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

Client端流程如下

Server端流程如下

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1 int res = mPolicy.checkAddPermission(attrs.type, isRoundedCornerOverlay, attrs.packageName, appOp); if (res != ADD_OKAY) { return res; } //父window WindowState parentWindow = null; //发起者Uid final int callingUid = Binder.getCallingUid(); //发起者Pid final 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2 final 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3 if (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; ------------------------------------------intres = mPolicy.checkAddPermission(attrs.type, isRoundedCornerOverlay, attrs.packageName, appOp);if(res != ADD_OKAY) {returnres; }

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. * *@paramtypeThe window type--窗口类型 *@paramisRoundedCornerOverlay{@codetrue} to indicate the adding window is * round corner overlay. 指示要add的窗口为圆角叠加层。 *@parampackageNamepackage name 包名 *@paramoutAppOpFirst 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{@linkWindowManagerGlobal#ADD_OKAY} if the add can proceed; * else an error code, usually * {@linkWindowManagerGlobal#ADD_PERMISSION_DENIED}, to abort the add. *//返回是否有权限添加，有则返回ADD_OKAY *@seeWindowManager.LayoutParams#PRIVATE_FLAG_IS_ROUNDED_CORNERS_OVERLAY */intcheckAddPermission(inttype,booleanisRoundedCornerOverlay, 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window if (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_TYPE if (!((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_OKAY if (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

finalDisplayContent 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 //tag1 final WindowToken wToken = mRoot.getWindowToken(token); if (wToken != null) { //tag2 return wToken.getDisplayContent(); } } //tag3 return 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RootWindowContainerclassRootWindowContainerextendsWindowContainer<DisplayContent>implementsDisplayManager.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。

privateWindowManagerService(Context context, InputManagerService inputManager,booleanshowBootMsgs, WindowManagerPolicy policy, ActivityTaskManagerService atm,DisplayWindowSettingsProvider displayWindowSettingsProvider, Supplier<SurfaceControl.Transaction> transactionFactory, Function<SurfaceSession, SurfaceControl.Builder> surfaceControlFactory) { ... mRoot =newRootWindowContainer(this);

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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。classWindowTokenextendsWindowContainer<WindowState> {

此外ActivityRecord继承WindowToken，一个ActivityRecord代表一个activityfinalclassActivityRecordextendsWindowTokenimplementsWindowManagerService.AppFreezeListener {

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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。classWindowContainer<EextendsWindowContainer>extendsConfigurationContainer<E>implementsComparable<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protectedfinalWindowList<E> mChildren =newWindowList<E>();

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

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包含具有重写配置并按层次结构组织的类的通用逻辑。publicabstractclassConfigurationContainer<EextendsConfigurationContainer> {

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(inti = mChildren.size() - 1; i >= 0; --i) {finalDisplayContent dc = mChildren.get(i);finalWindowToken wtoken = dc.getWindowToken(binder);if(wtoken != null) {returnwtoken; } }returnnull; }

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classDisplayContentextendsRootDisplayAreaimplementsWindowManagerPolicy.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. */finalHashMap<IBinder, WindowState> mWindowMap =newHashMap<>();

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_TOKEN parentWindow = 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_TOKEN if (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_DENIED if (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_DISPLAY if (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windowToken WindowToken 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windowContextToken final 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ActivityRecord activity = 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1 token = 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

classWindowTokenextendsWindowContainer<WindowState> {protectedWindowToken(WindowManagerService service, IBinder _token,inttype,booleanpersistOnEmpty, DisplayContent dc,booleanownerCanManageAppTokens) {this(service, _token, type, persistOnEmpty, dc, ownerCanManageAppTokens,false/* roundedCornerOverlay */,false/* fromClientToken */, null /* options */); }protectedWindowToken(WindowManagerService service, IBinder _token,inttype,booleanpersistOnEmpty, DisplayContent dc,booleanownerCanManageAppTokens,booleanroundedCornerOverlay,booleanfromClientToken, @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); } }---------------------------------------------staticclassBuilder {privatefinalWindowManagerService mService;privatefinalIBinder mToken; @WindowTypeprivatefinalintmType;privatebooleanmPersistOnEmpty;privateDisplayContent mDisplayContent;privatebooleanmOwnerCanManageAppTokens; @NullableprivateBundle mOptions; Builder(WindowManagerService service, IBinder token,inttype) { mService = service; mToken = token; mType = type; } /** Sets the {@linkDisplayContent} to be associated. */ Builder setDisplayContent(DisplayContent dc) { mDisplayContent = dc;returnthis; } /**@seeWindowToken#mOwnerCanManageAppTokens */ Builder setOwnerCanManageAppTokens(booleanownerCanManageAppTokens) { mOwnerCanManageAppTokens = ownerCanManageAppTokens;returnthis; } WindowToken build() {returnnewWindowToken(mService, mToken, mType, mPersistOnEmpty, mDisplayContent, mOwnerCanManageAppTokens, mRoundedCornerOverlay, mFromClientToken, mOptions); } }

四： 新建WindowState

创建WindowState final 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. */classWindowStateextendsWindowContainer<WindowState>implementsWindowManagerPolicy.WindowState, InsetsControlTarget, InputTarget {

五：adjustWindowParamsLw

获取DisplayPolicy final 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. */publicclassDisplayPolicy {

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

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 channel win.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windowstate win.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; }