Allow Services to be created through Dagger.

This is a significant change that allows Services to have their
constructed injected into.

The DozeService is now labeled as injectable (thought it takes no arguments).
At least one Service has to be marked as injectable for Dagger to be happy
compiling this code.

Bug: 138787339
Test: atest SystemUITests
Change-Id: I0ec92e01dd236bcee3083c8f8744c53b7ccc92d3
Merged-In: Ib58f8763c996fbc2aea07ead56493d2d9e936f5b

packages/CarSystemUI/Android.bp

@@ -26,8 +26,8 @@ android_app {
     ],
 
     static_libs: [
-        "CarNotificationLib",
         "SystemUI-core",
+        "CarNotificationLib",
         "SystemUIPluginLib",
         "SystemUISharedLib",
         "SettingsLib",

packages/SystemUI/AndroidManifest.xml

@@ -20,6 +20,7 @@
         xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
         package="com.android.systemui"
         android:sharedUserId="android.uid.systemui"
+        xmlns:tools="http://schemas.android.com/tools"
         coreApp="true">
 
     <!-- Using OpenGL ES 2.0 -->
@@ -259,7 +260,8 @@
         android:theme="@style/Theme.SystemUI"
         android:defaultToDeviceProtectedStorage="true"
         android:directBootAware="true"
-        android:appComponentFactory="androidx.core.app.CoreComponentFactory">
+        tools:replace="android:appComponentFactory"
+        android:appComponentFactory=".SystemUIAppComponentFactory">
         <!-- Keep theme in sync with SystemUIApplication.onCreate().
              Setting the theme on the application does not affect views inflated by services.
              The application theme is set again from onCreate to take effect for those views. -->

packages/SystemUI/docs/dagger.md

@@ -53,7 +53,7 @@ variants (like other form factors e.g. Car).
 ### Adding injection to a new SystemUI object
 
 Anything that depends on any `@Singleton` provider from SystemUIRootComponent
-should be declared as an `@Subcomponent` of the root component, this requires
+should be declared as a `@Subcomponent` of the root component. This requires
 declaring your own interface for generating your own modules or just the
 object you need injected. The subcomponent also needs to be added to
 SystemUIRootComponent in SystemUIFactory so it can be acquired.
@@ -204,6 +204,13 @@ public CustomView(@Named(VIEW_CONTEXT) Context themedViewContext, AttributeSet a
 }
 ```
 
+## Updating Dagger2
+
+Binaries can be downloaded from https://repo1.maven.org/maven2/com/google/dagger/ and then loaded
+into
+[/prebuilts/tools/common/m2/repository/com/google/dagger/](http://cs/android/prebuilts/tools/common/m2/repository/com/google/dagger/)
+
+
 ## TODO List
 
  - Eliminate usages of Dependency#get

packages/SystemUI/src/com/android/systemui/ContextComponentHelper.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui;
+
+/**
+ * Interface necessary to make Dagger happy. See {@link ContextComponentResolver}.
+ */
+public interface ContextComponentHelper {
+    /** Turns a classname into an instance of the class or returns null. */
+    <T> T resolve(String className);
+}

packages/SystemUI/src/com/android/systemui/ContextComponentResolver.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui;
+
+import java.util.Map;
+
+import javax.inject.Inject;
+import javax.inject.Provider;
+
+/**
+ * Used during Service and Activity instantiation to make them injectable.
+ */
+public class ContextComponentResolver implements ContextComponentHelper {
+    private final Map<Class<?>, Provider<Object>> mCreators;
+
+    @Inject
+    ContextComponentResolver(Map<Class<?>, Provider<Object>> creators) {
+        mCreators = creators;
+    }
+
+    /**
+     * Looks up the class name to see if Dagger has an instance of it.
+     */
+    @Override
+    public <T> T resolve(String className) {
+        for (Map.Entry<Class<?>, Provider<Object>> p : mCreators.entrySet()) {
+            if (p.getKey().getName().equals(className)) {
+                return (T) p.getValue().get();
+            }
+        }
+
+        return null;
+    }
+}

packages/SystemUI/src/com/android/systemui/ServiceBinder.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui;
+
+import com.android.systemui.doze.DozeService;
+
+import dagger.Binds;
+import dagger.Module;
+import dagger.multibindings.ClassKey;
+import dagger.multibindings.IntoMap;
+
+/**
+ * Services and Activities that are injectable should go here.
+ */
+@Module
+public abstract class ServiceBinder {
+
+    @Binds
+    public abstract ContextComponentHelper bindComponentHelper(
+            ContextComponentResolver componentHelper);
+
+    @Binds
+    @IntoMap
+    @ClassKey(DozeService.class)
+    public abstract Object bindDozeService(DozeService service);
+
+}

packages/SystemUI/src/com/android/systemui/SystemUIAppComponentFactory.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui;
+
+import android.app.Application;
+import android.app.Service;
+import android.content.Intent;
+
+import androidx.core.app.CoreComponentFactory;
+
+import javax.inject.Inject;
+
+/**
+ * Implementation of AppComponentFactory that injects into constructors.
+ */
+public class SystemUIAppComponentFactory extends CoreComponentFactory {
+
+    @Inject
+    public ContextComponentHelper mComponentHelper;
+
+    public SystemUIAppComponentFactory() {
+        super();
+    }
+
+    @Override
+    public Application instantiateApplication(ClassLoader cl, String className)
+            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
+        Application app = super.instantiateApplication(cl, className);
+        if (app instanceof SystemUIApplication) {
+            ((SystemUIApplication) app).setContextAvailableCallback(
+                    context -> {
+                        SystemUIFactory.createFromConfig(context);
+                        SystemUIFactory.getInstance().getRootComponent().inject(
+                                SystemUIAppComponentFactory.this);
+                    }
+            );
+        }
+
+        return app;
+    }
+
+    @Override
+    public Service instantiateService(ClassLoader cl, String className, Intent intent)
+            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
+        Service service = mComponentHelper.resolve(className);
+        if (service != null) {
+            return checkCompatWrapper(service);
+        }
+        return super.instantiateService(cl, className, intent);
+    }
+
+    static <T> T checkCompatWrapper(T obj) {
+        if (obj instanceof CompatWrapped) {
+            T wrapper = (T) ((CompatWrapped) obj).getWrapper();
+            if (wrapper != null) {
+                return wrapper;
+            }
+        }
+
+        return obj;
+    }
+}

packages/SystemUI/src/com/android/systemui/SystemUIApplication.java

@@ -60,16 +60,20 @@ public class SystemUIApplication extends Application implements SysUiServiceProv
     private boolean mServicesStarted;
     private boolean mBootCompleted;
     private final Map<Class<?>, Object> mComponents = new HashMap<>();
+    private ContextAvailableCallback mContextAvailableCallback;
 
     @Override
     public void onCreate() {
         super.onCreate();
+        // This line is used to setup Dagger's dependency injection and should be kept at the
+        // top of this method.
+        mContextAvailableCallback.onContextAvailable(this);
+
         // Set the application theme that is inherited by all services. Note that setting the
         // application theme in the manifest does only work for activities. Keep this in sync with
         // the theme set there.
         setTheme(R.style.Theme_SystemUI);
 
-        SystemUIFactory.createFromConfig(this);
 
         if (Process.myUserHandle().equals(UserHandle.SYSTEM)) {
             IntentFilter bootCompletedFilter = new IntentFilter(Intent.ACTION_BOOT_COMPLETED);
@@ -286,4 +290,12 @@ public class SystemUIApplication extends Application implements SysUiServiceProv
     public SystemUI[] getServices() {
         return mServices;
     }
+
+    void setContextAvailableCallback(ContextAvailableCallback callback) {
+        mContextAvailableCallback = callback;
+    }
+
+    interface ContextAvailableCallback {
+        void onContextAvailable(Context context);
+    }
 }

packages/SystemUI/src/com/android/systemui/SystemUIFactory.java

@@ -36,7 +36,6 @@ import com.android.keyguard.ViewMediatorCallback;
 import com.android.systemui.assist.AssistManager;
 import com.android.systemui.classifier.FalsingManagerFactory;
 import com.android.systemui.dock.DockManager;
-import com.android.systemui.fragments.FragmentService;
 import com.android.systemui.keyguard.DismissCallbackRegistry;
 import com.android.systemui.plugins.statusbar.StatusBarStateController;
 import com.android.systemui.power.EnhancedEstimates;
@@ -68,8 +67,6 @@ import com.android.systemui.statusbar.phone.UnlockMethodCache;
 import com.android.systemui.statusbar.policy.DeviceProvisionedController;
 import com.android.systemui.statusbar.policy.KeyguardMonitor;
 import com.android.systemui.util.AsyncSensorManager;
-import com.android.systemui.util.InjectionInflationController;
-import com.android.systemui.util.leak.GarbageMonitor;
 import com.android.systemui.volume.VolumeDialogComponent;
 
 import java.util.function.Consumer;
@@ -77,7 +74,6 @@ import java.util.function.Consumer;
 import javax.inject.Named;
 import javax.inject.Singleton;
 
-import dagger.Component;
 import dagger.Module;
 import dagger.Provides;
 
@@ -115,7 +111,7 @@ public class SystemUIFactory {
     public SystemUIFactory() {}
 
     protected void init(Context context) {
-        mRootComponent = DaggerSystemUIFactory_SystemUIRootComponent.builder()
+        mRootComponent = DaggerSystemUIRootComponent.builder()
                 .systemUIFactory(this)
                 .dependencyProvider(new com.android.systemui.DependencyProvider())
                 .contextHolder(new ContextHolder(context))
@@ -267,29 +263,4 @@ public class SystemUIFactory {
             return mContext;
         }
     }
-
-    @Singleton
-    @Component(modules = {SystemUIFactory.class, DependencyProvider.class, DependencyBinder.class,
-            ContextHolder.class})
-    public interface SystemUIRootComponent {
-        @Singleton
-        Dependency.DependencyInjector createDependency();
-
-        @Singleton
-        StatusBar.StatusBarInjector getStatusBarInjector();
-
-        /**
-         * FragmentCreator generates all Fragments that need injection.
-         */
-        @Singleton
-        FragmentService.FragmentCreator createFragmentCreator();
-
-        /**
-         * ViewCreator generates all Views that need injection.
-         */
-        InjectionInflationController.ViewCreator createViewCreator();
-
-        @Singleton
-        GarbageMonitor createGarbageMonitor();
-    }
 }

packages/SystemUI/src/com/android/systemui/SystemUIRootComponent.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui;
+
+import com.android.systemui.fragments.FragmentService;
+import com.android.systemui.statusbar.phone.StatusBar;
+import com.android.systemui.util.InjectionInflationController;
+import com.android.systemui.util.leak.GarbageMonitor;
+
+import javax.inject.Singleton;
+
+import dagger.Component;
+
+/**
+ * Root component for Dagger injection.
+ */
+@Singleton
+@Component(modules = {SystemUIFactory.class, DependencyProvider.class, DependencyBinder.class,
+        ServiceBinder.class, SystemUIFactory.ContextHolder.class})
+public interface SystemUIRootComponent {
+    /**
+     * Main dependency providing module.
+     */
+    @Singleton
+    Dependency.DependencyInjector createDependency();
+
+    /**
+     * Injects the StatusBar.
+     */
+    @Singleton
+    StatusBar.StatusBarInjector getStatusBarInjector();
+
+    /**
+     * FragmentCreator generates all Fragments that need injection.
+     */
+    @Singleton
+    FragmentService.FragmentCreator createFragmentCreator();
+
+    /**
+     * ViewCreator generates all Views that need injection.
+     */
+    InjectionInflationController.ViewCreator createViewCreator();
+
+    /**
+     * Creatse a GarbageMonitor.
+     */
+    @Singleton
+    GarbageMonitor createGarbageMonitor();
+
+    /**
+     * Injects into the supplied argument.
+     */
+    void inject(SystemUIAppComponentFactory factory);
+}

packages/SystemUI/src/com/android/systemui/doze/DozeService.java

@@ -31,6 +31,8 @@ import com.android.systemui.shared.plugins.PluginManager;
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 
+import javax.inject.Inject;
+
 public class DozeService extends DreamService
         implements DozeMachine.Service, RequestDoze, PluginListener<DozeServicePlugin> {
     private static final String TAG = "DozeService";
@@ -40,6 +42,7 @@ public class DozeService extends DreamService
     private DozeServicePlugin mDozePlugin;
     private PluginManager mPluginManager;
 
+    @Inject
     public DozeService() {
         setDebug(DEBUG);
     }

packages/SystemUI/src/com/android/systemui/fragments/FragmentService.java

@@ -22,7 +22,7 @@ import android.view.View;
 
 import com.android.systemui.ConfigurationChangedReceiver;
 import com.android.systemui.Dumpable;
-import com.android.systemui.SystemUIFactory;
+import com.android.systemui.SystemUIRootComponent;
 import com.android.systemui.qs.QSFragment;
 import com.android.systemui.statusbar.phone.NavigationBarFragment;
 
@@ -51,7 +51,7 @@ public class FragmentService implements ConfigurationChangedReceiver, Dumpable {
     private final FragmentCreator mFragmentCreator;
 
     @Inject
-    public FragmentService(SystemUIFactory.SystemUIRootComponent rootComponent) {
+    public FragmentService(SystemUIRootComponent rootComponent) {
         mFragmentCreator = rootComponent.createFragmentCreator();
         initInjectionMap();
     }

packages/SystemUI/src/com/android/systemui/util/InjectionInflationController.java

@@ -26,7 +26,7 @@ import android.view.View;
 import com.android.keyguard.KeyguardClockSwitch;
 import com.android.keyguard.KeyguardMessageArea;
 import com.android.keyguard.KeyguardSliceView;
-import com.android.systemui.SystemUIFactory;
+import com.android.systemui.SystemUIRootComponent;
 import com.android.systemui.qs.QSCarrierGroup;
 import com.android.systemui.qs.QSFooterImpl;
 import com.android.systemui.qs.QSPanel;
@@ -62,7 +62,7 @@ public class InjectionInflationController {
     private final LayoutInflater.Factory2 mFactory = new InjectionFactory();
 
     @Inject
-    public InjectionInflationController(SystemUIFactory.SystemUIRootComponent rootComponent) {
+    public InjectionInflationController(SystemUIRootComponent rootComponent) {
         mViewCreator = rootComponent.createViewCreator();
         initInjectionMap();
     }