Home | History | Annotate | Download | only in autofill 
      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package android.service.autofill;
     17 
     18 import android.annotation.NonNull;
     19 
     20 import com.android.internal.util.Preconditions;
     21 
     22 /**
     23  * Factory for {@link Validator} operations.
     24  *
     25  * <p>See {@link SaveInfo.Builder#setValidator(Validator)} for examples.
     26  */
     27 public final class Validators {
     28 
     29     private Validators() {
     30         throw new UnsupportedOperationException("contains static methods only");
     31     }
     32 
     33     /**
     34      * Creates a validator that is only valid if all {@code validators} are valid.
     35      *
     36      * <p>Used to represent an {@code AND} boolean operation in a chain of validators.
     37      *
     38      * @throws IllegalArgumentException if any element of {@code validators} is an instance of a
     39      * class that is not provided by the Android System.
     40      */
     41     @NonNull
     42     public static Validator and(@NonNull Validator...validators) {
     43         return new RequiredValidators(getInternalValidators(validators));
     44     }
     45 
     46     /**
     47      * Creates a validator that is valid if any of the {@code validators} is valid.
     48      *
     49      * <p>Used to represent an {@code OR} boolean operation in a chain of validators.
     50      *
     51      * @throws IllegalArgumentException if any element of {@code validators} is an instance of a
     52      * class that is not provided by the Android System.
     53      */
     54     @NonNull
     55     public static Validator or(@NonNull Validator...validators) {
     56         return new OptionalValidators(getInternalValidators(validators));
     57     }
     58 
     59     /**
     60      * Creates a validator that is valid when {@code validator} is not, and vice versa.
     61      *
     62      * <p>Used to represent a {@code NOT} boolean operation in a chain of validators.
     63      *
     64      * @throws IllegalArgumentException if {@code validator} is an instance of a class that is not
     65      * provided by the Android System.
     66      */
     67     @NonNull
     68     public static Validator not(@NonNull Validator validator) {
     69         Preconditions.checkArgument(validator instanceof InternalValidator,
     70                 "validator not provided by Android System: " + validator);
     71         return new NegationValidator((InternalValidator) validator);
     72     }
     73 
     74     private static InternalValidator[] getInternalValidators(Validator[] validators) {
     75         Preconditions.checkArrayElementsNotNull(validators, "validators");
     76 
     77         final InternalValidator[] internals = new InternalValidator[validators.length];
     78 
     79         for (int i = 0; i < validators.length; i++) {
     80             Preconditions.checkArgument((validators[i] instanceof InternalValidator),
     81                     "element " + i + " not provided by Android System: " + validators[i]);
     82             internals[i] = (InternalValidator) validators[i];
     83         }
     84         return internals;
     85     }
     86 }
     87