core/java/android/view/autofill/AutoFillType.java

/*
 * 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.view.autofill;

import static android.view.autofill.Helper.DEBUG;

import android.os.Parcel;
import android.os.Parcelable;
import android.view.View;
import android.widget.TextView;

/**
 * Defines the type of a object that can be used to auto-fill a {@link View} so the
 * {@link android.service.autofill.AutoFillService} can use the proper {@link AutoFillValue} to
 * fill it.
 *
 * <p>Some {@link AutoFillType}s can have an optional {@code sub-type}: the
 * main {@code type} defines the view's UI control category (like a text field), while the optional
 * {@code sub-type} define its semantics (like a postal address).
 */
public final class AutoFillType implements Parcelable {

    // Cached instance for types that don't have subtype; it uses the "lazy initialization holder
    // class idiom" (Effective Java, Item 71) to avoid memory utilization when auto-fill is not
    // enabled.
    private static class DefaultTypesHolder {
        static final AutoFillType TOGGLE = new AutoFillType(TYPE_TOGGLE, 0);
        static final AutoFillType LIST = new AutoFillType(TYPE_LIST, 0);
    }

    private static final int TYPE_TEXT = 1;
    private static final int TYPE_TOGGLE = 2;
    // TODO(b/33197203): make sure it works with Spinners and/or add a new type for them
    // (since they're often used for credit card selection)
    private static final int TYPE_LIST = 3;

    // TODO(b/33197203): add others, like date picker? That would be trick, because they're set as:
    // updateDate(int year, int month, int dayOfMonth)
    // So, we would have to either use a long representing the Date.time(), or a custom long
    // representing:
    // year * 10000 + month * 100 + day
    // Then a custom getDatePickerValue(Bundle) that returns an immutable object with these 3 fields

    private final int mType;
    private final int mSubType;

    private AutoFillType(int type, int subType) {
        mType = type;
        mSubType = subType;
    }

    /**
     * Checks if this is a type for a text field, which is filled by a {@link CharSequence}.
     *
     * <p>{@link AutoFillValue} instances for auto-filling a {@link View} can be obtained through
     * {@link AutoFillValue#forText(CharSequence)}, and the value of a bundle passed to auto-fill a
     * {@link View} can be fetched through {@link AutoFillValue#getTextValue()}.
     *
     * <p>Sub-type for this type is the value defined by {@link TextView#getInputType()}.
     */
    public boolean isText() {
        return mType == TYPE_TEXT;
    }

    /**
     * Checks if this is a a type for a togglable field, which is filled by a {@code boolean}.
     *
     * <p>{@link AutoFillValue} instances for auto-filling a {@link View} can be obtained through
     * {@link AutoFillValue#forToggle(boolean)}, and the value of a bundle passed to auto-fill a
     * {@link View} can be fetched through {@link AutoFillValue#getToggleValue()}.
     *
     * <p>This type has no sub-types.
     */
    public boolean isToggle() {
        return mType == TYPE_TOGGLE;
    }

    /**
     * Checks if this is a type for a selection list field, which is filled by a {@code integer}
     * representing the element index inside the list (starting at {@code 0}.
     *
     * <p>{@link AutoFillValue} instances for auto-filling a {@link View} can be obtained through
     * {@link AutoFillValue#forList(int)}, and the value of a bundle passed to auto-fill a
     * {@link View} can be fetched through {@link AutoFillValue#getListValue()}.
     *
     * <p>This type has no sub-types.
     */
    public boolean isList() {
        return mType == TYPE_LIST;
    }


    /**
     * Gets the optional sub-type, representing the {@link View}'s semantic.
     *
     * @return {@code 0} if type does not support sub-types.
     */
    public int getSubType() {
        return mSubType;
    }

    /////////////////////////////////////
    //  Object "contract" methods. //
    /////////////////////////////////////

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

        return "AutoFillType [type=" + mType + ", subType=" + mSubType + "]";
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + mSubType;
        result = prime * result + mType;
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (obj == null) return false;
        if (getClass() != obj.getClass()) return false;
        final AutoFillType other = (AutoFillType) obj;
        if (mSubType != other.mSubType) return false;
        if (mType != other.mType) return false;
        return true;
    }

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

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

    @Override
    public void writeToParcel(Parcel parcel, int flags) {
        parcel.writeInt(mType);
        parcel.writeInt(mSubType);
    }

    private AutoFillType(Parcel parcel) {
        mType = parcel.readInt();
        mSubType = parcel.readInt();
    }

    public static final Parcelable.Creator<AutoFillType> CREATOR =
            new Parcelable.Creator<AutoFillType>() {
        @Override
        public AutoFillType createFromParcel(Parcel source) {
            return new AutoFillType(source);
        }

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

    ////////////////////
    // Factory methods //
    ////////////////////

    /**
     * Creates a text field type, which is filled by a {@link CharSequence}.
     *
     * <p>See {@link #isText()} for more info.
     */
    public static AutoFillType forText(int inputType) {
        return new AutoFillType(TYPE_TEXT, inputType);
    }

    /**
     * Creates a type that can be toggled which is filled by a {@code boolean}.
     *
     * <p>See {@link #isToggle()} for more info.
     */
    public static AutoFillType forToggle() {
        return DefaultTypesHolder.TOGGLE;
    }

    /**
     * Creates a selection list, which is filled by a {@code integer} representing the element index
     * inside the list (starting at {@code 0}.
     *
     * <p>See {@link #isList()} for more info.
     */
    public static AutoFillType forList() {
        return DefaultTypesHolder.LIST;
    }
}