Android6.0 WMS（四） WMS中常用变量分析
这篇博客我们分析WMS的一些常用变量，我们依然从主线addWindow开始分析，碰到一些常用的变量再进行分析。
DisplayContent
我们再来看如下DisplayContent 类
final DisplayContent displayContent = getDisplayContentLocked(displayId);我们再来看getDisplayContentLocked函数，当mDisplayContents没有对应displayId对应的DisplayContent，会调用newDisplayContentLocked函数创建一个DisplayContent 然后放入mDisplayContents。
public DisplayContent getDisplayContentLocked(final int displayId) {
DisplayContent displayContent = mDisplayContents.get(displayId);
if (displayContent == null) {
final Display display = mDisplayManager.getDisplay(displayId);
if (display != null) {
displayContent = newDisplayContentLocked(display);
}
}
return displayContent;
}WindowManager.LayoutParams token
我们看addWindow这个函数的一个参数WindowManager.LayoutParams attrs，这个参数有很多地方修改，最基本的是在Activity应用中调用setContentView的时候会初始化。
现在我们来看其中一个重要的成员变量token。
先看下面代码，当该窗口是一个子窗口时，会调用windowForClientLocked来查找主窗口的WindowState。这个WindowState也就是子窗口的attachedWindow。
if (type >= FIRST_SUB_WINDOW && type <= LAST_SUB_WINDOW) {
attachedWindow = windowForClientLocked(null, attrs.token, false);
if (attachedWindow == null) {
Slog.w(TAG, "Attempted to add window with token that is not a window: "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
}
if (attachedWindow.mAttrs.type >= FIRST_SUB_WINDOW
&& attachedWindow.mAttrs.type <= LAST_SUB_WINDOW) {
Slog.w(TAG, "Attempted to add window with token that is a sub-window: "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
}
}我们来看下windowForClientLocked函数，就是从mWindowMap中获取其attrs.token的WindowState，说明子窗口的attrs.token放的是其父窗口的token。
final WindowState windowForClientLocked(Session session, IBinder client,
boolean throwOnError) {
WindowState win = mWindowMap.get(client);
......
return win;
}那我们先来看看这个token是从何而来，
我们知道WMS的addWindow，是用ActivityThread的handleResumeActivity函数调用如下代码发起的，我们先来看看WindowManagerImpl的addView函数
if (r.window == null && !a.mFinished && willBeVisible) {
r.window = r.activity.getWindow();
View decor = r.window.getDecorView();
decor.setVisibility(View.INVISIBLE);
ViewManager wm = a.getWindowManager();
WindowManager.LayoutParams l = r.window.getAttributes();
a.mDecor = decor;
l.type = WindowManager.LayoutParams.TYPE_BASE_APPLICATION;
l.softInputMode |= forwardBit;
if (a.mVisibleFromClient) {
a.mWindowAdded = true;
wm.addView(decor, l);
}WindowManagerImpl的addView函数，直接调用了WindowMangerGlobal的addView函数
@Override
public void addView(@NonNull View view, @NonNull ViewGroup.LayoutParams params) {
applyDefaultToken(params);
mGlobal.addView(view, params, mDisplay, mParentWindow);
}WindowMangerGlobal的addView函数先调用了其parentWindow的adjustLayoutParamsForSubWindow函数，然后就是创建ViewRooImpl对象，再调用其setView函数，就是在这个函数中通过Binder调用了WMS的addWindow函数。
public void addView(View view, ViewGroup.LayoutParams params,
Display display, Window parentWindow) {
if (view == null) {
throw new IllegalArgumentException("view must not be null");
}
if (display == null) {
throw new IllegalArgumentException("display must not be null");
}
if (!(params instanceof WindowManager.LayoutParams)) {
throw new IllegalArgumentException("Params must be WindowManager.LayoutParams");
}
final WindowManager.LayoutParams wparams = (WindowManager.LayoutParams) params;
if (parentWindow != null) {
parentWindow.adjustLayoutParamsForSubWindow(wparams);
}
......
root = new ViewRootImpl(view.getContext(), display);
view.setLayoutParams(wparams);
mViews.add(view);
mRoots.add(root);
mParams.add(wparams);
}
// do this last because it fires off messages to start doing things
try {
root.setView(view, wparams, panelParentView);
}
......
}那我们先要看这个parentWindow是谁，这个parentWindow是在创建WindowManagerImpl 时传进来的。
public WindowManagerImpl createLocalWindowManager(Window parentWindow) {
return new WindowManagerImpl(mDisplay, parentWindow);
}这个函数是在Activity的attach中调用的，代码如下：
mWindow.setWindowManager(
(WindowManager)context.getSystemService(Context.WINDOW_SERVICE),
mToken, mComponent.flattenToString(),
(info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0);最后我们看传参是this，就是代表Activity中创建的PhoneWindow对象。
public void setWindowManager(WindowManager wm, IBinder appToken, String appName,
boolean hardwareAccelerated) {
mAppToken = appToken;
mAppName = appName;
mHardwareAccelerated = hardwareAccelerated
|| SystemProperties.getBoolean(PROPERTY_HARDWARE_UI, false);
if (wm == null) {
wm = (WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE);
}
mWindowManager = ((WindowManagerImpl)wm).createLocalWindowManager(this);
}
Window的adjustLayoutParamsForSubWindow函数如下，会把wp的token改成mAppToken。
void adjustLayoutParamsForSubWindow(WindowManager.LayoutParams wp) {
CharSequence curTitle = wp.getTitle();
if (wp.type >= WindowManager.LayoutParams.FIRST_SUB_WINDOW &&
......
} else if (wp.type >= WindowManager.LayoutParams.FIRST_SYSTEM_WINDOW &&
.......
} else {
if (wp.token == null) {
wp.token = mContainer == null ? mAppToken : mContainer.mAppToken;
}
if ((curTitle == null || curTitle.length() == 0)
&& mAppName != null) {
wp.setTitle(mAppName);
}
}
if (wp.packageName == null) {
wp.packageName = mContext.getPackageName();
}
if (mHardwareAccelerated) {
wp.flags |= WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED;
}
}而这个mAppToken就是在setWindowManager时赋值的，因此这个token就是Activity的mToken。就是每一个Activity的全局唯一性。
public void setWindowManager(WindowManager wm, IBinder appToken, String appName,
boolean hardwareAccelerated) {
mAppToken = appToken;
mAppName = appName;
mHardwareAccelerated = hardwareAccelerated
|| SystemProperties.getBoolean(PROPERTY_HARDWARE_UI, false);
if (wm == null) {
wm = (WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE);
}
mWindowManager = ((WindowManagerImpl)wm).createLocalWindowManager(this);
}mTokenMap
我们再回想之前分析的博客，每个Activity启动的时候会在ActivityStack中调用mWindowManager.addAppToken函数，WMS的addAppToken函数如下，就是放入mTokenMap中，key就是appToken，Value就是APPWindowToken。
@Override
public void addAppToken(int addPos, IApplicationToken token, int taskId, int stackId,
int requestedOrientation, boolean fullscreen, boolean showForAllUsers, int userId,
int configChanges, boolean voiceInteraction, boolean launchTaskBehind) {
......
synchronized(mWindowMap) {
AppWindowToken atoken = findAppWindowToken(token.asBinder());
if (atoken != null) {
Slog.w(TAG, "Attempted to add existing app token: " + token);
return;
}
atoken = new AppWindowToken(this, token, voiceInteraction);
......
mTokenMap.put(token.asBinder(), atoken);
// Application tokens start out hidden.
atoken.hidden = true;
atoken.hiddenRequested = true;
}
}
继续回到addWindow函数，下面是一些出错处理。首先就是传来的appToken一定要在mTokenMap有对应的WindowToken。
WindowToken token = mTokenMap.get(attrs.token);
if (token == null) {
if (type >= FIRST_APPLICATION_WINDOW && type <= LAST_APPLICATION_WINDOW) {
Slog.w(TAG, "Attempted to add application window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (type == TYPE_INPUT_METHOD) {
Slog.w(TAG, "Attempted to add input method window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (type == TYPE_VOICE_INTERACTION) {
Slog.w(TAG, "Attempted to add voice interaction window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (type == TYPE_WALLPAPER) {
Slog.w(TAG, "Attempted to add wallpaper window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (type == TYPE_DREAM) {
Slog.w(TAG, "Attempted to add Dream window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
if (type == TYPE_ACCESSIBILITY_OVERLAY) {
Slog.w(TAG, "Attempted to add Accessibility overlay window with unknown token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
token = new WindowToken(this, attrs.token, -1, false);
addToken = true;
} else if (type >= FIRST_APPLICATION_WINDOW && type <= LAST_APPLICATION_WINDOW) {
AppWindowToken atoken = token.appWindowToken;
if (atoken == null) {
Slog.w(TAG, "Attempted to add window with non-application token "
+ token + ". Aborting.");
return WindowManagerGlobal.ADD_NOT_APP_TOKEN;
} else if (atoken.removed) {
Slog.w(TAG, "Attempted to add window with exiting application token "
+ token + ". Aborting.");
return WindowManagerGlobal.ADD_APP_EXITING;
}
if (type == TYPE_APPLICATION_STARTING && atoken.firstWindowDrawn) {
// No need for this guy!
if (localLOGV) Slog.v(
TAG, "**** NO NEED TO START: " + attrs.getTitle());
return WindowManagerGlobal.ADD_STARTING_NOT_NEEDED;
}
} else if (type == TYPE_INPUT_METHOD) {
if (token.windowType != TYPE_INPUT_METHOD) {
Slog.w(TAG, "Attempted to add input method window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (type == TYPE_VOICE_INTERACTION) {
if (token.windowType != TYPE_VOICE_INTERACTION) {
Slog.w(TAG, "Attempted to add voice interaction window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (type == TYPE_WALLPAPER) {
if (token.windowType != TYPE_WALLPAPER) {
Slog.w(TAG, "Attempted to add wallpaper window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (type == TYPE_DREAM) {
if (token.windowType != TYPE_DREAM) {
Slog.w(TAG, "Attempted to add Dream window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (type == TYPE_ACCESSIBILITY_OVERLAY) {
if (token.windowType != TYPE_ACCESSIBILITY_OVERLAY) {
Slog.w(TAG, "Attempted to add Accessibility overlay window with bad token "
+ attrs.token + ". Aborting.");
return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
}
} else if (token.appWindowToken != null) {
Slog.w(TAG, "Non-null appWindowToken for system window of type=" + type);
// 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).
attrs.token = null;
token = new WindowToken(this, null, -1, false);
addToken = true;
}mWindowMap
然后就新建一个WindowState对象，加入到mWindowMap中，注意这里的key是client.asBinder
WindowState win = new WindowState(this, session, client, token,
attachedWindow, appOp[0], seq, attrs, viewVisibility, displayContent);
......
win.attach();
mWindowMap.put(client.asBinder(), win);这里的client，是ViewRootImpl的mWindow 对象用来和WMS通信的，一个ViewRootImpl一个mWindow对象。
mWindow = new W(this);token.windows
再回到addWindow函数，下面是关于新窗口确定插入的位置的相关代码：
if (type == TYPE_INPUT_METHOD) {
win.mGivenInsetsPending = true;
mInputMethodWindow = win;
addInputMethodWindowToListLocked(win);
imMayMove = false;
} else if (type == TYPE_INPUT_METHOD_DIALOG) {
mInputMethodDialogs.add(win);
addWindowToListInOrderLocked(win, true);
moveInputMethodDialogsLocked(findDesiredInputMethodWindowIndexLocked(true));
imMayMove = false;
} else {
addWindowToListInOrderLocked(win, true);
if (type == TYPE_WALLPAPER) {
mLastWallpaperTimeoutTime = 0;
displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
} else if ((attrs.flags&FLAG_SHOW_WALLPAPER) != 0) {
displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
} else if (mWallpaperTarget != null
&& mWallpaperTarget.mLayer >= win.mBaseLayer) {
// If there is currently a wallpaper being shown, and
// the base layer of the new window is below the current
// layer of the target window, then adjust the wallpaper.
// This is to avoid a new window being placed between the
// wallpaper and its target.
displayContent.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
}
}我们主要看下addWindowToListInOrderLocked函数，这个函数分有附属窗口和没有附属窗口，我们先看下有附属窗口的处理。
private void addWindowToListInOrderLocked(final WindowState win, boolean addToToken) {
if (DEBUG_FOCUS_LIGHT) Slog.d(TAG, "addWindowToListInOrderLocked: win=" + win +
" Callers=" + Debug.getCallers(4));
if (win.mAttachedWindow == null) {
final WindowToken token = win.mToken;
int tokenWindowsPos = 0;
if (token.appWindowToken != null) {
tokenWindowsPos = addAppWindowToListLocked(win);
} else {
addFreeWindowToListLocked(win);
}
if (addToToken) {
if (DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + win + " to " + token);
token.windows.add(tokenWindowsPos, win);
}
} else {
addAttachedWindowToListLocked(win, addToToken);
}
if (win.mAppToken != null && addToToken) {
win.mAppToken.allAppWindows.add(win);
}
}addAttachedWindowToListLocked函数，先调用getTokenWindowsOnDisplay函数，来得到所有这个WindowToken的WindowState，然后根据这个WindowState插入合适位置。并且把要插入的windowState，也放入token.windows。
private void addAttachedWindowToListLocked(final WindowState win, boolean addToToken) {
final WindowToken token = win.mToken;
final DisplayContent displayContent = win.getDisplayContent();
if (displayContent == null) {
return;
}
final WindowState attached = win.mAttachedWindow;
WindowList tokenWindowList = getTokenWindowsOnDisplay(token, displayContent);
// Figure out this window's ordering relative to the window
// it is attached to.
final int NA = tokenWindowList.size();
final int sublayer = win.mSubLayer;
int largestSublayer = Integer.MIN_VALUE;
WindowState windowWithLargestSublayer = null;
int i;
for (i = 0; i < NA; i++) {
WindowState w = tokenWindowList.get(i);
final int wSublayer = w.mSubLayer;
if (wSublayer >= largestSublayer) {
largestSublayer = wSublayer;
windowWithLargestSublayer = w;
}
if (sublayer < 0) {
// For negative sublayers, we go below all windows
// in the same sublayer.
if (wSublayer >= sublayer) {
if (addToToken) {
if (DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + win + " to " + token);
token.windows.add(i, win);//放入WindowToken的windows
}
placeWindowBefore(wSublayer >= 0 ? attached : w, win);//插入合适位置
break;
}
} else {
// For positive sublayers, we go above all windows
// in the same sublayer.
if (wSublayer > sublayer) {
if (addToToken) {
if (DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + win + " to " + token);
token.windows.add(i, win);
}
placeWindowBefore(w, win);
break;
}
}
}
if (i >= NA) {
if (addToToken) {
if (DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + win + " to " + token);
token.windows.add(win);
}
if (sublayer < 0) {
placeWindowBefore(attached, win);
} else {
placeWindowAfter(largestSublayer >= 0
? windowWithLargestSublayer
: attached,
win);
}
}
}我们先看下getTokenWindowsOnDisplay函数，就是遍历WindowToken的windows，是得同一个DisplayContent对象。
WindowList getTokenWindowsOnDisplay(WindowToken token, DisplayContent displayContent) {
final WindowList windowList = new WindowList();
final int count = token.windows.size();
for (int i = 0; i < count; i++) {
final WindowState win = token.windows.get(i);
if (win.getDisplayContent() == displayContent) {
windowList.add(win);
}
}
return windowList;
}DisplayContent的mWindows
再来看placeWindowBefore函数，插入到windows的pos位置
private void placeWindowBefore(WindowState pos, WindowState window) {
final WindowList windows = pos.getWindowList();
int i = windows.indexOf(pos);
if (DEBUG_FOCUS || DEBUG_WINDOW_MOVEMENT || DEBUG_ADD_REMOVE) Slog.v(
TAG, "Adding window " + window + " at "
+ i + " of " + windows.size() + " (before " + pos + ")");
if (i < 0) {
Slog.w(TAG, "placeWindowBefore: Unable to find " + pos + " in " + windows);
i = 0;
}
windows.add(i, window);
mWindowsChanged = true;
}getWindowList就是返回DisplayContent 得到mWindows，所以在placeWindowBefore插入window，最终也都是插入DisplayContent的mWindows
WindowList getWindowList() {
final DisplayContent displayContent = getDisplayContent();
return displayContent == null ? null : displayContent.getWindowList();
}继续看addWindowToListInOrderLocked函数，对没有附属窗口的调用addAppWindowToListLocked，就是调用WindowState的getWindowList来获取displayContent.getWindowList，然后调用placeWindowBefore插入合适的位置。
private int addAppWindowToListLocked(final WindowState win) {
final IWindow client = win.mClient;
final WindowToken token = win.mToken;
final DisplayContent displayContent = win.getDisplayContent();
if (displayContent == null) {
// It doesn't matter this display is going away.
return 0;
}
final WindowList windows = win.getWindowList();
final int N = windows.size();
WindowList tokenWindowList = getTokenWindowsOnDisplay(token, displayContent);
int tokenWindowsPos = 0;
int windowListPos = tokenWindowList.size();
if (!tokenWindowList.isEmpty()) {
// If this application has existing windows, we
// simply place the new window on top of them... but
// keep the starting window on top.
if (win.mAttrs.type == TYPE_BASE_APPLICATION) {
// Base windows go behind everything else.
WindowState lowestWindow = tokenWindowList.get(0);
placeWindowBefore(lowestWindow, win);
......
}
}
}
Task TaskStack
我们再来看看WMS的addAppToken函数，这个函数中新建了APPWindowToken之后，会看mTaskIdToTask是否有这个taskId，没有会调用createTaskLocked根据AMS传进来的taskId和stackId创建Task和TaskStack。
AppWindowToken atoken = findAppWindowToken(token.asBinder());
if (atoken != null) {
Slog.w(TAG, "Attempted to add existing app token: " + token);
return;
}
atoken = new AppWindowToken(this, token, voiceInteraction);
......
Task task = mTaskIdToTask.get(taskId);
if (task == null) {
task = createTaskLocked(taskId, stackId, userId, atoken);
}
task.addAppToken(addPos, atoken);
mTokenMap.put(token.asBinder(), atoken); private Task createTaskLocked(int taskId, int stackId, int userId, AppWindowToken atoken) {
if (DEBUG_STACK) Slog.i(TAG, "createTaskLocked: taskId=" + taskId + " stackId=" + stackId
+ " atoken=" + atoken);
final TaskStack stack = mStackIdToStack.get(stackId);
if (stack == null) {
throw new IllegalArgumentException("addAppToken: invalid stackId=" + stackId);
}
EventLog.writeEvent(EventLogTags.WM_TASK_CREATED, taskId, stackId);
Task task = new Task(taskId, stack, userId, this);
mTaskIdToTask.put(taskId, task);
stack.addTask(task, !atoken.mLaunchTaskBehind /* toTop */, atoken.showForAllUsers);
return task;
} public void attachStack(int stackId, int displayId) {
final long origId = Binder.clearCallingIdentity();
try {
synchronized (mWindowMap) {
final DisplayContent displayContent = mDisplayContents.get(displayId);
if (displayContent != null) {
TaskStack stack = mStackIdToStack.get(stackId);
if (stack == null) {
if (DEBUG_STACK) Slog.d(TAG, "attachStack: stackId=" + stackId);
stack = new TaskStack(this, stackId);//新建TaskStack
mStackIdToStack.put(stackId, stack);//加入到mStackIdToStack
}
stack.attachDisplayContent(displayContent);
displayContent.attachStack(stack);
moveStackWindowsLocked(displayContent);
final WindowList windows = displayContent.getWindowList();
for (int winNdx = windows.size() - 1; winNdx >= 0; --winNdx) {
windows.get(winNdx).reportResized();
}
}
}AppWindowToken 的mTask
我们再回到WMS的addAppToken函数，创建完task，之后调用了Task的addAppToken函数
Task task = mTaskIdToTask.get(taskId);
if (task == null) {
task = createTaskLocked(taskId, stackId, userId, atoken);
}
task.addAppToken(addPos, atoken);Task的addAppToken把AppWindowToken 放入到Task的mAppTokens中，并且赋值AppWindowToken 的mTask
void addAppToken(int addPos, AppWindowToken wtoken) {
final int lastPos = mAppTokens.size();
if (addPos >= lastPos) {
addPos = lastPos;
} else {
for (int pos = 0; pos < lastPos && pos < addPos; ++pos) {
if (mAppTokens.get(pos).removed) {
// addPos assumes removed tokens are actually gone.
++addPos;
}
}
}
mAppTokens.add(addPos, wtoken);
wtoken.mTask = this;
mDeferRemoval = false;
}