalDisplayAdapters();
break;
case MSG_DELIVER_DISPLAY_EVENT:
deliverDisplayEvent(msg.arg1, msg.arg2);
break;
case MSG_REQUEST_TRAVERSAL:
mWindowManagerFuncs.requestTraversal();
break;
case MSG_UPDATE_VIEWPORT: {
synchronized (mSyncRoot) {
mTempDefaultViewport.copyFrom(mDefaultViewport);
mTempExternalTouchViewport.copyFrom(mExternalTouchViewport);
}
mInputManagerFuncs.setDisplayViewports(
mTempDefaultViewport,mTempExternalTouchViewport);
break;
}
}
}
}
DisplayAdapterListener类，
/*--------------DisplayManagerService.java---------------------------*/
privatefinalclassDisplayAdapterListenerimplementsDisplayAdapter.Listener {
@Override
publicvoidonDisplayDeviceEvent(DisplayDevicedevice, int event) {
switch (event) {
case DisplayAdapter.DISPLAY_DEVICE_EVENT_ADDED:
handleDisplayDeviceAdded(device);
break;
case DisplayAdapter.DISPLAY_DEVICE_EVENT_CHANGED:
handleDisplayDeviceChanged(device);
break;
case DisplayAdapter.DISPLAY_DEVICE_EVENT_REMOVED:
handleDisplayDeviceRemoved(device);
break;
}
}
@Override
publicvoidonTraversalRequested() {
synchronized (mSyncRoot) {
scheduleTraversalLocked(false);
}
}
}
mHeadless = SystemProperties.get(SYSTEM_HEADLESS).equals("1");
/* ro.config.headless
系统中判断ro.config.headless的总共有几个地方
a、SurfaceControl.java在构造函数中判断如果是headless设备则抛出异常，说明headless的设备不应该构造任何显示画面
b、在SystemUI中判断headless为true的情况下不启动WallpaperManagerService和SystemUIService
c、在PhoneWindowManager的systemReady中判断headless为true的情况下不起动KeyguardServiceDelegate，不显示启动提示消息，屏蔽滑盖(lid)状态，屏蔽一些按键
d、DisplayManagerService在创建默认显示设备的时候（registerDefaultDisplayAdapter）判断headless为true的情况下创建的是HeadlessDisplayAdapter而非LocalDisplayAdapter，前者并没有通过SurfaceFlinger.getBuiltInDisplay获取一个对应的DisplayDevice,也就是说上层的默认显示设备是空
e、ActivityManagerService在startHomeActivityLocked断headless为true的情况下不启动HomeActivity，不能启动Activity,不能重启挂掉的进程（即使是persistent），不能更新屏幕配置。
*/
mHandler的MSG_REGISTER_DEFAULT_DISPLAY_ADAPTER处理函数为，
/*--------------DisplayManagerService.java---------------------------*/
privatevoidregisterDefaultDisplayAdapter() {
// Register default display adapter.
synchronized (mSyncRoot) {
if (mHeadless) {
registerDisplayAdapterLocked(new HeadlessDisplayAdapter(
mSyncRoot, mContext,mHandler, mDisplayAdapterListener));
} else {
//走这个分支
registerDisplayAdapterLocked(new LocalDisplayAdapter(
mSyncRoot, mContext,mHandler, mDisplayAdapterListener));
}
}
}
LocalDisplayAdapter构造函数的mHandler和mDisplayAdapterListener分别为DisplayManagerHandler和DisplayAdapterListener。
/*--------------LocalDisplayAdapter.java---------------------------*/
/* class LocalDisplayAdapter extends DisplayAdapter */
// Called with SyncRoot lock held.
publicLocalDisplayAdapter(DisplayManagerService.SyncRoot syncRoot,
Contextcontext, Handlerhandler, Listener listener) {
super(syncRoot, context, handler, listener, TAG);
}
/*--------------DisplayAdapter.java---------------------------*/
// LocalDisplayAdapter是 DisplayAdapter的子类
public DisplayAdapter(DisplayManagerService.SyncRoot syncRoot,
Context context, Handlerhandler, Listenerlistener, String name) {
mSyncRoot =syncRoot;
mContext = context;
mHandler = handler;
mListener = listener;
mName = name;
}
/*--------------DisplayManagerService.java---------------------------*/
// private finalArrayList<DisplayAdapter> mDisplayAdapters = newArrayList<DisplayAdapter>();
privatevoidregisterDisplayAdapterLocked(DisplayAdapteradapter) {
mDisplayAdapters.add(adapter);
adapter.registerLocked();
}
LocalDisplayAdapter.registerLocked()，
/*--------------LocalDisplayAdapter.java---------------------------*/
privatestaticfinalint[] BUILT_IN_DISPLAY_IDS_TO_SCAN = newint[] {
SurfaceControl.BUILT_IN_DISPLAY_ID_MAIN,
SurfaceControl.BUILT_IN_DISPLAY_ID_HDMI,
};
// LocalDisplayAdapter.registerLocked
publicvoidregisterLocked() {
super.registerLocked();
mHotplugReceiver = new HotplugDisplayEventReceiver(getHandler().getLooper());
//对默认屏幕和HDMI调用tryConnectDisplayLocked
for (int builtInDisplayId : BUILT_IN_DISPLAY_IDS_TO_SCAN) {
tryConnectDisplayLocked(builtInDisplayId);
}
}
调用tryConnectDisplayLocked()，这里主要是和底层framework去交互，获取底层注册的displays的相关信息。
/*--------------LocalDisplayAdapter.java---------------------------*/
// LocalDisplayAdapter.mDevices
// private final SparseArray<LocalDisplayDevice> mDevices =newSparseArray<LocalDisplayDevice>();
privatevoidtryConnectDisplayLocked(int builtInDisplayId) {
//获取surface flinger中的new BBinder对应的client IBinder
IBinder displayToken =SurfaceControl.getBuiltInDisplay(builtInDisplayId);
//获取display的硬件属性，新建LocalDisplayDevice
if (displayToken != null && SurfaceControl.getDisplayInfo(displayToken, mTempPhys)) {
LocalDisplayDevice device =mDevices.get(builtInDisplayId);
if (device == null) {
// Display wasadded.
device = new LocalDisplayDevice(displayToken, builtInDisplayId, mTempPhys);
mDevices.put(builtInDisplayId,device);
//给DisplayManagerService的DisplayManagerHandler发消息
sendDisplayDeviceEventLocked(device, DISPLAY_DEVICE_EVENT_ADDED);
} elseif(device.updatePhysicalDisplayInfoLocked(mTempPhys)) {
// Displayproperties changed.
sendDisplayDeviceEventLocked(device, DISPLAY_DEVICE_EVENT_CHANGED);
}
} else {
// The display isno longer available. Ignore the attempt to add it.
// If it wasconnected but has already been disconnected, we'll get a
// disconnect eventthat will remove it from mDevices.
}
}
/*--------------SurfaceControl.java---------------------------*/
//SurfaceControl.java，都是static，类函数
//通过id获取display token
publicstatic IBinder getBuiltInDisplay(int builtInDisplayId) {
return nativeGetBuiltInDisplay(builtInDisplayId);
}
//通过display token，获取display硬件属性
publicstaticbooleangetDisplayInfo(IBinder displayToken, SurfaceControl.PhysicalDisplayInfo outInfo) {
if (displayToken == null) {
thrownew IllegalArgumentException("displayTokenmust not be null");
}
if (outInfo == null) {
thrownew IllegalArgumentException("outInfomust not be null");
}
return nativeGetDisplayInfo(displayToken,outInfo);
}
其中，nativeGetBuiltInDisplay最终会调用surfaceflinger中的getBuiltInDisplay，通过Binder传回代理对象。
/*--------------SurfaceFlinger.cpp---------------------------*/
sp<IBinder> SurfaceFlinger::getBuiltInDisplay(int32_tid) {
if (uint32_t(id) >= DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES) {
ALOGE("getDefaultDisplay: id=%d is not a valid default display id", id);
returnNULL;
}
return mBuiltinDisplays[id];
}
nativeGetDisplayInfo—>SurfaceFlinger::getDisplayInfo，
/*--------------SurfaceFlinger.cpp---------------------------*/
status_t SurfaceFlinger::getDisplayInfo(const sp<IBinder>& display, DisplayInfo* info) {
int32_t type = NAME_NOT_FOUND;
for (int i=0 ;i<DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES ; i++) {
if (display == mBuiltinDisplays[i]) {
type = i;
break;
}
}
if (type < 0) {
return type;
}
const HWComposer& hwc(getHwComposer());
float xdpi = hwc.getDpiX(type);
float ydpi = hwc.getDpiY(type);
// TODO: Not sure if display density should handled by SF any longer
class Density {
staticint getDensityFromProperty(charconst* propName) {
char property[PROPERTY_VALUE_MAX];
int density = 0;
if (property_get(propName, property, NULL) > 0) {
density = atoi(property);
}
return density;
}
public:
staticint getEmuDensity() {
return getDensityFromProperty("qemu.sf.lcd_density"); }
staticint getBuildDensity() {
return getDensityFromProperty("ro.sf.lcd_density"); }
};
if (type == DisplayDevice::DISPLAY_PRIMARY) {
// The density of the device is provided by a build property
float density = Density::getBuildDensity() / 160.0f;
if (density == 0) {
// the builddoesn't provide a density -- this is wrong!
// use xdpi instead
ALOGE("ro.sf.lcd_densitymust be defined as a build property");
density = xdpi / 160.0f;
}
if (Density::getEmuDensity()) {
// if"qemu.sf.lcd_density" is specified, it overrides everything
xdpi = ydpi = density =Density::getEmuDensity();
density /= 160.0f;
}
info->density = density;
// TODO: this needs to go away (currently needed only by webkit)
sp<const DisplayDevice>hw(getDefaultDisplayDevice());
info->orientation = hw->getOrientation();
} else {
// TODO: where should this value come from?
staticconstint TV_DENSITY = 213;
info->density = TV_DENSITY / 160.0f;
info->orientation = 0;
}
info->w = hwc.getWidth(type);
info->h = hwc.getHeight(type);
info->xdpi = xdpi;
info->ydpi = ydpi;
info->fps = float(1e9 / hwc.getRefreshPeriod(type));
// All non-virtual displays are currently considered secure.
info->secure = true;
return NO_ERROR;
}
创建完LocalDisplayDevice，给DisplayManagerService的DisplayManagerHandler发消息，
/*--------------DisplayAdapter.java---------------------------*/
/**
* Sends adisplay device event to the display adapter listener asynchronously.
*/
protectedfinalvoidsendDisplayDeviceEventLocked(
final DisplayDevice device, finalint event) {
mHandler.post(new Runnable() {
@Override
publicvoidrun() {
mListener.onDisplayDeviceEvent(device,event);
}
});
}
LocalDisplayAdapter构造函数的mHandler和mDisplayAdapterListener分别为DisplayManagerHandler和DisplayAdapterListener，进而会去调用,
/*--------------DisplayManagerService.java---------------------------*/
privatevoidhandleDisplayDeviceAdded(DisplayDevicedevice) {
synchronized (mSyncRoot) {
handleDisplayDeviceAddedLocked(device);
}
}
/*--------------DisplayManagerService.java---------------------------*/
//输入为LocalDisplayDevice
// private finalArrayList<DisplayDevice> mDisplayDevices = newArrayList<DisplayDevice>();
privatevoidhandleDisplayDeviceAddedLocked(DisplayDevicedevice) {
if (mDisplayDevices.contains(device)) {
Slog.w(TAG, "Attemptedto add already added display device: "
+device.getDisplayDeviceInfoLocked());
return;
}
Slog.i(TAG, "Display device added: " + device.getDisplayDeviceInfoLocked());
// List of all currently connected display devices.
//将LocalDisplayDevice添加到mDisplayDevices
mDisplayDevices.add(device);
//为一个物理display添加一个logical display
addLogicalDisplayLocked(device);
updateDisplayBlankingLocked(device);
scheduleTraversalLocked(false);
}
为物理屏幕创建一个logical display，
/*--------------DisplayManagerService.java---------------------------*/
// Adds a new logical display based on the given displaydevice.
// Sends notifications if needed.
privatevoidaddLogicalDisplayLocked(DisplayDevicedevice) {
DisplayDeviceInfo deviceInfo = device.getDisplayDeviceInfoLocked();
boolean isDefault = (deviceInfo.flags
&DisplayDeviceInfo.FLAG_DEFAULT_DISPLAY) != 0;
//主屏，同时mLogicalDisplays包含了这个device
if (isDefault && mLogicalDisplays.get(Display.DEFAULT_DISPLAY)!= null) {
Slog.w(TAG, "Ignoringattempt to add a second default display: " + deviceInfo);
isDefault = false;
}
//不是主屏，但是mSingleDisplayDemoMode为真，即设置了单屏模式
//这时候不会去为这个物理display创建新的logical display，如果
//有hdmi，这时候会mirror主屏的内容
//看来逻辑display就是和显示的内容有很大的关系
if (!isDefault &&mSingleDisplayDemoMode) {
Slog.i(TAG, "Notcreating a logical display for a secondary display "
+ " becausesingle display demo mode is enabled: " + deviceInfo);
return;
}
finalint displayId = assignDisplayIdLocked(isDefault);
// layerStack 就是displayId id,主屏0，hdmi 1
finalint layerStack = assignLayerStackLocked(displayId);
//新建LogicalDisplay
LogicalDisplay display = new LogicalDisplay(displayId, layerStack, device);
display.updateLocked(mDisplayDevices);
if (!display.isValidLocked()) {
// This shouldnever happen currently.
Slog.w(TAG, "Ignoringdisplay device because the logical display "
+ "created fromit was not considered valid: " + deviceInfo);
return;
}
mLogicalDisplays.put(displayId, display);
//如果添加的是built-in display，需要mSyncRoot.notifyAll()
//因为systemserver.java中调用了waitForDefaultDisplay,这时候systemserver可以继续运行了
// Wake up waitForDefaultDisplay.
if (isDefault) {
mSyncRoot.notifyAll();
}
//给mHandler发消息去处理
sendDisplayEventLocked(displayId,DisplayManagerGlobal.EVENT_DISPLAY_ADDED);
}
/*--------------LogicalDisplay.java---------------------------*/
publicLogicalDisplay(int displayId, int layerStack, DisplayDevice primaryDisplayDevice) {
mDisplayId = displayId;
mLayerStack = layerStack;
mPrimaryDisplayDevice = primaryDisplayDevice;
}
进而去调用mHandler的deliverDisplayEvent，先不去管mCallbacks是在哪里注册的，进而会去调用mTempCallbacks.get(i).notifyDisplayEventAsync(displayId, event);
/*--------------DisplayManagerService.java---------------------------*/
privatevoiddeliverDisplayEvent(int displayId, intevent) {
if (DEBUG) {
Slog.d(TAG, "Deliveringdisplay event: displayId="
+ displayId + ",event=" + event);
}
// Grab the lock and copy the callbacks.
final int count;
synchronized (mSyncRoot) {
//这里的mCallbacks是哪里注册的？？
count = mCallbacks.size();
mTempCallbacks.clear();
for (int i = 0; i < count; i++) {
mTempCallbacks.add(mCallbacks.valueAt(i));
}
}
// After releasing the lock, send the notifications out.
for (int i = 0; i < count; i++) {
mTempCallbacks.get(i).notifyDisplayEventAsync(displayId, event);
}
mTempCallbacks.clear();
}
2.
mCallbacks的由来，
上面在添加了默认display的LogicalDisplay后，会去调用下面代码，使得systemserver.java从waitForDefaultDisplay()中返回。
/*--------------systemserver.java---------------------------*/
if (isDefault) {
mSyncRoot.notifyAll();
}
进而，systemserver.java的initAndLoop() 会去注册WindowManagerService，
/*--------------systemserver.java---------------------------*/
wm = WindowManagerService.main(context, power, display, inputManager,
wmHandler, factoryTest !=SystemServer.FACTORY_TEST_LOW_LEVEL,
!firstBoot, onlyCore);
下面分析下，WindowManagerService的构造函数中做了什么和display相关的，
/*--------------WindowManagerService.java---------------------------*/
/*
class WindowManagerService extends IWindowManager.Stub
implementsWatchdog.Monitor, WindowManagerPolicy.WindowManagerFuncs,
DisplayManagerService.WindowManagerFuncs, DisplayManager.DisplayListener
*/
//WindowManagerService实现了DisplayManager.DisplayListener接口
privateWindowManagerService(Context context, PowerManagerService pm,
DisplayManagerServicedisplayManager, InputManagerService inputManager,
boolean haveInputMethods, boolean showBootMsgs, boolean onlyCore) {
mDisplayManagerService = displayManager;
//新建个DisplayManager
mDisplayManager =(DisplayManager)context.getSystemService(Context.DISPLAY_SERVICE);
//由于WindowManagerService实现了DisplayManager.DisplayListener接口，
//将WindowManagerService注册到DisplayManager中
mDisplayManager.registerDisplayListener(this, null);
}
/*--------------DisplayManager.java---------------------------*/
publicDisplayManager(Context context) {
mContext = context;
mGlobal = DisplayManagerGlobal.getInstance();
}
/*--------------DisplayManagerGlobal.java---------------------------*/
// class DisplayManagerService extendsIDisplayManager.Stub
publicstatic DisplayManagerGlobal getInstance() {
synchronized (DisplayManagerGlobal.class) {
if (sInstance == null) {
IBinder b =ServiceManager.getService(Context.DISPLAY_SERVICE);
if (b != null) {
//输入参数是DisplayManagerService 的代理
sInstance = new DisplayManagerGlobal(IDisplayManager.Stub.asInterface(b));
}
}
return sInstance;
}
}
publicfinalclassDisplayManagerGlobal {
//mDm是DisplayManagerService 的代理，用来和DisplayManagerService打交道
privatefinal IDisplayManager mDm;
privateDisplayManagerGlobal(IDisplayManager dm) {
mDm = dm;
}
}
接着将WindowManagerService注册到DisplayManager中，
/*--------------DisplayManager.java---------------------------*/
//输入参数为WindowManagerService,null
publicvoidregisterDisplayListener(DisplayListenerlistener, Handler handler) {
mGlobal.registerDisplayListener(listener, handler);
}
/*--------------DisplayManagerGlobal.java---------------------------*/
//DisplayManagerGlobal
publicvoidregisterDisplayListener(DisplayListenerlistener, Handler handler) {
if (listener == null) {
thrownew IllegalArgumentException("listenermust not be null");
}
// private final ArrayList<DisplayListenerDelegate>mDisplayListeners =
// newArrayList<DisplayListenerDelegate>();
synchronized (mLock) {
int index = findDisplayListenerLocked(listener);
if (index < 0) {
//新建一个display listener的代理者
mDisplayListeners.add(new DisplayListenerDelegate(listener, handler));
//将DisplayManagerGlobal 和DisplayManagerService 联系起来
registerCallbackIfNeededLocked();
}
}
}
publicDisplayListenerDelegate(DisplayListenerlistener, Handler handler) {
super(handler != null ?handler.getLooper() : Looper.myLooper(), null, true/*async*/);
mListener = listener;
}
/*--------------DisplayManagerGlobal.java---------------------------*/
// 将 DisplayManagerGlobal 和DisplayManagerService 联系起来
privatevoidregisterCallbackIfNeededLocked() {
if (mCallback == null) {
mCallback = new DisplayManagerCallback();
try {
//调用DisplayManagerService 的registerCallback将
//DisplayManagerGlobal中的DisplayManagerCallback注册到DisplayManagerService中
mDm.registerCallback(mCallback);
} catch (RemoteException ex) {
Log.e(TAG, "Failed toregister callback with display manager service.", ex);
mCallback = null;
}
}
}
privatefinalclassDisplayManagerCallbackextendsIDisplayManagerCallback.Stub {
@Override
publicvoidonDisplayEvent(int displayId, int event) {
if (DEBUG) {
Log.d(TAG, "onDisplayEvent:displayId=" + displayId + ",event=" + event);
}
handleDisplayEvent(displayId,event);
}
}
DisplayManagerService中调用registerCallback，将DisplayManagerCallback保存到mCallbacks中，
/*--------------DisplayManagerService.java---------------------------*/
@Override// Binder call
publicvoidregisterCallback(IDisplayManagerCallbackcallback) {
if (callback == null) {
thrownew IllegalArgumentException("listenermust not be null");
}
synchronized (mSyncRoot) {
int callingPid = Binder.getCallingPid();
if(mCallbacks.get(callingPid) != null) {
thrownew SecurityException("Thecalling process has already "
+ "registeredan IDisplayManagerCallback.");
}
CallbackRecord record = new CallbackRecord(callingPid, callback);
try {
IBinder binder =callback.asBinder();
binder.linkToDeath(record, 0);
} catch (RemoteException ex) {
// give up
thrownew RuntimeException(ex);
}
//保存的是CallbackRecord
mCallbacks.put(callingPid, record);
}
}
/*--------------DisplayManagerService.java---------------------------*/
privatefinalclassCallbackRecordimplementsDeathRecipient {
publicfinalint mPid;
privatefinal IDisplayManagerCallback mCallback;
publicboolean mWifiDisplayScanRequested;
publicCallbackRecord(int pid, IDisplayManagerCallback callback){
mPid = pid;
mCallback = callback;
}
@Override
publicvoidbinderDied() {
if (DEBUG) {
Slog.d(TAG, "Displaylistener for pid " + mPid + "died.");
}
onCallbackDied(this);
}
publicvoidnotifyDisplayEventAsync(int displayId, int event) {
try {
mCallback.onDisplayEvent(displayId,event);
} catch (RemoteException ex) {
Slog.w(TAG, "Failed tonotify process "
+ mPid + " thatdisplays changed, assuming it died.", ex);
binderDied();
}
}
}
3.
回到最开始的deliverDisplayEvent函数，会调用CallbackRecord的notifyDisplayEventAsync(displayId,event)，进而mCallback.onDisplayEvent(displayId, event)，进而调用DisplayManagerGlobal的handleDisplayEvent(displayId, event)，
/*--------------DisplayManagerService.java---------------------------*/
privatevoiddeliverDisplayEvent(int displayId, intevent) {
if (DEBUG) {
Slog.d(TAG, "Deliveringdisplay event: displayId="
+ displayId + ",event=" + event);
}
// Grab the lock and copy the callbacks.
final int count;
synchronized (mSyncRoot) {
//这里的mCallbacks是哪里注册的？？
count = mCallbacks.size();
mTempCallbacks.clear();
for (int i = 0; i < count; i++) {
mTempCallbacks.add(mCallbacks.valueAt(i));
}
}
// After releasing the lock, send the notifications out.
for (int i = 0; i < count; i++) {
mTempCallbacks.get(i).notifyDisplayEventAsync(displayId, event);
}
mTempCallbacks.clear();
}
handleDisplayEvent中的mDisplayListeners就是前面注册的DisplayListenerDelegate，其中的listener和handler分别为WindowManagerService和null，
/*--------------DisplayManagerGlobal.java---------------------------*/
privatevoidhandleDisplayEvent(int displayId, intevent) {
synchronized (mLock) {
if (USE_CACHE) {
mDisplayInfoCache.remove(displayId);
if (event == EVENT_DISPLAY_ADDED || event == EVENT_DISPLAY_REMOVED) {
mDisplayIdCache = null;
}
}
final int numListeners = mDisplayListeners.size();
for (int i = 0; i < numListeners; i++) {
mDisplayListeners.get(i).sendDisplayEvent(displayId, event);
}
}
}
调用DisplayListenerDelegate 的sendDisplayEvent，进而调用mListener.onDisplayAdded(msg.arg1);，即WindowManagerService的onDisplayAdded，
/*--------------DisplayManagerGlobal.java---------------------------*/
privatestaticfinalclassDisplayListenerDelegateextendsHandler {
publicfinal DisplayListener mListener;
publicDisplayListenerDelegate(DisplayListener listener, Handler handler) {
super(handler != null ?handler.getLooper() : Looper.myLooper(), null, true/*async*/);
mListener = listener;
}
publicvoidsendDisplayEvent(int displayId, int event) {
Message msg = obtainMessage(event,displayId, 0);
sendMessage(msg);
}
publicvoidclearEvents() {
removeCallbacksAndMessages(null);
}
@Override
publicvoidhandleMessage(Message msg) {
switch (msg.what) {
case EVENT_DISPLAY_ADDED:
mListener.onDisplayAdded(msg.arg1);
break;
case EVENT_DISPLAY_CHANGED:
mListener.onDisplayChanged(msg.arg1);
break;
case EVENT_DISPLAY_REMOVED:
mListener.onDisplayRemoved(msg.arg1);
break;
}
}
}
}
转到WindowManagerService中，
/*--------------WindowManagerService.java---------------------------*/
@Override
publicvoidonDisplayAdded(int displayId) {
mH.sendMessage(mH.obtainMessage(H.DO_DISPLAY_ADDED, displayId, 0));
}
/*--------------WindowManagerService.java---------------------------*/
case DO_DISPLAY_ADDED:
synchronized (mWindowMap) {
handleDisplayAddedLocked(msg.arg1);
}
break;
privatevoidhandleDisplayAddedLocked(int displayId) {
final Display display =mDisplayManager.getDisplay(displayId);
if (display != null) {
createDisplayContentLocked(display);
displayReady(displayId);
}
}
调用DisplayManager的getDisplay，
/*--------------DisplayManager.java---------------------------*/
public Display getDisplay(int displayId) {
synchronized (mLock) {
return getOrCreateDisplayLocked(displayId, false/*assumeValid*/);
}
}
/*--------------DisplayManager.java---------------------------*/
// private finalSparseArray<Display> mDisplays = new SparseArray<Display>();
private Display getOrCreateDisplayLocked(int displayId, boolean assumeValid) {
Display display = mDisplays.get(displayId);
if (display == null) {
display =mGlobal.getCompatibleDisplay(displayId,
mContext.getDisplayAdjustments(displayId));
if (display != null) {
mDisplays.put(displayId,display);
}
} elseif (!assumeValid && !display.isValid()) {
display = null;
}
return display;
}
/*--------------DisplayManagerGlobal.java---------------------------*/
public Display getCompatibleDisplay(int displayId, DisplayAdjustments daj) {
DisplayInfo displayInfo = getDisplayInfo(displayId);
if (displayInfo == null) {
returnnull;
}
returnnew Display(this, displayId, displayInfo, daj);
}
/*--------------DisplayManagerGlobal.java---------------------------*/
//mDm DisplayManagerService
public DisplayInfo getDisplayInfo(int displayId) {
try {
synchronized (mLock) {
DisplayInfo info;
if (USE_CACHE) {
info = mDisplayInfoCache.get(displayId);
if (info != null) {
return info;
}
}
//调用DisplayManagerService的getDisplayInfo，获取显示器信息
info =mDm.getDisplayInfo(displayId);
if (info == null) {
returnnull;
}
if (USE_CACHE) {
mDisplayInfoCache.put(displayId,info);
}
//前面已经注册过了，mCallback不为Null
registerCallbackIfNeededLocked();
if (DEBUG) {
Log.d(TAG, "getDisplayInfo:displayId=" + displayId + ", info=" + info);
}
return info;
}
} catch (RemoteException ex) {
Log.e(TAG, "Could not getdisplay information from display manager.", ex);
returnnull;
}
}
/*--------------DisplayManagerGlobal.java---------------------------*/
//已经注册过了，mCallback不为Null
privatevoidregisterCallbackIfNeededLocked() {
if (mCallback == null) {
mCallback = new DisplayManagerCallback();
try {
mDm.registerCallback(mCallback);
} catch (RemoteException ex) {
Log.e(TAG, "Failed toregister callback with display manager service.", ex);
mCallback = null;
}
}
}
/*--------------WindowManagerService.java---------------------------*/
//Display已经创建，创建display content
publicvoidcreateDisplayContentLocked(final Display display) {
if (display == null) {
thrownew IllegalArgumentException("getDisplayContent:display must not be null");
}
getDisplayContentLocked(display.getDisplayId());
}
/** All DisplayContents in the world, kept here */
// SparseArray<DisplayContent> mDisplayContents = newSparseArray<DisplayContent>(2);
public DisplayContent getDisplayContentLocked(finalint displayId) {
DisplayContent displayContent = mDisplayContents.get(displayId);
if (displayContent == null) {
final Display display = mDisplayManager.getDisplay(displayId);
// 走到这个分支，创建displayContent
if (display != null) {
displayContent =newDisplayContentLocked(display);
}
}
return displayContent;
}
新建一个DisplayContent，保存到WindowManagerService的mDisplayContents(displayId, displayContent)。
private DisplayContent newDisplayContentLocked(final Display display) {
DisplayContent displayContent = new DisplayContent(display, this);
final int displayId = display.getDisplayId();
mDisplayContents.put(displayId, displayContent);
DisplayInfo displayInfo = displayContent.getDisplayInfo();
final Rect rect = new Rect();
mDisplaySettings.getOverscanLocked(displayInfo.name, rect);
synchronized (displayContent.mDisplaySizeLock) {
displayInfo.overscanLeft = rect.left;
displayInfo.overscanTop = rect.top;
displayInfo.overscanRight = rect.right;
displayInfo.overscanBottom = rect.bottom;
mDisplayManagerService.setDisplayInfoOverrideFromWindowManager(
displayId, displayInfo);
}
configureDisplayPolicyLocked(displayContent);
// TODO: Create an input channel for each display with touch capability.
if (displayId == Display.DEFAULT_DISPLAY) {
displayContent.mTapDetector = new StackTapPointerEventListener(this, displayContent);
registerPointerEventListener(displayContent.mTapDetector);
}
return displayContent;
}
最后
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