Java Tutorial/SWT/Clipboard

Clipboard: enable/disable menu depending on clipboard content availability

/*******************************************************************************
 * Copyright (c) 2000, 2004 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
 *******************************************************************************/
/*
 * Clipboard example snippet: enable/disable menu depending on clipboard content availability
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.0
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.dnd.TransferData;
import org.eclipse.swt.events.MenuAdapter;
import org.eclipse.swt.events.MenuEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class MenuDisableEnableClipBoard {
  public static void main(String[] args) {
    Display display = new Display();
    final Clipboard cb = new Clipboard(display);
    Shell shell = new Shell(display);
    shell.setLayout(new FillLayout());
    final Text text = new Text(shell, SWT.BORDER | SWT.MULTI | SWT.WRAP);
    Menu menu = new Menu(shell, SWT.POP_UP);
    final MenuItem copyItem = new MenuItem(menu, SWT.PUSH);
    copyItem.setText("Copy");
    copyItem.addSelectionListener(new SelectionAdapter() {
      public void widgetSelected(SelectionEvent e) {
        String selection = text.getSelectionText();
        if (selection.length() == 0)
          return;
        Object[] data = new Object[] { selection };
        Transfer[] types = new Transfer[] { TextTransfer.getInstance() };
        cb.setContents(data, types);
      }
    });
    final MenuItem pasteItem = new MenuItem(menu, SWT.PUSH);
    pasteItem.setText("Paste");
    pasteItem.addSelectionListener(new SelectionAdapter() {
      public void widgetSelected(SelectionEvent e) {
        String string = (String) (cb.getContents(TextTransfer.getInstance()));
        if (string != null)
          text.insert(string);
      }
    });
    menu.addMenuListener(new MenuAdapter() {
      public void menuShown(MenuEvent e) {
        // is copy valid?
        String selection = text.getSelectionText();
        copyItem.setEnabled(selection.length() > 0);
        // is paste valid?
        TransferData[] available = cb.getAvailableTypes();
        boolean enabled = false;
        for (int i = 0; i < available.length; i++) {
          if (TextTransfer.getInstance().isSupportedType(available[i])) {
            enabled = true;
            break;
          }
        }
        pasteItem.setEnabled(enabled);
      }
    });
    text.setMenu(menu);
    shell.setSize(200, 200);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    cb.dispose();
    display.dispose();
  }
}

Using ClipBoard to copy and paste

import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class ClipBoardCopyPaster {
public static void main( String[] args) {
  Display display = new Display ();
  final Clipboard cb = new Clipboard(display);
  final Shell shell = new Shell (display);
  final Text text = new Text(shell, SWT.BORDER | SWT.SINGLE);
  text.setBounds(5,5,100,20);
  
  Button copy = new Button(shell, SWT.PUSH);
  copy.setBounds(5,50,100,20);
  copy.setText("Copy");
  copy.addListener (SWT.Selection, new Listener () {
    public void handleEvent (Event e) {
      String textData = text.getSelectionText();
      if (textData.length() > 0) {
        TextTransfer textTransfer = TextTransfer.getInstance();
        cb.setContents(new Object[]{textData}, new Transfer[]{textTransfer});
      }
    }
  });
  
  Button paste = new Button(shell, SWT.PUSH);
  paste.setBounds(5,90,100,20);
  paste.setText("Paste");
  paste.addListener (SWT.Selection, new Listener () {
    public void handleEvent (Event e) {
      TextTransfer transfer = TextTransfer.getInstance();
      String data = (String)cb.getContents(transfer);
      if (data != null) {
        text.insert(data);
      }
    }
  });
  
  shell.setSize(200, 200);
  shell.open();
  while (!shell.isDisposed ()) {
    if (!display.readAndDispatch ()) display.sleep ();
  }
  cb.dispose();
  display.dispose();
}
}