xml/impl/src/com/intellij/xml/util/documentation/XmlDocumentationProvider.java - platform/tools/idea - Git at Google

 /*
  * Copyright 2000-2014 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package com.intellij.xml.util.documentation;

 import com.intellij.codeInsight.completion.XmlCompletionData;
 import com.intellij.lang.Language;
 import com.intellij.lang.documentation.DocumentationProvider;
 import com.intellij.lang.documentation.DocumentationUtil;
 import com.intellij.lang.xhtml.XHTMLLanguage;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.Ref;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
 import com.intellij.psi.html.HtmlTag;
 import com.intellij.psi.impl.source.xml.SchemaPrefix;
 import com.intellij.psi.search.PsiElementProcessor;
 import com.intellij.psi.templateLanguages.TemplateLanguageFileViewProvider;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.xml.*;
 import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.Processor;
 import com.intellij.xml.*;
 import com.intellij.xml.impl.schema.*;
 import com.intellij.xml.util.XmlUtil;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 import java.util.Collections;
 import java.util.List;

 /**
  * @author maxim
  */
 public class XmlDocumentationProvider implements DocumentationProvider {
   private static final Key<XmlElementDescriptor> DESCRIPTOR_KEY = Key.create("Original element");

   private static final Logger LOG = Logger.getInstance("#com.intellij.xml.util.documentation.XmlDocumentationProvider");

   @NonNls private static final String NAME_ATTR_NAME = "name";
   @NonNls private static final String BASE_SITEPOINT_URL = "http://reference.sitepoint.com/html/";


   @Override
   @Nullable
   public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (element instanceof SchemaPrefix) {
       return ((SchemaPrefix)element).getQuickNavigateInfo();
     }
     return null;
   }

   @Override
   public List<String> getUrlFor(PsiElement element, PsiElement originalElement) {
     if (element instanceof XmlTag) {
       XmlTag tag = (XmlTag)element;

       MyPsiElementProcessor processor = new MyPsiElementProcessor();
       XmlUtil.processXmlElements(tag,processor, true);

       if (processor.url == null) {
         XmlTag declaration = getComplexOrSimpleTypeDefinition(element, originalElement);

         if (declaration != null) {
           XmlUtil.processXmlElements(declaration,processor, true);
         }
       }

       return processor.url != null ? Collections.singletonList(processor.url) : null;
     }
     return null;
   }

   @Override
   public String generateDoc(PsiElement element, final PsiElement originalElement) {
     if (element instanceof XmlElementDecl) {
       PsiElement curElement = findPreviousComment(element);

       if (curElement!=null) {
         return formatDocFromComment(curElement, ((XmlElementDecl)element).getNameElement().getText());
       }
     }
     else if (element instanceof XmlTag) {
       XmlTag tag = (XmlTag)element;
       MyPsiElementProcessor processor = new MyPsiElementProcessor();
       String name = tag.getAttributeValue(NAME_ATTR_NAME);
       String typeName = null;

       if (originalElement != null && originalElement.getParent() instanceof XmlAttributeValue) {
         XmlAttributeValue value = (XmlAttributeValue)originalElement.getParent();
         String toSearch = value.getValue();
         XmlTag enumerationTag;

         if (XmlUtil.ENUMERATION_TAG_NAME.equals(tag.getLocalName())) {
           enumerationTag = tag;
           name = enumerationTag.getAttributeValue(XmlUtil.VALUE_ATTR_NAME);
         } else {
           enumerationTag = findEnumerationValue(toSearch, tag);
           name = toSearch;
         }

         if (enumerationTag != null) {
           XmlUtil.processXmlElements(enumerationTag,processor, true);

           if (processor.result != null) {
             typeName = XmlBundle.message("xml.javadoc.enumeration.value.message");
           }
         }
       }

       if (processor.result == null) XmlUtil.processXmlElements(tag,processor, true);

       if (processor.result == null) {
         XmlTag declaration = getComplexOrSimpleTypeDefinition(element, originalElement);

         if (declaration != null) {
           XmlUtil.processXmlElements(declaration,processor, true);
           name = declaration.getAttributeValue(NAME_ATTR_NAME);
           typeName = XmlBundle.message("xml.javadoc.complex.type.message");
         }
       }
       if (processor.result == null) {
         final PsiElement comment = findPreviousComment(element);
         if (comment != null) {
           return formatDocFromComment(comment, ((XmlTag)element).getName());
         }
       }

       String doc = generateDoc(processor.result, name, typeName, processor.version);
       if (doc != null && originalElement != null) {
         doc += generateHtmlAdditionalDocTemplate(originalElement);
       }
       return doc;

     } else if (element instanceof XmlAttributeDecl) {
       // Check for comment before attlist, it should not be right after previous declaration
       final PsiElement parent = element.getParent();
       final PsiElement previousComment = findPreviousComment(parent);
       final String referenceName = ((XmlAttributeDecl)element).getNameElement().getText();

       if (previousComment instanceof PsiComment) {
         final PsiElement prevSibling = previousComment.getPrevSibling();

         if (prevSibling == null ||
             ( prevSibling instanceof PsiWhiteSpace &&
               prevSibling.getText().indexOf('\n') >= 0
             )
            ) {
           return formatDocFromComment(previousComment, referenceName);
         }
       }

       return findDocRightAfterElement(parent, referenceName);
     } else if (element instanceof XmlEntityDecl) {
       final XmlEntityDecl entityDecl = (XmlEntityDecl)element;

       return findDocRightAfterElement(element, entityDecl.getName());
     }

     return null;
   }

   private static XmlTag findEnumerationValue(final String text, XmlTag tag) {
     final Ref<XmlTag> enumerationTag = new Ref<XmlTag>();

     Processor<XmlTag> processor = new Processor<XmlTag>() {
       @Override
       public boolean process(XmlTag xmlTag) {
         if (text.equals(xmlTag.getAttributeValue(XmlUtil.VALUE_ATTR_NAME))) {
           enumerationTag.set(xmlTag);
         }
         return true;
       }
     };
     XmlUtil.processEnumerationValues(tag, processor);

     if (enumerationTag.get() == null) {
       final XmlElementDescriptorImpl elementDescriptor = (XmlElementDescriptorImpl)XmlUtil.findXmlDescriptorByType(
         tag,
         null
       );

       TypeDescriptor type = elementDescriptor != null ? elementDescriptor.getType():null;
       if (type instanceof ComplexTypeDescriptor) {
         XmlUtil.processEnumerationValues(((ComplexTypeDescriptor)type).getDeclaration(), processor);
       }
     }
     return enumerationTag.get();
   }

   static String generateHtmlAdditionalDocTemplate(@NotNull PsiElement element) {
     StringBuilder buf = new StringBuilder();
     final PsiFile containingFile = element.getContainingFile();
     if (containingFile != null) {
       final XmlTag tag = PsiTreeUtil.getParentOfType(element, XmlTag.class, false);
       boolean append;
       if (tag instanceof HtmlTag) {
         append = true;
       }
       else {
         final FileViewProvider provider = containingFile.getViewProvider();
         Language language;
         if (provider instanceof TemplateLanguageFileViewProvider) {
           language = ((TemplateLanguageFileViewProvider)provider).getTemplateDataLanguage();
         }
         else {
           language = provider.getBaseLanguage();
         }

         append = language == XHTMLLanguage.INSTANCE;
       }

       if (tag != null) {
         EntityDescriptor descriptor = HtmlDescriptorsTable.getTagDescriptor(tag.getName());
         if (descriptor != null && append) {
           buf.append("<br>");
           buf.append(XmlBundle.message("html.quickdoc.additional.template",
                                        descriptor.getHelpRef(),
                                        BASE_SITEPOINT_URL + tag.getName()));
         }
       }
     }

     return buf.toString();
   }

   public String findDocRightAfterElement(final PsiElement parent, final String referenceName) {
     // Check for comment right after the xml attlist decl
     PsiElement uncleElement = parent.getNextSibling();
     if (uncleElement instanceof PsiWhiteSpace && uncleElement.getText().indexOf('\n') == -1) uncleElement = uncleElement.getNextSibling();
     if (uncleElement instanceof PsiComment) {
       return formatDocFromComment(uncleElement, referenceName);
     }
     return null;
   }

   @Nullable
   public static PsiElement findPreviousComment(final PsiElement element) {
     PsiElement curElement = element;

     while(curElement!=null && !(curElement instanceof XmlComment)) {
       curElement = curElement.getPrevSibling();
       if (curElement instanceof XmlText && StringUtil.isEmptyOrSpaces(curElement.getText())) {
         continue;
       }
       if (!(curElement instanceof PsiWhiteSpace) &&
           !(curElement instanceof XmlProlog) &&
           !(curElement instanceof XmlComment)
          ) {
         curElement = null; // finding comment fails, we found another similar declaration
         break;
       }
     }
     return curElement;
   }

   private String formatDocFromComment(final PsiElement curElement, final String name) {
     String text = curElement.getText();
     text = text.substring("<!--".length(),text.length()-"-->".length()).trim();
     text = escapeDocumentationTextText(text);
     return generateDoc(text, name,null, null);
   }

   private static XmlTag getComplexOrSimpleTypeDefinition(PsiElement element, PsiElement originalElement) {
     XmlElementDescriptor descriptor = element.getUserData(DESCRIPTOR_KEY);

     XmlTag contextTag = null;

     XmlAttribute contextAttribute;

     if (descriptor == null &&
         originalElement != null &&
         (contextAttribute = PsiTreeUtil.getParentOfType(originalElement, XmlAttribute.class)) != null) {
       final XmlAttributeDescriptor attributeDescriptor = contextAttribute.getDescriptor();

       if (attributeDescriptor instanceof XmlAttributeDescriptorImpl) {
         final XmlElementDescriptorImpl elementDescriptor = (XmlElementDescriptorImpl)XmlUtil.findXmlDescriptorByType(
           (XmlTag)attributeDescriptor.getDeclaration(),
           contextAttribute.getParent()
         );

         TypeDescriptor type = elementDescriptor != null ? elementDescriptor.getType(contextAttribute) : null;

         if (type instanceof ComplexTypeDescriptor) {
           return ((ComplexTypeDescriptor)type).getDeclaration();
         }
       }
     }

     if (descriptor == null &&
         originalElement != null &&
         (contextTag = PsiTreeUtil.getParentOfType(originalElement, XmlTag.class)) != null) {
       descriptor = contextTag.getDescriptor();
     }

     if (descriptor instanceof XmlElementDescriptorImpl) {
       TypeDescriptor type = ((XmlElementDescriptorImpl)descriptor).getType(contextTag);

       if (type instanceof ComplexTypeDescriptor) {
         return ((ComplexTypeDescriptor)type).getDeclaration();
       }
     }

     return null;
   }

   protected String generateDoc(String str, String name, String typeName, String version) {
     if (str == null) return null;
     StringBuilder buf = new StringBuilder(str.length() + 20);

     DocumentationUtil.formatEntityName(typeName == null ? XmlBundle.message("xml.javadoc.tag.name.message"):typeName,name,buf);

     final String indent = "  ";
     final StringBuilder builder = buf.append(XmlBundle.message("xml.javadoc.description.message")).append(indent).
         append(HtmlDocumentationProvider.NBSP).append(str);
     if (version != null) {
       builder.append(HtmlDocumentationProvider.BR).append(XmlBundle.message("xml.javadoc.version.message")).append(indent)
           .append(HtmlDocumentationProvider.NBSP).append(version);
     }
     return builder.toString();
   }

   @Override
   public PsiElement getDocumentationElementForLookupItem(final PsiManager psiManager, Object object, PsiElement element) {

     if (object instanceof XmlExtension.TagInfo) {
       return ((XmlExtension.TagInfo)object).getDeclaration();
     }

     final PsiElement originalElement = element;
     boolean isAttrCompletion = element instanceof XmlAttribute;

     if (!isAttrCompletion && element instanceof XmlToken) {
       final IElementType tokenType = ((XmlToken)element).getTokenType();

       if (tokenType == XmlTokenType.XML_EMPTY_ELEMENT_END || tokenType == XmlTokenType.XML_TAG_END) {
         isAttrCompletion = true;
       } else if (element.getParent() instanceof XmlAttribute) {
         isAttrCompletion = true;
       }
     }

     element = PsiTreeUtil.getParentOfType(element, XmlTag.class, false);

     if (element instanceof XmlTag) {
       XmlTag xmlTag = (XmlTag)element;
       XmlElementDescriptor elementDescriptor;

       if (isAttrCompletion && object instanceof String) {
         elementDescriptor = xmlTag.getDescriptor();

         if (elementDescriptor != null) {
           final XmlAttributeDescriptor attributeDescriptor = elementDescriptor.getAttributeDescriptor((String)object, xmlTag);
           if (attributeDescriptor != null) {
             final PsiElement declaration = attributeDescriptor.getDeclaration();
             if (declaration != null) return declaration;
           }
         }
       }

       if (object == null) return null;
       try {
         @NonNls StringBuilder tagText = new StringBuilder(object.toString());
         String namespacePrefix = XmlUtil.findPrefixByQualifiedName(object.toString());
         String namespace = xmlTag.getNamespaceByPrefix(namespacePrefix);

         if (namespace!=null && namespace.length() > 0) {
           tagText.append(" xmlns");
           if (namespacePrefix.length() > 0) tagText.append(":").append(namespacePrefix);
           tagText.append("=\"").append(namespace).append("\"");
         }

         XmlTag tagFromText = XmlElementFactory.getInstance(xmlTag.getProject()).createTagFromText("<" + tagText +"/>");
         XmlElementDescriptor parentDescriptor = xmlTag.getDescriptor();
         elementDescriptor = (parentDescriptor!=null)?parentDescriptor.getElementDescriptor(tagFromText, xmlTag):null;

         if (elementDescriptor==null) {
           PsiElement parent = xmlTag.getParent();
           if (parent instanceof XmlTag) {
             parentDescriptor = ((XmlTag)parent).getDescriptor();
             elementDescriptor = (parentDescriptor!=null)?parentDescriptor.getElementDescriptor(tagFromText, (XmlTag)parent):null;
           }
         }

         if (elementDescriptor instanceof AnyXmlElementDescriptor) {
           final XmlNSDescriptor nsDescriptor = xmlTag.getNSDescriptor(xmlTag.getNamespaceByPrefix(namespacePrefix), true);
           elementDescriptor = (nsDescriptor != null)?nsDescriptor.getElementDescriptor(tagFromText):null;
         }

         // The very special case of xml file
         final PsiFile containingFile = xmlTag.getContainingFile();
         final XmlFile xmlFile = XmlUtil.getContainingFile(xmlTag);
         if (xmlFile != containingFile) {
           final XmlTag rootTag = xmlFile.getDocument().getRootTag();
           if (rootTag != null) {
             final XmlNSDescriptor nsDescriptor = rootTag.getNSDescriptor(rootTag.getNamespaceByPrefix(namespacePrefix), true);
             elementDescriptor = (nsDescriptor != null) ? nsDescriptor.getElementDescriptor(tagFromText) : null;
           }
         }

         if (elementDescriptor != null) {
           PsiElement declaration = elementDescriptor.getDeclaration();
           if (declaration!=null) declaration.putUserData(DESCRIPTOR_KEY,elementDescriptor);
           return declaration;
         }
       }
       catch (IncorrectOperationException e) {
         LOG.error(e);
       }
     }

     if (object instanceof String && originalElement != null) {
       PsiElement result = findDeclWithName((String)object, originalElement);

       if (result == null && element instanceof XmlTag) {
         XmlAttribute attribute = PsiTreeUtil.getParentOfType(originalElement, XmlAttribute.class, false);
         if (attribute != null) {
           XmlAttributeDescriptor descriptor = attribute.getDescriptor();
           if (descriptor != null && descriptor.getDeclaration() instanceof XmlTag) {
             result = findEnumerationValue((String)object, (XmlTag)descriptor.getDeclaration());
           }
         }
       }
       return result;
     }
     if (object instanceof XmlElementDescriptor) {
       return ((XmlElementDescriptor)object).getDeclaration();
     }
     return null;
   }

   public static PsiElement findDeclWithName(final String name, final @NotNull PsiElement element) {
     final XmlFile containingXmlFile = XmlUtil.getContainingFile(element);
     final XmlTag nearestTag = PsiTreeUtil.getParentOfType(element, XmlTag.class, false);
     final XmlFile xmlFile = nearestTag != null? XmlCompletionData.findDescriptorFile(nearestTag, containingXmlFile):containingXmlFile;

     if (xmlFile != null) {
       final PsiElement[] result = new PsiElement[1];

       XmlUtil.processXmlElements(
         xmlFile,
         new PsiElementProcessor() {
           @Override
           public boolean execute(@NotNull final PsiElement element) {
             if (element instanceof XmlEntityDecl) {
               final XmlEntityDecl entityDecl = (XmlEntityDecl)element;
               if (entityDecl.isInternalReference() && name.equals(entityDecl.getName())) {
                 result[0] = entityDecl;
                 return false;
               }
             } else if (element instanceof XmlElementDecl) {
               final XmlElementDecl entityDecl = (XmlElementDecl)element;
               if (name.equals(entityDecl.getName())) {
                 result[0] = entityDecl;
                 return false;
               }
             }
             return true;
           }
         },
         true
       );

       return result[0];
     }
     return null;
   }

   @Override
   public PsiElement getDocumentationElementForLink(final PsiManager psiManager, String link, PsiElement context) {
     return null;
   }

   private static class MyPsiElementProcessor implements PsiElementProcessor {
     String result;
     String version;
     String url;
     @NonNls public static final String DOCUMENTATION_ELEMENT_LOCAL_NAME = "documentation";
     private @NonNls static final String CDATA_PREFIX = "<![CDATA[";
     private @NonNls static final String CDATA_SUFFIX = "]]>";

     @Override
     public boolean execute(@NotNull PsiElement element) {
       if (element instanceof XmlTag &&
           ((XmlTag)element).getLocalName().equals(DOCUMENTATION_ELEMENT_LOCAL_NAME)
       ) {
         final XmlTag tag = ((XmlTag)element);
         result = tag.getValue().getText().trim();
         boolean withCData = false;

         if (result.startsWith(CDATA_PREFIX)) {
           result = result.substring(CDATA_PREFIX.length());
           withCData = true;
         }

         if (result.endsWith(CDATA_SUFFIX)) {
           result = result.substring(0, result.length() - CDATA_SUFFIX.length());
         }
         result = result.trim();

         if (withCData) {
           result = escapeDocumentationTextText(result);
         }

         final @NonNls String s = tag.getAttributeValue("source");
         if (s != null) {
           if (s.startsWith("http:")) url = s;
           else if ("version".equals(s)) {
             version = result;
             result = null;
             return true;
           }
         }
         return false;
       }
       return true;
     }
   }

   private static String escapeDocumentationTextText(final String result) {
     return StringUtil.escapeXml(result).replaceAll("&apos;","'").replaceAll("\n","<br>\n");
   }
 }
	/*
	* Copyright 2000-2014 JetBrains s.r.o.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package com.intellij.xml.util.documentation;

	import com.intellij.codeInsight.completion.XmlCompletionData;
	import com.intellij.lang.Language;
	import com.intellij.lang.documentation.DocumentationProvider;
	import com.intellij.lang.documentation.DocumentationUtil;
	import com.intellij.lang.xhtml.XHTMLLanguage;
	import com.intellij.openapi.diagnostic.Logger;
	import com.intellij.openapi.util.Key;
	import com.intellij.openapi.util.Ref;
	import com.intellij.openapi.util.text.StringUtil;
	import com.intellij.psi.*;
	import com.intellij.psi.html.HtmlTag;
	import com.intellij.psi.impl.source.xml.SchemaPrefix;
	import com.intellij.psi.search.PsiElementProcessor;
	import com.intellij.psi.templateLanguages.TemplateLanguageFileViewProvider;
	import com.intellij.psi.tree.IElementType;
	import com.intellij.psi.util.PsiTreeUtil;
	import com.intellij.psi.xml.*;
	import com.intellij.util.IncorrectOperationException;
	import com.intellij.util.Processor;
	import com.intellij.xml.*;
	import com.intellij.xml.impl.schema.*;
	import com.intellij.xml.util.XmlUtil;
	import org.jetbrains.annotations.NonNls;
	import org.jetbrains.annotations.NotNull;
	import org.jetbrains.annotations.Nullable;

	import java.util.Collections;
	import java.util.List;

	/**
	* @author maxim
	*/
	public class XmlDocumentationProvider implements DocumentationProvider {
	private static final Key<XmlElementDescriptor> DESCRIPTOR_KEY = Key.create("Original element");

	private static final Logger LOG = Logger.getInstance("#com.intellij.xml.util.documentation.XmlDocumentationProvider");

	@NonNls private static final String NAME_ATTR_NAME = "name";
	@NonNls private static final String BASE_SITEPOINT_URL = "http://reference.sitepoint.com/html/";


	@Override
	@Nullable
	public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
	if (element instanceof SchemaPrefix) {
	return ((SchemaPrefix)element).getQuickNavigateInfo();
	}
	return null;
	}

	@Override
	public List<String> getUrlFor(PsiElement element, PsiElement originalElement) {
	if (element instanceof XmlTag) {
	XmlTag tag = (XmlTag)element;

	MyPsiElementProcessor processor = new MyPsiElementProcessor();
	XmlUtil.processXmlElements(tag,processor, true);

	if (processor.url == null) {
	XmlTag declaration = getComplexOrSimpleTypeDefinition(element, originalElement);

	if (declaration != null) {
	XmlUtil.processXmlElements(declaration,processor, true);
	}
	}

	return processor.url != null ? Collections.singletonList(processor.url) : null;
	}
	return null;
	}

	@Override
	public String generateDoc(PsiElement element, final PsiElement originalElement) {
	if (element instanceof XmlElementDecl) {
	PsiElement curElement = findPreviousComment(element);

	if (curElement!=null) {
	return formatDocFromComment(curElement, ((XmlElementDecl)element).getNameElement().getText());
	}
	}
	else if (element instanceof XmlTag) {
	XmlTag tag = (XmlTag)element;
	MyPsiElementProcessor processor = new MyPsiElementProcessor();
	String name = tag.getAttributeValue(NAME_ATTR_NAME);
	String typeName = null;

	if (originalElement != null && originalElement.getParent() instanceof XmlAttributeValue) {
	XmlAttributeValue value = (XmlAttributeValue)originalElement.getParent();
	String toSearch = value.getValue();
	XmlTag enumerationTag;

	if (XmlUtil.ENUMERATION_TAG_NAME.equals(tag.getLocalName())) {
	enumerationTag = tag;
	name = enumerationTag.getAttributeValue(XmlUtil.VALUE_ATTR_NAME);
	} else {
	enumerationTag = findEnumerationValue(toSearch, tag);
	name = toSearch;
	}

	if (enumerationTag != null) {
	XmlUtil.processXmlElements(enumerationTag,processor, true);

	if (processor.result != null) {
	typeName = XmlBundle.message("xml.javadoc.enumeration.value.message");
	}
	}
	}

	if (processor.result == null) XmlUtil.processXmlElements(tag,processor, true);

	if (processor.result == null) {
	XmlTag declaration = getComplexOrSimpleTypeDefinition(element, originalElement);

	if (declaration != null) {
	XmlUtil.processXmlElements(declaration,processor, true);
	name = declaration.getAttributeValue(NAME_ATTR_NAME);
	typeName = XmlBundle.message("xml.javadoc.complex.type.message");
	}
	}
	if (processor.result == null) {
	final PsiElement comment = findPreviousComment(element);
	if (comment != null) {
	return formatDocFromComment(comment, ((XmlTag)element).getName());
	}
	}

	String doc = generateDoc(processor.result, name, typeName, processor.version);
	if (doc != null && originalElement != null) {
	doc += generateHtmlAdditionalDocTemplate(originalElement);
	}
	return doc;

	} else if (element instanceof XmlAttributeDecl) {
	// Check for comment before attlist, it should not be right after previous declaration
	final PsiElement parent = element.getParent();
	final PsiElement previousComment = findPreviousComment(parent);
	final String referenceName = ((XmlAttributeDecl)element).getNameElement().getText();

	if (previousComment instanceof PsiComment) {
	final PsiElement prevSibling = previousComment.getPrevSibling();

	if (prevSibling == null \|\|
	( prevSibling instanceof PsiWhiteSpace &&
	prevSibling.getText().indexOf('\n') >= 0
	)
	) {
	return formatDocFromComment(previousComment, referenceName);
	}
	}

	return findDocRightAfterElement(parent, referenceName);
	} else if (element instanceof XmlEntityDecl) {
	final XmlEntityDecl entityDecl = (XmlEntityDecl)element;

	return findDocRightAfterElement(element, entityDecl.getName());
	}

	return null;
	}

	private static XmlTag findEnumerationValue(final String text, XmlTag tag) {
	final Ref<XmlTag> enumerationTag = new Ref<XmlTag>();

	Processor<XmlTag> processor = new Processor<XmlTag>() {
	@Override
	public boolean process(XmlTag xmlTag) {
	if (text.equals(xmlTag.getAttributeValue(XmlUtil.VALUE_ATTR_NAME))) {
	enumerationTag.set(xmlTag);
	}
	return true;
	}
	};
	XmlUtil.processEnumerationValues(tag, processor);

	if (enumerationTag.get() == null) {
	final XmlElementDescriptorImpl elementDescriptor = (XmlElementDescriptorImpl)XmlUtil.findXmlDescriptorByType(
	tag,
	null
	);

	TypeDescriptor type = elementDescriptor != null ? elementDescriptor.getType():null;
	if (type instanceof ComplexTypeDescriptor) {
	XmlUtil.processEnumerationValues(((ComplexTypeDescriptor)type).getDeclaration(), processor);
	}
	}
	return enumerationTag.get();
	}

	static String generateHtmlAdditionalDocTemplate(@NotNull PsiElement element) {
	StringBuilder buf = new StringBuilder();
	final PsiFile containingFile = element.getContainingFile();
	if (containingFile != null) {
	final XmlTag tag = PsiTreeUtil.getParentOfType(element, XmlTag.class, false);
	boolean append;
	if (tag instanceof HtmlTag) {
	append = true;
	}
	else {
	final FileViewProvider provider = containingFile.getViewProvider();
	Language language;
	if (provider instanceof TemplateLanguageFileViewProvider) {
	language = ((TemplateLanguageFileViewProvider)provider).getTemplateDataLanguage();
	}
	else {
	language = provider.getBaseLanguage();
	}

	append = language == XHTMLLanguage.INSTANCE;
	}

	if (tag != null) {
	EntityDescriptor descriptor = HtmlDescriptorsTable.getTagDescriptor(tag.getName());
	if (descriptor != null && append) {
	buf.append("<br>");
	buf.append(XmlBundle.message("html.quickdoc.additional.template",
	descriptor.getHelpRef(),
	BASE_SITEPOINT_URL + tag.getName()));
	}
	}
	}

	return buf.toString();
	}

	public String findDocRightAfterElement(final PsiElement parent, final String referenceName) {
	// Check for comment right after the xml attlist decl
	PsiElement uncleElement = parent.getNextSibling();
	if (uncleElement instanceof PsiWhiteSpace && uncleElement.getText().indexOf('\n') == -1) uncleElement = uncleElement.getNextSibling();
	if (uncleElement instanceof PsiComment) {
	return formatDocFromComment(uncleElement, referenceName);
	}
	return null;
	}

	@Nullable
	public static PsiElement findPreviousComment(final PsiElement element) {
	PsiElement curElement = element;

	while(curElement!=null && !(curElement instanceof XmlComment)) {
	curElement = curElement.getPrevSibling();
	if (curElement instanceof XmlText && StringUtil.isEmptyOrSpaces(curElement.getText())) {
	continue;
	}
	if (!(curElement instanceof PsiWhiteSpace) &&
	!(curElement instanceof XmlProlog) &&
	!(curElement instanceof XmlComment)
	) {
	curElement = null; // finding comment fails, we found another similar declaration
	break;
	}
	}
	return curElement;
	}

	private String formatDocFromComment(final PsiElement curElement, final String name) {
	String text = curElement.getText();
	text = text.substring("<!--".length(),text.length()-"-->".length()).trim();
	text = escapeDocumentationTextText(text);
	return generateDoc(text, name,null, null);
	}

	private static XmlTag getComplexOrSimpleTypeDefinition(PsiElement element, PsiElement originalElement) {
	XmlElementDescriptor descriptor = element.getUserData(DESCRIPTOR_KEY);

	XmlTag contextTag = null;

	XmlAttribute contextAttribute;

	if (descriptor == null &&
	originalElement != null &&
	(contextAttribute = PsiTreeUtil.getParentOfType(originalElement, XmlAttribute.class)) != null) {
	final XmlAttributeDescriptor attributeDescriptor = contextAttribute.getDescriptor();

	if (attributeDescriptor instanceof XmlAttributeDescriptorImpl) {
	final XmlElementDescriptorImpl elementDescriptor = (XmlElementDescriptorImpl)XmlUtil.findXmlDescriptorByType(
	(XmlTag)attributeDescriptor.getDeclaration(),
	contextAttribute.getParent()
	);

	TypeDescriptor type = elementDescriptor != null ? elementDescriptor.getType(contextAttribute) : null;

	if (type instanceof ComplexTypeDescriptor) {
	return ((ComplexTypeDescriptor)type).getDeclaration();
	}
	}
	}

	if (descriptor == null &&
	originalElement != null &&
	(contextTag = PsiTreeUtil.getParentOfType(originalElement, XmlTag.class)) != null) {
	descriptor = contextTag.getDescriptor();
	}

	if (descriptor instanceof XmlElementDescriptorImpl) {
	TypeDescriptor type = ((XmlElementDescriptorImpl)descriptor).getType(contextTag);

	if (type instanceof ComplexTypeDescriptor) {
	return ((ComplexTypeDescriptor)type).getDeclaration();
	}
	}

	return null;
	}

	protected String generateDoc(String str, String name, String typeName, String version) {
	if (str == null) return null;
	StringBuilder buf = new StringBuilder(str.length() + 20);

	DocumentationUtil.formatEntityName(typeName == null ? XmlBundle.message("xml.javadoc.tag.name.message"):typeName,name,buf);

	final String indent = " ";
	final StringBuilder builder = buf.append(XmlBundle.message("xml.javadoc.description.message")).append(indent).
	append(HtmlDocumentationProvider.NBSP).append(str);
	if (version != null) {
	builder.append(HtmlDocumentationProvider.BR).append(XmlBundle.message("xml.javadoc.version.message")).append(indent)
	.append(HtmlDocumentationProvider.NBSP).append(version);
	}
	return builder.toString();
	}

	@Override
	public PsiElement getDocumentationElementForLookupItem(final PsiManager psiManager, Object object, PsiElement element) {

	if (object instanceof XmlExtension.TagInfo) {
	return ((XmlExtension.TagInfo)object).getDeclaration();
	}

	final PsiElement originalElement = element;
	boolean isAttrCompletion = element instanceof XmlAttribute;

	if (!isAttrCompletion && element instanceof XmlToken) {
	final IElementType tokenType = ((XmlToken)element).getTokenType();

	if (tokenType == XmlTokenType.XML_EMPTY_ELEMENT_END \|\| tokenType == XmlTokenType.XML_TAG_END) {
	isAttrCompletion = true;
	} else if (element.getParent() instanceof XmlAttribute) {
	isAttrCompletion = true;
	}
	}

	element = PsiTreeUtil.getParentOfType(element, XmlTag.class, false);

	if (element instanceof XmlTag) {
	XmlTag xmlTag = (XmlTag)element;
	XmlElementDescriptor elementDescriptor;

	if (isAttrCompletion && object instanceof String) {
	elementDescriptor = xmlTag.getDescriptor();

	if (elementDescriptor != null) {
	final XmlAttributeDescriptor attributeDescriptor = elementDescriptor.getAttributeDescriptor((String)object, xmlTag);
	if (attributeDescriptor != null) {
	final PsiElement declaration = attributeDescriptor.getDeclaration();
	if (declaration != null) return declaration;
	}
	}
	}

	if (object == null) return null;
	try {
	@NonNls StringBuilder tagText = new StringBuilder(object.toString());
	String namespacePrefix = XmlUtil.findPrefixByQualifiedName(object.toString());
	String namespace = xmlTag.getNamespaceByPrefix(namespacePrefix);

	if (namespace!=null && namespace.length() > 0) {
	tagText.append(" xmlns");
	if (namespacePrefix.length() > 0) tagText.append(":").append(namespacePrefix);
	tagText.append("=\"").append(namespace).append("\"");
	}

	XmlTag tagFromText = XmlElementFactory.getInstance(xmlTag.getProject()).createTagFromText("<" + tagText +"/>");
	XmlElementDescriptor parentDescriptor = xmlTag.getDescriptor();
	elementDescriptor = (parentDescriptor!=null)?parentDescriptor.getElementDescriptor(tagFromText, xmlTag):null;

	if (elementDescriptor==null) {
	PsiElement parent = xmlTag.getParent();
	if (parent instanceof XmlTag) {
	parentDescriptor = ((XmlTag)parent).getDescriptor();
	elementDescriptor = (parentDescriptor!=null)?parentDescriptor.getElementDescriptor(tagFromText, (XmlTag)parent):null;
	}
	}

	if (elementDescriptor instanceof AnyXmlElementDescriptor) {
	final XmlNSDescriptor nsDescriptor = xmlTag.getNSDescriptor(xmlTag.getNamespaceByPrefix(namespacePrefix), true);
	elementDescriptor = (nsDescriptor != null)?nsDescriptor.getElementDescriptor(tagFromText):null;
	}

	// The very special case of xml file
	final PsiFile containingFile = xmlTag.getContainingFile();
	final XmlFile xmlFile = XmlUtil.getContainingFile(xmlTag);
	if (xmlFile != containingFile) {
	final XmlTag rootTag = xmlFile.getDocument().getRootTag();
	if (rootTag != null) {
	final XmlNSDescriptor nsDescriptor = rootTag.getNSDescriptor(rootTag.getNamespaceByPrefix(namespacePrefix), true);
	elementDescriptor = (nsDescriptor != null) ? nsDescriptor.getElementDescriptor(tagFromText) : null;
	}
	}

	if (elementDescriptor != null) {
	PsiElement declaration = elementDescriptor.getDeclaration();
	if (declaration!=null) declaration.putUserData(DESCRIPTOR_KEY,elementDescriptor);
	return declaration;
	}
	}
	catch (IncorrectOperationException e) {
	LOG.error(e);
	}
	}

	if (object instanceof String && originalElement != null) {
	PsiElement result = findDeclWithName((String)object, originalElement);

	if (result == null && element instanceof XmlTag) {
	XmlAttribute attribute = PsiTreeUtil.getParentOfType(originalElement, XmlAttribute.class, false);
	if (attribute != null) {
	XmlAttributeDescriptor descriptor = attribute.getDescriptor();
	if (descriptor != null && descriptor.getDeclaration() instanceof XmlTag) {
	result = findEnumerationValue((String)object, (XmlTag)descriptor.getDeclaration());
	}
	}
	}
	return result;
	}
	if (object instanceof XmlElementDescriptor) {
	return ((XmlElementDescriptor)object).getDeclaration();
	}
	return null;
	}

	public static PsiElement findDeclWithName(final String name, final @NotNull PsiElement element) {
	final XmlFile containingXmlFile = XmlUtil.getContainingFile(element);
	final XmlTag nearestTag = PsiTreeUtil.getParentOfType(element, XmlTag.class, false);
	final XmlFile xmlFile = nearestTag != null? XmlCompletionData.findDescriptorFile(nearestTag, containingXmlFile):containingXmlFile;

	if (xmlFile != null) {
	final PsiElement[] result = new PsiElement[1];

	XmlUtil.processXmlElements(
	xmlFile,
	new PsiElementProcessor() {
	@Override
	public boolean execute(@NotNull final PsiElement element) {
	if (element instanceof XmlEntityDecl) {
	final XmlEntityDecl entityDecl = (XmlEntityDecl)element;
	if (entityDecl.isInternalReference() && name.equals(entityDecl.getName())) {
	result[0] = entityDecl;
	return false;
	}
	} else if (element instanceof XmlElementDecl) {
	final XmlElementDecl entityDecl = (XmlElementDecl)element;
	if (name.equals(entityDecl.getName())) {
	result[0] = entityDecl;
	return false;
	}
	}
	return true;
	}
	},
	true
	);

	return result[0];
	}
	return null;
	}

	@Override
	public PsiElement getDocumentationElementForLink(final PsiManager psiManager, String link, PsiElement context) {
	return null;
	}

	private static class MyPsiElementProcessor implements PsiElementProcessor {
	String result;
	String version;
	String url;
	@NonNls public static final String DOCUMENTATION_ELEMENT_LOCAL_NAME = "documentation";
	private @NonNls static final String CDATA_PREFIX = "<![CDATA[";
	private @NonNls static final String CDATA_SUFFIX = "]]>";

	@Override
	public boolean execute(@NotNull PsiElement element) {
	if (element instanceof XmlTag &&
	((XmlTag)element).getLocalName().equals(DOCUMENTATION_ELEMENT_LOCAL_NAME)
	) {
	final XmlTag tag = ((XmlTag)element);
	result = tag.getValue().getText().trim();
	boolean withCData = false;

	if (result.startsWith(CDATA_PREFIX)) {
	result = result.substring(CDATA_PREFIX.length());
	withCData = true;
	}

	if (result.endsWith(CDATA_SUFFIX)) {
	result = result.substring(0, result.length() - CDATA_SUFFIX.length());
	}
	result = result.trim();

	if (withCData) {
	result = escapeDocumentationTextText(result);
	}

	final @NonNls String s = tag.getAttributeValue("source");
	if (s != null) {
	if (s.startsWith("http:")) url = s;
	else if ("version".equals(s)) {
	version = result;
	result = null;
	return true;
	}
	}
	return false;
	}
	return true;
	}
	}

	private static String escapeDocumentationTextText(final String result) {
	return StringUtil.escapeXml(result).replaceAll("'","'").replaceAll("\n","<br>\n");
	}
	}