Android14 WMS-窗口添加流程(二)-Server端

Android14 WMS-窗口添加流程(一)-Client端-CSDN博客

本文接着上文"Android14 WMS-窗口添加流程(一)-Client端"往下讲。也就是WindowManagerService#addWindow流程。

目录

一. WindowManagerService#addWindow

标志1：mPolicy.checkAddPermission

标志2：getDisplayContentOrCreate

标志3： mWindowMap

二：窗口类型检查

三：新建WindowToken

标志1 WindowToken

四： 新建WindowState

 五：adjustWindowParamsLw

 六：窗口ADD_OKAY后续流程

---

整个流程如下

 

一. WindowManagerService#addWindow

http://aospxref.com/android-14.0.0_r2/xref/frameworks/base/services/core/java/com/android/server/wm/WindowManagerService.java#1431

    public int addWindow(Session session, IWindow client, LayoutParams attrs, int viewVisibility,int displayId, int requestUserId, @InsetsType int requestedVisibleTypes,InputChannel outInputChannel, InsetsState outInsetsState,InsetsSourceControl.Array outActiveControls, Rect outAttachedFrame,float[] outSizeCompatScale) {outActiveControls.set(null);int[] appOp = new int[1];
//权限检查final boolean isRoundedCornerOverlay = (attrs.privateFlags& PRIVATE_FLAG_IS_ROUNDED_CORNERS_OVERLAY) != 0;
//标志1int res = mPolicy.checkAddPermission(attrs.type, isRoundedCornerOverlay, attrs.packageName,appOp);if (res != ADD_OKAY) {return res;}
//父windowWindowState parentWindow = null;
//发起者Uidfinal int callingUid = Binder.getCallingUid();
//发起者Pidfinal int callingPid = Binder.getCallingPid();final long origId = Binder.clearCallingIdentity();
//窗口类型final int type = attrs.type;synchronized (mGlobalLock) {if (!mDisplayReady) {throw new IllegalStateException("Display has not been initialialized");}
//一个DisplayContent对应一个绘制屏幕
//标志2final DisplayContent displayContent = getDisplayContentOrCreate(displayId, attrs.token);if (displayContent == null) {ProtoLog.w(WM_ERROR, "Attempted to add window to a display that does "+ "not exist: %d. Aborting.", displayId);return WindowManagerGlobal.ADD_INVALID_DISPLAY;}if (!displayContent.hasAccess(session.mUid)) {ProtoLog.w(WM_ERROR,"Attempted to add window to a display for which the application "+ "does not have access: %d.  Aborting.",displayContent.getDisplayId());return WindowManagerGlobal.ADD_INVALID_DISPLAY;}
//是否已经添加对应的窗口， 去重判断
//标志3if (mWindowMap.containsKey(client.asBinder())) {ProtoLog.w(WM_ERROR, "Window %s is already added", client);return WindowManagerGlobal.ADD_DUPLICATE_ADD;}

 由于此方法太长，所以我会分开去讲

标志1：mPolicy.checkAddPermission

mPolicy定义如下，如果此方法返回ADD_OKAY，则代码无权限问题，否则直接返回。

    WindowManagerPolicy mPolicy;
------------------------------------------int res = mPolicy.checkAddPermission(attrs.type, isRoundedCornerOverlay, attrs.packageName, appOp);if (res != ADD_OKAY) {return res;}

WindowManagerPolicy.java - OpenGrok cross reference for /frameworks/base/services/core/java/com/android/server/policy/WindowManagerPolicy.java

    /**当add window的时候检查权限* Check permissions when adding a window.** @param type The window type--窗口类型* @param isRoundedCornerOverlay {@code true} to indicate the adding window is*           round corner overlay. 指示要add的窗口为圆角叠加层。* @param packageName package name  包名* @param outAppOp First element will be filled with the app op corresponding to this window, or OP_NONE.第一个元素将填充与此窗口对应的应用操作，或OP_NONE。** @return {@link WindowManagerGlobal#ADD_OKAY} if the add can proceed;*      else an error code, usually*      {@link WindowManagerGlobal#ADD_PERMISSION_DENIED}, to abort the add.*//返回是否有权限添加，有则返回ADD_OKAY* @see WindowManager.LayoutParams#PRIVATE_FLAG_IS_ROUNDED_CORNERS_OVERLAY*/int checkAddPermission(int type, boolean isRoundedCornerOverlay, String packageName, int[] outAppOp);

 这里只是声明，没有实现，具体实现如下

PhoneWindowManager.java - OpenGrok cross reference for /frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java

    public int checkAddPermission(int type, boolean isRoundedCornerOverlay, String packageName,int[] outAppOp) {
//如果是圆角覆盖并且无PERMISSION_GRANTED权限，也无法添加windowif (isRoundedCornerOverlay && mContext.checkCallingOrSelfPermission(INTERNAL_SYSTEM_WINDOW)!= PERMISSION_GRANTED) {return ADD_PERMISSION_DENIED;}outAppOp[0] = AppOpsManager.OP_NONE;
//如果窗口类型不在系统划分的三大窗口范围内，则返回不合法的type--ADD_INVALID_TYPEif (!((type >= FIRST_APPLICATION_WINDOW && type <= LAST_APPLICATION_WINDOW)|| (type >= FIRST_SUB_WINDOW && type <= LAST_SUB_WINDOW)|| (type >= FIRST_SYSTEM_WINDOW && type <= LAST_SYSTEM_WINDOW))) {return WindowManagerGlobal.ADD_INVALID_TYPE;}
//如果窗口类型不是系统窗口类型，比如是APP窗口类型或者是子窗口类型，系统最大窗口类型为LAST_SYSTEM_WINDOW，则可以添加，返回ADD_OKAYif (type < FIRST_SYSTEM_WINDOW || type > LAST_SYSTEM_WINDOW) {// Window manager will make sure these are okay.return ADD_OKAY;}
//如果窗口类型不是alert window， alert window有好几种，可以查看这个方法if (!isSystemAlertWindowType(type)) {switch (type) {case TYPE_TOAST:// Only apps that target older than O SDK can add window without a token, after// that we require a token so apps cannot add toasts directly as the token is// added by the notification system.// Window manager does the checking for this.outAppOp[0] = OP_TOAST_WINDOW;return ADD_OKAY;case TYPE_INPUT_METHOD:case TYPE_WALLPAPER:case TYPE_PRESENTATION:case TYPE_PRIVATE_PRESENTATION:case TYPE_VOICE_INTERACTION:case TYPE_ACCESSIBILITY_OVERLAY:case TYPE_QS_DIALOG:case TYPE_NAVIGATION_BAR_PANEL:// The window manager will check these.return ADD_OKAY;}return (mContext.checkCallingOrSelfPermission(INTERNAL_SYSTEM_WINDOW)== PERMISSION_GRANTED) ? ADD_OKAY : ADD_PERMISSION_DENIED;}// Things get a little more interesting for alert windows...outAppOp[0] = OP_SYSTEM_ALERT_WINDOW;final int callingUid = Binder.getCallingUid();// system processes will be automatically granted privilege to draw
//如果是系统进程，则直接允许if (UserHandle.getAppId(callingUid) == Process.SYSTEM_UID) {return ADD_OKAY;}...}

标志2：getDisplayContentOrCreate

            final DisplayContent displayContent = getDisplayContentOrCreate(displayId, attrs.token);

 此方法定义如下，其作用是"Get existing {@link DisplayContent} or create a new one if the display is registered in DisplayManager."，即“获取现有的DisplayContent，如果display已在 DisplayManager 中注册，则创建一个新DisplayContent”.

仅当尚未创建与刚刚添加到 DisplayManager 的display相对应的DisplayContent时，才应使用此选项。这通常意味着此方法的调用是从 Activity 或窗口管理器外部启动的。

    /*** Get existing {@link DisplayContent} or create a new one if the display is registered in* DisplayManager.** NOTE: This should only be used in cases when there is a chance that a {@link DisplayContent}* that corresponds to a display just added to DisplayManager has not yet been created. This* usually means that the call of this method was initiated from outside of Activity or Window* Manager. In most cases the regular getter should be used.* @param displayId The preferred display Id.* @param token The window token associated with the window we are trying to get display for.*              if not null then the display of the window token will be returned. Set to null*              is there isn't an a token associated with the request.* @see RootWindowContainer#getDisplayContent(int)*/private DisplayContent getDisplayContentOrCreate(int displayId, IBinder token) {if (token != null) {
//WM中相关联的窗口集合
//tag1final WindowToken wToken = mRoot.getWindowToken(token);if (wToken != null) {
//tag2return wToken.getDisplayContent();}}
//tag3return mRoot.getDisplayContentOrCreate(displayId);}

这块涉及到Container，我们来看看继承关系

设备的Root WindowContainer，一个设备只有一个RootWindowContainer
class RootWindowContainer extends WindowContainer<DisplayContent>implements DisplayManager.DisplayListener {

一个设备只有一个RootWindowContainer, 因为它的赋值是在WMS的实例化中,WMS实例在全局只有一个，是从SystemServer中发起的。

    private WindowManagerService(Context context, InputManagerService inputManager, boolean showBootMsgs, WindowManagerPolicy policy, ActivityTaskManagerService atm,DisplayWindowSettingsProvider displayWindowSettingsProvider, Supplier<SurfaceControl.Transaction> transactionFactory, Function<SurfaceSession, SurfaceControl.Builder> surfaceControlFactory) {
...mRoot = new RootWindowContainer(this);

-----------------------------------------------------------------------------------------------------------

一系列相关window的集合
通常，这是一个AppWindowToken(AppWindowToken就是activity)，它是用于显示窗口的 Activity的句柄。
这个主要用于表示窗口的令牌(Token)信息，主要负责管理窗口的一些属性和行为，通过WindowToken，WMS可以对窗口进行布局，层级排序，焦点管理，输入事件分发等操作。
class WindowToken extends WindowContainer<WindowState> {

此外ActivityRecord继承WindowToken，一个ActivityRecord代表一个activity
final class ActivityRecord extends WindowToken implements WindowManagerService.AppFreezeListener {

-----------------------------------------------------------------------------------------------------------

WindowContainer作为窗口层级结构中的基本单元，负责承载一个窗口的所有信息和状态。每个窗口容器都对应一个窗口，并包含了窗口的配置信息、绘制信息、动画状态等。
WindowContainer还提供了与窗口相关的操作接口，如设置窗口属性、绘制窗口内容等。
在源码层面，WindowContainer的实现通常涉及到多个类和接口。
例如，WindowContainer类可能包含了一些与窗口容器相关的属性和方法，如窗口的位置、大小、背景色等。此外，WindowContainer还可能与其他组件进行交互，如与SurfaceFlinger进行渲染交互，与InputManager进行输入事件处理等。
class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<E>implements Comparable<WindowContainer>, Animatable, SurfaceFreezer.Freezable, InsetsControlTarget {
...
一系列子级window container集合。此集合按 z 顺序排列，因为子项显示在屏幕上，最上面的window container位于列表的尾部。
mChildren.add和mChildren.remove操作都在WindowContainer.java中protected final WindowList<E> mChildren = new WindowList<E>();

WindowList介绍如下： 一个 ArrayList，存储WindowContainer中的子window container
class WindowList<E> extends ArrayList<E> {
添加到集合首位void addFirst(E e) {add(0, e);}
选择最后一位E peekLast() {return size() > 0 ? get(size() - 1) : null;}
选择第一位E peekFirst() {return size() > 0 ? get(0) : null;}
}

-----------------------------------------------------------------------------------------------------------

包含具有重写配置并按层次结构组织的类的通用逻辑。
public abstract class ConfigurationContainer<E extends ConfigurationContainer> {

回归正题，来看看tag1处mRoot.getWindowToken(token); 刚刚已经讲过mChildren是一系列子级window container集合，那我们通过binder对此集合遍历，找到binder对应的windowtoken，然后返回。

    /** Returns the window token for the input binder if it exist in the system.*/WindowToken getWindowToken(IBinder binder) {for (int i = mChildren.size() - 1; i >= 0; --i) {final DisplayContent dc = mChildren.get(i);final WindowToken wtoken = dc.getWindowToken(binder);if (wtoken != null) {return wtoken;}}return null;}

用于跟踪特定 Display 的 WindowStates 和其他相关内容的 辅助类。
DisplayContent 用于管理屏幕，一块屏幕对应一个 DisplayContent 对象，虽然手机只有一个显示屏，但是可以创建多个 DisplayContent 对象
class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.DisplayContentInfo {

 

标志3： mWindowMap

mWindowMap保存了每个WindowState和客户端窗口的映射关系，客户端应用请求窗口操作时，通过mWindowMap查询到对应的WindowState

    /** Mapping from an IWindow IBinder to the server's Window object. */final HashMap<IBinder, WindowState> mWindowMap = new HashMap<>();

二：窗口类型检查

如果是子窗口类型if (type >= FIRST_SUB_WINDOW && type <= LAST_SUB_WINDOW) {
先找到它的父窗口，子窗口需要依附在父窗口上，如果父窗口为null，则返回ADD_BAD_SUBWINDOW_TOKENparentWindow = windowForClientLocked(null, attrs.token, false);if (parentWindow == null) {ProtoLog.w(WM_ERROR, "Attempted to add window with token that is not a window: "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;}
如果父窗口也是一个子窗口，也直接返回ADD_BAD_SUBWINDOW_TOKENif (parentWindow.mAttrs.type >= FIRST_SUB_WINDOW&& parentWindow.mAttrs.type <= LAST_SUB_WINDOW) {ProtoLog.w(WM_ERROR, "Attempted to add window with token that is a sub-window: "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;}}
如果窗口是保密类型，但displayContent不是保密类型，则返回ADD_PERMISSION_DENIEDif (type == TYPE_PRIVATE_PRESENTATION && !displayContent.isPrivate()) {ProtoLog.w(WM_ERROR,"Attempted to add private presentation window to a non-private display.  "+ "Aborting.");return WindowManagerGlobal.ADD_PERMISSION_DENIED;}
如果窗口是保密类型，但displayContent的屏幕是公开演示显示器，返回ADD_INVALID_DISPLAYif (type == TYPE_PRESENTATION && !displayContent.getDisplay().isPublicPresentation()) {ProtoLog.w(WM_ERROR,"Attempted to add presentation window to a non-suitable display.  "+ "Aborting.");return WindowManagerGlobal.ADD_INVALID_DISPLAY;}

三：新建WindowToken

            ActivityRecord activity = null;final boolean hasParent = parentWindow != null;// Use existing parent window token for child windows since they go in the same token// as there parent window so we can apply the same policy on them.
子窗口使用现有的父窗口令牌，因为它们与父窗口使用相同的令牌，因此我们可以对它们应用相同的策略。
根据客户端传来的token获取windowTokenWindowToken token = displayContent.getWindowToken(hasParent ? parentWindow.mAttrs.token : attrs.token);// If this is a child window, we want to apply the same type checking rules as the// parent window type.
如果这是一个子窗口，我们希望应用与父窗口类型相同的类型检查规则。final int rootType = hasParent ? parentWindow.mAttrs.type : type;boolean addToastWindowRequiresToken = false;final IBinder windowContextToken = attrs.mWindowContextToken;if (token == null) {如果token为空if (!unprivilegedAppCanCreateTokenWith(parentWindow, callingUid, type,rootType, attrs.token, attrs.packageName)) {return WindowManagerGlobal.ADD_BAD_APP_TOKEN;}if (hasParent) {如果有父级window// Use existing parent window token for child windows.token = parentWindow.mToken;则直接用父级token给所有的子windows} else if (mWindowContextListenerController.hasListener(windowContextToken)) {// Respect the window context token if the user provided it.
如果用户提供了窗口上下文令牌，则用windowContextTokenfinal IBinder binder = attrs.token != null ? attrs.token : windowContextToken;final Bundle options = mWindowContextListenerController.getOptions(windowContextToken);token = new WindowToken.Builder(this, binder, type).setDisplayContent(displayContent).setOwnerCanManageAppTokens(session.mCanAddInternalSystemWindow).setRoundedCornerOverlay(isRoundedCornerOverlay).setFromClientToken(true).setOptions(options).build();} else {final IBinder binder = attrs.token != null ? attrs.token : client.asBinder();token = new WindowToken.Builder(this, binder, type).setDisplayContent(displayContent).setOwnerCanManageAppTokens(session.mCanAddInternalSystemWindow).setRoundedCornerOverlay(isRoundedCornerOverlay).build();}
如果是APP类型窗口} else if (rootType >= FIRST_APPLICATION_WINDOW&& rootType <= LAST_APPLICATION_WINDOW) {
通过token获取ActivityRecordactivity = token.asActivityRecord();if (activity == null) {ProtoLog.w(WM_ERROR, "Attempted to add window with non-application token "+ ".%s Aborting.", token);return WindowManagerGlobal.ADD_NOT_APP_TOKEN;} else if (activity.getParent() == null) {ProtoLog.w(WM_ERROR, "Attempted to add window with exiting application token "+ ".%s Aborting.", token);return WindowManagerGlobal.ADD_APP_EXITING;
窗口类型为starting window} else if (type == TYPE_APPLICATION_STARTING) {if (activity.mStartingWindow != null) {ProtoLog.w(WM_ERROR, "Attempted to add starting window to "+ "token with already existing starting window");return WindowManagerGlobal.ADD_DUPLICATE_ADD;}if (activity.mStartingData == null) {ProtoLog.w(WM_ERROR, "Attempted to add starting window to "+ "token but already cleaned");return WindowManagerGlobal.ADD_DUPLICATE_ADD;}}
窗口类型为input window} else if (rootType == TYPE_INPUT_METHOD) {if (token.windowType != TYPE_INPUT_METHOD) {ProtoLog.w(WM_ERROR, "Attempted to add input method window with bad token "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_APP_TOKEN;}
窗口类型为voice window} else if (rootType == TYPE_VOICE_INTERACTION) {if (token.windowType != TYPE_VOICE_INTERACTION) {ProtoLog.w(WM_ERROR, "Attempted to add voice interaction window with bad token "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_APP_TOKEN;}
窗口类型为壁纸} else if (rootType == TYPE_WALLPAPER) {if (token.windowType != TYPE_WALLPAPER) {ProtoLog.w(WM_ERROR, "Attempted to add wallpaper window with bad token "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_APP_TOKEN;}
窗口类型为辅助功能 OVERLAY} else if (rootType == TYPE_ACCESSIBILITY_OVERLAY) {if (token.windowType != TYPE_ACCESSIBILITY_OVERLAY) {ProtoLog.w(WM_ERROR,"Attempted to add Accessibility overlay window with bad token "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_APP_TOKEN;}
窗口类型为Toast类型} else if (type == TYPE_TOAST) {// Apps targeting SDK above N MR1 cannot arbitrary add toast windows.addToastWindowRequiresToken = doesAddToastWindowRequireToken(attrs.packageName,callingUid, parentWindow);if (addToastWindowRequiresToken && token.windowType != TYPE_TOAST) {ProtoLog.w(WM_ERROR, "Attempted to add a toast window with bad token "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_APP_TOKEN;}} else if (type == TYPE_QS_DIALOG) {if (token.windowType != TYPE_QS_DIALOG) {ProtoLog.w(WM_ERROR, "Attempted to add QS dialog window with bad token "+ "%s.  Aborting.", attrs.token);return WindowManagerGlobal.ADD_BAD_APP_TOKEN;}
通过token获取到的ActivityRecord不为空} else if (token.asActivityRecord() != null) {ProtoLog.w(WM_ERROR, "Non-null activity for system window of rootType=%d",rootType);// It is not valid to use an app token with other system types; we will// instead make a new token for it (as if null had been passed in for the token).
将应用令牌用于其他系统类型是无效的;
相反，我们将为它创建一个新的令牌（就好像已经为令牌传入了 null 一样）。attrs.token = null;
创建WindowToken
标志1token = new WindowToken.Builder(this, client.asBinder(), type).setDisplayContent(displayContent).setOwnerCanManageAppTokens(session.mCanAddInternalSystemWindow).build();}

标志1 WindowToken

通常，这是一个AppWindowToken(AppWindowToken就是activity)，它是用于显示窗口的 Activity的句柄。
这个主要用于表示窗口的令牌(Token)信息，主要负责管理窗口的一些属性和行为，通过WindowToken，WMS可以对窗口进行布局，层级排序，焦点管理，输入事件分发等操作。

                token = new WindowToken.Builder(this, client.asBinder(), type)
                        .setDisplayContent(displayContent)
                        .setOwnerCanManageAppTokens(session.mCanAddInternalSystemWindow)
                        .build(); //build()就能创建出来WindowToken对象

 

class WindowToken extends WindowContainer<WindowState> {protected WindowToken(WindowManagerService service, IBinder _token, int type,
boolean persistOnEmpty, DisplayContent dc, boolean ownerCanManageAppTokens) {this(service, _token, type, persistOnEmpty, dc, ownerCanManageAppTokens,
false /* roundedCornerOverlay */, false /* fromClientToken */, null /* options */);}protected WindowToken(WindowManagerService service, IBinder _token, int type,
boolean persistOnEmpty, DisplayContent dc, boolean ownerCanManageAppTokens,
boolean roundedCornerOverlay, boolean fromClientToken, @Nullable Bundle options) {super(service);token = _token;windowType = type;mOptions = options;mPersistOnEmpty = persistOnEmpty;mOwnerCanManageAppTokens = ownerCanManageAppTokens;mRoundedCornerOverlay = roundedCornerOverlay;mFromClientToken = fromClientToken;if (dc != null) {dc.addWindowToken(token, this);}}---------------------------------------------static class Builder {private final WindowManagerService mService;private final IBinder mToken;@WindowTypeprivate final int mType;private boolean mPersistOnEmpty;private DisplayContent mDisplayContent;private boolean mOwnerCanManageAppTokens;@Nullableprivate Bundle mOptions;Builder(WindowManagerService service, IBinder token, int type) {mService = service;mToken = token;mType = type;}/** Sets the {@link DisplayContent} to be associated. */Builder setDisplayContent(DisplayContent dc) {mDisplayContent = dc;return this;}/** @see WindowToken#mOwnerCanManageAppTokens */Builder setOwnerCanManageAppTokens(boolean ownerCanManageAppTokens) {mOwnerCanManageAppTokens = ownerCanManageAppTokens;return this;}WindowToken build() {return new WindowToken(mService, mToken, mType, mPersistOnEmpty, mDisplayContent, mOwnerCanManageAppTokens, mRoundedCornerOverlay, mFromClientToken, mOptions);}}

四： 新建WindowState

创建WindowStatefinal WindowState win = new WindowState(this, session, client, token, parentWindow,appOp[0], attrs, viewVisibility, session.mUid, userId,session.mCanAddInternalSystemWindow);if (win.mDeathRecipient == null) {// Client has apparently died, so there is no reason to// continue.ProtoLog.w(WM_ERROR, "Adding window client %s"+ " that is dead, aborting.", client.asBinder());return WindowManagerGlobal.ADD_APP_EXITING;}
WindowState对应的DisplayContent为空则没有对应的屏幕去显示window，所以报错if (win.getDisplayContent() == null) {ProtoLog.w(WM_ERROR, "Adding window to Display that has been removed.");return WindowManagerGlobal.ADD_INVALID_DISPLAY;}

WindowState表示一个窗口的所有属性，一个WindowState对应一个窗口，借用一张图来表示，也就解释了为什么WindowToken是一系列Window的集合的容器了。

WindowToken--"Container of a set of related windows in the window manager"

/** A window in the window manager. */
class WindowState extends WindowContainer<WindowState> implements WindowManagerPolicy.WindowState,InsetsControlTarget, InputTarget {

 五：adjustWindowParamsLw

获取DisplayPolicyfinal DisplayPolicy displayPolicy = displayContent.getDisplayPolicy();
调整窗口参数displayPolicy.adjustWindowParamsLw(win, win.mAttrs);attrs.flags = sanitizeFlagSlippery(attrs.flags, win.getName(), callingUid, callingPid);attrs.inputFeatures = sanitizeSpyWindow(attrs.inputFeatures, win.getName(), callingUid,callingPid);win.setRequestedVisibleTypes(requestedVisibleTypes);
检查窗口是否可以添加至系统，主要是检查权限相关res = displayPolicy.validateAddingWindowLw(attrs, callingPid, callingUid);if (res != ADD_OKAY) {return res;}

/**提供要显示的UI的基本行为和状态的策略。* The policy that provides the basic behaviors and states of a display to show UI.*/
public class DisplayPolicy {

在DisplayPolicy实例化中有关于手势相关的，比如下拉状态栏，左滑返回这种。

DisplayPolicy还可以调整布局相关

adjustWindowParamsLw作用：根据客户端的布局参数调整布局。 允许策略执行某些操作，例如确保特定类型的窗口不能采用输入焦点。

    public void adjustWindowParamsLw(WindowState win, WindowManager.LayoutParams attrs) {switch (attrs.type) {case TYPE_SYSTEM_OVERLAY:case TYPE_SECURE_SYSTEM_OVERLAY:
如果窗口类型是这个，则给窗口flag添加如下参数// These types of windows can't receive input events.attrs.flags |= WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE| WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;attrs.flags &= ~WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH;break;case TYPE_WALLPAPER:
如果是壁纸类型，则设置让窗口总是可以扩展到刘海区域中// Dreams and wallpapers don't have an app window token and can thus not be// letterboxed. Hence always let them extend under the cutout.attrs.layoutInDisplayCutoutMode = LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS;break;case TYPE_TOAST:
...attrs.flags |= WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;break;case TYPE_BASE_APPLICATION:
...break;}
...}

layoutInDisplayCutoutMode的默认值是LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT。

layoutInDisplayCutoutMode	Value	含义
LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT	0	这是默认行为，在竖屏模式下，内容会呈现到刘海区域中；但在横屏模式下，内容会显示黑边。
LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES	1	在竖屏模式和横屏模式下，内容都会呈现到刘海区域中
LAYOUT_IN_DISPLAY_CUTOUT_MODE_NEVER	2	内容从不呈现到刘海区域中
LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS	3	窗口总是可以扩展到刘海区域中

 六：窗口ADD_OKAY后续流程

            final boolean openInputChannels = (outInputChannel != null&& (attrs.inputFeatures & INPUT_FEATURE_NO_INPUT_CHANNEL) == 0);if  (openInputChannels) {
打开input channelwin.openInputChannel(outInputChannel);}
...// From now on, no exceptions or errors allowed!
能走到这里那就说明这个窗口可以添加，没有问题res = ADD_OKAY;
请求创建一个BLAST (Buffer as LayerState)层的标志。
如果没有指定，客户端将接收一个BufferQueue层。if (mUseBLAST) {res |= WindowManagerGlobal.ADD_FLAG_USE_BLAST;}
...
//    void attach() {
//        if (DEBUG) Slog.v(TAG, "Attaching " + this + " token=" + mToken);
//        mSession.windowAddedLocked();
//    }
将这个windowstate即这个窗口更新到Session中的 mNumWindow中win.attach();
mWindowMap更新，前面有讲过mWindowMap作用
保存 IWindow IBinder和windowstate的匹配
//"Mapping from an IWindow IBinder to the server's Window object."mWindowMap.put(client.asBinder(), win);win.initAppOpsState();
当前window对应的token添加windowstatewin.mToken.addWindow(win);
策略更新window及其对应的窗口属性displayPolicy.addWindowLw(win, attrs);displayPolicy.setDropInputModePolicy(win, win.mAttrs);if (type == TYPE_APPLICATION_STARTING && activity != null) {
activityrecord添加starting window窗口activity.attachStartingWindow(win);ProtoLog.v(WM_DEBUG_STARTING_WINDOW, "addWindow: %s startingWindow=%s",activity, win);} else if (type == TYPE_INPUT_METHOD// IME window is always touchable.// Ignore non-touchable windows e.g. Stylus InkWindow.java.&& (win.getAttrs().flags & FLAG_NOT_TOUCHABLE) == 0) {
如果是输入法，且可触摸，则给这个display设置输入法displayContent.setInputMethodWindowLocked(win);imMayMove = false;} else if (type == TYPE_INPUT_METHOD_DIALOG) {
如果是输入法dialog，则计算输入法目标displayContent.computeImeTarget(true /* updateImeTarget */);imMayMove = false;
...
窗口可以接受输入事件if (win.canReceiveKeys()) {
更新焦点窗口focusChanged = updateFocusedWindowLocked(UPDATE_FOCUS_WILL_ASSIGN_LAYERS,false /*updateInputWindows*/);if (focusChanged) {imMayMove = false;}}
...// Don't do layout here, the window must call// relayout to be displayed, so we'll do it there.win.getParent().assignChildLayers();
窗口焦点更新了，所以当前输入焦点窗口也要重新设置if (focusChanged) {displayContent.getInputMonitor().setInputFocusLw(displayContent.mCurrentFocus,false /*updateInputWindows*/);}
更新输入窗口displayContent.getInputMonitor().updateInputWindowsLw(false /*force*/);
...// This window doesn't have a frame yet. Don't let this window cause the insets change.displayContent.getInsetsStateController().updateAboveInsetsState(false /* notifyInsetsChanged */);outInsetsState.set(win.getCompatInsetsState(), true /* copySources */);getInsetsSourceControls(win, outActiveControls);
...return res;}