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.jet.lang.psi;
018    
019    import com.intellij.lang.ASTNode;
020    import com.intellij.psi.PsiElement;
021    import com.intellij.psi.PsiReference;
022    import com.intellij.psi.PsiReferenceService;
023    import com.intellij.psi.impl.source.resolve.reference.ReferenceProvidersRegistry;
024    import org.jetbrains.annotations.NotNull;
025    import org.jetbrains.annotations.Nullable;
026    import org.jetbrains.jet.JetNodeTypes;
027    import org.jetbrains.jet.lang.resolve.name.FqName;
028    import org.jetbrains.jet.lang.resolve.name.Name;
029    
030    import java.util.List;
031    
032    public class JetNamespaceHeader extends JetReferenceExpression {
033        private String qualifiedNameCache = null;
034    
035        public JetNamespaceHeader(@NotNull ASTNode node) {
036            super(node);
037        }
038    
039        @NotNull
040        public List<JetSimpleNameExpression> getParentNamespaceNames() {
041            List<JetSimpleNameExpression> parentParts = findChildrenByType(JetNodeTypes.REFERENCE_EXPRESSION);
042            JetSimpleNameExpression lastPart = (JetSimpleNameExpression)findLastChildByType(JetNodeTypes.REFERENCE_EXPRESSION);
043            parentParts.remove(lastPart);
044            return parentParts;
045        }
046    
047        @Nullable
048        public JetSimpleNameExpression getLastPartExpression() {
049            return (JetSimpleNameExpression)findLastChildByType(JetNodeTypes.REFERENCE_EXPRESSION);
050        }
051    
052        @NotNull
053        @Override
054        public PsiReference[] getReferences() {
055            return ReferenceProvidersRegistry.getReferencesFromProviders(this, PsiReferenceService.Hints.NO_HINTS);
056        }
057    
058        @Nullable
059        @Override
060        public PsiReference getReference() {
061            PsiReference[] references = getReferences();
062            return references.length == 1 ? references[0] : null;
063        }
064    
065        @Nullable
066        public PsiElement getNameIdentifier() {
067            JetSimpleNameExpression lastPart = (JetSimpleNameExpression)findLastChildByType(JetNodeTypes.REFERENCE_EXPRESSION);
068            if (lastPart == null) {
069                return null;
070            }
071    
072            return lastPart.getIdentifier();
073        }
074    
075        @Override
076        @NotNull
077        public String getName() {
078            PsiElement nameIdentifier = getNameIdentifier();
079            return nameIdentifier == null ? "" : nameIdentifier.getText();
080        }
081    
082        @NotNull
083        public Name getNameAsName() {
084            PsiElement nameIdentifier = getNameIdentifier();
085            return nameIdentifier == null ? JetPsiUtil.ROOT_NAMESPACE_NAME : Name.identifier(nameIdentifier.getText());
086        }
087    
088        public boolean isRoot() {
089            return getName().length() == 0;
090        }
091    
092        @NotNull
093        public FqName getFqName() {
094            String qualifiedName = getQualifiedName();
095            return qualifiedName.isEmpty() ? FqName.ROOT : new FqName(qualifiedName);
096        }
097    
098        @NotNull
099        public FqName getParentFqName(JetReferenceExpression nameExpression) {
100            String parentQualifiedName = getQualifiedNameParentOf(nameExpression);
101            return parentQualifiedName.isEmpty() ? FqName.ROOT : new FqName(parentQualifiedName);
102        }
103    
104        @NotNull
105        public String getQualifiedName() {
106            if (qualifiedNameCache == null) {
107                qualifiedNameCache = getQualifiedNameParentOf(null);
108            }
109    
110            return qualifiedNameCache;
111        }
112    
113        @NotNull
114        private String getQualifiedNameParentOf(@Nullable JetReferenceExpression nameExpression) {
115            StringBuilder builder = new StringBuilder();
116            for (JetSimpleNameExpression e : findChildrenByClass(JetSimpleNameExpression.class)) {
117                if (e == nameExpression) {
118                    break;
119                }
120    
121                if (builder.length() > 0) {
122                    builder.append(".");
123                }
124                builder.append(e.getReferencedName());
125            }
126            return builder.toString();
127        }
128    
129        @Override
130        public void subtreeChanged() {
131            qualifiedNameCache = null;
132        }
133    }
134