| /** |
| * Copyright (C) 2016 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.server.vr; |
| |
| import android.annotation.NonNull; |
| import android.content.BroadcastReceiver; |
| import android.content.ContentResolver; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.database.ContentObserver; |
| import android.net.Uri; |
| import android.os.Handler; |
| import android.os.UserHandle; |
| import android.provider.Settings; |
| import android.util.ArraySet; |
| |
| import java.util.Objects; |
| import java.util.Set; |
| |
| /** |
| * Detects changes in a given setting. |
| * |
| * @hide |
| */ |
| public class SettingsObserver { |
| |
| private final String mSecureSettingName; |
| private final BroadcastReceiver mSettingRestoreReceiver; |
| private final ContentObserver mContentObserver; |
| private final Set<SettingChangeListener> mSettingsListeners = new ArraySet<>(); |
| |
| /** |
| * Implement this to receive callbacks when the setting tracked by this observer changes. |
| */ |
| public interface SettingChangeListener { |
| |
| /** |
| * Called when the tracked setting has changed. |
| */ |
| void onSettingChanged(); |
| |
| |
| /** |
| * Called when the tracked setting has been restored for a particular user. |
| * |
| * @param prevValue the previous value of the setting. |
| * @param newValue the new value of the setting. |
| * @param userId the user ID for which this setting has been restored. |
| */ |
| void onSettingRestored(String prevValue, String newValue, int userId); |
| } |
| |
| private SettingsObserver(@NonNull final Context context, @NonNull final Handler handler, |
| @NonNull final Uri settingUri, @NonNull final String secureSettingName) { |
| |
| mSecureSettingName = secureSettingName; |
| mSettingRestoreReceiver = new BroadcastReceiver() { |
| @Override |
| public void onReceive(Context context, Intent intent) { |
| if (Intent.ACTION_SETTING_RESTORED.equals(intent.getAction())) { |
| String element = intent.getStringExtra(Intent.EXTRA_SETTING_NAME); |
| if (Objects.equals(element, secureSettingName)) { |
| String prevValue = intent.getStringExtra(Intent.EXTRA_SETTING_PREVIOUS_VALUE); |
| String newValue = intent.getStringExtra(Intent.EXTRA_SETTING_NEW_VALUE); |
| sendSettingRestored(prevValue, newValue, getSendingUserId()); |
| } |
| } |
| } |
| }; |
| |
| mContentObserver = new ContentObserver(handler) { |
| @Override |
| public void onChange(boolean selfChange, Uri uri) { |
| if (uri == null || settingUri.equals(uri)) { |
| sendSettingChanged(); |
| } |
| } |
| }; |
| |
| ContentResolver resolver = context.getContentResolver(); |
| resolver.registerContentObserver(settingUri, false, mContentObserver, |
| UserHandle.USER_ALL); |
| } |
| |
| /** |
| * Create a SettingsObserver instance. |
| * |
| * @param context the context to query for settings changes. |
| * @param handler the handler to use for a settings ContentObserver. |
| * @param settingName the setting to track. |
| * @return a SettingsObserver instance. |
| */ |
| public static SettingsObserver build(@NonNull Context context, @NonNull Handler handler, |
| @NonNull String settingName) { |
| Uri settingUri = Settings.Secure.getUriFor(settingName); |
| |
| return new SettingsObserver(context, handler, settingUri, settingName); |
| } |
| |
| /** |
| * Add a listener for setting changes. |
| * |
| * @param listener a {@link SettingChangeListener} instance. |
| */ |
| public void addListener(@NonNull SettingChangeListener listener) { |
| mSettingsListeners.add(listener); |
| } |
| |
| /** |
| * Remove a listener for setting changes. |
| * |
| * @param listener a {@link SettingChangeListener} instance. |
| */ |
| public void removeListener(@NonNull SettingChangeListener listener) { |
| mSettingsListeners.remove(listener); |
| |
| } |
| |
| private void sendSettingChanged() { |
| for (SettingChangeListener l : mSettingsListeners) { |
| l.onSettingChanged(); |
| } |
| } |
| |
| private void sendSettingRestored(final String prevValue, final String newValue, final int userId) { |
| for (SettingChangeListener l : mSettingsListeners) { |
| l.onSettingRestored(prevValue, newValue, userId); |
| } |
| } |
| |
| } |