Android P SystemUI之StatusBar加载流程

缺乏、安全感 2021-10-15 12:29 593阅读 0赞

相关源码：  
\\frameworks\\base\\packages\\SystemUI\\src\\com\\android\\systemui\\statusbar\\phone\\StatusBar.java  
\\frameworks\\base\\packages\\SystemUI\\src\\com\\android\\systemui\\statusbar\\phone\\StatusBarWindowManager.java  
\\frameworks\\base\\packages\\SystemUI\\src\\com\\android\\systemui\\statusbar\\phone\\StatusBarWindowView.java  
\\frameworks\\base\\services\\java\\com\\android\\server\\SystemServer.java  
\\frameworks\\base\\packages\\SystemUI\\src\\com\\android\\systemui\\SystemUIService.java  
\\frameworks\\base\\packages\\SystemUI\\src\\com\\android\\systemui\\SystemUIApplication.java  
\\frameworks\\base\\packages\\SystemUI\\src\\com\\android\\systemui\\SystemBars.java

### SystemServer.java ###

\\frameworks\\base\\services\\java\\com\\android\\server\\SystemServer.java  
在Zeyote进程启动中我们讲到，Zeyote启动后会去执行SystemServer，在SystemServer中启动了SystemUIService

static final void startSystemUi(Context context, WindowManagerService windowManager) { 
        Intent intent = new Intent();
        intent.setComponent(new ComponentName("com.android.systemui",
                    "com.android.systemui.SystemUIService"));
        intent.addFlags(Intent.FLAG_DEBUG_TRIAGED_MISSING);
        //Slog.d(TAG, "Starting service: " + intent);
        context.startServiceAsUser(intent, UserHandle.SYSTEM);
        windowManager.onSystemUiStarted();
    }

### SystemUIService.java ###

SystemUIService去初始化SystemUI的一系列组件。

@Override
    public void onCreate() { 
        super.onCreate();
        ((SystemUIApplication) getApplication()).startServicesIfNeeded();
        //省略了一部分代码
        //...
    }

### SystemUIApplication.java ###

初始化config\_systemUIServiceComponents中的组件：

public void startServicesIfNeeded() { 
        String[] names = getResources().getStringArray(R.array.config_systemUIServiceComponents);
        startServicesIfNeeded(names);
    }

源码：\\frameworks\\base\\packages\\SystemUI\\res\\values\\config.xml  
config\_systemUIServiceComponents的定义：

<string-array name="config_systemUIServiceComponents" translatable="false">
        <item>com.android.systemui.Dependency</item>
        <item>com.android.systemui.util.NotificationChannels</item>
        <item>com.android.systemui.statusbar.CommandQueue$CommandQueueStart</item>
        <item>com.android.systemui.keyguard.KeyguardViewMediator</item>
        <item>com.android.systemui.recents.Recents</item>
        <item>com.android.systemui.volume.VolumeUI</item>
        <item>com.android.systemui.stackdivider.Divider</item>
        <item>com.android.systemui.SystemBars</item>		//启动状态栏和导航栏
        <item>com.android.systemui.usb.StorageNotification</item>
        <item>com.android.systemui.power.PowerUI</item>
        <item>com.android.systemui.media.RingtonePlayer</item>
        <item>com.android.systemui.keyboard.KeyboardUI</item>
        <item>com.android.systemui.pip.PipUI</item>
        <item>com.android.systemui.shortcut.ShortcutKeyDispatcher</item>
        <item>@string/config_systemUIVendorServiceComponent</item>
        <item>com.android.systemui.util.leak.GarbageMonitor$Service</item>
        <item>com.android.systemui.LatencyTester</item>
        <item>com.android.systemui.globalactions.GlobalActionsComponent</item>
        <item>com.android.systemui.ScreenDecorations</item>
        <item>com.android.systemui.fingerprint.FingerprintDialogImpl</item>
        <item>com.android.systemui.SliceBroadcastRelayHandler</item>
    </string-array>

这其中就包括SystemBars，SystemBar包括StatusBar和NavigationBar。

private void startServicesIfNeeded(String[] services) { 
        //省略了一部分代码
        //...
            log.traceBegin("StartServices");
            final int N = services.length;
            for (int i = 0; i < N; i++) { 
                String clsName = services[i];
                if (DEBUG) Log.d(TAG, "loading: " + clsName);
                log.traceBegin("StartServices" + clsName);
                long ti = System.currentTimeMillis();
                Class cls;
                try { 
                    cls = Class.forName(clsName);
                    mServices[i] = (SystemUI) cls.newInstance();
                } catch(ClassNotFoundException ex){ 
                    throw new RuntimeException(ex);
                } catch (IllegalAccessException ex) { 
                    throw new RuntimeException(ex);
                } catch (InstantiationException ex) { 
                    throw new RuntimeException(ex);
                }
    
                mServices[i].mContext = this;
                mServices[i].mComponents = mComponents;
                if (DEBUG) Log.d(TAG, "running: " + mServices[i]);
                mServices[i].start();
                log.traceEnd();
    
                // Warn if initialization of component takes too long
                ti = System.currentTimeMillis() - ti;
                if (ti > 1000) { 
                    Log.w(TAG, "Initialization of " + cls.getName() + " took " + ti + " ms");
                }
                if (mBootCompleted) { 
                    mServices[i].onBootCompleted();
                }
            }
            log.traceEnd();
        //省略了一部分代码
        //...
    }

关键点：mServices\[i\].start();依次启动了config\_systemUIServiceComponents中的每一个services.

关于状态栏和导航栏，我们主要SystemBar。

### SystemBars.java ###

@Override
    public void start() { 
        if (DEBUG) Log.d(TAG, "start");
        createStatusBarFromConfig();
    }
    
    private void createStatusBarFromConfig() { 
        if (DEBUG) Log.d(TAG, "createStatusBarFromConfig");
        final String clsName = mContext.getString(R.string.config_statusBarComponent);
        if (clsName == null || clsName.length() == 0) { 
            throw andLog("No status bar component configured", null);
        }
        Class<?> cls = null;
        try { 
            cls = mContext.getClassLoader().loadClass(clsName);
        } catch (Throwable t) { 
            throw andLog("Error loading status bar component: " + clsName, t);
        }
        try { 
            mStatusBar = (SystemUI) cls.newInstance();
        } catch (Throwable t) { 
            throw andLog("Error creating status bar component: " + clsName, t);
        }
        mStatusBar.mContext = mContext;
        mStatusBar.mComponents = mComponents;
        mStatusBar.start();
        if (DEBUG) Log.d(TAG, "started " + mStatusBar.getClass().getSimpleName());
    }

根据config\_statusBarComponent配置去决定加载那个StatusBar对象。  
源码：\\frameworks\\base\\packages\\SystemUI\\res\\values\\config.xml  
config\_statusBarComponent的定义：

<string name="config_statusBarComponent" translatable="false">com.android.systemui.statusbar.phone.StatusBar</string>

所以，执行了StatusBar中的start()，来进行了一些系列的StatusBar加载。

### StatusBar.java ###

**1、加载super\_status\_bar.xml**

protected StatusBarWindowView mStatusBarWindow;
    protected void inflateStatusBarWindow(Context context) { 
        mStatusBarWindow = (StatusBarWindowView) View.inflate(context,R.layout.super_status_bar, null);
    }

**2、创建mStatusBarWindow**  
关键点：mStatusBarWindowManager.add(mStatusBarWindow, getStatusBarHeight());

private void addStatusBarWindow() { 
        makeStatusBarView();
        mStatusBarWindowManager = Dependency.get(StatusBarWindowManager.class);
        mRemoteInputManager.setUpWithPresenter(this, mEntryManager, this,
                new RemoteInputController.Delegate() { 
                    public void setRemoteInputActive(NotificationData.Entry entry,
                            boolean remoteInputActive) { 
                        mHeadsUpManager.setRemoteInputActive(entry, remoteInputActive);
                        entry.row.notifyHeightChanged(true /* needsAnimation */);
                        updateFooter();
                    }
                    public void lockScrollTo(NotificationData.Entry entry) { 
                        mStackScroller.lockScrollTo(entry.row);
                    }
                    public void requestDisallowLongPressAndDismiss() { 
                        mStackScroller.requestDisallowLongPress();
                        mStackScroller.requestDisallowDismiss();
                    }
                });
        mRemoteInputManager.getController().addCallback(mStatusBarWindowManager);
        mStatusBarWindowManager.add(mStatusBarWindow, getStatusBarHeight());
    }

**3、将状态栏视图添加到窗口管理器**  
StatusBarWindowManager.java中：

public void add(View statusBarView, int barHeight) { 
    
        // Now that the status bar window encompasses the sliding panel and its
        // translucent backdrop, the entire thing is made TRANSLUCENT and is
        // hardware-accelerated.
        mLp = new WindowManager.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                barHeight,
                WindowManager.LayoutParams.TYPE_STATUS_BAR,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                        | WindowManager.LayoutParams.FLAG_TOUCHABLE_WHEN_WAKING
                        | WindowManager.LayoutParams.FLAG_SPLIT_TOUCH
                        | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
                        | WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS,
                PixelFormat.TRANSLUCENT);
        mLp.token = new Binder();
        mLp.gravity = Gravity.TOP;
        mLp.softInputMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE;
        mLp.setTitle("StatusBar");
        mLp.packageName = mContext.getPackageName();
        mLp.layoutInDisplayCutoutMode = LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS;
        mStatusBarView = statusBarView;
        mBarHeight = barHeight;
        mWindowManager.addView(mStatusBarView, mLp);
        mLpChanged = new WindowManager.LayoutParams();
        mLpChanged.copyFrom(mLp);
    }