content: /*******************************************************************************
   * Copyright (c) 2000, 2008 IBM Corporation and others.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.ui.actions;
  
  import java.util.LinkedList;
  import java.util.List;
  import java.util.ResourceBundle;
  
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.jface.text.BadLocationException;
  import org.eclipse.jface.text.BadPartitioningException;
  import org.eclipse.jface.text.IDocument;
  import org.eclipse.jface.text.IDocumentExtension3;
  import org.eclipse.jface.text.ITextSelection;
  import org.eclipse.jface.text.ITypedRegion;
  import org.eclipse.ui.texteditor.ITextEditor;
  import org.eclipse.wst.jsdt.ui.text.IJavaScriptPartitions;
  
  
  /**
   * Action that encloses the editor's current selection with Java block comment terminators
   * (<code>&#47;&#42;</code> and <code>&#42;&#47;</code>).
   * 
   * 
   */
  public class AddBlockCommentAction extends BlockCommentAction {
  
  	/**
  	 * Creates a new instance.
  	 * 
  	 * @param bundle the resource bundle
  	 * @param prefix a prefix to be prepended to the various resource keys
  	 *   (described in <code>ResourceAction</code> constructor), or 
  	 *   <code>null</code> if none
  	 * @param editor the text editor
  	 */
  	public AddBlockCommentAction(ResourceBundle bundle, String prefix, ITextEditor editor) {
  		super(bundle, prefix, editor);
  	}
  	
  	/*
  	 * @see org.eclipse.wst.jsdt.internal.ui.actions.BlockCommentAction#runInternal(org.eclipse.jface.text.ITextSelection, org.eclipse.jface.text.IDocumentExtension3, org.eclipse.wst.jsdt.internal.ui.actions.BlockCommentAction.Edit.EditFactory)
  	 */
  	protected void runInternal(ITextSelection selection, IDocumentExtension3 docExtension, Edit.EditFactory factory) throws BadLocationException, BadPartitioningException {
  		int selectionOffset= selection.getOffset();
  		int selectionEndOffset= selectionOffset + selection.getLength();
  		List edits= new LinkedList();
  		ITypedRegion partition= docExtension.getPartition(IJavaScriptPartitions.JAVA_PARTITIONING, selectionOffset, false);
  
  		handleFirstPartition(partition, edits, factory, selectionOffset);
  
  		while (partition.getOffset() + partition.getLength() < selectionEndOffset) {
  			partition= handleInteriorPartition(partition, edits, factory, docExtension);
  		}
  		
  		handleLastPartition(partition, edits, factory, selectionEndOffset);
  		
  		executeEdits(edits);
  	}
  
  	/**
  	 * Handle the partition under the start offset of the selection.
  	 * 
  	 * @param partition the partition under the start of the selection
  	 * @param edits the list of edits to later execute
  	 * @param factory the factory for edits
  	 * @param offset the start of the selection, which must lie inside
  	 *        <code>partition</code>
  	 */
  	private void handleFirstPartition(ITypedRegion partition, List edits, Edit.EditFactory factory, int offset) throws BadLocationException {
  		
  		int partOffset= partition.getOffset();
  		String partType= partition.getType();
  		
  		Assert.isTrue(partOffset <= offset, "illegal partition"); //$NON-NLS-1$
  		
  		// first partition: mark start of comment
  		if (partType == IDocument.DEFAULT_CONTENT_TYPE) {
  			// Java code: right where selection starts
  			edits.add(factory.createEdit(offset, 0, getCommentStart()));
  		} else if (isSpecialPartition(partType)) {
  			// special types: include the entire partition
  			edits.add(factory.createEdit(partOffset, 0, getCommentStart()));
  		}	// javadoc: no mark, will only start after comment
  		
  	}
  
  	/**
  	 * Handles partition boundaries within the selection. The end of the current
  	 * partition and the start of the next partition are examined for whether
  	 * they contain comment tokens that interfere with the created comment.
  	 * <p>
  	 * Comment tokens are removed from interior multi-line comments. Javadoc
  	 * comments are left as is; instead, multi-line comment tokens are inserted
  	 * before and after Javadoc partitions to ensure that the entire selected
  	 * area is commented.
  	 * </p>
  	 * <p>
  	 * The next partition is returned.
  	 * </p>
  	 * 
  	 * @param partition the current partition
  	 * @param edits the list of edits to add to
  	 * @param factory the edit factory
  	 * @param docExtension the document to get the partitions from
  	 * @return the next partition after the current
  	 * @throws BadLocationException if accessing the document fails - this can
  	 *         only happen if the document gets modified concurrently
  	 * @throws BadPartitioningException if the document does not have a Java
  	 *         partitioning
  	 */
  	private ITypedRegion handleInteriorPartition(ITypedRegion partition, List edits, Edit.EditFactory factory, IDocumentExtension3 docExtension) throws BadPartitioningException, BadLocationException {
  
  		// end of previous partition
  		String partType= partition.getType();
  		int partEndOffset= partition.getOffset() + partition.getLength();
  		int tokenLength= getCommentStart().length();
  		
  		boolean wasJavadoc= false; // true if the previous partition is javadoc
  		
  		if (partType == IJavaScriptPartitions.JAVA_DOC) {
  			
  			wasJavadoc= true;
  			
  		} else if (partType == IJavaScriptPartitions.JAVA_MULTI_LINE_COMMENT) {
  			
  			// already in a comment - remove ending mark
  			edits.add(factory.createEdit(partEndOffset - tokenLength, tokenLength, "")); //$NON-NLS-1$
  			
  		}
  
  		// advance to next partition
  		partition= docExtension.getPartition(IJavaScriptPartitions.JAVA_PARTITIONING, partEndOffset, false);
  		partType= partition.getType();
  
  		// start of next partition
  		if (wasJavadoc) {
  			
  			// if previous was javadoc, and the current one is not a comment,
  			// then add a block comment start
  			if (partType == IDocument.DEFAULT_CONTENT_TYPE
  					|| isSpecialPartition(partType)) {
  				edits.add(factory.createEdit(partition.getOffset(), 0, getCommentStart()));
  			}
  			
  		} else { // !wasJavadoc
  		
  			if (partType == IJavaScriptPartitions.JAVA_DOC) {
  				// if next is javadoc, end block comment before
  				edits.add(factory.createEdit(partition.getOffset(), 0, getCommentEnd()));
  			} else if (partType == IJavaScriptPartitions.JAVA_MULTI_LINE_COMMENT) {
  				// already in a comment - remove startToken
  				edits.add(factory.createEdit(partition.getOffset(), getCommentStart().length(), "")); //$NON-NLS-1$
  			}
  		}
  		
  		return partition;
  	}
  
  	/**
  	 * Handles the partition under the end of the selection. For normal java
  	 * code, the comment end token is inserted at the selection end; if the
  	 * selection ends inside a special (i.e. string, character, line comment)
  	 * partition, the entire partition is included inside the comment.
  	 * 
  	 * @param partition the partition under the selection end offset
  	 * @param edits the list of edits to add to
  	 * @param factory the edit factory
  	 * @param endOffset the end offset of the selection
  	 */
  	private void handleLastPartition(ITypedRegion partition, List edits, Edit.EditFactory factory, int endOffset) throws BadLocationException {
  
  		String partType= partition.getType();
  		
  		if (partType == IDocument.DEFAULT_CONTENT_TYPE) {
  			// normal java: end comment where selection ends
  			edits.add(factory.createEdit(endOffset, 0, getCommentEnd()));
  		} else if (isSpecialPartition(partType)) {
  			// special types: consume entire partition
  			edits.add(factory.createEdit(partition.getOffset() + partition.getLength(), 0, getCommentEnd()));
  		}
  		
  	}
  
  	/**
  	 * Returns whether <code>partType</code> is special, i.e. a Java
  	 * <code>String</code>,<code>Character</code>, or
  	 * <code>Line End Comment</code> partition.
  	 * 
  	 * @param partType the partition type to check
  	 * @return <code>true</code> if <code>partType</code> is special,
  	 *         <code>false</code> otherwise
  	 */
  	private boolean isSpecialPartition(String partType) {
  		return partType == IJavaScriptPartitions.JAVA_CHARACTER
  				|| partType == IJavaScriptPartitions.JAVA_STRING
  				|| partType == IJavaScriptPartitions.JAVA_SINGLE_LINE_COMMENT;
  	}
  
  	/*
  	 * @see org.eclipse.wst.jsdt.internal.ui.actions.BlockCommentAction#validSelection(org.eclipse.jface.text.ITextSelection)
  	 */
  	protected boolean isValidSelection(ITextSelection selection) {
  		return selection != null && !selection.isEmpty() && selection.getLength() > 0;
  	}
  
  }
  