| /* |
| * Copyright (C) 2021 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 androidx.window.common; |
| |
| import android.annotation.NonNull; |
| import android.content.ContentResolver; |
| import android.content.Context; |
| import android.database.ContentObserver; |
| import android.net.Uri; |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.provider.Settings; |
| import android.text.TextUtils; |
| |
| import androidx.window.util.BaseDataProducer; |
| |
| import com.android.internal.R; |
| |
| import java.util.Optional; |
| import java.util.Set; |
| |
| /** |
| * Implementation of {@link androidx.window.util.DataProducer} that produces a |
| * {@link String} that can be parsed to a {@link CommonFoldingFeature}. |
| * {@link RawFoldingFeatureProducer} searches for the value in two places. The first check is in |
| * settings where the {@link String} property is saved with the key |
| * {@link RawFoldingFeatureProducer#DISPLAY_FEATURES}. If this value is null or empty then the |
| * value in {@link android.content.res.Resources} is used. If both are empty then |
| * {@link RawFoldingFeatureProducer#getData()} returns an empty object. |
| * {@link RawFoldingFeatureProducer} listens to changes in the setting so that it can override |
| * the system {@link CommonFoldingFeature} data. |
| */ |
| public final class RawFoldingFeatureProducer extends BaseDataProducer<String> { |
| private static final String DISPLAY_FEATURES = "display_features"; |
| |
| private final Uri mDisplayFeaturesUri = |
| Settings.Global.getUriFor(DISPLAY_FEATURES); |
| |
| private final ContentResolver mResolver; |
| private final ContentObserver mObserver; |
| private final String mResourceFeature; |
| private boolean mRegisteredObservers; |
| |
| public RawFoldingFeatureProducer(@NonNull Context context) { |
| mResolver = context.getContentResolver(); |
| mObserver = new SettingsObserver(); |
| mResourceFeature = context.getResources().getString(R.string.config_display_features); |
| } |
| |
| @Override |
| @NonNull |
| public Optional<String> getData() { |
| String displayFeaturesString = getFeatureString(); |
| if (displayFeaturesString == null) { |
| return Optional.empty(); |
| } |
| return Optional.of(displayFeaturesString); |
| } |
| |
| /** |
| * Returns the {@link String} representation for a {@link CommonFoldingFeature} from settings if |
| * present and falls back to the resource value if empty or {@code null}. |
| */ |
| private String getFeatureString() { |
| String settingsFeature = Settings.Global.getString(mResolver, DISPLAY_FEATURES); |
| if (TextUtils.isEmpty(settingsFeature)) { |
| return mResourceFeature; |
| } |
| return settingsFeature; |
| } |
| |
| @Override |
| protected void onListenersChanged(Set<Runnable> callbacks) { |
| if (callbacks.isEmpty()) { |
| unregisterObserversIfNeeded(); |
| } else { |
| registerObserversIfNeeded(); |
| } |
| } |
| |
| /** |
| * Registers settings observers, if needed. When settings observers are registered for this |
| * producer callbacks for changes in data will be triggered. |
| */ |
| private void registerObserversIfNeeded() { |
| if (mRegisteredObservers) { |
| return; |
| } |
| mRegisteredObservers = true; |
| mResolver.registerContentObserver(mDisplayFeaturesUri, false /* notifyForDescendants */, |
| mObserver /* ContentObserver */); |
| } |
| |
| /** |
| * Unregisters settings observers, if needed. When settings observers are unregistered for this |
| * producer callbacks for changes in data will not be triggered. |
| */ |
| private void unregisterObserversIfNeeded() { |
| if (!mRegisteredObservers) { |
| return; |
| } |
| mRegisteredObservers = false; |
| mResolver.unregisterContentObserver(mObserver); |
| } |
| |
| private final class SettingsObserver extends ContentObserver { |
| SettingsObserver() { |
| super(new Handler(Looper.getMainLooper())); |
| } |
| |
| @Override |
| public void onChange(boolean selfChange, Uri uri) { |
| if (mDisplayFeaturesUri.equals(uri)) { |
| notifyDataChanged(); |
| } |
| } |
| } |
| } |