descriptioneditordialog.java

这是java编写的一个开发例子,很值得参考!!!!!!!!!!!!!!!!

/*******************************************************************************
 * Copyright (c) 2004 Berthold Daum. All rights reserved. This program and the
 * accompanying materials are made available under the terms of the Common
 * Public License v1.0 which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors: Berthold Daum
 ******************************************************************************/
package com.bdaum.jukebox;

import java.util.ArrayList;
import java.util.List;
import org.eclipse.jface.dialogs.TitleAreaDialog;
import org.eclipse.jface.text.*;
import org.eclipse.jface.text.contentassist.*;
import org.eclipse.jface.text.presentation.IPresentationReconciler;
import org.eclipse.jface.text.presentation.PresentationReconciler;
import org.eclipse.jface.text.rules.*;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.jface.text.source.SourceViewerConfiguration;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.VerifyKeyListener;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.VerifyEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class DescriptionEditorDialog extends TitleAreaDialog {

  /**
   * This class allows editing descriptions in a separate
   * window. Key words starting with '$' and HTML tags are
   * coded in a different color. In addition, a content
   * assistant is implemented. This assistant is activated via
   * Ctrl+Spacebar, and automatically after entering a '$'. In
   * case of a '$' the content assistant makes proposals for
   * keywords. If text is selected, the content assistant
   * makes proposals for HTML character formatting. Also undo
   * functions are implemented( Ctrl+Z for Undo, Ctrl+Y for
   * Redo).
   */

  public class KeywordCodeScanner extends RuleBasedScanner {

    // This class implements a specific RuleBasedScanner.
    // It assigns specific colors to keywords.
    public KeywordCodeScanner() {
      // We fetch the current Display instance
      // for later retrieval of system colors
      Display display = Display.getCurrent();
      // We create a token for keywords and paint it green
      IToken keyToken = new Token(new TextAttribute(display
                      .getSystemColor(SWT.COLOR_DARK_GREEN)));
      // We create a token for HTML tags and paint it red
      IToken htmlToken = new Token(new TextAttribute(display
                      .getSystemColor(SWT.COLOR_DARK_RED)));
      // We only need a single rule to recognize a keyword
      IRule[] rules = new IRule[2];
      // By using a SingleLineRule we make sure that
      // the keyword does not stretch across line breaks
      rules[0] = new SingleLineRule("$", " ", keyToken, '\\');
      rules[1] = new SingleLineRule("<", ">", htmlToken, '\\');
      // We set this rule for the scanner
      setRules(rules);
    }
  }

  // All keywords
  private final static String[] KEYWORDS = new String[]{
                  "performers", "producer", "publisher",
                  "pubDate", "title"};
  // HTML style tags proposed for character formatting
  private final static String[] HTMLTAGS = new String[]{"b",
                  "em", "i", "strong"};
  // Display text for HTML style tags
  private final static String[] STYLELABELS = new String[]{
                  "bold", "emphasis", "italic", "strong"};

  public class KeywordContentAssistProcessor
                  implements
                    IContentAssistProcessor {
    /**
     * Compiles an array of CompletionProposal instances.
     * 
     * @param viewer -
     *        The viewer, from which this method is called
     * @param documentOffset -
     *        The current position in the document
     */

    /**
     * Make automatic proposals after a $-character
     */
    public char[] getCompletionProposalAutoActivationCharacters() {
      return new char[]{'$'};
    }

    public ICompletionProposal[] computeCompletionProposals(
                    ITextViewer viewer, int documentOffset) {
      IDocument doc = viewer.getDocument();
      // Get text selection
      Point selectedRange = viewer.getSelectedRange();
      List propList;
      try {
        propList = (selectedRange.y == 0)
            ? computeKeywordProposals(getQualifier(doc, documentOffset),
                                        documentOffset)
            : computeHtmlProposals(selectedRange.x, doc.get(
                                     selectedRange.x, selectedRange.y));
        // Convert into Array
        return (CompletionProposal[]) 
            propList.toArray(new CompletionProposal[propList.size()]);
      } catch (BadLocationException e) {
        return new CompletionProposal[0];
      }
    }

    /**
     * Compiles proposals for HTML mark-up.
     * 
     * @param documentOffset -
     *        the current position in the text
     * @param selectedText -
     *        the currently selected text
     * @return - list of proposals
     */
    private List computeHtmlProposals(int documentOffset,
                    String selectedText) {
      List propList = new ArrayList();
      for (int i = 0; i < HTMLTAGS.length; i++) {
        // Compute the string that will replace the selection
        String insert = "<" + HTMLTAGS[i] + ">" + selectedText
                        + "</" + HTMLTAGS[i] + ">";
        int cursor = insert.length();
        // Construct proposal with replacement string and
        // display label
        CompletionProposal proposal = new CompletionProposal(
              insert, documentOffset, selectedText.length(), cursor,
                null, STYLELABELS[i], null, insert);
        propList.add(proposal);
      }
      return propList;
    }

    /**
     * Retrieves qualifying user input.
     * 
     * @param viewer - 
     *        The viewer under which we work
     * @param documentOffset -
     *        The current position in the document
     * @return String