001    /*
002     * Copyright 2010-2013 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.k2js.translate.reference;
018    
019    import com.google.dart.compiler.backend.js.ast.JsExpression;
020    import com.google.dart.compiler.backend.js.ast.JsNameRef;
021    import org.jetbrains.annotations.NotNull;
022    import org.jetbrains.annotations.Nullable;
023    import org.jetbrains.k2js.translate.context.TemporaryVariable;
024    import org.jetbrains.k2js.translate.context.TranslationContext;
025    
026    import java.util.Collections;
027    import java.util.List;
028    
029    import static java.util.Collections.singletonList;
030    
031    public final class CachedPropertyAccessTranslator implements CachedAccessTranslator {
032    
033        @NotNull
034        private final PropertyAccessTranslator baseTranslator;
035        @Nullable
036        private final TemporaryVariable cachedReceiver;
037    
038        /*package*/ CachedPropertyAccessTranslator(@Nullable JsExpression receiverExpression,
039                                                   @NotNull PropertyAccessTranslator baseTranslator,
040                                                   @NotNull TranslationContext context) {
041            this.cachedReceiver = receiverExpression != null ? context.declareTemporary(receiverExpression) : null;
042            this.baseTranslator = baseTranslator;
043        }
044    
045        @NotNull
046        @Override
047        public JsExpression translateAsGet() {
048            return baseTranslator.translateAsGet(receiverOrNull());
049        }
050    
051        @NotNull
052        @Override
053        public JsExpression translateAsSet(@NotNull JsExpression toSetTo) {
054            return baseTranslator.translateAsSet(receiverOrNull(), toSetTo);
055        }
056    
057        @Nullable
058        private JsNameRef receiverOrNull() {
059            return cachedReceiver != null ? cachedReceiver.reference() : null;
060        }
061    
062        @NotNull
063        @Override
064        public CachedAccessTranslator getCached() {
065            return this;
066        }
067    
068        @NotNull
069        @Override
070        public List<TemporaryVariable> declaredTemporaries() {
071            return cachedReceiver != null ? singletonList(cachedReceiver) : Collections.<TemporaryVariable>emptyList();
072        }
073    }