Sysui: Add support for view injection

Test: Existing tests pass
Change-Id: Ic6931ebec38ca9514e9368239dd9502ae2dee33c
diff --git a/packages/SystemUI/docs/dagger.md b/packages/SystemUI/docs/dagger.md
index 8bfa1c2..f81e8cc 100644
--- a/packages/SystemUI/docs/dagger.md
+++ b/packages/SystemUI/docs/dagger.md
@@ -147,6 +147,52 @@
 FragmentHostManager.get(view).create(NavigationBarFragment.class);
 ```
 
+### Using injection with Views
+
+Generally, you shouldn't need to inject for a view, as the view should
+be relatively self contained and logic that requires injection should be
+moved to a higher level construct such as a Fragment or a top-level SystemUI
+component, see above for how to do injection for both of which.
+
+Still here? Yeah, ok, sysui has a lot of pre-existing views that contain a
+lot of code that could benefit from injection and will need to be migrated
+off from Dependency#get uses. Similar to how fragments are injected, the view
+needs to be added to the interface
+com.android.systemui.util.InjectionInflationController$ViewInstanceCreator.
+
+```java
+public interface ViewInstanceCreator {
++   QuickStatusBarHeader createQsHeader();
+}
+```
+
+Presumably you need to inflate that view from XML (otherwise why do you
+need anything special? see earlier sections about generic injection). To obtain
+an inflater that supports injected objects, call InjectionInflationController#injectable,
+which will wrap the inflater it is passed in one that can create injected
+objects when needed.
+
+```java
+@Override
+public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
+        Bundle savedInstanceState) {
+    return mInjectionInflater.injectable(inflater).inflate(R.layout.my_layout, container, false);
+}
+```
+
+There is one other important thing to note about injecting with views. SysUI
+already has a Context in its global dagger component, so if you simply inject
+a Context, you will not get the one that the view should have with proper
+theming. Because of this, always ensure to tag views that have @Inject with
+the @Named view context.
+
+```java
+public CustomView(@Named(VIEW_CONTEXT) Context themedViewContext, AttributeSet attrs,
+        OtherCustomDependency something) {
+    ...
+}
+```
+
 ## TODO List
 
  - Eliminate usages of Depndency#get
diff --git a/packages/SystemUI/proguard.flags b/packages/SystemUI/proguard.flags
index d57fe8a..22b0ab7 100644
--- a/packages/SystemUI/proguard.flags
+++ b/packages/SystemUI/proguard.flags
@@ -31,4 +31,7 @@
 -keep class com.android.systemui.fragments.FragmentService$FragmentCreator {
     *;
 }
+-keep class com.android.systemui.util.InjectionInflationController$ViewInstanceCreator {
+    *;
+}
 -keep class androidx.core.app.CoreComponentFactory
diff --git a/packages/SystemUI/src/com/android/systemui/DependencyProvider.java b/packages/SystemUI/src/com/android/systemui/DependencyProvider.java
index 76336bb..b11e189 100644
--- a/packages/SystemUI/src/com/android/systemui/DependencyProvider.java
+++ b/packages/SystemUI/src/com/android/systemui/DependencyProvider.java
@@ -33,7 +33,6 @@
 import android.os.ServiceManager;
 import android.os.UserHandle;
 import android.util.DisplayMetrics;
-import android.util.Log;
 import android.view.IWindowManager;
 import android.view.WindowManagerGlobal;
 
@@ -470,7 +469,6 @@
     @Singleton
     @Provides
     public UiOffloadThread provideUiOffloadThread() {
-        Log.d("TestTest", "provideUiOffloadThread");
         return new UiOffloadThread();
     }
 
diff --git a/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java b/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java
index 1a2473e..7689dfc 100644
--- a/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java
+++ b/packages/SystemUI/src/com/android/systemui/SystemUIFactory.java
@@ -42,7 +42,6 @@
 import com.android.systemui.statusbar.ScrimView;
 import com.android.systemui.statusbar.notification.NotificationData;
 import com.android.systemui.statusbar.notification.NotificationEntryManager;
-import com.android.systemui.statusbar.notification.NotificationRowBinder;
 import com.android.systemui.statusbar.phone.DozeParameters;
 import com.android.systemui.statusbar.phone.KeyguardBouncer;
 import com.android.systemui.statusbar.phone.KeyguardEnvironmentImpl;
@@ -55,6 +54,7 @@
 import com.android.systemui.statusbar.phone.StatusBarIconController;
 import com.android.systemui.statusbar.phone.StatusBarKeyguardViewManager;
 import com.android.systemui.statusbar.policy.DeviceProvisionedController;
+import com.android.systemui.util.InjectionInflationController;
 import com.android.systemui.volume.VolumeDialogComponent;
 
 import java.util.function.Consumer;
@@ -223,5 +223,10 @@
          */
         @Singleton
         FragmentService.FragmentCreator createFragmentCreator();
+
+        /**
+         * ViewCreator generates all Views that need injection.
+         */
+        InjectionInflationController.ViewCreator createViewCreator();
     }
 }
diff --git a/packages/SystemUI/src/com/android/systemui/qs/QSFragment.java b/packages/SystemUI/src/com/android/systemui/qs/QSFragment.java
index fa775c0..93130d4 100644
--- a/packages/SystemUI/src/com/android/systemui/qs/QSFragment.java
+++ b/packages/SystemUI/src/com/android/systemui/qs/QSFragment.java
@@ -45,6 +45,7 @@
 import com.android.systemui.statusbar.notification.stack.StackStateAnimator;
 import com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer;
 import com.android.systemui.statusbar.policy.RemoteInputQuickSettingsDisabler;
+import com.android.systemui.util.InjectionInflationController;
 
 import javax.inject.Inject;
 
@@ -76,16 +77,20 @@
     private boolean mQsDisabled;
 
     private final RemoteInputQuickSettingsDisabler mRemoteInputQuickSettingsDisabler;
+    private final InjectionInflationController mInjectionInflater;
 
     @Inject
-    public QSFragment(RemoteInputQuickSettingsDisabler remoteInputQsDisabler) {
+    public QSFragment(RemoteInputQuickSettingsDisabler remoteInputQsDisabler,
+            InjectionInflationController injectionInflater) {
         mRemoteInputQuickSettingsDisabler = remoteInputQsDisabler;
+        mInjectionInflater = injectionInflater;
     }
 
     @Override
     public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
             Bundle savedInstanceState) {
-        inflater = inflater.cloneInContext(new ContextThemeWrapper(getContext(), R.style.qs_theme));
+        inflater = mInjectionInflater.injectable(
+                inflater.cloneInContext(new ContextThemeWrapper(getContext(), R.style.qs_theme)));
         return inflater.inflate(R.layout.qs_panel, container, false);
     }
 
diff --git a/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java b/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java
index 3cecff0..f2f83c0 100644
--- a/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java
+++ b/packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java
@@ -17,6 +17,8 @@
 import static android.app.StatusBarManager.DISABLE2_QUICK_SETTINGS;
 import static android.provider.Settings.System.SHOW_BATTERY_PERCENT;
 
+import static com.android.systemui.util.InjectionInflationController.VIEW_CONTEXT;
+
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.annotation.ColorInt;
@@ -58,7 +60,6 @@
 
 import com.android.settingslib.Utils;
 import com.android.systemui.BatteryMeterView;
-import com.android.systemui.Dependency;
 import com.android.systemui.Prefs;
 import com.android.systemui.R;
 import com.android.systemui.plugins.ActivityStarter;
@@ -84,6 +85,9 @@
 import java.util.Locale;
 import java.util.Objects;
 
+import javax.inject.Inject;
+import javax.inject.Named;
+
 /**
  * View that contains the top-most bits of the screen (primarily the status bar with date, time, and
  * battery) and also contains the {@link QuickQSPanel} along with some of the panel's inner
@@ -102,6 +106,11 @@
     public static final int MAX_TOOLTIP_SHOWN_COUNT = 2;
 
     private final Handler mHandler = new Handler();
+    private final BatteryController mBatteryController;
+    private final NextAlarmController mAlarmController;
+    private final ZenModeController mZenController;
+    private final StatusBarIconController mStatusBarIconController;
+    private final ActivityStarter mActivityStarter;
 
     private QSPanel mQsPanel;
 
@@ -141,8 +150,6 @@
     private TextView mBatteryRemainingText;
     private boolean mShowBatteryPercentAndEstimate;
 
-    private NextAlarmController mAlarmController;
-    private ZenModeController mZenController;
     private PrivacyItemController mPrivacyItemController;
     /** Counts how many times the long press tooltip has been shown to the user. */
     private int mShownCount;
@@ -172,10 +179,17 @@
         }
     };
 
-    public QuickStatusBarHeader(Context context, AttributeSet attrs) {
+    @Inject
+    public QuickStatusBarHeader(@Named(VIEW_CONTEXT) Context context, AttributeSet attrs,
+            NextAlarmController nextAlarmController, ZenModeController zenModeController,
+            BatteryController batteryController, StatusBarIconController statusBarIconController,
+            ActivityStarter activityStarter) {
         super(context, attrs);
-        mAlarmController = Dependency.get(NextAlarmController.class);
-        mZenController = Dependency.get(ZenModeController.class);
+        mAlarmController = nextAlarmController;
+        mZenController = zenModeController;
+        mBatteryController = batteryController;
+        mStatusBarIconController = statusBarIconController;
+        mActivityStarter = activityStarter;
         mPrivacyItemController = new PrivacyItemController(context, mPICCallback);
         mShownCount = getStoredShownCount();
     }
@@ -405,8 +419,7 @@
         if (!mShowBatteryPercentAndEstimate) {
             return;
         }
-        mBatteryRemainingText.setText(
-                Dependency.get(BatteryController.class).getEstimatedTimeRemainingString());
+        mBatteryRemainingText.setText(mBatteryController.getEstimatedTimeRemainingString());
     }
 
     public void setExpanded(boolean expanded) {
@@ -472,7 +485,7 @@
     @Override
     public void onAttachedToWindow() {
         super.onAttachedToWindow();
-        Dependency.get(StatusBarIconController.class).addIconGroup(mIconManager);
+        mStatusBarIconController.addIconGroup(mIconManager);
         requestApplyInsets();
         mContext.getContentResolver().registerContentObserver(
                 Settings.System.getUriFor(SHOW_BATTERY_PERCENT), false, mPercentSettingObserver,
@@ -515,7 +528,7 @@
     @VisibleForTesting
     public void onDetachedFromWindow() {
         setListening(false);
-        Dependency.get(StatusBarIconController.class).removeIconGroup(mIconManager);
+        mStatusBarIconController.removeIconGroup(mIconManager);
         mContext.getContentResolver().unregisterContentObserver(mPercentSettingObserver);
         super.onDetachedFromWindow();
     }
@@ -544,10 +557,10 @@
     @Override
     public void onClick(View v) {
         if (v == mClockView) {
-            Dependency.get(ActivityStarter.class).postStartActivityDismissingKeyguard(new Intent(
+            mActivityStarter.postStartActivityDismissingKeyguard(new Intent(
                     AlarmClock.ACTION_SHOW_ALARMS),0);
         } else if (v == mBatteryMeterView) {
-            Dependency.get(ActivityStarter.class).postStartActivityDismissingKeyguard(new Intent(
+            mActivityStarter.postStartActivityDismissingKeyguard(new Intent(
                     Intent.ACTION_POWER_USAGE_SUMMARY),0);
         } else if (v == mPrivacyChip) {
             Handler mUiHandler = new Handler(Looper.getMainLooper());
diff --git a/packages/SystemUI/src/com/android/systemui/util/InjectionInflationController.java b/packages/SystemUI/src/com/android/systemui/util/InjectionInflationController.java
new file mode 100644
index 0000000..e458e63
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/util/InjectionInflationController.java
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 2018 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.util;
+
+import android.content.Context;
+import android.util.ArrayMap;
+import android.util.AttributeSet;
+import android.view.InflateException;
+import android.view.LayoutInflater;
+import android.view.View;
+
+import com.android.systemui.SystemUIFactory;
+import com.android.systemui.qs.QuickStatusBarHeader;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+
+import javax.inject.Inject;
+import javax.inject.Named;
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+import dagger.Subcomponent;
+
+/**
+ * Manages inflation that requires dagger injection.
+ * See docs/dagger.md for details.
+ */
+@Singleton
+public class InjectionInflationController {
+
+    public static final String VIEW_CONTEXT = "view_context";
+    private final ViewCreator mViewCreator;
+    private final ArrayMap<String, Method> mInjectionMap = new ArrayMap<>();
+    private final LayoutInflater.Factory2 mFactory = new InjectionFactory();
+
+    @Inject
+    public InjectionInflationController(SystemUIFactory.SystemUIRootComponent rootComponent) {
+        mViewCreator = rootComponent.createViewCreator();
+        initInjectionMap();
+    }
+
+    ArrayMap<String, Method> getInjectionMap() {
+        return mInjectionMap;
+    }
+
+    ViewCreator getFragmentCreator() {
+        return mViewCreator;
+    }
+
+    /**
+     * Wraps a {@link LayoutInflater} to support creating dagger injected views.
+     * See docs/dagger.md for details.
+     */
+    public LayoutInflater injectable(LayoutInflater inflater) {
+        LayoutInflater ret = inflater.cloneInContext(inflater.getContext());
+        ret.setPrivateFactory(mFactory);
+        return ret;
+    }
+
+    private void initInjectionMap() {
+        for (Method method : ViewInstanceCreator.class.getDeclaredMethods()) {
+            if (View.class.isAssignableFrom(method.getReturnType())
+                    && (method.getModifiers() & Modifier.PUBLIC) != 0) {
+                mInjectionMap.put(method.getReturnType().getName(), method);
+            }
+        }
+    }
+
+    /**
+     * The subcomponent of dagger that holds all views that need injection.
+     */
+    @Subcomponent
+    public interface ViewCreator {
+        /**
+         * Creates another subcomponent to actually generate the view.
+         */
+        ViewInstanceCreator createInstanceCreator(ViewAttributeProvider attributeProvider);
+    }
+
+    /**
+     * Secondary sub-component that actually creates the views.
+     *
+     * Having two subcomponents lets us hide the complexity of providing the named context
+     * and AttributeSet from the SystemUIRootComponent, instead we have one subcomponent that
+     * creates a new ViewInstanceCreator any time we need to inflate a view.
+     */
+    @Subcomponent(modules = ViewAttributeProvider.class)
+    public interface ViewInstanceCreator {
+        /**
+         * Creates the QuickStatusBarHeader.
+         */
+        QuickStatusBarHeader createQsHeader();
+    }
+
+    /**
+     * Module for providing view-specific constructor objects.
+     */
+    @Module
+    public class ViewAttributeProvider {
+        private final Context mContext;
+        private final AttributeSet mAttrs;
+
+        private ViewAttributeProvider(Context context, AttributeSet attrs) {
+            mContext = context;
+            mAttrs = attrs;
+        }
+
+        /**
+         * Provides the view-themed context (as opposed to the global sysui application context).
+         */
+        @Provides
+        @Named(VIEW_CONTEXT)
+        public Context provideContext() {
+            return mContext;
+        }
+
+        /**
+         * Provides the AttributeSet for the current view being inflated.
+         */
+        @Provides
+        public AttributeSet provideAttributeSet() {
+            return mAttrs;
+        }
+    }
+
+    private class InjectionFactory implements LayoutInflater.Factory2 {
+
+        @Override
+        public View onCreateView(String name, Context context, AttributeSet attrs) {
+            Method creationMethod = mInjectionMap.get(name);
+            if (creationMethod != null) {
+                ViewAttributeProvider provider = new ViewAttributeProvider(context, attrs);
+                try {
+                    return (View) creationMethod.invoke(
+                            mViewCreator.createInstanceCreator(provider));
+                } catch (IllegalAccessException e) {
+                    throw new InflateException("Could not inflate " + name, e);
+                } catch (InvocationTargetException e) {
+                    throw new InflateException("Could not inflate " + name, e);
+                }
+            }
+            return null;
+        }
+
+        @Override
+        public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
+            return onCreateView(name, context, attrs);
+        }
+    }
+}
diff --git a/packages/SystemUI/tests/src/com/android/systemui/qs/QSFragmentTest.java b/packages/SystemUI/tests/src/com/android/systemui/qs/QSFragmentTest.java
index 39afbac..ab508a2 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/qs/QSFragmentTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/qs/QSFragmentTest.java
@@ -34,11 +34,13 @@
 import com.android.keyguard.CarrierText;
 import com.android.systemui.Dependency;
 import com.android.systemui.R;
+import com.android.systemui.SystemUIFactory;
 import com.android.systemui.SysuiBaseFragmentTest;
 import com.android.systemui.statusbar.phone.StatusBarIconController;
 import com.android.systemui.statusbar.policy.Clock;
 import com.android.systemui.statusbar.policy.RemoteInputQuickSettingsDisabler;
 import com.android.systemui.statusbar.policy.UserSwitcherController;
+import com.android.systemui.util.InjectionInflationController;
 
 import org.junit.Before;
 import org.junit.Ignore;
@@ -122,6 +124,7 @@
 
     @Override
     protected Fragment instantiate(Context context, String className, Bundle arguments) {
-        return new QSFragment(new RemoteInputQuickSettingsDisabler(context));
+        return new QSFragment(new RemoteInputQuickSettingsDisabler(context),
+                new InjectionInflationController(SystemUIFactory.getInstance().getRootComponent()));
     }
 }