system_server_AMS類圖.png

Activity_Window_相關(guān)類圖.png

system_server_AMS類圖.png

總體類圖.png

流程圖.png

    public final class ActivityThread {
      private void handleLaunchActivity(ActivityClientRecord r, Intent customIntent, String reason) {
        // Initialize before creating the activity
        WindowManagerGlobal.initialize();
        Activity a = performLaunchActivity(r, customIntent);
        if (a != null) {
            r.createdConfig = new Configuration(mConfiguration);
            reportSizeConfigurations(r);
            Bundle oldState = r.state;
            handleResumeActivity(r.token, false, r.isForward,
                    !r.activity.mFinished && !r.startsNotResumed, r.lastProcessedSeq, reason);
        ...
        } 
    }
}

其中WindowManagerGlobal.initialize;是先取到WMS(WindowManagerService)的遠(yuǎn)程代理IWindowManager

WindowManagerGlobal.java

public final class WindowManagerGlobal {
    public static void initialize() {
        getWindowManagerService();
    }
    public static IWindowManager getWindowManagerService() {
        synchronized (WindowManagerGlobal.class) {
            if (sWindowManagerService == null) {
                sWindowManagerService = IWindowManager.Stub.asInterface(
                        ServiceManager.getService("window"));
                try {
                    sWindowManagerService = getWindowManagerService();
                    ValueAnimator.setDurationScale(sWindowManagerService.getCurrentAnimatorScale());
                } catch (RemoteException e) {
                    throw e.rethrowFromSystemServer();
                }
            }
            return sWindowManagerService;
        }
    }
}

Activity a = performLaunchActivity(r, customIntent);使用ClassLoader加載XXXActivity当犯，這其中會(huì)創(chuàng)建ContextImpl垢村、如果Application還沒啟動(dòng)過，會(huì)先把Applicaition創(chuàng)建并onCreate,然后調(diào)用XXXActivity的attach();
在attach中：會(huì)創(chuàng)建改activity的對(duì)應(yīng)的window即PhoneWindow嚎卫，以及phoneWindow和WindowManagerImpl關(guān)聯(lián)：
Activity:

final void attach(Context context, ActivityThread aThread,
            Instrumentation instr, IBinder token, int ident,
            Application application, Intent intent, ActivityInfo info,
            CharSequence title, Activity parent, String id,
            NonConfigurationInstances lastNonConfigurationInstances,
            Configuration config, String referrer, IVoiceInteractor voiceInteractor,
            Window window) {
        attachBaseContext(context);
        mFragments.attachHost(null /*parent*/);
        mWindow = new PhoneWindow(this, window);
        mWindow.setWindowControllerCallback(this);
        mWindow.setCallback(this);
        mWindow.setOnWindowDismissedCallback(this);
        mWindow.getLayoutInflater().setPrivateFactory(this);
        mMainThread = aThread;
        mInstrumentation = instr;
        mWindow.setWindowManager(
                (WindowManager)context.getSystemService(Context.WINDOW_SERVICE),
                mToken, mComponent.flattenToString(),
                (info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0);
        if (mParent != null) {
            mWindow.setContainer(mParent.getWindow());
        }
        mWindowManager = mWindow.getWindowManager();
        mCurrentConfig = config;
}

其中：(WindowManager)context.getSystemService(Context.WINDOW_SERVICE)獲取到是WindowManagerImpl：
這邊會(huì)走到ContextImpl.getSystemService：

class ContextImpl extends Context {   
  @Override
    public Object getSystemService(String name) {
        return SystemServiceRegistry.getSystemService(this, name);
    }
}

SystemServiceRegistry:

final class SystemServiceRegistry {
  public static Object getSystemService(ContextImpl ctx, String name) {
        ServiceFetcher<?> fetcher = SYSTEM_SERVICE_FETCHERS.get(name);
        return fetcher != null ? fetcher.getService(ctx) : null;
    }
  private static final HashMap<Class<?>, String> SYSTEM_SERVICE_NAMES =
            new HashMap<Class<?>, String>();
    private static final HashMap<String, ServiceFetcher<?>> SYSTEM_SERVICE_FETCHERS =
            new HashMap<String, ServiceFetcher<?>>();
    private static int sServiceCacheSize;
    static {
        registerService(Context.ACCESSIBILITY_SERVICE, AccessibilityManager.class,
                new CachedServiceFetcher<AccessibilityManager>() {
            @Override
            public AccessibilityManager createService(ContextImpl ctx) {
                return AccessibilityManager.getInstance(ctx);
            }});
    registerService(Context.WINDOW_SERVICE, WindowManager.class,
                new CachedServiceFetcher<WindowManager>() {
            @Override
            public WindowManager createService(ContextImpl ctx) {
                return new WindowManagerImpl(ctx);
            }});
}

返回是new WindowManagerImpl(ctx);在performLaunchActivity函數(shù)中嘉栓，走完attach后，繼續(xù)調(diào)用mInstrumentation.callActivityOnCreate去實(shí)行XXXActivity的onCreate拓诸，這時(shí)候大家會(huì)寫setContentView(R.layout.xxx)
Step3:
Activity.setContentView():
會(huì)調(diào)用getWindow().setContentView(layoutResID),即PhoneWindow類中的setContentView：主要是在PhoneWindow創(chuàng)建DecorView mDecor(This is the top-level view of the window, containing the window decor),然后從mDecor找出android.R.id.content: mContentParent(ViewGroup), 然后把a(bǔ)ctivity設(shè)置的View添加到mContentParent.addView(view, params);

public void setContentView(@LayoutRes int layoutResID) {
        getWindow().setContentView(layoutResID);
        initWindowDecorActionBar();
}

PhoneWindow:

public class PhoneWindow extends Window implements MenuBuilder.Callback {
  public void setContentView(int layoutResID) {
        
        if (mContentParent == null) {
            installDecor();
        } else if (!hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
            mContentParent.removeAllViews();
        }

        if (hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
            final Scene newScene = Scene.getSceneForLayout(mContentParent, layoutResID,
                    getContext());
            transitionTo(newScene);
        } else {
            mLayoutInflater.inflate(layoutResID, mContentParent);
        }
        mContentParent.requestApplyInsets();
        final Callback cb = getCallback();
        if (cb != null && !isDestroyed()) {
            cb.onContentChanged();
        }
        mContentParentExplicitlySet = true;
    }
}

Step4：
在ActivitThread.handleLaunchActivity函數(shù)走完performLaunchActivity后侵佃，接著走h(yuǎn)andleResumeActivity函數(shù)中，顯示啟動(dòng)r = performResumeActivity(token, clearHide, reason);去走XXXActivity的onResume奠支。
接著會(huì)對(duì)Activity的對(duì)應(yīng)的window設(shè)置窗口類型：l.type = WindowManager.LayoutParams.TYPE_BASE_APPLICATION馋辈，WMS是對(duì)窗口進(jìn)行操作，每個(gè)activity對(duì)應(yīng)一個(gè)窗口倍谜，F(xiàn)ramework會(huì)定義好幾種窗口類型迈螟，比如系統(tǒng)Window、應(yīng)用程序window枢劝、子Window等井联。這邊的type類型很重要，沒有這個(gè)您旁，window顯示不出來的烙常。
接著會(huì)調(diào)用到ViewManager wm = a.getWindowManager();wm.addView(decor, l);走到WindowManagerImpl.addView：
ActivityThread:

final void handleResumeActivity(IBinder token,
            boolean clearHide, boolean isForward, boolean reallyResume, int seq, String reason) {
        ActivityClientRecord r = mActivities.get(token);
        ...
        r = performResumeActivity(token, clearHide, reason);
        ...
            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 (r.mPreserveWindow) {
                    a.mWindowAdded = true;
                    r.mPreserveWindow = false;
                   
                    ViewRootImpl impl = decor.getViewRootImpl();
                    if (impl != null) {
                        impl.notifyChildRebuilt();
                    }
                }
                if (a.mVisibleFromClient && !a.mWindowAdded) {
                    a.mWindowAdded = true;
                    wm.addView(decor, l);
                }
             ...
    }

Step5：
WindowManagerImpl的addView又調(diào)用到WindowManagerGlobal.getInstance()的addView：
這個(gè)函數(shù)會(huì)創(chuàng)建root = new ViewRootImpl(view.getContext(), display);然后保存到mRoots.add(root)
接著調(diào)用到 root.setView(view, wparams, panelParentView);

public final class WindowManagerImpl implements WindowManager {
    private final WindowManagerGlobal mGlobal = WindowManagerGlobal.getInstance();
    @Override
    public void addView(@NonNull View view, @NonNull ViewGroup.LayoutParams params) {
        applyDefaultToken(params);
        mGlobal.addView(view, params, mContext.getDisplay(), mParentWindow);
    }
}

public final class WindowManagerGlobal {
    public void addView(View view, ViewGroup.LayoutParams params,
            Display display, Window parentWindow) {
        ...
        ViewRootImpl root;
        View panelParentView = null;
        synchronized (mLock) {
            ...
            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);
        } catch (RuntimeException e) {
           
        }
    }
}

Step6：
ViewRootImpl.setView():
這個(gè)函數(shù)中，通過WindowManagerGloabl拿到IWindowSession mWindowSession及遠(yuǎn)程WMS的Seesion的對(duì)象鹤盒，進(jìn)行mWindowSession.addToDisplay蚕脏，到system_server進(jìn)程的Session中。

public final class ViewRootImpl implements ViewParent,
        View.AttachInfo.Callbacks, ThreadedRenderer.HardwareDrawCallbacks {
    public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {
        synchronized (this) {
                ....
                try {
                    res = mWindowSession.addToDisplay(mWindow, mSeq, mWindowAttributes,
                            getHostVisibility(), mDisplay.getDisplayId(),
                            mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,
                            mAttachInfo.mOutsets, mInputChannel);
                }            
            }
        ...
    }
}

這個(gè)mWindowSession是

public static IWindowSession getWindowSession() {
        synchronized (WindowManagerGlobal.class) {
            if (sWindowSession == null) {
                try {
                    InputMethodManager imm = InputMethodManager.getInstance();
                    IWindowManager windowManager = getWindowManagerService();
                    sWindowSession = windowManager.openSession(
                            new IWindowSessionCallback.Stub() {
                                @Override
                                public void onAnimatorScaleChanged(float scale) {
                                    ValueAnimator.setDurationScale(scale);
                                }
                            },
                            imm.getClient(), imm.getInputContext());
                } catch (RemoteException e) {
                    throw e.rethrowFromSystemServer();
                }
            }
            return sWindowSession;
        }
    }

調(diào)用到WindowManagerService的openSession方法：

public class WindowManagerService extends IWindowManager.Stub
        implements Watchdog.Monitor, WindowManagerPolicy.WindowManagerFuncs {
   @Override
    public IWindowSession openSession(IWindowSessionCallback callback, IInputMethodClient client,
            IInputContext inputContext) {
        if (client == null) throw new IllegalArgumentException("null client");
        if (inputContext == null) throw new IllegalArgumentException("null inputContext");
        Session session = new Session(this, callback, client, inputContext);
        return session;
    }
}