~repos /gdx-studio

/*
 * 01/11/2010
 *
 * Copyright (C) 2011 Robert Futrell
 * robert_futrell at users.sourceforge.net
 * http://fifesoft.com/rsyntaxtextarea
 *
 * This library is distributed under a modified BSD license.  See the included
 * RSTALanguageSupport.License.txt file for details.
 */
package org.fife.rsta.ac.common;

import javax.swing.text.Element;

import org.fife.rsta.ac.LanguageSupport;
import org.fife.ui.rsyntaxtextarea.RSyntaxDocument;
import org.fife.ui.rsyntaxtextarea.RSyntaxTextArea;
import org.fife.ui.rsyntaxtextarea.Token;


/**
 * Returns non-whitespace, non-comment tokens from an {@link RSyntaxDocument},
 * one at a time.  This can be used by simplistic {@link LanguageSupport}s to
 * "parse" for simple, easily-identifiable tokens, such as curly braces and
 * {@link Token#VARIABLE}s.  For example, to identify code blocks for languages
 * structured like C and Java, you can use this class in conjunction with
 * {@link CodeBlock} and {@link VariableDeclaration} to create an
 * easily-parsable model of your source code.
 *
 * @author Robert Futrell
 * @version 1.0
 */
public class TokenScanner {

  private RSyntaxDocument doc;
  private Element root;
  private Token t;
  private int line;


  public TokenScanner(RSyntaxTextArea textArea) {
    this((RSyntaxDocument)textArea.getDocument());
  }


  public TokenScanner(RSyntaxDocument doc) {
    this.doc = doc;
    root = doc.getDefaultRootElement();
    line = 0;
    t = null;//textArea.getTokenListForLine(line++);
  }


  /**
   * Returns the document being parsed.
   *
   * @return The document.
   */
  public RSyntaxDocument getDocument() {
    return doc;
  }


  /**
   * Returns the next non-whitespace, non-comment token in the text area.
   *
   * @return The next token, or <code>null</code> if we are at the end of
   *         its document.
   */
  public Token next() {
    Token next = nextRaw();
    while (next!=null && (next.isWhitespace() || next.isComment())) {
      next = nextRaw();
    }
    return next;
  }


  /**
   * Returns the next token in the text area.
   *
   * @return The next token, or <code>null</code> if we are at the end of
   *         its document.
   */
  private Token nextRaw() {
    if (t==null || !t.isPaintable()) {
      int lineCount = root.getElementCount();
      while (line<lineCount && (t==null || !t.isPaintable())) {
        t = doc.getTokenListForLine(line++);
      }
      if (line==lineCount) {
        return null;
      }
    }
    Token next = t;
    t = t.getNextToken();
    return next;
  }


}