1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.

     2 // Use of this source code is governed by a BSD-style license that can be

     3 // found in the LICENSE file.

     4 

     5 package org.chromium.sdk.internal.protocolparser.dynamicimpl;

     6 

     7 import java.lang.reflect.Method;

     8 import java.util.ArrayList;

     9 import java.util.List;

    10 

    11 import org.chromium.sdk.internal.protocolparser.JsonProtocolModelParseException;

    12 import org.chromium.sdk.internal.protocolparser.JsonProtocolParseException;

    13 import org.chromium.sdk.internal.protocolparser.JsonSubtypeCondition;

    14 import org.chromium.sdk.internal.protocolparser.JsonSubtypeConditionBoolValue;

    15 import org.chromium.sdk.internal.protocolparser.JsonSubtypeConditionCustom;

    16 import org.chromium.sdk.internal.protocolparser.JsonValueCondition;

    17 

    18 /**

    19  * An interface to field conditions logic. Some conditions are simple and never need parsed

    20  * values, others are more fine-grained and require quick parser before making actual checks.

    21  */

    22 abstract class FieldConditionLogic {

    23   private final boolean logicRequiresQuickParser;

    24 

    25   FieldConditionLogic(boolean logicRequiresQuickParser) {

    26     this.logicRequiresQuickParser = logicRequiresQuickParser;

    27   }

    28 

    29   boolean requiresQuickParser() {

    30     return logicRequiresQuickParser;

    31   }

    32 

    33   /**

    34    * @param hasValue whether field exists in JSON object (however its value may be null)

    35    * @param quickParser parser that may be used if {@link #requiresQuickParser()} is true

    36    */

    37   abstract boolean checkValue(boolean hasValue, Object unparsedValue, QuickParser<?> quickParser)

    38       throws JsonProtocolParseException;

    39 

    40   /**

    41    * Constructor function that creates field condition logic from method annotations.

    42    */

    43   static FieldConditionLogic readLogic(Method m) throws JsonProtocolModelParseException {

    44     List<FieldConditionLogic> results = new ArrayList<FieldConditionLogic>(1);

    45     JsonSubtypeConditionBoolValue boolValueAnn =

    46         m.getAnnotation(JsonSubtypeConditionBoolValue.class);

    47     if (boolValueAnn != null) {

    48       final Boolean required = boolValueAnn.value();

    49       results.add(new FieldConditionLogic(true) {

    50         @Override

    51         boolean checkValue(boolean hasValue, Object unparsedValue, QuickParser<?> parser)

    52             throws JsonProtocolParseException {

    53           return hasValue && required == parser.parseValueQuick(unparsedValue);

    54         }

    55       });

    56     }

    57     JsonSubtypeConditionCustom customAnn = m.getAnnotation(JsonSubtypeConditionCustom.class);

    58     if (customAnn != null) {

    59       final CustomConditionWrapper<?> constraint =

    60           CustomConditionWrapper.create(customAnn.condition());

    61       results.add(new FieldConditionLogic(true) {

    62         @Override

    63         boolean checkValue(boolean hasValue, Object unparsedValue, QuickParser<?> parser)

    64             throws JsonProtocolParseException {

    65           return hasValue && constraint.checkValue(parser.parseValueQuick(unparsedValue));

    66         }

    67       });

    68     }

    69     JsonSubtypeCondition conditionAnn = m.getAnnotation(JsonSubtypeCondition.class);

    70     if (conditionAnn != null) {

    71       int savedResSize = results.size();

    72       if (conditionAnn.fieldIsAbsent()) {

    73         results.add(new FieldConditionLogic(false) {

    74           @Override

    75           boolean checkValue(boolean hasValue, Object unparsedValue, QuickParser<?> parser) {

    76             return !hasValue;

    77           }

    78         });

    79       }

    80       if (conditionAnn.valueIsNull()) {

    81         results.add(new FieldConditionLogic(false) {

    82           @Override

    83           boolean checkValue(boolean hasValue, Object unparsedValue, QuickParser<?> parser) {

    84             return hasValue && unparsedValue != null;

    85           }

    86         });

    87       }

    88       if (savedResSize == results.size()) {

    89         results.add(new FieldConditionLogic(false) {

    90           @Override

    91           boolean checkValue(boolean hasValue, Object unparsedValue, QuickParser<?> parser) {

    92             return hasValue;

    93           }

    94         });

    95       }

    96     }

    97     if (results.size() == 0) {

    98       return null;

    99     }

   100     if (results.size() > 1) {

   101       throw new JsonProtocolModelParseException("Too many constraints for field getter " + m);

   102     }

   103     return results.get(0);

   104   }

   105 

   106   private static class CustomConditionWrapper<T> {

   107     static <T, CL extends JsonValueCondition<T>> CustomConditionWrapper<T> create(

   108         Class<CL> constraintClass) {

   109       return new CustomConditionWrapper<T>(constraintClass);

   110     }

   111 

   112     private final JsonValueCondition<? super T> constraint;

   113 

   114     private CustomConditionWrapper(Class<? extends JsonValueCondition<? super T>> constraintClass) {

   115       try {

   116         constraint = constraintClass.newInstance();

   117       } catch (InstantiationException e) {

   118         throw new RuntimeException(e);

   119       } catch (IllegalAccessException e) {

   120         throw new RuntimeException(e);

   121       }

   122     }

   123 

   124     boolean checkValue(Object parsedValue) {

   125       return constraint.conforms((T)parsedValue);

   126     }

   127   }

   128 

   129 }