FontRequestEmojiCompatConfig.java revision a55160adc4ac7481c48512c7c146e7875a380021 
1/*
2 * Copyright (C) 2017 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 android.support.text.emoji;
18
19import android.content.Context;
20import android.graphics.Typeface;
21import android.os.Bundle;
22import android.os.ParcelFileDescriptor;
23import android.support.annotation.NonNull;
24import android.support.annotation.RequiresApi;
25import android.support.annotation.RestrictTo;
26import android.support.v4.graphics.TypefaceCompat;
27import android.support.v4.graphics.TypefaceCompat.FontRequestCallback;
28import android.support.v4.graphics.fonts.FontResult;
29import android.support.v4.os.ResultReceiver;
30import android.support.v4.provider.FontRequest;
31import android.support.v4.provider.FontsContractCompat;
32import android.support.v4.provider.FontsContractInternal;
33import android.support.v4.util.Preconditions;
34
35import java.io.FileInputStream;
36import java.io.IOException;
37import java.nio.ByteBuffer;
38import java.nio.channels.FileChannel;
39import java.util.Arrays;
40import java.util.List;
41
42/**
43 * {@link EmojiCompat.Config} implementation that asynchronously fetches the required font and the
44 * metadata using a {@link FontRequest}. FontRequest should be constructed to fetch an EmojiCompat
45 * compatible emoji font.
46 * <p/>
47 * See {@link FontsContractCompat.FontRequestCallback#onTypefaceRequestFailed(int)} for more
48 * information about the cases where the font loading can fail.
49 */
50public class FontRequestEmojiCompatConfig extends EmojiCompat.Config {
51
52    /**
53     * @param context Context instance, cannot be {@code null}
54     * @param request {@link FontRequest} to fetch the font asynchronously, cannot be {@code null}
55     */
56    public FontRequestEmojiCompatConfig(@NonNull Context context, @NonNull FontRequest request) {
57        super(new FontRequestMetadataLoader(context, request));
58    }
59
60    /**
61     * @hide
62     */
63    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
64    public FontRequestEmojiCompatConfig(@NonNull Context context, @NonNull FontRequest request,
65            @NonNull FontsContractInternal fontsContract) {
66        super(new FontRequestMetadataLoader(context, request, fontsContract));
67    }
68
69
70    /**
71     * MetadataLoader implementation that uses FontsContractInternal and TypefaceCompat to load a
72     * given FontRequest.
73     */
74    private static class FontRequestMetadataLoader implements EmojiCompat.MetadataLoader {
75        private final Context mContext;
76        private final FontRequest mRequest;
77        private final FontsContractInternal mFontsContract;
78
79        FontRequestMetadataLoader(@NonNull Context context, @NonNull FontRequest request) {
80            this(context, request, new FontsContractInternal(context));
81        }
82
83        FontRequestMetadataLoader(@NonNull Context context, @NonNull FontRequest request,
84                @NonNull FontsContractInternal fontsContract) {
85            Preconditions.checkNotNull(context, "Context cannot be null");
86            Preconditions.checkNotNull(request, "FontRequest cannot be null");
87            mContext = context.getApplicationContext();
88            mRequest = request;
89            mFontsContract = fontsContract;
90        }
91
92        @Override
93        @RequiresApi(19)
94        public void load(@NonNull final EmojiCompat.LoaderCallback loaderCallback) {
95            Preconditions.checkNotNull(loaderCallback, "LoaderCallback cannot be null");
96            final ResultReceiver receiver = new ResultReceiver(null) {
97                @Override
98                public void onReceiveResult(final int resultCode, final Bundle resultData) {
99                    receiveResult(loaderCallback, resultCode, resultData);
100                }
101            };
102            try {
103                mFontsContract.getFont(mRequest, receiver);
104            } catch (Throwable throwable) {
105                loaderCallback.onFailed(throwable);
106            }
107        }
108
109        @RequiresApi(19)
110        private void receiveResult(final EmojiCompat.LoaderCallback loaderCallback,
111                final int resultCode, final Bundle resultData) {
112            try {
113                if (resultCode != FontsContractCompat.Columns.RESULT_CODE_OK) {
114                    throwException(resultCode);
115                }
116
117                if (resultData == null) {
118                    throwException(FontRequestCallback.FAIL_REASON_FONT_NOT_FOUND);
119                }
120
121                final List<FontResult> fontResults = resultData.getParcelableArrayList(
122                        FontsContractInternal.PARCEL_FONT_RESULTS);
123                if (fontResults == null || fontResults.isEmpty()) {
124                    throwException(FontRequestCallback.FAIL_REASON_FONT_NOT_FOUND);
125                }
126
127                final InitRunnable runnable = new InitRunnable(mContext, fontResults.get(0),
128                        loaderCallback);
129                final Thread thread = new Thread(runnable);
130                thread.setDaemon(false);
131                thread.start();
132            } catch (Throwable t) {
133                loaderCallback.onFailed(t);
134            }
135        }
136    }
137
138    /**
139     * Runnable used to create the Typeface and MetadataRepo from a given FontResult.
140     */
141    @RequiresApi(19)
142    private static class InitRunnable implements Runnable {
143        private final EmojiCompat.LoaderCallback mLoaderCallback;
144        private final Context mContext;
145        private final FontResult mFontResult;
146
147        private InitRunnable(final Context context,
148                final FontResult fontResult,
149                final EmojiCompat.LoaderCallback loaderCallback) {
150            mContext = context;
151            mFontResult = fontResult;
152            mLoaderCallback = loaderCallback;
153        }
154
155        @Override
156        public void run() {
157            try {
158                final ParcelFileDescriptor dupFd = mFontResult.getFileDescriptor().dup();
159                // this one will close fd that is in mFontResult
160                final Typeface typeface = TypefaceCompat.createTypeface(mContext,
161                        Arrays.asList(mFontResult));
162                if (typeface == null) {
163                    throwException(FontRequestCallback.FAIL_REASON_FONT_LOAD_ERROR);
164                }
165                // this one will close dupFd
166                final MetadataRepo metadataRepo = createMetadataRepo(typeface, dupFd);
167                mLoaderCallback.onLoaded(metadataRepo);
168            } catch (Throwable t) {
169                mLoaderCallback.onFailed(t);
170            }
171        }
172
173        private MetadataRepo createMetadataRepo(final Typeface typeface,
174                final ParcelFileDescriptor parcelFileDescriptor) throws IOException {
175            try (ParcelFileDescriptor pfd = parcelFileDescriptor;
176                 FileInputStream inputStream = new FileInputStream(pfd.getFileDescriptor())) {
177                final FileChannel fileChannel = inputStream.getChannel();
178                final ByteBuffer buffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0,
179                        fileChannel.size());
180                final MetadataRepo metadataRepo = MetadataRepo.create(typeface, buffer);
181                return metadataRepo;
182            }
183        }
184    }
185
186    private static void throwException(int code) {
187        throw new RuntimeException("Cannot load metadata, error code:" + Integer.toString(code));
188    }
189}
190