StyledText: embed controls : StyledText « SWT « Java Tutorial






StyledText: embed controls
/*******************************************************************************
 * Copyright (c) 2000, 2005 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;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.PaintObjectEvent;
import org.eclipse.swt.custom.PaintObjectListener;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.VerifyEvent;
import org.eclipse.swt.events.VerifyListener;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GlyphMetrics;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

/**
 * StyledText snippet: embed controls
 * 
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.2
 */
public class StyledTextEmbebControls {

  static StyledText styledText;

  static String text = "This snippet shows how to embed widgets in a StyledText.\n"
      + "Here is one: \uFFFC, and here is another: \uFFFC.";

  static int[] offsets;

  static Control[] controls;

  static int MARGIN = 5;

  static void addControl(Control control, int offset) {
    StyleRange style = new StyleRange();
    style.start = offset;
    style.length = 1;
    control.pack();
    Rectangle rect = control.getBounds();
    int ascent = 2 * rect.height / 3;
    int descent = rect.height - ascent;
    style.metrics = new GlyphMetrics(ascent + MARGIN, descent + MARGIN, rect.width + 2 * MARGIN);
    styledText.setStyleRange(style);
  }

  public static void main(String[] args) {
    final Display display = new Display();
    Font font = new Font(display, "Tahoma", 32, SWT.NORMAL);
    final Shell shell = new Shell(display);
    shell.setLayout(new GridLayout());
    styledText = new StyledText(shell, SWT.WRAP | SWT.BORDER);
    styledText.setFont(font);
    styledText.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
    styledText.setText(text);
    controls = new Control[2];
    Button button = new Button(styledText, SWT.PUSH);
    button.setText("Button 1");
    controls[0] = button;
    Combo combo = new Combo(styledText, SWT.NONE);
    combo.add("item 1");
    combo.add("another item");
    controls[1] = combo;
    offsets = new int[controls.length];
    int lastOffset = 0;
    for (int i = 0; i < controls.length; i++) {
      int offset = text.indexOf("\uFFFC", lastOffset);
      offsets[i] = offset;
      addControl(controls[i], offsets[i]);
      lastOffset = offset + 1;
    }

    // use a verify listener to keep the offsets up to date
    styledText.addVerifyListener(new VerifyListener() {
      public void verifyText(VerifyEvent e) {
        int start = e.start;
        int replaceCharCount = e.end - e.start;
        int newCharCount = e.text.length();
        for (int i = 0; i < offsets.length; i++) {
          int offset = offsets[i];
          if (start <= offset && offset < start + replaceCharCount) {
            // this widget is being deleted from the text
            if (controls[i] != null && !controls[i].isDisposed()) {
              controls[i].dispose();
              controls[i] = null;
            }
            offset = -1;
          }
          if (offset != -1 && offset >= start)
            offset += newCharCount - replaceCharCount;
          offsets[i] = offset;
        }
      }
    });

    // reposition widgets on paint event
    styledText.addPaintObjectListener(new PaintObjectListener() {
      public void paintObject(PaintObjectEvent event) {
        StyleRange style = event.style;
        int start = style.start;
        for (int i = 0; i < offsets.length; i++) {
          int offset = offsets[i];
          if (start == offset) {
            Point pt = controls[i].getSize();
            int x = event.x + MARGIN;
            int y = event.y + event.ascent - 2 * pt.y / 3;
            controls[i].setLocation(x, y);
            break;
          }
        }
      }
    });

    shell.setSize(400, 400);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    font.dispose();
    display.dispose();
  }
}








17.42.StyledText
17.42.1.Creating a StyledText Widget
17.42.2.Create a StyledText that scrolls vertically, wraps text, and displays a border:Create a StyledText that scrolls vertically, wraps text, and displays a border:
17.42.3.Using the ClipboardUsing the Clipboard
17.42.4.Draw a box around textDraw a box around text
17.42.5.StyledText: embed imagesStyledText: embed images
17.42.6.StyledText: use gradient backgroundStyledText: use gradient background
17.42.7.StyledText: embed controlsStyledText: embed controls
17.42.8.Getting Statistics: Caret Offset, Total Lines of Text, Total Characters and Current LineGetting Statistics: Caret Offset, Total Lines of Text, Total Characters and Current Line
17.42.9.Print StyledText outPrint StyledText out
17.42.10.Print to the default printer in a separate thread
17.42.11.Set page format for printing
17.42.12.Make a StyledText read-only
17.42.13.Limit the number of characters that the StyledText acceptsLimit the number of characters that the StyledText accepts
17.42.14.Replace Text RangeReplace Text Range
17.42.15.Understanding the Repercussions
17.42.16.A simple editorA simple editor