1/*
2 * Copyright (C) 2013 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.calendar.selectcalendars;
18
19import android.content.Context;
20import android.database.Cursor;
21import android.provider.CalendarContract.Colors;
22
23import com.android.calendar.AsyncQueryService;
24
25import java.util.HashSet;
26
27/**
28 * CalendarColorCache queries the provider and stores the account identifiers (name and type)
29 * of the accounts which contain optional calendar colors, and thus should allow for the
30 * user to choose calendar colors.
31 */
32public class CalendarColorCache {
33
34    private HashSet<String> mCache = new HashSet<String>();
35
36    private static final String SEPARATOR = "::";
37
38    private AsyncQueryService mService;
39    private OnCalendarColorsLoadedListener mListener;
40
41    private StringBuffer mStringBuffer = new StringBuffer();
42
43    private static String[] PROJECTION = new String[] {Colors.ACCOUNT_NAME, Colors.ACCOUNT_TYPE };
44
45    /**
46     * Interface which provides callback after provider query of calendar colors.
47     */
48    public interface OnCalendarColorsLoadedListener {
49
50        /**
51         * Callback after the set of accounts with additional calendar colors are loaded.
52         */
53        void onCalendarColorsLoaded();
54    }
55
56    public CalendarColorCache(Context context, OnCalendarColorsLoadedListener listener) {
57        mListener = listener;
58        mService = new AsyncQueryService(context) {
59
60            @Override
61            public void onQueryComplete(int token, Object cookie, Cursor c) {
62                if (c == null) {
63                    return;
64                }
65                if (c.moveToFirst()) {
66                    clear();
67                    do {
68                        insert(c.getString(0), c.getString(1));
69                    } while (c.moveToNext());
70                    mListener.onCalendarColorsLoaded();
71                }
72                if (c != null) {
73                    c.close();
74                }
75            }
76        };
77        mService.startQuery(0, null, Colors.CONTENT_URI, PROJECTION,
78                Colors.COLOR_TYPE + "=" + Colors.TYPE_CALENDAR, null, null);
79    }
80
81    /**
82     * Inserts a specified account into the set.
83     */
84    private void insert(String accountName, String accountType) {
85        mCache.add(generateKey(accountName, accountType));
86    }
87
88    /**
89     * Does a set lookup to determine if a specified account has more optional calendar colors.
90     */
91    public boolean hasColors(String accountName, String accountType) {
92        return mCache.contains(generateKey(accountName, accountType));
93    }
94
95    /**
96     * Clears the cached set.
97     */
98    private void clear() {
99        mCache.clear();
100    }
101
102    /**
103     * Generates a single key based on account name and account type for map lookup/insertion.
104     */
105    private String generateKey(String accountName, String accountType) {
106        mStringBuffer.setLength(0);
107        return mStringBuffer.append(accountName).append(SEPARATOR).append(accountType).toString();
108    }
109}
110