1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License
15 */
16
17package com.android.providers.contacts;
18
19import android.accounts.AccountManager;
20import android.accounts.AuthenticatorDescription;
21import android.content.Context;
22import android.content.pm.PackageInfo;
23import android.content.pm.PackageManager;
24import android.content.pm.PackageManager.NameNotFoundException;
25import android.content.pm.ServiceInfo;
26import android.content.res.XmlResourceParser;
27import android.util.Log;
28
29import com.android.internal.util.XmlUtils;
30import com.google.android.collect.Maps;
31
32import org.xmlpull.v1.XmlPullParser;
33import org.xmlpull.v1.XmlPullParserException;
34
35import java.io.IOException;
36import java.util.HashMap;
37
38/**
39 * Maintains a cache of photo priority per account type.  During contact aggregation
40 * photo with a higher priority is chosen for the the entire contact, barring an
41 * explicit override by the user, which is captured as the is_superprimary flag
42 * on the photo itself.
43 */
44public class PhotoPriorityResolver  {
45    private static final String TAG = "PhotoPriorityResolver";
46
47    public static final int DEFAULT_PRIORITY = 7;
48
49    /**
50     * Meta-data key for the contacts configuration associated with a sync service.
51     */
52    private static final String METADATA_CONTACTS = "android.provider.CONTACTS_STRUCTURE";
53
54    /**
55     * The XML tag capturing the picture priority. The syntax is:
56     * <code>&lt;Picture android:priority="6"/&gt;</code>
57     */
58    private static final String PICTURE_TAG = "Picture";
59
60    /**
61     * Name of the attribute of the Picture tag capturing the priority itself.
62     */
63    private static final String PRIORITY_ATTR = "priority";
64
65    private Context mContext;
66    private HashMap<String, Integer> mPhotoPriorities = Maps.newHashMap();
67
68    public PhotoPriorityResolver(Context context) {
69        mContext = context;
70    }
71
72    /**
73     * Returns the photo priority for the specified account type.  Maintains cache
74     * of photo priorities.
75     */
76    public synchronized int getPhotoPriority(String accountType) {
77        if (accountType == null) {
78            return DEFAULT_PRIORITY;
79        }
80
81        Integer priority = mPhotoPriorities.get(accountType);
82        if (priority == null) {
83            priority = resolvePhotoPriority(accountType);
84            mPhotoPriorities.put(accountType, priority);
85        }
86        return priority;
87     }
88
89    /**
90     * Finds photo priority for the specified account type.
91     */
92    private int resolvePhotoPriority(String accountType) {
93        final AccountManager am = AccountManager.get(mContext);
94
95        for (AuthenticatorDescription auth : am.getAuthenticatorTypes()) {
96            if (accountType.equals(auth.type)) {
97                return resolvePhotoPriorityFromMetaData(auth.packageName);
98            }
99        }
100
101        return DEFAULT_PRIORITY;
102    }
103
104    /**
105     * Finds the meta-data XML containing the contacts configuration and
106     * reads the picture priority from that file.
107     */
108    /* package */ int resolvePhotoPriorityFromMetaData(String packageName) {
109        final PackageManager pm = mContext.getPackageManager();
110        try {
111            PackageInfo pi = pm.getPackageInfo(packageName, PackageManager.GET_SERVICES
112                    | PackageManager.GET_META_DATA);
113            if (pi != null && pi.services != null) {
114                for (ServiceInfo si : pi.services) {
115                    final XmlResourceParser parser = si.loadXmlMetaData(pm, METADATA_CONTACTS);
116                    if (parser != null) {
117                        return loadPhotoPriorityFromXml(mContext, parser);
118                    }
119                }
120            }
121        } catch (NameNotFoundException e) {
122            Log.w(TAG, "Problem loading photo priorities: " + e.toString());
123        }
124        return DEFAULT_PRIORITY;
125    }
126
127    private int loadPhotoPriorityFromXml(Context context, XmlPullParser parser) {
128        int priority = DEFAULT_PRIORITY;
129        try {
130            int type;
131            while ((type = parser.next()) != XmlPullParser.START_TAG
132                    && type != XmlPullParser.END_DOCUMENT) {
133                // Drain comments and whitespace
134            }
135
136            if (type != XmlPullParser.START_TAG) {
137                throw new IllegalStateException("No start tag found");
138            }
139
140            final int depth = parser.getDepth();
141            while (((type = parser.next()) != XmlPullParser.END_TAG || parser.getDepth() > depth)
142                    && type != XmlPullParser.END_DOCUMENT) {
143                String name = parser.getName();
144                if (type == XmlPullParser.START_TAG && PICTURE_TAG.equals(name)) {
145                    int attributeCount = parser.getAttributeCount();
146                    for (int i = 0; i < attributeCount; i++) {
147                        String attr = parser.getAttributeName(i);
148                        if (PRIORITY_ATTR.equals(attr)) {
149                            priority = XmlUtils.convertValueToInt(parser.getAttributeValue(i),
150                                    DEFAULT_PRIORITY);
151                        } else {
152                            throw new IllegalStateException("Unsupported attribute " + attr);
153                        }
154                    }
155                }
156            }
157        } catch (XmlPullParserException e) {
158            throw new IllegalStateException("Problem reading XML", e);
159        } catch (IOException e) {
160            throw new IllegalStateException("Problem reading XML", e);
161        }
162
163        return priority;
164    }
165}
166