Java tutorial
/* * Copyright (c) 2012, the Dart project authors. * * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html * * 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.google.dart.tools.ui.internal.text.dartdoc; import com.google.dart.tools.ui.text.DartPartitions; import org.apache.commons.lang3.StringUtils; import org.eclipse.jface.text.BadLocationException; import org.eclipse.jface.text.DefaultIndentLineAutoEditStrategy; import org.eclipse.jface.text.DocumentCommand; import org.eclipse.jface.text.IDocument; import org.eclipse.jface.text.IRegion; import org.eclipse.jface.text.ITypedRegion; import org.eclipse.jface.text.TextUtilities; /** * A simple auto indent strategy for DartDoc comments (as well as regular multi-line comments). * * @coverage dart.editor.ui.text.dart */ public class DartDocAutoIndentStrategy extends DefaultIndentLineAutoEditStrategy { private String partitioning; public DartDocAutoIndentStrategy(String partitioning) { this.partitioning = partitioning; } @Override public void customizeDocumentCommand(IDocument document, DocumentCommand command) { if (!isValidPartition(document, command.offset)) { return; } if (command.text != null) { if (command.length == 0) { String[] lineDelimiters = document.getLegalLineDelimiters(); int idx = TextUtilities.endsWith(lineDelimiters, command.text); if (idx > -1) { if (lineDelimiters[idx].equals(command.text)) { // auto-indent only if adding a newline and nothing else autoIndentAfterNewLine(document, command); } return; } } } } /** * Copies the indentation of the previous line * {@link #customizeDocumentCommand(IDocument, DocumentCommand)}. * * @see DartDocAutoIndentStrategy * @param d the document to work on * @param c the command to deal with */ protected void autoIndentAfterNewLine(IDocument d, DocumentCommand c) { int offset = c.offset; if (offset == -1 || d.getLength() == 0) { return; } try { // find start of line int p = (offset == d.getLength() ? offset - 1 : offset); IRegion info = d.getLineInformationOfOffset(p); int start = info.getOffset(); int end = start + info.getLength(); // split line String strLine = d.get(start, end - start); int firstNotWS = StringUtils.indexOfAnyBut(strLine, " \t"); if (firstNotWS == -1) { firstNotWS = 0; } String strWS = strLine.substring(0, firstNotWS); String strAfterWS = strLine.substring(firstNotWS); String lineDelimiter = TextUtilities.getDefaultLineDelimiter(d); StringBuffer buf = new StringBuffer(); buf.append(lineDelimiter); buf.append(strWS); if (strAfterWS.startsWith("/")) { buf.append(" "); } else if (firstNotWS == 0) { buf.append(" "); } buf.append("* "); int newCaretOffset = offset + buf.length(); if (strLine.endsWith("*/")) { buf.append(lineDelimiter); buf.append(strWS); buf.append(" "); } else if (isNewComment(d, offset)) { buf.append(lineDelimiter); buf.append(strWS); buf.append(" */"); } c.shiftsCaret = false; c.caretOffset = newCaretOffset; c.text = buf.toString(); } catch (BadLocationException excp) { // stop work } } protected String getLineStart(IDocument document, int offset, int end, boolean includeNonWs) throws BadLocationException { int start = offset; while (offset < end) { char c = document.getChar(offset); if (c != ' ' && c != '\t') { if (includeNonWs) { return document.get(start, offset + 1 - start); } else { return document.get(start, offset - start); } } offset++; } return document.get(start, end - start); } /** * Guesses if the command operates within a newly created DartDoc comment or not. If in doubt, it * will assume that the DartDoc is new. * * @param document the document * @param commandOffset the command offset * @return <code>true</code> if the comment should be closed, <code>false</code> if not */ private boolean isNewComment(IDocument document, int commandOffset) { try { int lineIndex = document.getLineOfOffset(commandOffset) + 1; if (lineIndex >= document.getNumberOfLines()) { return true; } IRegion line = document.getLineInformation(lineIndex); ITypedRegion partition = TextUtilities.getPartition(document, partitioning, commandOffset, false); int partitionEnd = partition.getOffset() + partition.getLength(); if (line.getOffset() >= partitionEnd) { return false; } if (document.getLength() == partitionEnd) { return true; // partition goes to end of document - probably a new comment } String comment = document.get(partition.getOffset(), partition.getLength()); int openCount = StringUtils.countMatches(comment, "/*"); int closeCount = StringUtils.countMatches(comment, "*/"); return openCount > closeCount; // if (comment.indexOf("/*", 2) != -1) { // return true; // enclosed another comment -> probably a new comment // } // // return false; } catch (BadLocationException e) { return false; } } private boolean isValidPartition(IDocument document, int offset) { try { String contentType = TextUtilities.getContentType(document, partitioning, offset, false); return DartPartitions.DART_DOC.equals(contentType) || DartPartitions.DART_MULTI_LINE_COMMENT.equals(contentType) || DartPartitions.DART_SINGLE_LINE_DOC.equals(contentType); } catch (BadLocationException e) { } return false; } }