Add Paint Object Listener : StyledText Event « SWT « Java Tutorial






Add Paint Object Listener
/*******************************************************************************
 * Copyright (c) 2000, 2006 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.swt.snippets;
/* 
 * example snippet: StyledText bulleted list example
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.2
 */

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.Bullet;
import org.eclipse.swt.custom.PaintObjectEvent;
import org.eclipse.swt.custom.PaintObjectListener;
import org.eclipse.swt.custom.ST;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GlyphMetrics;
import org.eclipse.swt.graphics.TextLayout;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class StyledTextPaintObjectListener {

  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("StyledText Bullet Example");
    shell.setLayout(new FillLayout());
    final StyledText styledText = new StyledText(shell, SWT.FULL_SELECTION | SWT.BORDER | SWT.WRAP
        | SWT.V_SCROLL);
    StringBuffer text = new StringBuffer();
    text.append("Here is StyledText with some bulleted lists:\n\n");
    for (int i = 0; i < 4; i++)
      text.append("Red Bullet List Item " + i + "\n");
    text.append("\n");
    for (int i = 0; i < 2; i++)
      text.append("Numbered List Item " + i + "\n");
    for (int i = 0; i < 4; i++)
      text.append("Sub List Item " + i + "\n");
    for (int i = 0; i < 2; i++)
      text.append("Numbered List Item " + (2 + i) + "\n");
    text.append("\n");
    for (int i = 0; i < 4; i++)
      text.append("Custom Draw List Item " + i + "\n");
    styledText.setText(text.toString());

    StyleRange style0 = new StyleRange();
    style0.metrics = new GlyphMetrics(0, 0, 40);
    style0.foreground = display.getSystemColor(SWT.COLOR_RED);
    Bullet bullet0 = new Bullet(style0);
    StyleRange style1 = new StyleRange();
    style1.metrics = new GlyphMetrics(0, 0, 50);
    style1.foreground = display.getSystemColor(SWT.COLOR_BLUE);
    Bullet bullet1 = new Bullet(ST.BULLET_NUMBER | ST.BULLET_TEXT, style1);
    bullet1.text = ".";
    StyleRange style2 = new StyleRange();
    style2.metrics = new GlyphMetrics(0, 0, 80);
    style2.foreground = display.getSystemColor(SWT.COLOR_GREEN);
    Bullet bullet2 = new Bullet(ST.BULLET_TEXT, style2);
    bullet2.text = "\u2713";
    StyleRange style3 = new StyleRange();
    style3.metrics = new GlyphMetrics(0, 0, 50);
    Bullet bullet3 = new Bullet(ST.BULLET_CUSTOM, style2);

    styledText.setLineBullet(2, 4, bullet0);
    styledText.setLineBullet(7, 2, bullet1);
    styledText.setLineBullet(9, 4, bullet2);
    styledText.setLineBullet(13, 2, bullet1);
    styledText.setLineBullet(16, 4, bullet3);

    styledText.addPaintObjectListener(new PaintObjectListener() {
      public void paintObject(PaintObjectEvent event) {
        Display display = event.display;
        StyleRange style = event.style;
        Font font = style.font;
        if (font == null)
          font = styledText.getFont();
        TextLayout layout = new TextLayout(display);
        layout.setAscent(event.ascent);
        layout.setDescent(event.descent);
        layout.setFont(font);
        layout.setText("\u2023 1." + event.bulletIndex + ")");
        layout.draw(event.gc, event.x + 10, event.y);
        layout.dispose();
      }
    });
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}








17.45.StyledText Event
17.45.1.Handling Events
17.45.2.Filtering Change with VerifyKeyListenersFiltering Change with VerifyKeyListeners
17.45.3.Allow backspace and deleteAllow backspace and delete
17.45.4.Allow Arrow Key
17.45.5.Allow return
17.45.6.After all VerifyKeyListeners are notified, any VerifyListeners are then notified.
17.45.7.Print out VerifyEvent detail
17.45.8.Against cut-and-paste: Modify the data in VerifyEvent to change the effect of user's keystrokes
17.45.9.Veto the event by setting its doit member to false.
17.45.10.Reacting to Change
17.45.11.Add Paint event listener to StyledTextAdd Paint event listener to StyledText
17.45.12.Use a verify listener in StyledTextUse a verify listener in StyledText
17.45.13.Add Paint Object ListenerAdd Paint Object Listener
17.45.14.Dragging text in a StyledText widgetDragging text in a StyledText widget
17.45.15.Use ExtendedModifyEvent