Lazy load VolumeDialogComponent

Bug: 147455109
Test: manual (compare boot time of car.volume.VolumeUI vs
volume.VolumeUI)

Change-Id: I1ebb67d06fe5c7f1253ae970223128d3b53a3df5

packages/CarSystemUI/res/values/config.xml

@@ -87,7 +87,7 @@
         <item>com.android.systemui.util.NotificationChannels</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.volume.VolumeUI</item>-->
 <!--        <item>com.android.systemui.stackdivider.Divider</item>-->
 <!--        <item>com.android.systemui.statusbar.phone.StatusBar</item>-->
         <item>com.android.systemui.usb.StorageNotification</item>
@@ -110,5 +110,6 @@
         <item>com.android.systemui.toast.ToastUI</item>
         <item>com.android.systemui.car.voicerecognition.ConnectedDeviceVoiceRecognitionNotifier</item>
         <item>com.android.systemui.window.SystemUIOverlayWindowManager</item>
+        <item>com.android.systemui.car.volume.VolumeUI</item>
     </string-array>
 </resources>

packages/CarSystemUI/src/com/android/systemui/CarSystemUIBinder.java

@@ -20,6 +20,7 @@ import com.android.systemui.biometrics.AuthController;
 import com.android.systemui.bubbles.dagger.BubbleModule;
 import com.android.systemui.car.notification.CarNotificationModule;
 import com.android.systemui.car.voicerecognition.ConnectedDeviceVoiceRecognitionNotifier;
+import com.android.systemui.car.volume.VolumeUI;
 import com.android.systemui.globalactions.GlobalActionsComponent;
 import com.android.systemui.keyguard.KeyguardViewMediator;
 import com.android.systemui.keyguard.dagger.KeyguardModule;
@@ -39,7 +40,6 @@ import com.android.systemui.statusbar.tv.TvStatusBar;
 import com.android.systemui.theme.ThemeOverlayController;
 import com.android.systemui.toast.ToastUI;
 import com.android.systemui.util.leak.GarbageMonitor;
-import com.android.systemui.volume.VolumeUI;
 import com.android.systemui.window.OverlayWindowModule;
 import com.android.systemui.window.SystemUIOverlayWindowManager;
 
@@ -65,7 +65,7 @@ public abstract class CarSystemUIBinder {
     @ClassKey(Divider.class)
     public abstract SystemUI bindDivider(Divider sysui);
 
-    /** */
+    /** Inject Car Navigation Bar. */
     @Binds
     @IntoMap
     @ClassKey(CarNavigationBar.class)

packages/CarSystemUI/src/com/android/systemui/car/volume/VolumeUI.java

@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2020 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.car.volume;
+
+import android.car.Car;
+import android.car.media.CarAudioManager;
+import android.content.Context;
+import android.content.res.Configuration;
+import android.content.res.Resources;
+import android.os.Handler;
+import android.util.Log;
+
+import com.android.systemui.R;
+import com.android.systemui.SystemUI;
+import com.android.systemui.car.CarServiceProvider;
+import com.android.systemui.dagger.qualifiers.Main;
+import com.android.systemui.volume.VolumeDialogComponent;
+
+import java.io.FileDescriptor;
+import java.io.PrintWriter;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import dagger.Lazy;
+
+/** The entry point for controlling the volume ui in cars. */
+@Singleton
+public class VolumeUI extends SystemUI {
+
+    private static final String TAG = "VolumeUI";
+    private final Resources mResources;
+    private final Handler mMainHandler;
+    private final CarServiceProvider mCarServiceProvider;
+    private final Lazy<VolumeDialogComponent> mVolumeDialogComponentLazy;
+
+    private final CarAudioManager.CarVolumeCallback mVolumeChangeCallback =
+            new CarAudioManager.CarVolumeCallback() {
+                @Override
+                public void onGroupVolumeChanged(int zoneId, int groupId, int flags) {
+                    if (mVolumeDialogComponent == null) {
+                        mMainHandler.post(() -> {
+                            mVolumeDialogComponent = mVolumeDialogComponentLazy.get();
+                            mVolumeDialogComponent.register();
+                        });
+                        mCarAudioManager.unregisterCarVolumeCallback(mVolumeChangeCallback);
+                    }
+                }
+
+                @Override
+                public void onMasterMuteChanged(int zoneId, int flags) {
+                    // ignored
+                }
+            };
+
+    private boolean mEnabled;
+    private CarAudioManager mCarAudioManager;
+    private VolumeDialogComponent mVolumeDialogComponent;
+
+    @Inject
+    public VolumeUI(
+            Context context,
+            @Main Resources resources,
+            @Main Handler mainHandler,
+            CarServiceProvider carServiceProvider,
+            Lazy<VolumeDialogComponent> volumeDialogComponentLazy
+    ) {
+        super(context);
+        mResources = resources;
+        mMainHandler = mainHandler;
+        mCarServiceProvider = carServiceProvider;
+        mVolumeDialogComponentLazy = volumeDialogComponentLazy;
+    }
+
+    @Override
+    public void start() {
+        boolean enableVolumeUi = mResources.getBoolean(R.bool.enable_volume_ui);
+        mEnabled = enableVolumeUi;
+        if (!mEnabled) return;
+
+        mCarServiceProvider.addListener(car -> {
+            if (mCarAudioManager != null) {
+                return;
+            }
+
+            mCarAudioManager = (CarAudioManager) car.getCarManager(Car.AUDIO_SERVICE);
+            Log.d(TAG, "Registering mVolumeChangeCallback.");
+            // This volume call back is never unregistered because CarStatusBar is
+            // never destroyed.
+            mCarAudioManager.registerCarVolumeCallback(mVolumeChangeCallback);
+        });
+    }
+
+    @Override
+    protected void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+        if (!mEnabled) return;
+        if (mVolumeDialogComponent != null) {
+            mVolumeDialogComponent.onConfigurationChanged(newConfig);
+        }
+    }
+
+    @Override
+    public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
+        pw.print("mEnabled="); pw.println(mEnabled);
+        if (!mEnabled) return;
+        if (mVolumeDialogComponent != null) {
+            mVolumeDialogComponent.dump(fd, pw, args);
+        }
+    }
+}

packages/CarSystemUI/src/com/android/systemui/volume/CarVolumeDialogComponent.java

@@ -45,6 +45,7 @@ public class CarVolumeDialogComponent extends VolumeDialogComponent {
     @Override
     protected VolumeDialog createDefault() {
         mCarVolumeDialog = new CarVolumeDialogImpl(mContext);
+        mCarVolumeDialog.show(Events.SHOW_REASON_VOLUME_CHANGED);
         return mCarVolumeDialog;
     }
 }

packages/CarSystemUI/src/com/android/systemui/volume/CarVolumeDialogImpl.java

@@ -234,6 +234,20 @@ public class CarVolumeDialogImpl implements VolumeDialog {
         cleanupAudioManager();
     }
 
+    /**
+     * Reveals volume dialog.
+     */
+    public void show(int reason) {
+        mHandler.obtainMessage(H.SHOW, reason).sendToTarget();
+    }
+
+    /**
+     * Hides volume dialog.
+     */
+    public void dismiss(int reason) {
+        mHandler.obtainMessage(H.DISMISS, reason).sendToTarget();
+    }
+
     private void initDialog() {
         loadAudioUsageItems();
         mCarVolumeLineItems.clear();