| /* |
| * 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.car.settings.common; |
| |
| import android.annotation.NonNull; |
| import android.annotation.XmlRes; |
| import android.content.Context; |
| import android.content.res.TypedArray; |
| import android.content.res.XmlResourceParser; |
| import android.os.Bundle; |
| import android.util.AttributeSet; |
| import android.util.Xml; |
| |
| import androidx.annotation.IntDef; |
| |
| import com.android.car.settings.R; |
| |
| import org.xmlpull.v1.XmlPullParser; |
| import org.xmlpull.v1.XmlPullParserException; |
| |
| import java.io.IOException; |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| |
| /** |
| * Utility class to parse elements of XML preferences. This is a reduced version of {@code com |
| * .android.settings.core.PreferenceXmlParserUtils}. |
| */ |
| public class PreferenceXmlParser { |
| |
| private static final Logger LOG = new Logger(PreferenceXmlParser.class); |
| |
| private static final String PREF_TAG_ENDS_WITH = "Preference"; |
| private static final String PREF_GROUP_TAG_ENDS_WITH = "PreferenceGroup"; |
| private static final List<String> SUPPORTED_PREF_TYPES = Arrays.asList("Preference", |
| "PreferenceCategory", "PreferenceScreen"); |
| |
| /** |
| * Flag definition to indicate which metadata should be extracted when |
| * {@link #extractMetadata(Context, int, int)} is called. The flags can be combined by using | |
| * (binary or). |
| */ |
| @IntDef(flag = true, value = { |
| MetadataFlag.FLAG_NEED_KEY, |
| MetadataFlag.FLAG_NEED_PREF_CONTROLLER}) |
| @Retention(RetentionPolicy.SOURCE) |
| public @interface MetadataFlag { |
| int FLAG_NEED_KEY = 1; |
| int FLAG_NEED_PREF_CONTROLLER = 1 << 1; |
| } |
| |
| static final String METADATA_KEY = "key"; |
| static final String METADATA_CONTROLLER = "controller"; |
| |
| /** |
| * Extracts metadata from each preference XML and puts them into a {@link Bundle}. |
| * |
| * @param xmlResId xml res id of a preference screen |
| * @param flags one or more of {@link MetadataFlag} |
| * @return a list of Bundles containing the extracted metadata |
| */ |
| @NonNull |
| public static List<Bundle> extractMetadata(Context context, @XmlRes int xmlResId, int flags) |
| throws IOException, XmlPullParserException { |
| final List<Bundle> metadata = new ArrayList<>(); |
| if (xmlResId <= 0) { |
| LOG.d(xmlResId + " is invalid."); |
| return metadata; |
| } |
| final XmlResourceParser parser = context.getResources().getXml(xmlResId); |
| |
| int type; |
| while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && type != XmlPullParser.START_TAG) { |
| // Parse next until start tag is found |
| } |
| final int outerDepth = parser.getDepth(); |
| |
| do { |
| if (type != XmlPullParser.START_TAG) { |
| continue; |
| } |
| final String nodeName = parser.getName(); |
| if (!SUPPORTED_PREF_TYPES.contains(nodeName) && !nodeName.endsWith(PREF_TAG_ENDS_WITH) |
| && !nodeName.endsWith(PREF_GROUP_TAG_ENDS_WITH)) { |
| continue; |
| } |
| final Bundle preferenceMetadata = new Bundle(); |
| final AttributeSet attrs = Xml.asAttributeSet(parser); |
| final TypedArray preferenceAttributes = context.obtainStyledAttributes(attrs, |
| R.styleable.Preference); |
| |
| if (hasFlag(flags, MetadataFlag.FLAG_NEED_KEY)) { |
| preferenceMetadata.putString(METADATA_KEY, getKey(preferenceAttributes)); |
| } |
| if (hasFlag(flags, MetadataFlag.FLAG_NEED_PREF_CONTROLLER)) { |
| preferenceMetadata.putString(METADATA_CONTROLLER, |
| getController(preferenceAttributes)); |
| } |
| metadata.add(preferenceMetadata); |
| |
| preferenceAttributes.recycle(); |
| } while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)); |
| parser.close(); |
| |
| return metadata; |
| } |
| |
| private static boolean hasFlag(int flags, @MetadataFlag int flag) { |
| return (flags & flag) != 0; |
| } |
| |
| private static String getKey(TypedArray styledAttributes) { |
| return styledAttributes.getString(com.android.internal.R.styleable.Preference_key); |
| } |
| |
| private static String getController(TypedArray styledAttributes) { |
| return styledAttributes.getString(R.styleable.Preference_controller); |
| } |
| } |