| /* |
| * 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.view.textclassifier; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.annotation.SystemService; |
| import android.content.Context; |
| import android.os.ParcelFileDescriptor; |
| import android.util.Log; |
| |
| import com.android.internal.util.Preconditions; |
| |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Locale; |
| |
| /** |
| * Interface to the text classification service. |
| */ |
| @SystemService(Context.TEXT_CLASSIFICATION_SERVICE) |
| public final class TextClassificationManager { |
| |
| private static final String LOG_TAG = "TextClassificationManager"; |
| |
| private final Object mTextClassifierLock = new Object(); |
| private final Object mLangIdLock = new Object(); |
| |
| private final Context mContext; |
| private ParcelFileDescriptor mLangIdFd; |
| private TextClassifier mTextClassifier; |
| private LangId mLangId; |
| |
| /** @hide */ |
| public TextClassificationManager(Context context) { |
| mContext = Preconditions.checkNotNull(context); |
| } |
| |
| /** |
| * Returns the text classifier. |
| */ |
| public TextClassifier getTextClassifier() { |
| synchronized (mTextClassifierLock) { |
| if (mTextClassifier == null) { |
| mTextClassifier = new TextClassifierImpl(mContext); |
| } |
| return mTextClassifier; |
| } |
| } |
| |
| /** |
| * Sets the text classifier. |
| * Set to null to use the system default text classifier. |
| * Set to {@link TextClassifier#NO_OP} to disable text classifier features. |
| */ |
| public void setTextClassifier(@Nullable TextClassifier textClassifier) { |
| synchronized (mTextClassifierLock) { |
| mTextClassifier = textClassifier; |
| } |
| } |
| |
| /** |
| * Returns information containing languages that were detected in the provided text. |
| * This is a blocking operation you should avoid calling it on the UI thread. |
| * |
| * @throws IllegalArgumentException if text is null |
| * @hide |
| */ |
| public List<TextLanguage> detectLanguages(@NonNull CharSequence text) { |
| Preconditions.checkArgument(text != null); |
| try { |
| if (text.length() > 0) { |
| final LangId.ClassificationResult[] results = |
| getLanguageDetector().findLanguages(text.toString()); |
| final TextLanguage.Builder tlBuilder = new TextLanguage.Builder(0, text.length()); |
| final int size = results.length; |
| for (int i = 0; i < size; i++) { |
| tlBuilder.setLanguage( |
| new Locale.Builder().setLanguageTag(results[i].mLanguage).build(), |
| results[i].mScore); |
| } |
| |
| return Collections.unmodifiableList(Arrays.asList(tlBuilder.build())); |
| } |
| } catch (Throwable t) { |
| // Avoid throwing from this method. Log the error. |
| Log.e(LOG_TAG, "Error detecting languages for text. Returning empty result.", t); |
| } |
| // Getting here means something went wrong. Return an empty result. |
| return Collections.emptyList(); |
| } |
| |
| private LangId getLanguageDetector() throws FileNotFoundException { |
| synchronized (mLangIdLock) { |
| if (mLangId == null) { |
| mLangIdFd = ParcelFileDescriptor.open( |
| new File("/etc/textclassifier/textclassifier.langid.model"), |
| ParcelFileDescriptor.MODE_READ_ONLY); |
| mLangId = new LangId(mLangIdFd.getFd()); |
| } |
| return mLangId; |
| } |
| } |
| } |