Java tutorial
/* * Copyright (C) 2017 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 android.support.v4.provider; import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP; import android.annotation.SuppressLint; import android.content.ContentResolver; import android.content.ContentUris; import android.content.Context; import android.content.pm.PackageInfo; import android.content.pm.PackageManager; import android.content.pm.ProviderInfo; import android.content.pm.Signature; import android.content.res.Resources; import android.database.Cursor; import android.graphics.Typeface; import android.net.Uri; import android.os.Build; import android.os.CancellationSignal; import android.os.Handler; import android.os.ParcelFileDescriptor; import android.os.Process; import android.provider.BaseColumns; import android.support.annotation.GuardedBy; import android.support.annotation.IntDef; import android.support.annotation.IntRange; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.annotation.RequiresApi; import android.support.annotation.RestrictTo; import android.support.annotation.VisibleForTesting; import android.support.v4.content.res.FontResourcesParserCompat; import android.support.v4.content.res.ResourcesCompat; import android.support.v4.graphics.TypefaceCompat; import android.support.v4.graphics.TypefaceCompatUtil; import android.support.v4.provider.SelfDestructiveThread.ReplyCallback; import android.support.v4.util.LruCache; import android.support.v4.util.Preconditions; import android.support.v4.util.SimpleArrayMap; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.nio.ByteBuffer; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.concurrent.Callable; /** * Utility class to deal with Font ContentProviders. */ public class FontsContractCompat { private static final String TAG = "FontsContractCompat"; private FontsContractCompat() { } /** * Defines the constants used in a response from a Font Provider. The cursor returned from the * query should have the ID column populated with the content uri ID for the resulting font. * This should point to a real file or shared memory, as the client will mmap the given file * descriptor. Pipes, sockets and other non-mmap-able file descriptors will fail to load in the * client application. */ public static final class Columns implements BaseColumns { /** * Constant used to request data from a font provider. The cursor returned from the query * may populate this column with a long for the font file ID. The client will request a file * descriptor to "file/FILE_ID" with this ID immediately under the top-level content URI. If * not present, the client will request a file descriptor to the top-level URI with the * given base font ID. Note that several results may return the same file ID, e.g. for TTC * files with different indices. */ public static final String FILE_ID = "file_id"; /** * Constant used to request data from a font provider. The cursor returned from the query * should have this column populated with an int for the ttc index for the resulting font. */ public static final String TTC_INDEX = android.provider.FontsContract.Columns.TTC_INDEX; /** * Constant used to request data from a font provider. The cursor returned from the query * may populate this column with the font variation settings String information for the * font. */ public static final String VARIATION_SETTINGS = android.provider.FontsContract.Columns.VARIATION_SETTINGS; /** * Constant used to request data from a font provider. The cursor returned from the query * should have this column populated with the int weight for the resulting font. This value * should be between 100 and 900. The most common values are 400 for regular weight and 700 * for bold weight. */ public static final String WEIGHT = android.provider.FontsContract.Columns.WEIGHT; /** * Constant used to request data from a font provider. The cursor returned from the query * should have this column populated with the int italic for the resulting font. This should * be 0 for regular style and 1 for italic. */ public static final String ITALIC = android.provider.FontsContract.Columns.ITALIC; /** * Constant used to request data from a font provider. The cursor returned from the query * should have this column populated to indicate the result status of the * query. This will be checked before any other data in the cursor. Possible values are * {@link #RESULT_CODE_OK}, {@link #RESULT_CODE_FONT_NOT_FOUND}, * {@link #RESULT_CODE_MALFORMED_QUERY} and {@link #RESULT_CODE_FONT_UNAVAILABLE}. If not * present, {@link #RESULT_CODE_OK} will be assumed. */ public static final String RESULT_CODE = android.provider.FontsContract.Columns.RESULT_CODE; /** * Constant used to represent a result was retrieved successfully. The given fonts will be * attempted to retrieve immediately via * {@link android.content.ContentProvider#openFile(Uri, String)}. See {@link #RESULT_CODE}. */ public static final int RESULT_CODE_OK = android.provider.FontsContract.Columns.RESULT_CODE_OK; /** * Constant used to represent a result was not found. See {@link #RESULT_CODE}. */ public static final int RESULT_CODE_FONT_NOT_FOUND = android.provider.FontsContract.Columns.RESULT_CODE_FONT_NOT_FOUND; /** * Constant used to represent a result was found, but cannot be provided at this moment. Use * this to indicate, for example, that a font needs to be fetched from the network. See * {@link #RESULT_CODE}. */ public static final int RESULT_CODE_FONT_UNAVAILABLE = android.provider.FontsContract.Columns.RESULT_CODE_FONT_UNAVAILABLE; /** * Constant used to represent that the query was not in a supported format by the provider. * See {@link #RESULT_CODE}. */ public static final int RESULT_CODE_MALFORMED_QUERY = android.provider.FontsContract.Columns.RESULT_CODE_MALFORMED_QUERY; } /** * Constant used to identify the List of {@link ParcelFileDescriptor} item in the Bundle * returned to the ResultReceiver in getFont. * @hide */ @RestrictTo(LIBRARY_GROUP) public static final String PARCEL_FONT_RESULTS = "font_results"; // Error codes internal to the system, which can not come from a provider. To keep the number // space open for new provider codes, these should all be negative numbers. /** @hide */ @RestrictTo(LIBRARY_GROUP) /* package */ static final int RESULT_CODE_PROVIDER_NOT_FOUND = -1; /** @hide */ @RestrictTo(LIBRARY_GROUP) /* package */ static final int RESULT_CODE_WRONG_CERTIFICATES = -2; // Note -3 is used by FontRequestCallback to indicate the font failed to load. private static final LruCache<String, Typeface> sTypefaceCache = new LruCache<>(16); private static final int BACKGROUND_THREAD_KEEP_ALIVE_DURATION_MS = 10000; private static final SelfDestructiveThread sBackgroundThread = new SelfDestructiveThread("fonts", Process.THREAD_PRIORITY_BACKGROUND, BACKGROUND_THREAD_KEEP_ALIVE_DURATION_MS); @NonNull private static TypefaceResult getFontInternal(final Context context, final FontRequest request, int style) { FontFamilyResult result; try { result = fetchFonts(context, null /* CancellationSignal */, request); } catch (PackageManager.NameNotFoundException e) { return new TypefaceResult(null, FontRequestCallback.FAIL_REASON_PROVIDER_NOT_FOUND); } if (result.getStatusCode() == FontFamilyResult.STATUS_OK) { final Typeface typeface = TypefaceCompat.createFromFontInfo(context, null /* CancellationSignal */, result.getFonts(), style); return new TypefaceResult(typeface, typeface != null ? FontRequestCallback.RESULT_OK : FontRequestCallback.FAIL_REASON_FONT_LOAD_ERROR); } int resultCode = result.getStatusCode() == FontFamilyResult.STATUS_WRONG_CERTIFICATES ? FontRequestCallback.FAIL_REASON_WRONG_CERTIFICATES : FontRequestCallback.FAIL_REASON_FONT_LOAD_ERROR; return new TypefaceResult(null, resultCode); } private static final Object sLock = new Object(); @GuardedBy("sLock") private static final SimpleArrayMap<String, ArrayList<ReplyCallback<TypefaceResult>>> sPendingReplies = new SimpleArrayMap<>(); private static final class TypefaceResult { final Typeface mTypeface; @FontRequestCallback.FontRequestFailReason final int mResult; TypefaceResult(@Nullable Typeface typeface, @FontRequestCallback.FontRequestFailReason int result) { mTypeface = typeface; mResult = result; } } /** * Used for tests, should not be used otherwise. * @hide **/ @RestrictTo(LIBRARY_GROUP) public static final void resetCache() { sTypefaceCache.evictAll(); } /** @hide */ @RestrictTo(LIBRARY_GROUP) public static Typeface getFontSync(final Context context, final FontRequest request, final @Nullable ResourcesCompat.FontCallback fontCallback, final @Nullable Handler handler, boolean isBlockingFetch, int timeout, final int style) { final String id = request.getIdentifier() + "-" + style; Typeface cached = sTypefaceCache.get(id); if (cached != null) { if (fontCallback != null) { fontCallback.onFontRetrieved(cached); } return cached; } if (isBlockingFetch && timeout == FontResourcesParserCompat.INFINITE_TIMEOUT_VALUE) { // Wait forever. No need to post to the thread. TypefaceResult typefaceResult = getFontInternal(context, request, style); if (fontCallback != null) { if (typefaceResult.mResult == FontFamilyResult.STATUS_OK) { fontCallback.callbackSuccessAsync(typefaceResult.mTypeface, handler); } else { fontCallback.callbackFailAsync(typefaceResult.mResult, handler); } } return typefaceResult.mTypeface; } final Callable<TypefaceResult> fetcher = new Callable<TypefaceResult>() { @Override public TypefaceResult call() throws Exception { TypefaceResult typeface = getFontInternal(context, request, style); if (typeface.mTypeface != null) { sTypefaceCache.put(id, typeface.mTypeface); } return typeface; } }; if (isBlockingFetch) { try { return sBackgroundThread.postAndWait(fetcher, timeout).mTypeface; } catch (InterruptedException e) { return null; } } else { final ReplyCallback<TypefaceResult> reply = fontCallback == null ? null : new ReplyCallback<TypefaceResult>() { @Override public void onReply(final TypefaceResult typeface) { if (typeface.mResult == FontFamilyResult.STATUS_OK) { fontCallback.callbackSuccessAsync(typeface.mTypeface, handler); } else { fontCallback.callbackFailAsync(typeface.mResult, handler); } } }; synchronized (sLock) { if (sPendingReplies.containsKey(id)) { // Already requested. Do not request the same provider again and insert the // reply to the queue instead. if (reply != null) { sPendingReplies.get(id).add(reply); } return null; } if (reply != null) { ArrayList<ReplyCallback<TypefaceResult>> pendingReplies = new ArrayList<>(); pendingReplies.add(reply); sPendingReplies.put(id, pendingReplies); } } sBackgroundThread.postAndReply(fetcher, new ReplyCallback<TypefaceResult>() { @Override public void onReply(final TypefaceResult typeface) { final ArrayList<ReplyCallback<TypefaceResult>> replies; synchronized (sLock) { replies = sPendingReplies.get(id); if (replies == null) { return; // Nobody requested replies. Do nothing. } sPendingReplies.remove(id); } for (int i = 0; i < replies.size(); ++i) { replies.get(i).onReply(typeface); } } }); return null; } } /** * Object represent a font entry in the family returned from {@link #fetchFonts}. */ public static class FontInfo { private final Uri mUri; private final int mTtcIndex; private final int mWeight; private final boolean mItalic; private final int mResultCode; /** * Creates a Font with all the information needed about a provided font. * @param uri A URI associated to the font file. * @param ttcIndex If providing a TTC_INDEX file, the index to point to. Otherwise, 0. * @param weight An integer that indicates the font weight. * @param italic A boolean that indicates the font is italic style or not. * @param resultCode A boolean that indicates the font contents is ready. * * @hide */ @RestrictTo(LIBRARY_GROUP) public FontInfo(@NonNull Uri uri, @IntRange(from = 0) int ttcIndex, @IntRange(from = 1, to = 1000) int weight, boolean italic, int resultCode) { mUri = Preconditions.checkNotNull(uri); mTtcIndex = ttcIndex; mWeight = weight; mItalic = italic; mResultCode = resultCode; } /** * Returns a URI associated to this record. */ public @NonNull Uri getUri() { return mUri; } /** * Returns the index to be used to access this font when accessing a TTC file. */ public @IntRange(from = 0) int getTtcIndex() { return mTtcIndex; } /** * Returns the weight value for this font. */ public @IntRange(from = 1, to = 1000) int getWeight() { return mWeight; } /** * Returns whether this font is italic. */ public boolean isItalic() { return mItalic; } /** * Returns result code. * * {@link FontsContractCompat.Columns#RESULT_CODE} */ public int getResultCode() { return mResultCode; } } /** * Object returned from {@link #fetchFonts}. */ public static class FontFamilyResult { /** * Constant represents that the font was successfully retrieved. Note that when this value * is set and {@link #getFonts} returns an empty array, it means there were no fonts * matching the given query. */ public static final int STATUS_OK = 0; /** * Constant represents that the given certificate was not matched with the provider's * signature. {@link #getFonts} returns null if this status was set. */ public static final int STATUS_WRONG_CERTIFICATES = 1; /** * Constant represents that the provider returns unexpected data. {@link #getFonts} returns * null if this status was set. For example, this value is set when the font provider * gives invalid format of variation settings. */ public static final int STATUS_UNEXPECTED_DATA_PROVIDED = 2; /** @hide */ @RestrictTo(LIBRARY_GROUP) @IntDef({ STATUS_OK, STATUS_WRONG_CERTIFICATES, STATUS_UNEXPECTED_DATA_PROVIDED }) @Retention(RetentionPolicy.SOURCE) @interface FontResultStatus { } private final @FontResultStatus int mStatusCode; private final FontInfo[] mFonts; /** @hide */ @RestrictTo(LIBRARY_GROUP) public FontFamilyResult(@FontResultStatus int statusCode, @Nullable FontInfo[] fonts) { mStatusCode = statusCode; mFonts = fonts; } public @FontResultStatus int getStatusCode() { return mStatusCode; } public FontInfo[] getFonts() { return mFonts; } } /** * Interface used to receive asynchronously fetched typefaces. */ public static class FontRequestCallback { /** @hide */ @RestrictTo(LIBRARY_GROUP) public static final int RESULT_OK = Columns.RESULT_CODE_OK; /** * Constant returned by {@link #onTypefaceRequestFailed(int)} signaling that the given * provider was not found on the device. */ public static final int FAIL_REASON_PROVIDER_NOT_FOUND = RESULT_CODE_PROVIDER_NOT_FOUND; /** * Constant returned by {@link #onTypefaceRequestFailed(int)} signaling that the given * provider must be authenticated and the given certificates do not match its signature. */ public static final int FAIL_REASON_WRONG_CERTIFICATES = RESULT_CODE_WRONG_CERTIFICATES; /** * Constant returned by {@link #onTypefaceRequestFailed(int)} signaling that the font * returned by the provider was not loaded properly. */ public static final int FAIL_REASON_FONT_LOAD_ERROR = -3; /** * Constant that signals that the font was not loaded due to security issues. This usually * means the font was attempted to load on a restricted context. */ public static final int FAIL_REASON_SECURITY_VIOLATION = -4; /** * Constant returned by {@link #onTypefaceRequestFailed(int)} signaling that the font * provider did not return any results for the given query. */ public static final int FAIL_REASON_FONT_NOT_FOUND = Columns.RESULT_CODE_FONT_NOT_FOUND; /** * Constant returned by {@link #onTypefaceRequestFailed(int)} signaling that the font * provider found the queried font, but it is currently unavailable. */ public static final int FAIL_REASON_FONT_UNAVAILABLE = Columns.RESULT_CODE_FONT_UNAVAILABLE; /** * Constant returned by {@link #onTypefaceRequestFailed(int)} signaling that the given * query was not supported by the provider. */ public static final int FAIL_REASON_MALFORMED_QUERY = Columns.RESULT_CODE_MALFORMED_QUERY; /** @hide */ @RestrictTo(LIBRARY_GROUP) @IntDef({ FAIL_REASON_PROVIDER_NOT_FOUND, FAIL_REASON_FONT_LOAD_ERROR, FAIL_REASON_FONT_NOT_FOUND, FAIL_REASON_FONT_UNAVAILABLE, FAIL_REASON_MALFORMED_QUERY, FAIL_REASON_WRONG_CERTIFICATES, FAIL_REASON_SECURITY_VIOLATION, RESULT_OK }) @Retention(RetentionPolicy.SOURCE) public @interface FontRequestFailReason { } public FontRequestCallback() { } /** * Called then a Typeface request done via {@link #requestFont(Context, FontRequest, * FontRequestCallback, Handler)} is complete. Note that this method will not be called if * {@link #onTypefaceRequestFailed(int)} is called instead. * @param typeface The Typeface object retrieved. */ public void onTypefaceRetrieved(Typeface typeface) { } /** * Called when a Typeface request done via {@link #requestFont(Context, FontRequest, * FontRequestCallback, Handler)} fails. * @param reason May be one of {@link #FAIL_REASON_PROVIDER_NOT_FOUND}, * {@link #FAIL_REASON_FONT_NOT_FOUND}, * {@link #FAIL_REASON_FONT_LOAD_ERROR}, * {@link #FAIL_REASON_FONT_UNAVAILABLE}, * {@link #FAIL_REASON_MALFORMED_QUERY} or * {@link #FAIL_REASON_WRONG_CERTIFICATES}, or a provider defined positive * code number. */ public void onTypefaceRequestFailed(@FontRequestFailReason int reason) { } } /** * Create a typeface object given a font request. The font will be asynchronously fetched, * therefore the result is delivered to the given callback. See {@link FontRequest}. * Only one of the methods in callback will be invoked, depending on whether the request * succeeds or fails. These calls will happen on the caller thread. * @param context A context to be used for fetching from font provider. * @param request A {@link FontRequest} object that identifies the provider and query for the * request. May not be null. * @param callback A callback that will be triggered when results are obtained. May not be null. * @param handler A handler to be processed the font fetching. */ public static void requestFont(final @NonNull Context context, final @NonNull FontRequest request, final @NonNull FontRequestCallback callback, final @NonNull Handler handler) { final Handler callerThreadHandler = new Handler(); handler.post(new Runnable() { @Override public void run() { // TODO: Cache the result. FontFamilyResult result; try { result = fetchFonts(context, null /* cancellation signal */, request); } catch (PackageManager.NameNotFoundException e) { callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed(FontRequestCallback.FAIL_REASON_PROVIDER_NOT_FOUND); } }); return; } if (result.getStatusCode() != FontFamilyResult.STATUS_OK) { switch (result.getStatusCode()) { case FontFamilyResult.STATUS_WRONG_CERTIFICATES: callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed( FontRequestCallback.FAIL_REASON_WRONG_CERTIFICATES); } }); return; case FontFamilyResult.STATUS_UNEXPECTED_DATA_PROVIDED: callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed(FontRequestCallback.FAIL_REASON_FONT_LOAD_ERROR); } }); return; default: // fetchFont returns unexpected status type. Fallback to load error. callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed(FontRequestCallback.FAIL_REASON_FONT_LOAD_ERROR); } }); return; } } final FontInfo[] fonts = result.getFonts(); if (fonts == null || fonts.length == 0) { callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed(FontRequestCallback.FAIL_REASON_FONT_NOT_FOUND); } }); return; } for (final FontInfo font : fonts) { if (font.getResultCode() != Columns.RESULT_CODE_OK) { // We proceed if all font entry is ready to use. Otherwise report the first // error. final int resultCode = font.getResultCode(); if (resultCode < 0) { // Negative values are reserved for internal errors. Fallback to load // error. callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed( FontRequestCallback.FAIL_REASON_FONT_LOAD_ERROR); } }); } else { callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed(resultCode); } }); } return; } } final Typeface typeface = buildTypeface(context, null /* cancellation signal */, fonts); if (typeface == null) { // Something went wrong during reading font files. This happens if the given // font file is an unsupported font type. callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRequestFailed(FontRequestCallback.FAIL_REASON_FONT_LOAD_ERROR); } }); return; } callerThreadHandler.post(new Runnable() { @Override public void run() { callback.onTypefaceRetrieved(typeface); } }); } }); } /** * Build a Typeface from an array of {@link FontInfo} * * Results that are marked as not ready will be skipped. * * @param context A {@link Context} that will be used to fetch the font contents. * @param cancellationSignal A signal to cancel the operation in progress, or null if none. If * the operation is canceled, then {@link * android.os.OperationCanceledException} will be thrown. * @param fonts An array of {@link FontInfo} to be used to create a Typeface. * @return A Typeface object. Returns null if typeface creation fails. */ @Nullable public static Typeface buildTypeface(@NonNull Context context, @Nullable CancellationSignal cancellationSignal, @NonNull FontInfo[] fonts) { return TypefaceCompat.createFromFontInfo(context, cancellationSignal, fonts, Typeface.NORMAL); } /** * A helper function to create a mapping from {@link Uri} to {@link ByteBuffer}. * * Skip if the file contents is not ready to be read. * * @param context A {@link Context} to be used for resolving content URI in * {@link FontInfo}. * @param fonts An array of {@link FontInfo}. * @return A map from {@link Uri} to {@link ByteBuffer}. * @hide */ @RestrictTo(LIBRARY_GROUP) @RequiresApi(19) public static Map<Uri, ByteBuffer> prepareFontData(Context context, FontInfo[] fonts, CancellationSignal cancellationSignal) { final HashMap<Uri, ByteBuffer> out = new HashMap<>(); for (FontInfo font : fonts) { if (font.getResultCode() != Columns.RESULT_CODE_OK) { continue; } final Uri uri = font.getUri(); if (out.containsKey(uri)) { continue; } ByteBuffer buffer = TypefaceCompatUtil.mmap(context, cancellationSignal, uri); out.put(uri, buffer); } return Collections.unmodifiableMap(out); } /** * Fetch fonts given a font request. * * @param context A {@link Context} to be used for fetching fonts. * @param cancellationSignal A signal to cancel the operation in progress, or null if none. If * the operation is canceled, then {@link * android.os.OperationCanceledException} will be thrown when the * query is executed. * @param request A {@link FontRequest} object that identifies the provider and query for the * request. * * @return {@link FontFamilyResult} * * @throws PackageManager.NameNotFoundException If requested package or authority was not found * in the system. */ @NonNull public static FontFamilyResult fetchFonts(@NonNull Context context, @Nullable CancellationSignal cancellationSignal, @NonNull FontRequest request) throws PackageManager.NameNotFoundException { ProviderInfo providerInfo = getProvider(context.getPackageManager(), request, context.getResources()); if (providerInfo == null) { return new FontFamilyResult(FontFamilyResult.STATUS_WRONG_CERTIFICATES, null); } FontInfo[] fonts = getFontFromProvider(context, request, providerInfo.authority, cancellationSignal); return new FontFamilyResult(FontFamilyResult.STATUS_OK, fonts); } /** @hide */ @VisibleForTesting @RestrictTo(LIBRARY_GROUP) public static @Nullable ProviderInfo getProvider(@NonNull PackageManager packageManager, @NonNull FontRequest request, @Nullable Resources resources) throws PackageManager.NameNotFoundException { String providerAuthority = request.getProviderAuthority(); ProviderInfo info = packageManager.resolveContentProvider(providerAuthority, 0); if (info == null) { throw new PackageManager.NameNotFoundException("No package found for authority: " + providerAuthority); } if (!info.packageName.equals(request.getProviderPackage())) { throw new PackageManager.NameNotFoundException("Found content provider " + providerAuthority + ", but package was not " + request.getProviderPackage()); } List<byte[]> signatures; // We correctly check all signatures returned, as advised in the lint error. @SuppressLint("PackageManagerGetSignatures") PackageInfo packageInfo = packageManager.getPackageInfo(info.packageName, PackageManager.GET_SIGNATURES); signatures = convertToByteArrayList(packageInfo.signatures); Collections.sort(signatures, sByteArrayComparator); List<List<byte[]>> requestCertificatesList = getCertificates(request, resources); for (int i = 0; i < requestCertificatesList.size(); ++i) { // Make a copy so we can sort it without modifying the incoming data. List<byte[]> requestSignatures = new ArrayList<>(requestCertificatesList.get(i)); Collections.sort(requestSignatures, sByteArrayComparator); if (equalsByteArrayList(signatures, requestSignatures)) { return info; } } return null; } private static List<List<byte[]>> getCertificates(FontRequest request, Resources resources) { if (request.getCertificates() != null) { return request.getCertificates(); } int resourceId = request.getCertificatesArrayResId(); return FontResourcesParserCompat.readCerts(resources, resourceId); } private static final Comparator<byte[]> sByteArrayComparator = new Comparator<byte[]>() { @Override public int compare(byte[] l, byte[] r) { if (l.length != r.length) { return l.length - r.length; } for (int i = 0; i < l.length; ++i) { if (l[i] != r[i]) { return l[i] - r[i]; } } return 0; } }; private static boolean equalsByteArrayList(List<byte[]> signatures, List<byte[]> requestSignatures) { if (signatures.size() != requestSignatures.size()) { return false; } for (int i = 0; i < signatures.size(); ++i) { if (!Arrays.equals(signatures.get(i), requestSignatures.get(i))) { return false; } } return true; } private static List<byte[]> convertToByteArrayList(Signature[] signatures) { List<byte[]> shas = new ArrayList<>(); for (int i = 0; i < signatures.length; ++i) { shas.add(signatures[i].toByteArray()); } return shas; } @VisibleForTesting @NonNull static FontInfo[] getFontFromProvider(Context context, FontRequest request, String authority, CancellationSignal cancellationSignal) { ArrayList<FontInfo> result = new ArrayList<>(); final Uri uri = new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority).build(); final Uri fileBaseUri = new Uri.Builder().scheme(ContentResolver.SCHEME_CONTENT).authority(authority) .appendPath("file").build(); Cursor cursor = null; try { if (Build.VERSION.SDK_INT > 16) { cursor = context.getContentResolver().query(uri, new String[] { Columns._ID, Columns.FILE_ID, Columns.TTC_INDEX, Columns.VARIATION_SETTINGS, Columns.WEIGHT, Columns.ITALIC, Columns.RESULT_CODE }, "query = ?", new String[] { request.getQuery() }, null, cancellationSignal); } else { // No cancellation signal. cursor = context.getContentResolver().query(uri, new String[] { Columns._ID, Columns.FILE_ID, Columns.TTC_INDEX, Columns.VARIATION_SETTINGS, Columns.WEIGHT, Columns.ITALIC, Columns.RESULT_CODE }, "query = ?", new String[] { request.getQuery() }, null); } if (cursor != null && cursor.getCount() > 0) { final int resultCodeColumnIndex = cursor.getColumnIndex(Columns.RESULT_CODE); result = new ArrayList<>(); final int idColumnIndex = cursor.getColumnIndex(Columns._ID); final int fileIdColumnIndex = cursor.getColumnIndex(Columns.FILE_ID); final int ttcIndexColumnIndex = cursor.getColumnIndex(Columns.TTC_INDEX); final int weightColumnIndex = cursor.getColumnIndex(Columns.WEIGHT); final int italicColumnIndex = cursor.getColumnIndex(Columns.ITALIC); while (cursor.moveToNext()) { int resultCode = resultCodeColumnIndex != -1 ? cursor.getInt(resultCodeColumnIndex) : Columns.RESULT_CODE_OK; final int ttcIndex = ttcIndexColumnIndex != -1 ? cursor.getInt(ttcIndexColumnIndex) : 0; Uri fileUri; if (fileIdColumnIndex == -1) { long id = cursor.getLong(idColumnIndex); fileUri = ContentUris.withAppendedId(uri, id); } else { long id = cursor.getLong(fileIdColumnIndex); fileUri = ContentUris.withAppendedId(fileBaseUri, id); } int weight = weightColumnIndex != -1 ? cursor.getInt(weightColumnIndex) : 400; boolean italic = italicColumnIndex != -1 && cursor.getInt(italicColumnIndex) == 1; result.add(new FontInfo(fileUri, ttcIndex, weight, italic, resultCode)); } } } finally { if (cursor != null) { cursor.close(); } } return result.toArray(new FontInfo[0]); } }