xml/dom-openapi/src/com/intellij/util/xml/WrappingConverter.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   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
  17 package com.intellij.util.xml;
  18
  19 import org.jetbrains.annotations.NonNls;
  20 import org.jetbrains.annotations.NotNull;
  21 import org.jetbrains.annotations.Nullable;
  22
  23 import java.util.List;
  24 import java.util.Collections;
  25
  26 /**
  27  * @author Gregory.Shrago
  28  */
  29 public abstract class WrappingConverter extends Converter<Object> {
  30
  31   public Object fromString(@Nullable @NonNls String s, final ConvertContext context) {
  32     final List<Converter> converters = getConverters((GenericDomValue)context.getInvocationElement());
  33     if (converters.isEmpty()) return s;
  34     for (Converter converter : converters) {
  35       final Object o = converter.fromString(s, context);
  36       if (o != null) {
  37         return o;
  38       }
  39     }
  40     return null;
  41   }
  42
  43   public String toString(@Nullable Object t, final ConvertContext context) {
  44     final List<Converter> converters = getConverters((GenericDomValue)context.getInvocationElement());
  45     if (converters.isEmpty()) return String.valueOf(t);
  46     for (Converter converter : converters) {
  47       final String s = converter.toString(t, context);
  48       if (s != null) {
  49         return s;
  50       }
  51     }
  52     return null;
  53   }
  54
  55   @NotNull
  56   public List<Converter> getConverters(@NotNull final GenericDomValue domElement) {
  57     final Converter converter = getConverter(domElement);
  58     return converter == null ? Collections.<Converter>emptyList() : Collections.singletonList(converter);
  59   }
  60
  61   @Nullable
  62   public abstract Converter getConverter(@NotNull final GenericDomValue domElement);
  63
  64   public static Converter getDeepestConverter(final Converter converter, final GenericDomValue domValue) {
  65     Converter cur = converter;
  66     Converter next;
  67     int guard = 0;
  68     while (cur instanceof WrappingConverter) {
  69       next = ((WrappingConverter)cur).getConverter(domValue);
  70       if (next == null) break;
  71       cur = next;
  72       if (guard++ > 10) {
  73         throw new RuntimeException("Too deep wrapping for " + converter);
  74       }
  75     }
  76     return cur;
  77   }
  78 }