Made following changes to Settings:

- Moved the Voice Input setting from Digital assistant app to Languages & input.
- Bundled Voice Input and Text-to-speech settings together under Speech
  category.

Bug: 218609449

Test: refactoring CL. Existing unit tests still pass.
Change-Id: I3107a410ed35685f5f1081cbe448b105b5c79c24

src/com/android/settings/language/DefaultVoiceInputPreferenceController.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2022 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.settings.language;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.text.TextUtils;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceScreen;
+
+import com.android.settings.applications.defaultapps.DefaultAppPreferenceController;
+import com.android.settingslib.applications.DefaultAppInfo;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnPause;
+import com.android.settingslib.core.lifecycle.events.OnResume;
+
+/** Controller of the Voice Input preference. */
+public class DefaultVoiceInputPreferenceController extends DefaultAppPreferenceController
+        implements LifecycleObserver, OnResume, OnPause {
+
+    private static final String KEY_VOICE_INPUT = "voice_input_settings";
+
+    private VoiceInputHelper mHelper;
+    private PreferenceScreen mScreen;
+    private Preference mPreference;
+    private Context mContext;
+
+    public DefaultVoiceInputPreferenceController(Context context, Lifecycle lifecycle) {
+        super(context);
+        mContext = context;
+        mHelper = new VoiceInputHelper(context);
+        mHelper.buildUi();
+        if (lifecycle != null) {
+            lifecycle.addObserver(this);
+        }
+    }
+
+    @Override
+    public boolean isAvailable() {
+        return mContext.getPackageManager().hasSystemFeature(
+                PackageManager.FEATURE_VOICE_RECOGNIZERS);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_VOICE_INPUT;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        mScreen = screen;
+        mPreference = screen.findPreference(getPreferenceKey());
+        super.displayPreference(screen);
+    }
+
+    @Override
+    public void onResume() {
+        updatePreference();
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        super.updateState(mPreference);
+        updatePreference();
+    }
+
+    @Override
+    public void onPause() {}
+
+    @Override
+    protected DefaultAppInfo getDefaultAppInfo() {
+        final String defaultKey = getDefaultAppKey();
+        if (defaultKey == null) {
+            return null;
+        }
+
+        for (VoiceInputHelper.RecognizerInfo info : mHelper.mAvailableRecognizerInfos) {
+            if (TextUtils.equals(defaultKey, info.mKey)) {
+                return new DefaultVoiceInputPicker.VoiceInputDefaultAppInfo(mContext,
+                        mPackageManager, mUserId, info, true /* enabled */);
+            }
+        }
+        return null;
+    }
+
+    @Override
+    protected Intent getSettingIntent(DefaultAppInfo info) {
+        final DefaultAppInfo appInfo = getDefaultAppInfo();
+        if (appInfo == null
+                || !(appInfo instanceof DefaultVoiceInputPicker.VoiceInputDefaultAppInfo)) {
+            return null;
+        }
+        return ((DefaultVoiceInputPicker.VoiceInputDefaultAppInfo) appInfo).getSettingIntent();
+    }
+
+    private void updatePreference() {
+        if (mPreference == null) {
+            return;
+        }
+        mHelper.buildUi();
+        if (isAvailable()) {
+            if (mScreen.findPreference(getPreferenceKey()) == null) {
+                // add it if it's not on scree
+                mScreen.addPreference(mPreference);
+            }
+        } else {
+            mScreen.removePreference(mPreference);
+        }
+    }
+
+    private String getDefaultAppKey() {
+        final ComponentName currentService = DefaultVoiceInputPicker.getCurrentService(mHelper);
+        if (currentService == null) {
+            return null;
+        }
+        return currentService.flattenToShortString();
+    }
+}