platform/lang-impl/src/com/intellij/codeInsight/folding/impl/PsiNamesElementSignatureProvider.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.codeInsight.folding.impl;

 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 import java.util.Arrays;
 import java.util.StringTokenizer;

 /**
  * Performs {@code 'PSI element <-> signature'} mappings on the basis of unique path of {@link PsiNamedElement PSI named elements}
  * to the PSI root.
  * <p/>
  * Thread-safe.
  *
  * @author Denis Zhdanov
  * @since 11/7/11 11:58 AM
  */
 public class PsiNamesElementSignatureProvider extends AbstractElementSignatureProvider {

   private static final String TYPE_MARKER            = "n";
   private static final String TOP_LEVEL_CHILD_MARKER = "!!top";
   private static final String DOC_COMMENT_MARKER     = "!!doc";
   private static final String CODE_BLOCK_MARKER      = "!!block";

   @Override
   protected PsiElement restoreBySignatureTokens(@NotNull PsiFile file,
                                                 @NotNull PsiElement parent,
                                                 @NotNull final String type,
                                                 @NotNull StringTokenizer tokenizer,
                                                 @Nullable StringBuilder processingInfoStorage)
   {
     if (!TYPE_MARKER.equals(type)) {
       if (processingInfoStorage != null) {
         processingInfoStorage.append(String.format(
           "Stopping '%s' provider because given signature doesn't have expected type - can work with '%s' but got '%s'%n",
           getClass().getName(), TYPE_MARKER, type
         ));
       }
       return null;
     }
     String elementMarker = tokenizer.nextToken();
     if (TOP_LEVEL_CHILD_MARKER.equals(elementMarker)) {
       PsiElement result = null;
       for (PsiElement child = file.getFirstChild(); child != null; child = child.getNextSibling()) {
         if (child instanceof PsiWhiteSpace) {
           continue;
         }
         if (result == null) {
           result = child;
         }
         else {
           if (processingInfoStorage != null) {
             processingInfoStorage.append(String.format(
               "Stopping '%s' provider because it has top level marker but more than one non white-space child: %s%n",
               getClass().getName(), Arrays.toString(file.getChildren())
             ));
           }
           // More than one top-level non-white space children. Can't match.
           return null;
         }
       }
       if (processingInfoStorage != null) {
         processingInfoStorage.append(String.format(
           "Finished processing of '%s' provider because all of its top-level children have been processed: %s%n",
           getClass().getName(), Arrays.toString(file.getChildren())
         ));
       }
       return result;
     }
     else if (DOC_COMMENT_MARKER.equals(elementMarker)) {
       PsiElement candidate = parent.getFirstChild();
       return candidate instanceof PsiComment ? candidate : null;
     }
     else if (CODE_BLOCK_MARKER.equals(elementMarker)) {
       int index = 0;
       if (tokenizer.hasMoreTokens()) {
         String indexStr = tokenizer.nextToken();
         try {
           index = Integer.parseInt(indexStr);
         }
         catch (NumberFormatException e) {
           if (processingInfoStorage != null) {
             processingInfoStorage.append("Invalid block index: ").append(indexStr).append("\n");
           }
         }
       }
       for (PsiElement child = parent.getFirstChild(); child != null; child = child.getNextSibling()) {
         if (isBlockElement(child)) {
           if (--index < 0) {
             return child;
           }
         }
       }
       return null;
     }

     if (!tokenizer.hasMoreTokens()) {
       if (processingInfoStorage != null) {
         processingInfoStorage.append(String.format("Stopping '%s' provider because it has no more data to process%n", getClass().getName()));
       }
       return null;
     }
     try {
       int index = Integer.parseInt(tokenizer.nextToken());
       if (processingInfoStorage != null) {
         processingInfoStorage.append(String.format("Looking for the child with a name '%s' # %d at the element '%s'%n",
                                                    elementMarker, index, parent));
       }
       return restoreElementInternal(parent, unescape(elementMarker), index, PsiNamedElement.class);
     }
     catch (NumberFormatException e) {
       return null;
     }
   }

   @Override
   public String getSignature(@NotNull final PsiElement element) {
     StringBuilder buffer = null;
     int length;
     for (PsiElement current = element; current != null && !(current instanceof PsiFile); current = current.getParent()) {
       length = buffer == null ? 0 : buffer.length();
       StringBuilder b = getSignature(current, buffer);
       if (b == null && buffer != null && current.getParent() instanceof PsiFile && canResolveTopLevelChild(current)) {
         buffer.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(TOP_LEVEL_CHILD_MARKER).append(ELEMENTS_SEPARATOR);
         break;
       }
       buffer = b;
       if (buffer == null || length >= buffer.length()) {
         return null;
       }
       buffer.append(ELEMENTS_SEPARATOR);
     }

     if (buffer == null) {
       return null;
     }

     buffer.setLength(buffer.length() - 1);
     return buffer.toString();
   }

   /**
    * Allows to answer if it's possible to use {@link #TOP_LEVEL_CHILD_MARKER} for the given element.
    *
    * @param element  element to check
    * @return         <code>true</code> if {@link #TOP_LEVEL_CHILD_MARKER} can be used for the given element; <code>false</code> otherwise
    */
   private static boolean canResolveTopLevelChild(@NotNull PsiElement element) {
     final PsiElement parent = element.getParent();
     if (parent == null) {
       return false;
     }
     for (PsiElement child = parent.getFirstChild(); child != null; child = child.getNextSibling()) {
       if (child instanceof PsiWhiteSpace) {
         continue;
       }
       if (child != element) {
         return false;
       }
     }
     return true;
   }

   /**
    * Tries to produce signature for the exact given PSI element.
    *
    * @param element  target element
    * @param buffer   buffer to store the signature in
    * @return         buffer that contains signature of the given element if it was produced;
    *                 <code>null</code> as an indication that signature for the given element was not produced
    */
   @SuppressWarnings("unchecked")
   @Nullable
   private static StringBuilder getSignature(@NotNull PsiElement element, @Nullable StringBuilder buffer) {
     if (element instanceof PsiNamedElement) {
       PsiNamedElement named = (PsiNamedElement)element;
       final String name = named.getName();
       if (StringUtil.isEmpty(name)) {
         return null;
       }
       int index = getChildIndex(named, element.getParent(), name, PsiNamedElement.class);
       StringBuilder bufferToUse = buffer;
       if (bufferToUse == null) {
         bufferToUse = new StringBuilder();
       }
       bufferToUse.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(escape(name))
         .append(ELEMENT_TOKENS_SEPARATOR).append(index);
       return bufferToUse;
     }
     else if (element instanceof PsiComment) {
       PsiElement parent = element.getParent();
       boolean nestedComment = false;
       if (parent instanceof PsiComment && parent.getTextRange().equals(element.getTextRange())) {
         parent = parent.getParent();
         nestedComment = true;
       }
       if (parent instanceof PsiNamedElement && (nestedComment || parent.getFirstChild() == element)) {
         // Consider doc comment element that is the first child of named element to be a doc comment.
         StringBuilder bufferToUse = buffer;
         if (bufferToUse == null) {
           bufferToUse = new StringBuilder();
         }
         bufferToUse.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(DOC_COMMENT_MARKER);
         return bufferToUse;
       }
     }

     PsiElement parent = element.getParent();
     if (parent instanceof PsiNamedElement && !(parent instanceof PsiFile)) {
       if (isBlockElement(element)) {
         int index = getBlockElementIndex(element);
         StringBuilder bufferToUse = buffer;
         if (bufferToUse == null) {
           bufferToUse = new StringBuilder();
         }
         bufferToUse.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(CODE_BLOCK_MARKER);
         if (index > 0) {
           bufferToUse.append(ELEMENT_TOKENS_SEPARATOR).append(index);
         }
         return bufferToUse;
       }
     }

     return null;
   }

   private static boolean isBlockElement(@NotNull PsiElement element) {
     PsiElement firstChild = element.getFirstChild();
     PsiElement lastChild = element.getLastChild();
     return firstChild != null && "{".equals(firstChild.getText()) && lastChild != null && "}".equals(lastChild.getText());
   }

   private static int getBlockElementIndex(@NotNull PsiElement element) {
     int i = 0;
     for (PsiElement sibling : element.getParent().getChildren()) {
       if (element.equals(sibling)) {
         return i;
       }
       if (isBlockElement(sibling)) {
         i++;
       }
     }
     throw new RuntimeException("Malformed PSI");
   }
 }
	/*
	* 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.codeInsight.folding.impl;

	import com.intellij.openapi.util.text.StringUtil;
	import com.intellij.psi.*;
	import org.jetbrains.annotations.NotNull;
	import org.jetbrains.annotations.Nullable;

	import java.util.Arrays;
	import java.util.StringTokenizer;

	/**
	* Performs {@code 'PSI element <-> signature'} mappings on the basis of unique path of {@link PsiNamedElement PSI named elements}
	* to the PSI root.
	* <p/>
	* Thread-safe.
	*
	* @author Denis Zhdanov
	* @since 11/7/11 11:58 AM
	*/
	public class PsiNamesElementSignatureProvider extends AbstractElementSignatureProvider {

	private static final String TYPE_MARKER = "n";
	private static final String TOP_LEVEL_CHILD_MARKER = "!!top";
	private static final String DOC_COMMENT_MARKER = "!!doc";
	private static final String CODE_BLOCK_MARKER = "!!block";

	@Override
	protected PsiElement restoreBySignatureTokens(@NotNull PsiFile file,
	@NotNull PsiElement parent,
	@NotNull final String type,
	@NotNull StringTokenizer tokenizer,
	@Nullable StringBuilder processingInfoStorage)
	{
	if (!TYPE_MARKER.equals(type)) {
	if (processingInfoStorage != null) {
	processingInfoStorage.append(String.format(
	"Stopping '%s' provider because given signature doesn't have expected type - can work with '%s' but got '%s'%n",
	getClass().getName(), TYPE_MARKER, type
	));
	}
	return null;
	}
	String elementMarker = tokenizer.nextToken();
	if (TOP_LEVEL_CHILD_MARKER.equals(elementMarker)) {
	PsiElement result = null;
	for (PsiElement child = file.getFirstChild(); child != null; child = child.getNextSibling()) {
	if (child instanceof PsiWhiteSpace) {
	continue;
	}
	if (result == null) {
	result = child;
	}
	else {
	if (processingInfoStorage != null) {
	processingInfoStorage.append(String.format(
	"Stopping '%s' provider because it has top level marker but more than one non white-space child: %s%n",
	getClass().getName(), Arrays.toString(file.getChildren())
	));
	}
	// More than one top-level non-white space children. Can't match.
	return null;
	}
	}
	if (processingInfoStorage != null) {
	processingInfoStorage.append(String.format(
	"Finished processing of '%s' provider because all of its top-level children have been processed: %s%n",
	getClass().getName(), Arrays.toString(file.getChildren())
	));
	}
	return result;
	}
	else if (DOC_COMMENT_MARKER.equals(elementMarker)) {
	PsiElement candidate = parent.getFirstChild();
	return candidate instanceof PsiComment ? candidate : null;
	}
	else if (CODE_BLOCK_MARKER.equals(elementMarker)) {
	int index = 0;
	if (tokenizer.hasMoreTokens()) {
	String indexStr = tokenizer.nextToken();
	try {
	index = Integer.parseInt(indexStr);
	}
	catch (NumberFormatException e) {
	if (processingInfoStorage != null) {
	processingInfoStorage.append("Invalid block index: ").append(indexStr).append("\n");
	}
	}
	}
	for (PsiElement child = parent.getFirstChild(); child != null; child = child.getNextSibling()) {
	if (isBlockElement(child)) {
	if (--index < 0) {
	return child;
	}
	}
	}
	return null;
	}

	if (!tokenizer.hasMoreTokens()) {
	if (processingInfoStorage != null) {
	processingInfoStorage.append(String.format("Stopping '%s' provider because it has no more data to process%n", getClass().getName()));
	}
	return null;
	}
	try {
	int index = Integer.parseInt(tokenizer.nextToken());
	if (processingInfoStorage != null) {
	processingInfoStorage.append(String.format("Looking for the child with a name '%s' # %d at the element '%s'%n",
	elementMarker, index, parent));
	}
	return restoreElementInternal(parent, unescape(elementMarker), index, PsiNamedElement.class);
	}
	catch (NumberFormatException e) {
	return null;
	}
	}

	@Override
	public String getSignature(@NotNull final PsiElement element) {
	StringBuilder buffer = null;
	int length;
	for (PsiElement current = element; current != null && !(current instanceof PsiFile); current = current.getParent()) {
	length = buffer == null ? 0 : buffer.length();
	StringBuilder b = getSignature(current, buffer);
	if (b == null && buffer != null && current.getParent() instanceof PsiFile && canResolveTopLevelChild(current)) {
	buffer.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(TOP_LEVEL_CHILD_MARKER).append(ELEMENTS_SEPARATOR);
	break;
	}
	buffer = b;
	if (buffer == null \|\| length >= buffer.length()) {
	return null;
	}
	buffer.append(ELEMENTS_SEPARATOR);
	}

	if (buffer == null) {
	return null;
	}

	buffer.setLength(buffer.length() - 1);
	return buffer.toString();
	}

	/**
	* Allows to answer if it's possible to use {@link #TOP_LEVEL_CHILD_MARKER} for the given element.
	*
	* @param element element to check
	* @return <code>true</code> if {@link #TOP_LEVEL_CHILD_MARKER} can be used for the given element; <code>false</code> otherwise
	*/
	private static boolean canResolveTopLevelChild(@NotNull PsiElement element) {
	final PsiElement parent = element.getParent();
	if (parent == null) {
	return false;
	}
	for (PsiElement child = parent.getFirstChild(); child != null; child = child.getNextSibling()) {
	if (child instanceof PsiWhiteSpace) {
	continue;
	}
	if (child != element) {
	return false;
	}
	}
	return true;
	}

	/**
	* Tries to produce signature for the exact given PSI element.
	*
	* @param element target element
	* @param buffer buffer to store the signature in
	* @return buffer that contains signature of the given element if it was produced;
	* <code>null</code> as an indication that signature for the given element was not produced
	*/
	@SuppressWarnings("unchecked")
	@Nullable
	private static StringBuilder getSignature(@NotNull PsiElement element, @Nullable StringBuilder buffer) {
	if (element instanceof PsiNamedElement) {
	PsiNamedElement named = (PsiNamedElement)element;
	final String name = named.getName();
	if (StringUtil.isEmpty(name)) {
	return null;
	}
	int index = getChildIndex(named, element.getParent(), name, PsiNamedElement.class);
	StringBuilder bufferToUse = buffer;
	if (bufferToUse == null) {
	bufferToUse = new StringBuilder();
	}
	bufferToUse.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(escape(name))
	.append(ELEMENT_TOKENS_SEPARATOR).append(index);
	return bufferToUse;
	}
	else if (element instanceof PsiComment) {
	PsiElement parent = element.getParent();
	boolean nestedComment = false;
	if (parent instanceof PsiComment && parent.getTextRange().equals(element.getTextRange())) {
	parent = parent.getParent();
	nestedComment = true;
	}
	if (parent instanceof PsiNamedElement && (nestedComment \|\| parent.getFirstChild() == element)) {
	// Consider doc comment element that is the first child of named element to be a doc comment.
	StringBuilder bufferToUse = buffer;
	if (bufferToUse == null) {
	bufferToUse = new StringBuilder();
	}
	bufferToUse.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(DOC_COMMENT_MARKER);
	return bufferToUse;
	}
	}

	PsiElement parent = element.getParent();
	if (parent instanceof PsiNamedElement && !(parent instanceof PsiFile)) {
	if (isBlockElement(element)) {
	int index = getBlockElementIndex(element);
	StringBuilder bufferToUse = buffer;
	if (bufferToUse == null) {
	bufferToUse = new StringBuilder();
	}
	bufferToUse.append(TYPE_MARKER).append(ELEMENT_TOKENS_SEPARATOR).append(CODE_BLOCK_MARKER);
	if (index > 0) {
	bufferToUse.append(ELEMENT_TOKENS_SEPARATOR).append(index);
	}
	return bufferToUse;
	}
	}

	return null;
	}

	private static boolean isBlockElement(@NotNull PsiElement element) {
	PsiElement firstChild = element.getFirstChild();
	PsiElement lastChild = element.getLastChild();
	return firstChild != null && "{".equals(firstChild.getText()) && lastChild != null && "}".equals(lastChild.getText());
	}

	private static int getBlockElementIndex(@NotNull PsiElement element) {
	int i = 0;
	for (PsiElement sibling : element.getParent().getChildren()) {
	if (element.equals(sibling)) {
	return i;
	}
	if (isBlockElement(sibling)) {
	i++;
	}
	}
	throw new RuntimeException("Malformed PSI");
	}
	}