SWT StyledText : StyledText « SWT JFace Eclipse « Java

1. Java
2. SWT JFace Eclipse
3. StyledText

SWT StyledText

/*
SWT/JFace in Action
GUI Design with Eclipse 3.0
Matthew Scarpino, Stephen Holder, Stanford Ng, and Laurent Mihalkovic

ISBN: 1932394273

Publisher: Manning
*/


import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.StringTokenizer;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ExtendedModifyEvent;
import org.eclipse.swt.custom.ExtendedModifyListener;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;

public class Ch5Persistent extends Composite {
  private static final String END_STYLES_MARK = "***EndStyles***";

  private static final String START_STYLES_MARK = "***Styles***";

  private static final String START_TEXT_MARK = "***Text***";

  private static final String FILE_NAME = "editorData.txt";

  private boolean doBold = false;

  private StyledText styledText;

  public Ch5Persistent(Composite parent) {
    super(parent, SWT.NONE);
    buildControls();
  }

  protected void buildControls() {
    this.setLayout(new FillLayout());
    styledText = new StyledText(this, SWT.MULTI | SWT.V_SCROLL);
    load();

    styledText.addExtendedModifyListener(new ExtendedModifyListener() {
      public void modifyText(ExtendedModifyEvent event) {
        if (doBold) {
          StyleRange style = new StyleRange(event.start,
              event.length, null, null, SWT.BOLD);
          styledText.setStyleRange(style);
        }
      }
    });

    styledText.addKeyListener(new KeyAdapter() {
      public void keyPressed(KeyEvent e) {
        switch (e.keyCode) {
        case SWT.F1:
          toggleBold();
          break;
        default:
        //ignore everything else
        }
      }
    });
  }

  private void toggleBold() {
    doBold = !doBold;
    if (styledText.getSelectionCount() > 0) {
      Point selectionRange = styledText.getSelectionRange();
      StyleRange style = new StyleRange(selectionRange.x,
          selectionRange.y, null, null, doBold ? SWT.BOLD
              : SWT.NORMAL);
      styledText.setStyleRange(style);
    }
  }

  private void load() {
    File file = new File(FILE_NAME);
    if (file.exists()) {
      try {
        BufferedReader reader = new BufferedReader(new FileReader(file));
        String currLine = reader.readLine();

        StringTokenizer tokenizer = new StringTokenizer(currLine);
        tokenizer.nextToken(); //discard START_TEXT_MARKER
        String contentLengthString = tokenizer.nextToken();
        int contentLength = Integer.parseInt(contentLengthString);

        readContent(reader, contentLength);

        //find the beginning of the styles section
        while (((currLine = reader.readLine()) != null)
            && !START_STYLES_MARK.equals(currLine))
          ;

        readStyles(reader, currLine);
        reader.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

  private void readStyles(BufferedReader reader, String currLine)
      throws IOException {
    while (!END_STYLES_MARK.equals(currLine)) {
      currLine = reader.readLine();
      if (!END_STYLES_MARK.equals(currLine))
        buildOneStyle(currLine);
    }
  }

  private void readContent(BufferedReader reader, int contentLength)
      throws IOException {
    char[] buffer = new char[contentLength];
    reader.read(buffer, 0, contentLength);

    styledText.append(new String(buffer));
  }

  private void buildOneStyle(String styleText) {
    StringTokenizer tokenizer = new StringTokenizer(styleText);
    int startPos = Integer.parseInt(tokenizer.nextToken());
    int length = Integer.parseInt(tokenizer.nextToken());

    StyleRange style = new StyleRange(startPos, length, null, null,
        SWT.BOLD);
    styledText.setStyleRange(style);
  }

  private void save() {
    try {
      PrintWriter writer = new PrintWriter(new BufferedWriter(
          new FileWriter(FILE_NAME)));
      String text = styledText.getText();
      writer.println(START_TEXT_MARK + " " + text.length());
      writer.println(text);
      writer.println(START_STYLES_MARK);
      StyleRange[] styles = styledText.getStyleRanges();
      for (int i = 0; i < styles.length; i++) {
        writer.println(styles[i].start + " " + styles[i].length);
      }
      writer.println(END_STYLES_MARK);
      writer.flush();
      writer.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

           
       

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4.	SetLine Background
5.	Demonstrates StyleRanges
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7.	Text with underline and strike through
8.	Setting the font style, foreground and background colors of StyledText