https://source.android.com/ 
/*
 * Copyright (C) 2018 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.service.autofill;

import static com.android.internal.util.function.pooled.PooledLambda.obtainMessage;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.SystemApi;
import android.app.Service;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.RemoteCallback;
import android.os.RemoteException;
import android.util.Log;
import android.view.autofill.AutofillValue;

import java.util.Arrays;
import java.util.List;


A service that calculates field classification scores.

A field classification score is a float representing how well an AutofillValue filled matches a expected value predicted by an autofill service —a full match is 1.0 (representing 100%), while a full mismatch is 0.0. 
The exact score depends on the algorithm used to calculate it—the service must provide
at least one default algorithm (which is used when the algorithm is not specified or is invalid),
but it could provide more (in which case the algorithm name should be specified by the caller
when calculating the scores).
{@hide}

/**
 * A service that calculates field classification scores.
 *
 * <p>A field classification score is a {@code float} representing how well an
 * {@link AutofillValue} filled matches a expected value predicted by an autofill service
 * &mdash;a full match is {@code 1.0} (representing 100%), while a full mismatch is {@code 0.0}.
 *
 * <p>The exact score depends on the algorithm used to calculate it&mdash;the service must provide
 * at least one default algorithm (which is used when the algorithm is not specified or is invalid),
 * but it could provide more (in which case the algorithm name should be specified by the caller
 * when calculating the scores).
 *
 * {@hide}
 */
@SystemApi
public abstract class AutofillFieldClassificationService extends Service {

    private static final String TAG = "AutofillFieldClassificationService";

    
The Intent action that must be declared as handled by a service in its manifest for the system to recognize it as a quota providing service. 
/**
     * The {@link Intent} action that must be declared as handled by a service
     * in its manifest for the system to recognize it as a quota providing service.
     */
    public static final String SERVICE_INTERFACE =
            "android.service.autofill.AutofillFieldClassificationService";

    
Manifest metadata key for the resource string containing the name of the default field
classification algorithm.

/**
     * Manifest metadata key for the resource string containing the name of the default field
     * classification algorithm.
     */
    public static final String SERVICE_META_DATA_KEY_DEFAULT_ALGORITHM =
            "android.autofill.field_classification.default_algorithm";
    
Manifest metadata key for the resource string array containing the names of all field
classification algorithms provided by the service.

/**
     * Manifest metadata key for the resource string array containing the names of all field
     * classification algorithms provided by the service.
     */
    public static final String SERVICE_META_DATA_KEY_AVAILABLE_ALGORITHMS =
            "android.autofill.field_classification.available_algorithms";


    
{@hide} 
/** {@hide} **/
    public static final String EXTRA_SCORES = "scores";

    private AutofillFieldClassificationServiceWrapper mWrapper;

    private void getScores(RemoteCallback callback, String algorithmName, Bundle algorithmArgs,
            List<AutofillValue> actualValues, String[] userDataValues) {
        final Bundle data = new Bundle();
        final float[][] scores = onGetScores(algorithmName, algorithmArgs, actualValues,
                Arrays.asList(userDataValues));
        if (scores != null) {
            data.putParcelable(EXTRA_SCORES, new Scores(scores));
        }
        callback.sendResult(data);
    }

    private final Handler mHandler = new Handler(Looper.getMainLooper(), null, true);

    
@hide
/** @hide */
    public AutofillFieldClassificationService() {

    }

    @Override
    public void onCreate() {
        super.onCreate();
        mWrapper = new AutofillFieldClassificationServiceWrapper();
    }

    @Override
    public IBinder onBind(Intent intent) {
        return mWrapper;
    }

    
Calculates field classification scores in a batch.

A field classification score is a float representing how well an AutofillValue filled matches a expected value predicted by an autofill service —a full match is 1.0 (representing 100%), while a full mismatch is 0.0. 
The exact score depends on the algorithm used to calculate it—the service must
provide at least one default algorithm (which is used when the algorithm is not specified
or is invalid), but it could provide more (in which case the algorithm name should be
specified by the caller when calculating the scores).

For example, if the service provides an algorithm named EXACT_MATCH that returns 1.0 if all characters match or 0.0 otherwise, a call to: 
service.onGetScores("EXACT_MATCH", null,
  Arrays.asList(AutofillValue.forText("email1"), AutofillValue.forText("PHONE1")),
  Arrays.asList("email1", "phone1"));



Returns:

[
  [1.0, 0.0], // "email1" compared against ["email1", "phone1"]
  [0.0, 0.0]  // "PHONE1" compared against ["email1", "phone1"]
];



If the same algorithm allows the caller to specify whether the comparisons should be case sensitive by passing a boolean option named "case_sensitive", then a call to: 
Bundle algorithmOptions = new Bundle();
algorithmOptions.putBoolean("case_sensitive", false);
service.onGetScores("EXACT_MATCH", algorithmOptions,
  Arrays.asList(AutofillValue.forText("email1"), AutofillValue.forText("PHONE1")),
  Arrays.asList("email1", "phone1"));



Returns:

[
  [1.0, 0.0], // "email1" compared against ["email1", "phone1"]
  [0.0, 1.0]  // "PHONE1" compared against ["email1", "phone1"]
];



Params:
  • algorithm – name of the algorithm to be used to calculate the scores. If invalid or null, the default algorithm is used instead.
  • algorithmOptions – optional arguments to be passed to the algorithm.
  • actualValues – values entered by the user.
  • userDataValues – values predicted from the user data.
Returns:the calculated scores of actualValues x userDataValues. {@hide}
/**
     * Calculates field classification scores in a batch.
     *
     * <p>A field classification score is a {@code float} representing how well an
     * {@link AutofillValue} filled matches a expected value predicted by an autofill service
     * &mdash;a full match is {@code 1.0} (representing 100%), while a full mismatch is {@code 0.0}.
     *
     * <p>The exact score depends on the algorithm used to calculate it&mdash;the service must
     * provide at least one default algorithm (which is used when the algorithm is not specified
     * or is invalid), but it could provide more (in which case the algorithm name should be
     * specified by the caller when calculating the scores).
     *
     * <p>For example, if the service provides an algorithm named {@code EXACT_MATCH} that
     * returns {@code 1.0} if all characters match or {@code 0.0} otherwise, a call to:
     *
     * <pre>
     * service.onGetScores("EXACT_MATCH", null,
     *   Arrays.asList(AutofillValue.forText("email1"), AutofillValue.forText("PHONE1")),
     *   Arrays.asList("email1", "phone1"));
     * </pre>
     *
     * <p>Returns:
     *
     * <pre>
     * [
     *   [1.0, 0.0], // "email1" compared against ["email1", "phone1"]
     *   [0.0, 0.0]  // "PHONE1" compared against ["email1", "phone1"]
     * ];
     * </pre>
     *
     * <p>If the same algorithm allows the caller to specify whether the comparisons should be
     * case sensitive by passing a boolean option named {@code "case_sensitive"}, then a call to:
     *
     * <pre>
     * Bundle algorithmOptions = new Bundle();
     * algorithmOptions.putBoolean("case_sensitive", false);
     *
     * service.onGetScores("EXACT_MATCH", algorithmOptions,
     *   Arrays.asList(AutofillValue.forText("email1"), AutofillValue.forText("PHONE1")),
     *   Arrays.asList("email1", "phone1"));
     * </pre>
     *
     * <p>Returns:
     *
     * <pre>
     * [
     *   [1.0, 0.0], // "email1" compared against ["email1", "phone1"]
     *   [0.0, 1.0]  // "PHONE1" compared against ["email1", "phone1"]
     * ];
     * </pre>
     *
     * @param algorithm name of the algorithm to be used to calculate the scores. If invalid or
     * {@code null}, the default algorithm is used instead.
     * @param algorithmOptions optional arguments to be passed to the algorithm.
     * @param actualValues values entered by the user.
     * @param userDataValues values predicted from the user data.
     * @return the calculated scores of {@code actualValues} x {@code userDataValues}.
     *
     * {@hide}
     */
    @Nullable
    @SystemApi
    public float[][] onGetScores(@Nullable String algorithm,
            @Nullable Bundle algorithmOptions, @NonNull List<AutofillValue> actualValues,
            @NonNull List<String> userDataValues) {
        Log.e(TAG, "service implementation (" + getClass() + " does not implement onGetScore()");
        return null;
    }

    private final class AutofillFieldClassificationServiceWrapper
            extends IAutofillFieldClassificationService.Stub {
        @Override
        public void getScores(RemoteCallback callback, String algorithmName, Bundle algorithmArgs,
                List<AutofillValue> actualValues, String[] userDataValues)
                        throws RemoteException {
            mHandler.sendMessage(obtainMessage(
                    AutofillFieldClassificationService::getScores,
                    AutofillFieldClassificationService.this,
                    callback, algorithmName, algorithmArgs, actualValues, userDataValues));
        }
    }

    
Helper class used to encapsulate a float[][] in a Parcelable.
{@hide}

/**
     * Helper class used to encapsulate a float[][] in a Parcelable.
     *
     * {@hide}
     */
    public static final class Scores implements Parcelable {
        @NonNull
        public final float[][] scores;

        private Scores(Parcel parcel) {
            final int size1 = parcel.readInt();
            final int size2 = parcel.readInt();
            scores = new float[size1][size2];
            for (int i = 0; i < size1; i++) {
                for (int j = 0; j < size2; j++) {
                    scores[i][j] = parcel.readFloat();
                }
            }
        }

        private Scores(@NonNull float[][] scores) {
            this.scores = scores;
        }

        @Override
        public String toString() {
            final int size1 = scores.length;
            final int size2 = size1 > 0 ? scores[0].length : 0;
            final StringBuilder builder = new StringBuilder("Scores [")
                    .append(size1).append("x").append(size2).append("] ");
            for (int i = 0; i < size1; i++) {
                builder.append(i).append(": ").append(Arrays.toString(scores[i])).append(' ');
            }
            return builder.toString();
        }

        @Override
        public int describeContents() {
            return 0;
        }

        @Override
        public void writeToParcel(Parcel parcel, int flags) {
            int size1 = scores.length;
            int size2 = scores[0].length;
            parcel.writeInt(size1);
            parcel.writeInt(size2);
            for (int i = 0; i < size1; i++) {
                for (int j = 0; j < size2; j++) {
                    parcel.writeFloat(scores[i][j]);
                }
            }
        }

        public static final Creator<Scores> CREATOR = new Creator<Scores>() {
            @Override
            public Scores createFromParcel(Parcel parcel) {
                return new Scores(parcel);
            }

            @Override
            public Scores[] newArray(int size) {
                return new Scores[size];
            }
        };
    }
}