core/java/android/service/autofill/Dataset.java - platform/frameworks/base - Gitiles

 /*
  * Copyright (C) 2016 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 android.view.autofill.Helper.sDebug;

 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.IntentSender;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.view.autofill.AutofillId;
 import android.view.autofill.AutofillValue;
 import android.widget.RemoteViews;

 import com.android.internal.util.Preconditions;

 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.regex.Pattern;

 /**
  * A dataset object represents a group of fields (key / value pairs) used to autofill parts of a
  * screen.
  *
  * <a name="BasicUsage"></a>
  * <h3>Basic usage</h3>
  *
  * <p>In its simplest form, a dataset contains one or more fields (comprised of
  * an {@link AutofillId id}, a {@link AutofillValue value}, and an optional filter
  * {@link Pattern regex}); and one or more {@link RemoteViews presentations} for these fields
  * (each field could have its own {@link RemoteViews presentation}, or use the default
  * {@link RemoteViews presentation} associated with the whole dataset).
  *
  * <p>When an autofill service returns datasets in a {@link FillResponse}
  * and the screen input is focused in a view that is present in at least one of these datasets,
  * the Android System displays a UI containing the {@link RemoteViews presentation} of
  * all datasets pairs that have that view's {@link AutofillId}. Then, when the user selects a
  * dataset from the UI, all views in that dataset are autofilled.
  *
  * <a name="Authentication"></a>
  * <h3>Dataset authentication</h3>
  *
  * <p>In a more sophisticated form, the dataset values can be protected until the user authenticates
  * the dataset&mdash;in that case, when a dataset is selected by the user, the Android System
  * launches an intent set by the service to "unlock" the dataset.
  *
  * <p>For example, when a data set contains credit card information (such as number,
  * expiration date, and verification code), you could provide a dataset presentation saying
  * "Tap to authenticate". Then when the user taps that option, you would launch an activity asking
  * the user to enter the credit card code, and if the user enters a valid code, you could then
  * "unlock" the dataset.
  *
  * <p>You can also use authenticated datasets to offer an interactive UI for the user. For example,
  * if the activity being autofilled is an account creation screen, you could use an authenticated
  * dataset to automatically generate a random password for the user.
  *
  * <p>See {@link Dataset.Builder#setAuthentication(IntentSender)} for more details about the dataset
  * authentication mechanism.
  *
  * <a name="Filtering"></a>
  * <h3>Filtering</h3>
  * <p>The autofill UI automatically changes which values are shown based on value of the view
  * anchoring it, following the rules below:
  * <ol>
  *   <li>If the view's {@link android.view.View#getAutofillValue() autofill value} is not
  * {@link AutofillValue#isText() text} or is empty, all datasets are shown.
  *   <li>Datasets that have a filter regex (set through
  * {@link Dataset.Builder#setValue(AutofillId, AutofillValue, Pattern)} or
  * {@link Dataset.Builder#setValue(AutofillId, AutofillValue, Pattern, RemoteViews)}) and whose
  * regex matches the view's text value converted to lower case are shown.
  *   <li>Datasets that do not require authentication, have a field value that is
  * {@link AutofillValue#isText() text} and whose {@link AutofillValue#getTextValue() value} starts
  * with the lower case value of the view's text are shown.
  *   <li>All other datasets are hidden.
  * </ol>
  *
  * <a name="MoreInfo"></a>
  * <h3>More information</h3>
  * <p>See {@link android.service.autofill.AutofillService} for more information and examples about
  * the role of datasets in the autofill workflow.
  */
 public final class Dataset implements Parcelable {

     private final ArrayList<AutofillId> mFieldIds;
     private final ArrayList<AutofillValue> mFieldValues;
     private final ArrayList<RemoteViews> mFieldPresentations;
     private final ArrayList<Pattern> mFieldFilters;
     private final RemoteViews mPresentation;
     private final IntentSender mAuthentication;
     @Nullable String mId;

     private Dataset(Builder builder) {
         mFieldIds = builder.mFieldIds;
         mFieldValues = builder.mFieldValues;
         mFieldPresentations = builder.mFieldPresentations;
         mFieldFilters = builder.mFieldFilters;
         mPresentation = builder.mPresentation;
         mAuthentication = builder.mAuthentication;
         mId = builder.mId;
     }

     /** @hide */
     public @Nullable ArrayList<AutofillId> getFieldIds() {
         return mFieldIds;
     }

     /** @hide */
     public @Nullable ArrayList<AutofillValue> getFieldValues() {
         return mFieldValues;
     }

     /** @hide */
     public RemoteViews getFieldPresentation(int index) {
         final RemoteViews customPresentation = mFieldPresentations.get(index);
         return customPresentation != null ? customPresentation : mPresentation;
     }

     /** @hide */
     @Nullable
     public Pattern getFilter(int index) {
         return mFieldFilters.get(index);
     }

     /** @hide */
     public @Nullable IntentSender getAuthentication() {
         return mAuthentication;
     }

     /** @hide */
     public boolean isEmpty() {
         return mFieldIds == null || mFieldIds.isEmpty();
     }

     @Override
     public String toString() {
         if (!sDebug) return super.toString();

         return new StringBuilder("Dataset " + mId + " [")
                 .append("fieldIds=").append(mFieldIds)
                 .append(", fieldValues=").append(mFieldValues)
                 .append(", fieldPresentations=")
                 .append(mFieldPresentations == null ? 0 : mFieldPresentations.size())
                 .append(", fieldFilters=")
                 .append(mFieldFilters == null ? 0 : mFieldFilters.size())
                 .append(", hasPresentation=").append(mPresentation != null)
                 .append(", hasAuthentication=").append(mAuthentication != null)
                 .append(']').toString();
     }

     /**
      * Gets the id of this dataset.
      *
      * @return The id of this dataset or {@code null} if not set
      *
      * @hide
      */
     public String getId() {
         return mId;
     }

     /**
      * A builder for {@link Dataset} objects. You must provide at least
      * one value for a field or set an authentication intent.
      */
     public static final class Builder {
         private ArrayList<AutofillId> mFieldIds;
         private ArrayList<AutofillValue> mFieldValues;
         private ArrayList<RemoteViews> mFieldPresentations;
         private ArrayList<Pattern> mFieldFilters;
         private RemoteViews mPresentation;
         private IntentSender mAuthentication;
         private boolean mDestroyed;
         @Nullable private String mId;

         /**
          * Creates a new builder.
          *
          * @param presentation The presentation used to visualize this dataset.
          */
         public Builder(@NonNull RemoteViews presentation) {
             Preconditions.checkNotNull(presentation, "presentation must be non-null");
             mPresentation = presentation;
         }

         /**
          * Creates a new builder for a dataset where each field will be visualized independently.
          *
          * <p>When using this constructor, fields must be set through
          * {@link #setValue(AutofillId, AutofillValue, RemoteViews)}.
          */
         public Builder() {
         }

         /**
          * Requires a dataset authentication before autofilling the activity with this dataset.
          *
          * <p>This method is called when you need to provide an authentication
          * UI for the data set. For example, when a data set contains credit card information
          * (such as number, expiration date, and verification code), you can display UI
          * asking for the verification code before filing in the data. Even if the
          * data set is completely populated the system will launch the specified authentication
          * intent and will need your approval to fill it in. Since the data set is "locked"
          * until the user authenticates it, typically this data set name is masked
          * (for example, "VISA....1234"). Typically you would want to store the data set
          * labels non-encrypted and the actual sensitive data encrypted and not in memory.
          * This allows showing the labels in the UI while involving the user if one of
          * the items with these labels is chosen. Note that if you use sensitive data as
          * a label, for example an email address, then it should also be encrypted.</p>
          *
          * <p>When a user triggers autofill, the system launches the provided intent
          * whose extras will have the {@link
          * android.view.autofill.AutofillManager#EXTRA_ASSIST_STRUCTURE screen content},
          * and your {@link android.view.autofill.AutofillManager#EXTRA_CLIENT_STATE client
          * state}. Once you complete your authentication flow you should set the activity
          * result to {@link android.app.Activity#RESULT_OK} and provide the fully populated
          * {@link Dataset dataset} or a fully-populated {@link FillResponse response} by
          * setting it to the {@link
          * android.view.autofill.AutofillManager#EXTRA_AUTHENTICATION_RESULT} extra. If you
          * provide a dataset in the result, it will replace the authenticated dataset and
          * will be immediately filled in. If you provide a response, it will replace the
          * current response and the UI will be refreshed. For example, if you provided
          * credit card information without the CVV for the data set in the {@link FillResponse
          * response} then the returned data set should contain the CVV entry.
          *
          * <p><b>Note:</b> Do not make the provided pending intent
          * immutable by using {@link android.app.PendingIntent#FLAG_IMMUTABLE} as the
          * platform needs to fill in the authentication arguments.
          *
          * @param authentication Intent to an activity with your authentication flow.
          * @return this builder.
          *
          * @see android.app.PendingIntent
          */
         public @NonNull Builder setAuthentication(@Nullable IntentSender authentication) {
             throwIfDestroyed();
             mAuthentication = authentication;
             return this;
         }

         /**
          * Sets the id for the dataset so its usage can be tracked.
          *
          * <p>Dataset usage can be tracked for 2 purposes:
          *
          * <ul>
          *   <li>For statistical purposes, the service can call
          * {@link AutofillService#getFillEventHistory()} when handling {@link
          * AutofillService#onFillRequest(FillRequest, android.os.CancellationSignal, FillCallback)}
          * calls.
          *   <li>For normal autofill workflow, the service can call
          *   {@link SaveRequest#getDatasetIds()} when handling
          *   {@link AutofillService#onSaveRequest(SaveRequest, SaveCallback)} calls.
          * </ul>
          *
          * @param id id for this dataset or {@code null} to unset.
          *
          * @return this builder.
          */
         public @NonNull Builder setId(@Nullable String id) {
             throwIfDestroyed();
             mId = id;
             return this;
         }

         /**
          * Sets the value of a field.
          *
          * @param id id returned by {@link
          *         android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
          * @param value value to be autofilled. Pass {@code null} if you do not have the value
          *        but the target view is a logical part of the dataset. For example, if
          *        the dataset needs authentication and you have no access to the value.
          * @return this builder.
          * @throws IllegalStateException if the builder was constructed without a
          * {@link RemoteViews presentation}.
          */
         public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value) {
             throwIfDestroyed();
             Preconditions.checkState(mPresentation != null,
                     "Dataset presentation not set on constructor");
             setLifeTheUniverseAndEverything(id, value, null, null);
             return this;
         }

         /**
          * Sets the value of a field, using a custom {@link RemoteViews presentation} to
          * visualize it.
          *
          * @param id id returned by {@link
          *         android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
          * @param value the value to be autofilled. Pass {@code null} if you do not have the value
          *        but the target view is a logical part of the dataset. For example, if
          *        the dataset needs authentication and you have no access to the value.
          * @param presentation the presentation used to visualize this field.
          * @return this builder.
          *
          */
         public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value,
                 @NonNull RemoteViews presentation) {
             throwIfDestroyed();
             Preconditions.checkNotNull(presentation, "presentation cannot be null");
             setLifeTheUniverseAndEverything(id, value, presentation, null);
             return this;
         }

         /**
          * Sets the value of a field using an <a href="#Filtering">explicit filter</a>.
          *
          * <p>This method is typically used when the dataset is not authenticated and the field
          * value is not {@link AutofillValue#isText() text} but the service still wants to allow
          * the user to filter it out.
          *
          * @param id id returned by {@link
          *         android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
          * @param value the value to be autofilled. Pass {@code null} if you do not have the value
          *        but the target view is a logical part of the dataset. For example, if
          *        the dataset needs authentication and you have no access to the value.
          * @param filter regex used to determine if the dataset should be shown in the autofill UI.
          *
          * @return this builder.
          * @throws IllegalStateException if the builder was constructed without a
          * {@link RemoteViews presentation}.
          */
         public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value,
                 @NonNull Pattern filter) {
             throwIfDestroyed();
             Preconditions.checkNotNull(filter, "filter cannot be null");
             Preconditions.checkState(mPresentation != null,
                     "Dataset presentation not set on constructor");
             setLifeTheUniverseAndEverything(id, value, null, filter);
             return this;
         }

         /**
          * Sets the value of a field, using a custom {@link RemoteViews presentation} to
          * visualize it and a <a href="#Filtering">explicit filter</a>.
          *
          * <p>Typically used to allow filtering on
          * {@link Dataset.Builder#setAuthentication(IntentSender) authenticated datasets}. For
          * example, if the dataset represents a credit card number and the service does not want to
          * show the "Tap to authenticate" message until the user tapped 4 digits, in which case
          * the filter would be {@code Pattern.compile("\\d.{4,}")}.
          *
          * @param id id returned by {@link
          *         android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
          * @param value the value to be autofilled. Pass {@code null} if you do not have the value
          *        but the target view is a logical part of the dataset. For example, if
          *        the dataset needs authentication and you have no access to the value.
          * @param presentation the presentation used to visualize this field.
          * @param filter regex used to determine if the dataset should be shown in the autofill UI.
          *
          * @return this builder.
          */
         public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value,
                 @NonNull Pattern filter, @NonNull RemoteViews presentation) {
             throwIfDestroyed();
             Preconditions.checkNotNull(filter, "filter cannot be null");
             Preconditions.checkNotNull(presentation, "presentation cannot be null");
             setLifeTheUniverseAndEverything(id, value, presentation, filter);
             return this;
         }

         private void setLifeTheUniverseAndEverything(@NonNull AutofillId id,
                 @Nullable AutofillValue value, @Nullable RemoteViews presentation,
                 @Nullable Pattern filter) {
             Preconditions.checkNotNull(id, "id cannot be null");
             if (mFieldIds != null) {
                 final int existingIdx = mFieldIds.indexOf(id);
                 if (existingIdx >= 0) {
                     mFieldValues.set(existingIdx, value);
                     mFieldPresentations.set(existingIdx, presentation);
                     return;
                 }
             } else {
                 mFieldIds = new ArrayList<>();
                 mFieldValues = new ArrayList<>();
                 mFieldPresentations = new ArrayList<>();
                 mFieldFilters = new ArrayList<>();
             }
             mFieldIds.add(id);
             mFieldValues.add(value);
             mFieldPresentations.add(presentation);
             mFieldFilters.add(filter);
         }

         /**
          * Creates a new {@link Dataset} instance.
          *
          * <p>You should not interact with this builder once this method is called.
          *
          * @throws IllegalStateException if no field was set (through
          * {@link #setValue(AutofillId, AutofillValue)} or
          * {@link #setValue(AutofillId, AutofillValue, RemoteViews)}).
          *
          * @return The built dataset.
          */
         public @NonNull Dataset build() {
             throwIfDestroyed();
             mDestroyed = true;
             if (mFieldIds == null) {
                 throw new IllegalStateException("at least one value must be set");
             }
             return new Dataset(this);
         }

         private void throwIfDestroyed() {
             if (mDestroyed) {
                 throw new IllegalStateException("Already called #build()");
             }
         }
     }

     /////////////////////////////////////
     //  Parcelable "contract" methods. //
     /////////////////////////////////////

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

     @Override
     public void writeToParcel(Parcel parcel, int flags) {
         parcel.writeParcelable(mPresentation, flags);
         parcel.writeTypedList(mFieldIds, flags);
         parcel.writeTypedList(mFieldValues, flags);
         parcel.writeParcelableList(mFieldPresentations, flags);
         parcel.writeSerializable(mFieldFilters);
         parcel.writeParcelable(mAuthentication, flags);
         parcel.writeString(mId);
     }

     public static final Creator<Dataset> CREATOR = new Creator<Dataset>() {
         @Override
         public Dataset createFromParcel(Parcel parcel) {
             // Always go through the builder to ensure the data ingested by
             // the system obeys the contract of the builder to avoid attacks
             // using specially crafted parcels.
             final RemoteViews presentation = parcel.readParcelable(null);
             final Builder builder = (presentation == null)
                     ? new Builder()
                     : new Builder(presentation);
             final ArrayList<AutofillId> ids = parcel.createTypedArrayList(AutofillId.CREATOR);
             final ArrayList<AutofillValue> values =
                     parcel.createTypedArrayList(AutofillValue.CREATOR);
             final ArrayList<RemoteViews> presentations = new ArrayList<>();
             parcel.readParcelableList(presentations, null);
             @SuppressWarnings("unchecked")
             final ArrayList<Serializable> filters =
                     (ArrayList<Serializable>) parcel.readSerializable();
             final int idCount = (ids != null) ? ids.size() : 0;
             final int valueCount = (values != null) ? values.size() : 0;
             for (int i = 0; i < idCount; i++) {
                 final AutofillId id = ids.get(i);
                 final AutofillValue value = (valueCount > i) ? values.get(i) : null;
                 final RemoteViews fieldPresentation = presentations.isEmpty() ? null
                         : presentations.get(i);
                 final Pattern filter = (Pattern) filters.get(i);
                 builder.setLifeTheUniverseAndEverything(id, value, fieldPresentation, filter);
             }
             builder.setAuthentication(parcel.readParcelable(null));
             builder.setId(parcel.readString());
             return builder.build();
         }

         @Override
         public Dataset[] newArray(int size) {
             return new Dataset[size];
         }
     };
 }
	/*
	* Copyright (C) 2016 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 android.view.autofill.Helper.sDebug;

	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.content.IntentSender;
	import android.os.Parcel;
	import android.os.Parcelable;
	import android.view.autofill.AutofillId;
	import android.view.autofill.AutofillValue;
	import android.widget.RemoteViews;

	import com.android.internal.util.Preconditions;

	import java.io.Serializable;
	import java.util.ArrayList;
	import java.util.regex.Pattern;

	/**
	* A dataset object represents a group of fields (key / value pairs) used to autofill parts of a
	* screen.
	*
	* <a name="BasicUsage"></a>
	* <h3>Basic usage</h3>
	*
	* <p>In its simplest form, a dataset contains one or more fields (comprised of
	* an {@link AutofillId id}, a {@link AutofillValue value}, and an optional filter
	* {@link Pattern regex}); and one or more {@link RemoteViews presentations} for these fields
	* (each field could have its own {@link RemoteViews presentation}, or use the default
	* {@link RemoteViews presentation} associated with the whole dataset).
	*
	* <p>When an autofill service returns datasets in a {@link FillResponse}
	* and the screen input is focused in a view that is present in at least one of these datasets,
	* the Android System displays a UI containing the {@link RemoteViews presentation} of
	* all datasets pairs that have that view's {@link AutofillId}. Then, when the user selects a
	* dataset from the UI, all views in that dataset are autofilled.
	*
	* <a name="Authentication"></a>
	* <h3>Dataset authentication</h3>
	*
	* <p>In a more sophisticated form, the dataset values can be protected until the user authenticates
	* the dataset—in that case, when a dataset is selected by the user, the Android System
	* launches an intent set by the service to "unlock" the dataset.
	*
	* <p>For example, when a data set contains credit card information (such as number,
	* expiration date, and verification code), you could provide a dataset presentation saying
	* "Tap to authenticate". Then when the user taps that option, you would launch an activity asking
	* the user to enter the credit card code, and if the user enters a valid code, you could then
	* "unlock" the dataset.
	*
	* <p>You can also use authenticated datasets to offer an interactive UI for the user. For example,
	* if the activity being autofilled is an account creation screen, you could use an authenticated
	* dataset to automatically generate a random password for the user.
	*
	* <p>See {@link Dataset.Builder#setAuthentication(IntentSender)} for more details about the dataset
	* authentication mechanism.
	*
	* <a name="Filtering"></a>
	* <h3>Filtering</h3>
	* <p>The autofill UI automatically changes which values are shown based on value of the view
	* anchoring it, following the rules below:
	* <ol>
	* <li>If the view's {@link android.view.View#getAutofillValue() autofill value} is not
	* {@link AutofillValue#isText() text} or is empty, all datasets are shown.
	* <li>Datasets that have a filter regex (set through
	* {@link Dataset.Builder#setValue(AutofillId, AutofillValue, Pattern)} or
	* {@link Dataset.Builder#setValue(AutofillId, AutofillValue, Pattern, RemoteViews)}) and whose
	* regex matches the view's text value converted to lower case are shown.
	* <li>Datasets that do not require authentication, have a field value that is
	* {@link AutofillValue#isText() text} and whose {@link AutofillValue#getTextValue() value} starts
	* with the lower case value of the view's text are shown.
	* <li>All other datasets are hidden.
	* </ol>
	*
	* <a name="MoreInfo"></a>
	* <h3>More information</h3>
	* <p>See {@link android.service.autofill.AutofillService} for more information and examples about
	* the role of datasets in the autofill workflow.
	*/
	public final class Dataset implements Parcelable {

	private final ArrayList<AutofillId> mFieldIds;
	private final ArrayList<AutofillValue> mFieldValues;
	private final ArrayList<RemoteViews> mFieldPresentations;
	private final ArrayList<Pattern> mFieldFilters;
	private final RemoteViews mPresentation;
	private final IntentSender mAuthentication;
	@Nullable String mId;

	private Dataset(Builder builder) {
	mFieldIds = builder.mFieldIds;
	mFieldValues = builder.mFieldValues;
	mFieldPresentations = builder.mFieldPresentations;
	mFieldFilters = builder.mFieldFilters;
	mPresentation = builder.mPresentation;
	mAuthentication = builder.mAuthentication;
	mId = builder.mId;
	}

	/** @hide */
	public @Nullable ArrayList<AutofillId> getFieldIds() {
	return mFieldIds;
	}

	/** @hide */
	public @Nullable ArrayList<AutofillValue> getFieldValues() {
	return mFieldValues;
	}

	/** @hide */
	public RemoteViews getFieldPresentation(int index) {
	final RemoteViews customPresentation = mFieldPresentations.get(index);
	return customPresentation != null ? customPresentation : mPresentation;
	}

	/** @hide */
	@Nullable
	public Pattern getFilter(int index) {
	return mFieldFilters.get(index);
	}

	/** @hide */
	public @Nullable IntentSender getAuthentication() {
	return mAuthentication;
	}

	/** @hide */
	public boolean isEmpty() {
	return mFieldIds == null \|\| mFieldIds.isEmpty();
	}

	@Override
	public String toString() {
	if (!sDebug) return super.toString();

	return new StringBuilder("Dataset " + mId + " [")
	.append("fieldIds=").append(mFieldIds)
	.append(", fieldValues=").append(mFieldValues)
	.append(", fieldPresentations=")
	.append(mFieldPresentations == null ? 0 : mFieldPresentations.size())
	.append(", fieldFilters=")
	.append(mFieldFilters == null ? 0 : mFieldFilters.size())
	.append(", hasPresentation=").append(mPresentation != null)
	.append(", hasAuthentication=").append(mAuthentication != null)
	.append(']').toString();
	}

	/**
	* Gets the id of this dataset.
	*
	* @return The id of this dataset or {@code null} if not set
	*
	* @hide
	*/
	public String getId() {
	return mId;
	}

	/**
	* A builder for {@link Dataset} objects. You must provide at least
	* one value for a field or set an authentication intent.
	*/
	public static final class Builder {
	private ArrayList<AutofillId> mFieldIds;
	private ArrayList<AutofillValue> mFieldValues;
	private ArrayList<RemoteViews> mFieldPresentations;
	private ArrayList<Pattern> mFieldFilters;
	private RemoteViews mPresentation;
	private IntentSender mAuthentication;
	private boolean mDestroyed;
	@Nullable private String mId;

	/**
	* Creates a new builder.
	*
	* @param presentation The presentation used to visualize this dataset.
	*/
	public Builder(@NonNull RemoteViews presentation) {
	Preconditions.checkNotNull(presentation, "presentation must be non-null");
	mPresentation = presentation;
	}

	/**
	* Creates a new builder for a dataset where each field will be visualized independently.
	*
	* <p>When using this constructor, fields must be set through
	* {@link #setValue(AutofillId, AutofillValue, RemoteViews)}.
	*/
	public Builder() {
	}

	/**
	* Requires a dataset authentication before autofilling the activity with this dataset.
	*
	* <p>This method is called when you need to provide an authentication
	* UI for the data set. For example, when a data set contains credit card information
	* (such as number, expiration date, and verification code), you can display UI
	* asking for the verification code before filing in the data. Even if the
	* data set is completely populated the system will launch the specified authentication
	* intent and will need your approval to fill it in. Since the data set is "locked"
	* until the user authenticates it, typically this data set name is masked
	* (for example, "VISA....1234"). Typically you would want to store the data set
	* labels non-encrypted and the actual sensitive data encrypted and not in memory.
	* This allows showing the labels in the UI while involving the user if one of
	* the items with these labels is chosen. Note that if you use sensitive data as
	* a label, for example an email address, then it should also be encrypted.</p>
	*
	* <p>When a user triggers autofill, the system launches the provided intent
	* whose extras will have the {@link
	* android.view.autofill.AutofillManager#EXTRA_ASSIST_STRUCTURE screen content},
	* and your {@link android.view.autofill.AutofillManager#EXTRA_CLIENT_STATE client
	* state}. Once you complete your authentication flow you should set the activity
	* result to {@link android.app.Activity#RESULT_OK} and provide the fully populated
	* {@link Dataset dataset} or a fully-populated {@link FillResponse response} by
	* setting it to the {@link
	* android.view.autofill.AutofillManager#EXTRA_AUTHENTICATION_RESULT} extra. If you
	* provide a dataset in the result, it will replace the authenticated dataset and
	* will be immediately filled in. If you provide a response, it will replace the
	* current response and the UI will be refreshed. For example, if you provided
	* credit card information without the CVV for the data set in the {@link FillResponse
	* response} then the returned data set should contain the CVV entry.
	*
	* <p><b>Note:</b> Do not make the provided pending intent
	* immutable by using {@link android.app.PendingIntent#FLAG_IMMUTABLE} as the
	* platform needs to fill in the authentication arguments.
	*
	* @param authentication Intent to an activity with your authentication flow.
	* @return this builder.
	*
	* @see android.app.PendingIntent
	*/
	public @NonNull Builder setAuthentication(@Nullable IntentSender authentication) {
	throwIfDestroyed();
	mAuthentication = authentication;
	return this;
	}

	/**
	* Sets the id for the dataset so its usage can be tracked.
	*
	* <p>Dataset usage can be tracked for 2 purposes:
	*
	* <ul>
	* <li>For statistical purposes, the service can call
	* {@link AutofillService#getFillEventHistory()} when handling {@link
	* AutofillService#onFillRequest(FillRequest, android.os.CancellationSignal, FillCallback)}
	* calls.
	* <li>For normal autofill workflow, the service can call
	* {@link SaveRequest#getDatasetIds()} when handling
	* {@link AutofillService#onSaveRequest(SaveRequest, SaveCallback)} calls.
	* </ul>
	*
	* @param id id for this dataset or {@code null} to unset.
	*
	* @return this builder.
	*/
	public @NonNull Builder setId(@Nullable String id) {
	throwIfDestroyed();
	mId = id;
	return this;
	}

	/**
	* Sets the value of a field.
	*
	* @param id id returned by {@link
	* android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
	* @param value value to be autofilled. Pass {@code null} if you do not have the value
	* but the target view is a logical part of the dataset. For example, if
	* the dataset needs authentication and you have no access to the value.
	* @return this builder.
	* @throws IllegalStateException if the builder was constructed without a
	* {@link RemoteViews presentation}.
	*/
	public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value) {
	throwIfDestroyed();
	Preconditions.checkState(mPresentation != null,
	"Dataset presentation not set on constructor");
	setLifeTheUniverseAndEverything(id, value, null, null);
	return this;
	}

	/**
	* Sets the value of a field, using a custom {@link RemoteViews presentation} to
	* visualize it.
	*
	* @param id id returned by {@link
	* android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
	* @param value the value to be autofilled. Pass {@code null} if you do not have the value
	* but the target view is a logical part of the dataset. For example, if
	* the dataset needs authentication and you have no access to the value.
	* @param presentation the presentation used to visualize this field.
	* @return this builder.
	*
	*/
	public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value,
	@NonNull RemoteViews presentation) {
	throwIfDestroyed();
	Preconditions.checkNotNull(presentation, "presentation cannot be null");
	setLifeTheUniverseAndEverything(id, value, presentation, null);
	return this;
	}

	/**
	* Sets the value of a field using an <a href="#Filtering">explicit filter</a>.
	*
	* <p>This method is typically used when the dataset is not authenticated and the field
	* value is not {@link AutofillValue#isText() text} but the service still wants to allow
	* the user to filter it out.
	*
	* @param id id returned by {@link
	* android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
	* @param value the value to be autofilled. Pass {@code null} if you do not have the value
	* but the target view is a logical part of the dataset. For example, if
	* the dataset needs authentication and you have no access to the value.
	* @param filter regex used to determine if the dataset should be shown in the autofill UI.
	*
	* @return this builder.
	* @throws IllegalStateException if the builder was constructed without a
	* {@link RemoteViews presentation}.
	*/
	public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value,
	@NonNull Pattern filter) {
	throwIfDestroyed();
	Preconditions.checkNotNull(filter, "filter cannot be null");
	Preconditions.checkState(mPresentation != null,
	"Dataset presentation not set on constructor");
	setLifeTheUniverseAndEverything(id, value, null, filter);
	return this;
	}

	/**
	* Sets the value of a field, using a custom {@link RemoteViews presentation} to
	* visualize it and a <a href="#Filtering">explicit filter</a>.
	*
	* <p>Typically used to allow filtering on
	* {@link Dataset.Builder#setAuthentication(IntentSender) authenticated datasets}. For
	* example, if the dataset represents a credit card number and the service does not want to
	* show the "Tap to authenticate" message until the user tapped 4 digits, in which case
	* the filter would be {@code Pattern.compile("\\d.{4,}")}.
	*
	* @param id id returned by {@link
	* android.app.assist.AssistStructure.ViewNode#getAutofillId()}.
	* @param value the value to be autofilled. Pass {@code null} if you do not have the value
	* but the target view is a logical part of the dataset. For example, if
	* the dataset needs authentication and you have no access to the value.
	* @param presentation the presentation used to visualize this field.
	* @param filter regex used to determine if the dataset should be shown in the autofill UI.
	*
	* @return this builder.
	*/
	public @NonNull Builder setValue(@NonNull AutofillId id, @Nullable AutofillValue value,
	@NonNull Pattern filter, @NonNull RemoteViews presentation) {
	throwIfDestroyed();
	Preconditions.checkNotNull(filter, "filter cannot be null");
	Preconditions.checkNotNull(presentation, "presentation cannot be null");
	setLifeTheUniverseAndEverything(id, value, presentation, filter);
	return this;
	}

	private void setLifeTheUniverseAndEverything(@NonNull AutofillId id,
	@Nullable AutofillValue value, @Nullable RemoteViews presentation,
	@Nullable Pattern filter) {
	Preconditions.checkNotNull(id, "id cannot be null");
	if (mFieldIds != null) {
	final int existingIdx = mFieldIds.indexOf(id);
	if (existingIdx >= 0) {
	mFieldValues.set(existingIdx, value);
	mFieldPresentations.set(existingIdx, presentation);
	return;
	}
	} else {
	mFieldIds = new ArrayList<>();
	mFieldValues = new ArrayList<>();
	mFieldPresentations = new ArrayList<>();
	mFieldFilters = new ArrayList<>();
	}
	mFieldIds.add(id);
	mFieldValues.add(value);
	mFieldPresentations.add(presentation);
	mFieldFilters.add(filter);
	}

	/**
	* Creates a new {@link Dataset} instance.
	*
	* <p>You should not interact with this builder once this method is called.
	*
	* @throws IllegalStateException if no field was set (through
	* {@link #setValue(AutofillId, AutofillValue)} or
	* {@link #setValue(AutofillId, AutofillValue, RemoteViews)}).
	*
	* @return The built dataset.
	*/
	public @NonNull Dataset build() {
	throwIfDestroyed();
	mDestroyed = true;
	if (mFieldIds == null) {
	throw new IllegalStateException("at least one value must be set");
	}
	return new Dataset(this);
	}

	private void throwIfDestroyed() {
	if (mDestroyed) {
	throw new IllegalStateException("Already called #build()");
	}
	}
	}

	/////////////////////////////////////
	// Parcelable "contract" methods. //
	/////////////////////////////////////

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

	@Override
	public void writeToParcel(Parcel parcel, int flags) {
	parcel.writeParcelable(mPresentation, flags);
	parcel.writeTypedList(mFieldIds, flags);
	parcel.writeTypedList(mFieldValues, flags);
	parcel.writeParcelableList(mFieldPresentations, flags);
	parcel.writeSerializable(mFieldFilters);
	parcel.writeParcelable(mAuthentication, flags);
	parcel.writeString(mId);
	}

	public static final Creator<Dataset> CREATOR = new Creator<Dataset>() {
	@Override
	public Dataset createFromParcel(Parcel parcel) {
	// Always go through the builder to ensure the data ingested by
	// the system obeys the contract of the builder to avoid attacks
	// using specially crafted parcels.
	final RemoteViews presentation = parcel.readParcelable(null);
	final Builder builder = (presentation == null)
	? new Builder()
	: new Builder(presentation);
	final ArrayList<AutofillId> ids = parcel.createTypedArrayList(AutofillId.CREATOR);
	final ArrayList<AutofillValue> values =
	parcel.createTypedArrayList(AutofillValue.CREATOR);
	final ArrayList<RemoteViews> presentations = new ArrayList<>();
	parcel.readParcelableList(presentations, null);
	@SuppressWarnings("unchecked")
	final ArrayList<Serializable> filters =
	(ArrayList<Serializable>) parcel.readSerializable();
	final int idCount = (ids != null) ? ids.size() : 0;
	final int valueCount = (values != null) ? values.size() : 0;
	for (int i = 0; i < idCount; i++) {
	final AutofillId id = ids.get(i);
	final AutofillValue value = (valueCount > i) ? values.get(i) : null;
	final RemoteViews fieldPresentation = presentations.isEmpty() ? null
	: presentations.get(i);
	final Pattern filter = (Pattern) filters.get(i);
	builder.setLifeTheUniverseAndEverything(id, value, fieldPresentation, filter);
	}
	builder.setAuthentication(parcel.readParcelable(null));
	builder.setId(parcel.readString());
	return builder.build();
	}

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