这篇博客我们主要分析下,窗口位置排序的一些原理。
一、添加窗口的时候 调整窗口位置
上篇博客我们分析了WMS的addWindow函数,这里我们就窗口的次序问题继续分析。
- boolean imMayMove = true;
-
- if (type == TYPE_INPUT_METHOD) {//如果窗口类是输入法窗口
- win.mGivenInsetsPending = true;
- mInputMethodWindow = win;
- addInputMethodWindowToListLocked(win);//插入输入法窗口到应用窗口上层
- imMayMove = false;
- } else if (type == TYPE_INPUT_METHOD_DIALOG) {//如果窗口是输入法对话框
- mInputMethodDialogs.add(win);
- addWindowToListInOrderLocked(win, true);//插入到正常位置
- moveInputMethodDialogsLocked(findDesiredInputMethodWindowIndexLocked(true));//调整对话框位置
- imMayMove = false;
- } else {
- addWindowToListInOrderLocked(win, true);//插入正常位置
- 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;
- }
- }
DisplayContent类的mWindows列表按Z序保存了每个窗口,这段代码就是在根据窗口类型把窗口加入到DisplayContent合适位置。
addInputMethodWindowToListLocked方法作用就是一个输入法窗口放子啊需要显示输入法窗口的上面。
addWindowToListInOrderLocked将一个窗口插入到窗口堆栈的当前位置。
我们继续看addWindow函数,
- final WindowStateAnimator winAnimator = win.mWinAnimator;
- winAnimator.mEnterAnimationPending = true;
- winAnimator.mEnteringAnimation = true;
-
- if (displayContent.isDefaultDisplay) {
- mPolicy.getInsetHintLw(win.mAttrs, mRotation, outContentInsets, outStableInsets,//计算窗口大小
- outOutsets);
- } else {
- outContentInsets.setEmpty();
- outStableInsets.setEmpty();
- }
-
- if (mInTouchMode) {
- res |= WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE;//加入支持触屏的标志
- }
- if (win.mAppToken == null || !win.mAppToken.clientHidden) {
- res |= WindowManagerGlobal.ADD_FLAG_APP_VISIBLE;//加入应用可用的标志
- }
-
- mInputMonitor.setUpdateInputWindowsNeededLw();//设置更新输入法窗口的标志
-
- boolean focusChanged = false;
- if (win.canReceiveKeys()) {//如果窗口能接受输入计算是否引起焦点变化
- focusChanged = updateFocusedWindowLocked(UPDATE_FOCUS_WILL_ASSIGN_LAYERS,
- false /*updateInputWindows*/);
- if (focusChanged) {
- imMayMove = false;
- }
- }
-
- if (imMayMove) {
- moveInputMethodWindowsIfNeededLocked(false);//调整输入法的窗口位置
- }
-
- assignLayersLocked(displayContent.getWindowList());//重新计算z轴的位置
- // Don't do layout here, the window must call
- // relayout to be displayed, so we'll do it there.
-
- if (focusChanged) {
- mInputMonitor.setInputFocusLw(mCurrentFocus, false /*updateInputWindows*/);
- }
- mInputMonitor.updateInputWindowsLw(false /*force*/);//更新输入法窗口的信息
-
- if (localLOGV || DEBUG_ADD_REMOVE) Slog.v(TAG, "addWindow: New client "
- + client.asBinder() + ": window=" + win + " Callers=" + Debug.getCallers(5));
-
- if (win.isVisibleOrAdding() && updateOrientationFromAppTokensLocked(false)) {
- reportNewConfig = true;//配置发生变化
- }
- }
-
- if (reportNewConfig) {
- sendNewConfiguration();//发送新的配置
- }
-
- Binder.restoreCallingIdentity(origId);
-
- return res;
- }
如果窗口显示在缺省的显示设备,调用mPolicy的getInsetHintLw函数来获得除了状态条、导航条所占区域后的窗口大小。
接下来如果窗口能接受输入,调用updateFocusedWindowLocked来重新确定系统的焦点位置。如果焦点发生变化,则将imMayMove置为false。
新加入的窗口的位置在前面调用addWindowToListInOrderLocked的时候位置已经确定了,所以这里调用assignLayersLocked只是重新计算Z轴的位置。如果调用updateOrientationFromAppTokensLocked函数计算窗口的配置发生变化,调用sendNewConfiguration函数发送配置。
二、确定窗口的mLayer值
显示设备的水平方向,垂直方向作为X轴Y轴,我们还可以想象有一个垂直于屏幕的Z轴,Z轴的值越来越靠近屏幕。系统中所有的窗口都按次序排列在Z轴上。窗口对象WindowState的成员变量mLayer表示窗口在Z轴的值,值越小越靠近底层。
WMS作用之一就是管理各个窗口Z轴位置,确保正确显示。在所有窗口中输入法和壁纸窗口比较特殊。输入法窗口出现时,需要显示在应用窗口的前面。壁纸窗口通常在底层,但是又不是位于所有窗口的底层,而是位于当前Activity窗口的下面。
因此,当系统调整某个应用窗口的位置时,如果需要也会调整输入法和壁纸窗口,使当前Activity的窗口位于输入法窗口和壁纸窗口之间。
WindowState的成员变量mLayer的值表示窗口在Z轴的位置,这个值越小,位置越靠下。mLayer是通过计算得到,会经常变化。WindowState的另一个成员变量mBaseLayer的值是固定不变的,只和窗口类型有关。mLayer的值是根据mBaseLayer的值计算而来。
下面我们先来看看mBaseLayer的值如何而来,在WindowState的构造函数中有如下代码:
- if ((mAttrs.type >= FIRST_SUB_WINDOW &&
- mAttrs.type <= LAST_SUB_WINDOW)) {//如果是子窗口
- // The multiplier here is to reserve space for multiple
- // windows in the same type layer.
- mBaseLayer = mPolicy.windowTypeToLayerLw(//使用依附窗口的类型
- attachedWindow.mAttrs.type) * WindowManagerService.TYPE_LAYER_MULTIPLIER
- + WindowManagerService.TYPE_LAYER_OFFSET;
- mSubLayer = mPolicy.subWindowTypeToLayerLw(a.type);//计算mSubLayer
- ......
- } else {//非子窗口
- // The multiplier here is to reserve space for multiple
- // windows in the same type layer.
- mBaseLayer = mPolicy.windowTypeToLayerLw(a.type)
- * WindowManagerService.TYPE_LAYER_MULTIPLIER
- + WindowManagerService.TYPE_LAYER_OFFSET;
- mSubLayer = 0;
- ......
- }
如果窗口类型是子窗口,则使用它所依附的窗口类型来计算mBaseLayer,否则使用窗口类型来计算mBaseLayer。计算的方法是先调用mPolicy.windowTypeToLayerLw方法将窗口的类型转化成一个基数,然后再乘以TYPE_LAYER_MULTIPLIER(10000),最后加上TYPE_LAYER_OFFSET(1000),我们先来看看windowTypeToLayerLw函数是如果根据类型返回一个基数的。
- public int windowTypeToLayerLw(int type) {
- if (type >= FIRST_APPLICATION_WINDOW && type <= LAST_APPLICATION_WINDOW) {//应用窗口
- return 2;
- }
- switch (type) {
- case TYPE_PRIVATE_PRESENTATION:
- return 2;
- case TYPE_WALLPAPER:
- // wallpaper is at the bottom, though the window manager may move it.
- return 2;
- case TYPE_PHONE:
- return 3;
- case TYPE_SEARCH_BAR:
- case TYPE_VOICE_INTERACTION_STARTING:
- return 4;
- case TYPE_VOICE_INTERACTION:
- // voice interaction layer is almost immediately above apps.
- return 5;
- case TYPE_INPUT_CONSUMER:
- return 6;
- case TYPE_SYSTEM_DIALOG:
- return 7;
- case TYPE_TOAST:
- // toasts and the plugged-in battery thing
- return 8;
- case TYPE_PRIORITY_PHONE:
- // SIM errors and unlock. Not sure if this really should be in a high layer.
- return 9;
- case TYPE_DREAM:
- // used for Dreams (screensavers with TYPE_DREAM windows)
- return 10;
- case TYPE_SYSTEM_ALERT:
- // like the ANR / app crashed dialogs
- return 11;
- case TYPE_INPUT_METHOD:
- // on-screen keyboards and other such input method user interfaces go here.
- return 12;
- case TYPE_INPUT_METHOD_DIALOG:
- // on-screen keyboards and other such input method user interfaces go here.
- return 13;
- case TYPE_KEYGUARD_SCRIM:
- // the safety window that shows behind keyguard while keyguard is starting
- return 14;
- case TYPE_STATUS_BAR_SUB_PANEL:
- return 15;
- case TYPE_STATUS_BAR:
- return 16;
- case TYPE_STATUS_BAR_PANEL:
- return 17;
- case TYPE_KEYGUARD_DIALOG:
- return 18;
- case TYPE_VOLUME_OVERLAY:
- // the on-screen volume indicator and controller shown when the user
- // changes the device volume
- return 19;
- case TYPE_SYSTEM_OVERLAY:
- // the on-screen volume indicator and controller shown when the user
- // changes the device volume
- return 20;
- case TYPE_NAVIGATION_BAR:
- // the navigation bar, if available, shows atop most things
- return 21;
- case TYPE_NAVIGATION_BAR_PANEL:
- // some panels (e.g. search) need to show on top of the navigation bar
- return 22;
- case TYPE_SYSTEM_ERROR:
- // system-level error dialogs
- return 23;
- case TYPE_MAGNIFICATION_OVERLAY:
- // used to highlight the magnified portion of a display
- return 24;
- case TYPE_DISPLAY_OVERLAY:
- // used to simulate secondary display devices
- return 25;
- case TYPE_DRAG:
- // the drag layer: input for drag-and-drop is associated with this window,
- // which sits above all other focusable windows
- return 26;
- case TYPE_ACCESSIBILITY_OVERLAY:
- // overlay put by accessibility services to intercept user interaction
- return 27;
- case TYPE_SECURE_SYSTEM_OVERLAY:
- return 28;
- case TYPE_BOOT_PROGRESS:
- return 29;
- case TYPE_POINTER:
- // the (mouse) pointer layer
- return 30;
- }
- Log.e(TAG, "Unknown window type: " + type);
- return 2;
- }
这个方法很简单就是根据类型返回一个基数。
WindowState中的成员变量mSubLayer只有在窗口是子窗口的时候才有作用,它表示在窗口和父窗口之间的相对位置。代码如下
- public int subWindowTypeToLayerLw(int type) {
- switch (type) {
- case TYPE_APPLICATION_PANEL:
- case TYPE_APPLICATION_ATTACHED_DIALOG:
- return APPLICATION_PANEL_SUBLAYER;//等于1
- case TYPE_APPLICATION_MEDIA:
- return APPLICATION_MEDIA_SUBLAYER;//等于-2
- case TYPE_APPLICATION_MEDIA_OVERLAY:
- return APPLICATION_MEDIA_OVERLAY_SUBLAYER;//等于-1
- case TYPE_APPLICATION_SUB_PANEL:
- return APPLICATION_SUB_PANEL_SUBLAYER;//等于2
- case TYPE_APPLICATION_ABOVE_SUB_PANEL:
- return APPLICATION_ABOVE_SUB_PANEL_SUBLAYER;//等于3
- }
- Log.e(TAG, "Unknown sub-window type: " + type);
- return 0;
- }
理解了mBaseLayer和mSubLayer后,我们再来看看mLayer是如何计算出来的,是通过assignLayersLocked方法:
- private final void assignLayersLocked(WindowList windows) {
- int N = windows.size();
- int curBaseLayer = 0;
- int curLayer = 0;
- int i;
-
- boolean anyLayerChanged = false;
-
- for (i=0; i<N; i++) {
- final WindowState w = windows.get(i);
- final WindowStateAnimator winAnimator = w.mWinAnimator;
- boolean layerChanged = false;
- int oldLayer = w.mLayer;
- if (w.mBaseLayer == curBaseLayer || w.mIsImWindow
- || (i > 0 && w.mIsWallpaper)) {//如果窗口的mBaseLayer和前一个相同、或者是输入法和壁纸窗口
- curLayer += WINDOW_LAYER_MULTIPLIER;
- w.mLayer = curLayer;
- } else {
- curBaseLayer = curLayer = w.mBaseLayer;
- w.mLayer = curLayer;
- }
- if (w.mLayer != oldLayer) {//层级发生改变
- layerChanged = true;
- anyLayerChanged = true;
- }
- final AppWindowToken wtoken = w.mAppToken;
- oldLayer = winAnimator.mAnimLayer;//后面都是调整mAnimLayerd的值
- if (w.mTargetAppToken != null) {
- winAnimator.mAnimLayer =
- w.mLayer + w.mTargetAppToken.mAppAnimator.animLayerAdjustment;
- } else if (wtoken != null) {
- winAnimator.mAnimLayer =
- w.mLayer + wtoken.mAppAnimator.animLayerAdjustment;
- } else {
- winAnimator.mAnimLayer = w.mLayer;
- }
- if (w.mIsImWindow) {
- winAnimator.mAnimLayer += mInputMethodAnimLayerAdjustment;
- } else if (w.mIsWallpaper) {
- winAnimator.mAnimLayer += mWallpaperAnimLayerAdjustment;
- }
- if (winAnimator.mAnimLayer != oldLayer) {
- layerChanged = true;
- anyLayerChanged = true;
- }
- final TaskStack stack = w.getStack();
- if (layerChanged && stack != null && stack.isDimming(winAnimator)) {
- // Force an animation pass just to update the mDimLayer layer.
- scheduleAnimationLocked();
- }
- }
-
- if (mAccessibilityController != null && anyLayerChanged
- && windows.get(windows.size() - 1).getDisplayId() == Display.DEFAULT_DISPLAY) {
- mAccessibilityController.onWindowLayersChangedLocked();
- }
- }
在调用assignLayersLocked函数之前,WindowList中的窗口其实已经排好序了,前面调用的函数addWindowToListInOrderLocked就是插入窗口到合适的位置,assignLayersLocked函数并不会改变窗口的位置,只是根据窗口的位置计算mLayer的值。
调整方法是从最底层的窗口开始,具有相同的mBaseLayer的值作为一组,每组窗口的mLayer的值从mBaseLayer的值开始,依次加上WINDOW_LAYER_MULTIPLIER(等于5),这样做的目的是在同层的窗口中每隔一个窗口就留下4个空位,方便下次插入新窗口。
这个方法还对输入法和壁纸窗口做了特殊处理。这两类窗口和它插入位置前面的窗口处于一个层级,而不是根据他们的mBaseLayer值计算。(就是前面说的当输入法和壁纸出现是在当前Activity的窗口之间的)。
三、插入窗口的位置
在addWindow函数中我们会调用addAppWindowToListLocked来确定窗口的位置,现在我们来看下这个函数。
- private void addWindowToListInOrderLocked(final WindowState win, boolean addToToken) {
- if (win.mAttachedWindow == null) {//非子窗口
- final WindowToken token = win.mToken;
- int tokenWindowsPos = 0;
- if (token.appWindowToken != null) {//应用窗口的顶层窗口
- tokenWindowsPos = addAppWindowToListLocked(win);
- } else {
- addFreeWindowToListLocked(win);//系统窗口
- }
- if (addToToken) {
- if (DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + win + " to " + token);
- token.windows.add(tokenWindowsPos, win);
- }
- } else {
- addAttachedWindowToListLocked(win, addToToken);//添加子窗口
- }
-
- if (win.mAppToken != null && addToToken) {
- win.mAppToken.allAppWindows.add(win);
- }
- }
上面这个函数根据窗口的类型,应用顶层窗口,系统窗口,子窗口。
我们现在分别对这三类窗口的处理方法进行解析,先来看插入Activity顶层窗口的addAppWindowToListLocked
1.插入Activity顶层方法的addAppWindowToListLocked方法
addAppWindowToListLocked方法先判断系统中是否存在和待插入的窗口是否有相同的Token,如果有代表它不是Activity的第一个窗口,因此再判断这个窗口的类型是不是TYPE_BASE_APPLICATION,如果是这类窗口需要放在所有和它相同Token的窗口下面,否则在判断这个应用的启动窗口是否位于最前面(说明正在启动),如果是放在启动窗口的下面。如果不是下面两种情况,则寻找同一应用中位置最高的窗口,然后插在它上面,这表示加入的窗口将覆盖在前面的窗口之上。
下面是部分代码,
- 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()) {//如果有,说明它不是第一个窗口
- // 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) {//放在和它相同Token的窗口下面
- // Base windows go behind everything else.
- WindowState lowestWindow = tokenWindowList.get(0);//第一个0,代表最底层的window
- placeWindowBefore(lowestWindow, win);//放在这个window前面
- tokenWindowsPos = indexOfWinInWindowList(lowestWindow, token.windows);
- } else {
- AppWindowToken atoken = win.mAppToken;
- WindowState lastWindow = tokenWindowList.get(windowListPos - 1);
- if (atoken != null && lastWindow == atoken.startingWindow) {
- placeWindowBefore(lastWindow, win);
- tokenWindowsPos = indexOfWinInWindowList(lastWindow, token.windows);
- } else {
- int newIdx = findIdxBasedOnAppTokens(win);//寻找同一token位置最前面的window
- //there is a window above this one associated with the same
- //apptoken note that the window could be a floating window
- //that was created later or a window at the top of the list of
- //windows associated with this token.
- windows.add(newIdx + 1, win);//插在它前面
- if (newIdx < 0) {
- // No window from token found on win's display.
- tokenWindowsPos = 0;
- } else {
- tokenWindowsPos = indexOfWinInWindowList(
- windows.get(newIdx), token.windows) + 1;
- }
- mWindowsChanged = true;
- }
- }
- return tokenWindowsPos;
- }
我们再来看几个函数
placeWindowBefore函数就是插入到windows这个位置前
- private void placeWindowBefore(WindowState pos, WindowState window) {
- final WindowList windows = pos.getWindowList();
- int i = windows.indexOf(pos);
- if (i < 0) {
- Slog.w(TAG, "placeWindowBefore: Unable to find " + pos + " in " + windows);
- i = 0;
- }
- windows.add(i, window);
- mWindowsChanged = true;
- }
findIdxBasedOnAppTokens函数就是寻找相同token的最前面的window,所以要注意遍历循环的时候是从window的size最大的时候反过来遍历的。
- private int findIdxBasedOnAppTokens(WindowState win) {
- WindowList windows = win.getWindowList();
- for(int j = windows.size() - 1; j >= 0; j--) {
- WindowState wentry = windows.get(j);
- if(wentry.mAppToken == win.mAppToken) {
- return j;
- }
- }
- return -1;
- }
继续看这个函数,如果系统中不存在和窗口具有相同token的窗口(说明Activity刚启动,第一个窗口还没有创建完成),这时就会遍历系统所有的task以及task中包含的AppWindowToken,找到窗口的位置,再在task中排在本窗口前面的窗口中,找出离自己最近的,并且APPWindowToken的窗口列表不为NULL的窗口,插入到它的最后一个子窗口后面。如果前面的窗口的列表也都为NULL,则寻找排在本窗口后面的第一个包含有窗口对象的APPWindowToken,把本窗口插在前面。
- WindowState pos = null;
-
- final ArrayList<Task> tasks = displayContent.getTasks();
- int taskNdx;
- int tokenNdx = -1;
- for (taskNdx = tasks.size() - 1; taskNdx >= 0; --taskNdx) {
- AppTokenList tokens = tasks.get(taskNdx).mAppTokens;
- for (tokenNdx = tokens.size() - 1; tokenNdx >= 0; --tokenNdx) {
- final AppWindowToken t = tokens.get(tokenNdx);
- if (t == token) {
- --tokenNdx;
- if (tokenNdx < 0) {
- --taskNdx;
- if (taskNdx >= 0) {
- tokenNdx = tasks.get(taskNdx).mAppTokens.size() - 1;
- }
- }
- break;
- }
-
- // We haven't reached the token yet; if this token
- // is not going to the bottom and has windows on this display, we can
- // use it as an anchor for when we do reach the token.
- tokenWindowList = getTokenWindowsOnDisplay(t, displayContent);
- if (!t.sendingToBottom && tokenWindowList.size() > 0) {
- pos = tokenWindowList.get(0);
- }
- }
- if (tokenNdx >= 0) {
- // early exit
- break;
- }
- }
-
- // We now know the index into the apps. If we found
- // an app window above, that gives us the position; else
- // we need to look some more.
- if (pos != null) {
- // Move behind any windows attached to this one.
- WindowToken atoken = mTokenMap.get(pos.mClient.asBinder());
- if (atoken != null) {
- tokenWindowList =
- getTokenWindowsOnDisplay(atoken, displayContent);
- final int NC = tokenWindowList.size();
- if (NC > 0) {
- WindowState bottom = tokenWindowList.get(0);
- if (bottom.mSubLayer < 0) {
- pos = bottom;
- }
- }
- }
- placeWindowBefore(pos, win);
- return tokenWindowsPos;
- }
-
- // Continue looking down until we find the first
- // token that has windows on this display.
- for ( ; taskNdx >= 0; --taskNdx) {
- AppTokenList tokens = tasks.get(taskNdx).mAppTokens;
- for ( ; tokenNdx >= 0; --tokenNdx) {
- final AppWindowToken t = tokens.get(tokenNdx);
- tokenWindowList = getTokenWindowsOnDisplay(t, displayContent);
- final int NW = tokenWindowList.size();
- if (NW > 0) {
- pos = tokenWindowList.get(NW-1);
- break;
- }
- }
- if (tokenNdx >= 0) {
- // found
- break;
- }
- }
-
- if (pos != null) {
- // Move in front of any windows attached to this
- // one.
- WindowToken atoken = mTokenMap.get(pos.mClient.asBinder());
- if (atoken != null) {
- final int NC = atoken.windows.size();
- if (NC > 0) {
- WindowState top = atoken.windows.get(NC-1);
- if (top.mSubLayer >= 0) {
- pos = top;
- }
- }
- }
- placeWindowAfter(pos, win);
- return tokenWindowsPos;
- }
-
- ......
如果前面窗口的APPWindowToken的窗口列表也为空,则重新遍历整个窗口,然后根据mBaseLayer的值来确定窗口的位置。
- final int myLayer = win.mBaseLayer;
- int i;
- for (i = N - 1; i >= 0; --i) {
- WindowState w = windows.get(i);
- if (w.mBaseLayer <= myLayer) {
- break;
- }
- }
- if (DEBUG_FOCUS_LIGHT || DEBUG_WINDOW_MOVEMENT || DEBUG_ADD_REMOVE) Slog.v(TAG,
- "Based on layer: Adding window " + win + " at " + (i + 1) + " of " + N);
- windows.add(i + 1, win);
- mWindowsChanged = true;
- return tokenWindowsPos;
2. 插入子窗口的addAttachedWindowToListLocked函数
addAttachedWindowToListLocked方法,如果mSubLayer大于0的子窗口,按mSubLayer的值大小插入到有相同WindowToken的子窗口的合适位置中,如果mSubLayer相同,插入已插入窗口的下层位置,如果mSubLayer小于0,如果还存在mSubLayer小于0,并且大于等于该窗口的mSubLayer的值的子窗口,则插入到该子窗口之下,否则插入到子窗口所依附的窗口下面。
- 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);
- }
- placeWindowBefore(wSublayer >= 0 ? attached : w, win);
- 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);
- }
- }
- }
3.插入系统窗口的addFreeWindowToListLocked
addFreeWindowToListLocked方法简单,只是遍历同一显示设备上的Windows,比较mBaseLayer值的大小,插入合适位置。
- private void addFreeWindowToListLocked(final WindowState win) {
- final WindowList windows = win.getWindowList();
-
- // Figure out where window should go, based on layer.
- final int myLayer = win.mBaseLayer;
- int i;
- for (i = windows.size() - 1; i >= 0; i--) {
- if (windows.get(i).mBaseLayer <= myLayer) {
- break;
- }
- }
- i++;
- if (DEBUG_FOCUS_LIGHT || DEBUG_WINDOW_MOVEMENT || DEBUG_ADD_REMOVE) Slog.v(TAG,
- "Free window: Adding window " + win + " at " + i + " of " + windows.size());
- windows.add(i, win);
- mWindowsChanged = true;
- }
这篇博客我们分析了window插入到什么位置,以及mLayer的计算。但是具体里面有很多变量,stack task windows等,不是很熟悉,下篇博客我们主要分析这。