repeatingbutton.java

mywork是rcp开发的很好的例子

/*

 *  RepeatingButton.java  - A push button that repeats selection event based on timer.

 *  Author: Sergey Prigogin

 *  swtcalendar.sourceforge.net

 *

 *  This program is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Lesser General Public License

 *  as published by the Free Software Foundation; either version 2

 *  of the License, or (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU Lesser General Public License for more details.

 *

 *  You should have received a copy of the GNU Lesser General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */
package net.sf.component.calendar;

import java.util.ArrayList;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseTrackAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;

/**
 * 
 * Push button that repeats selection event based on timer.
 * 
 */
public class RepeatingButton extends Button {
	public static final int DEFAULT_INITIAL_REPEAT_DELAY = 200; // Milliseconds

	public static final int DEFAULT_REPEAT_DELAY = 50; // Milliseconds

	private int initialRepeatDelay = DEFAULT_INITIAL_REPEAT_DELAY;

	private int repeatDelay = DEFAULT_REPEAT_DELAY;

	private ArrayList selectionListeners = new ArrayList(3);

	private Repeater repeater;

	/**
	 * 
	 * @param parent
	 *            Parent container.
	 * 
	 * @param style
	 *            Button style.
	 * 
	 */
	public RepeatingButton(Composite parent, int style) {
		super(parent, style);
		addMouseListener(new MouseAdapter() {
			public void mouseDown(MouseEvent event) {
				cancelRepeater();
				if (event.button == 1) { // Left click
					buttonPressed(event.stateMask, event.time);
					repeater = new Repeater(event.stateMask);
					getDisplay().timerExec(initialRepeatDelay, repeater);
				}
			}

			public void mouseUp(MouseEvent event) {
				if (event.button == 1) { // Left click
					cancelRepeater();
				}
			}
		});
		addMouseTrackListener(new MouseTrackAdapter() {
			public void mouseExit(MouseEvent e) {
				cancelRepeater();
			}
		});
	}

	public void addSelectionListener(SelectionListener listener) {
		selectionListeners.add(listener);
	}

	public void removeSelectionListener(SelectionListener listener) {
		selectionListeners.remove(listener);
	}

	/**
	 * 
	 * @return Returns the initial repeat delay in milliseconds.
	 * 
	 */
	public int getInitialRepeatDelay() {
		return initialRepeatDelay;
	}

	/**
	 * 
	 * @param initialRepeatDelay
	 *            The new initial repeat delay in milliseconds.
	 * 
	 */
	public void setInitialRepeatDelay(int initialRepeatDelay) {
		this.initialRepeatDelay = initialRepeatDelay;
	}

	/**
	 * 
	 * @return Returns the repeat delay in millisecons.
	 * 
	 */
	public int getRepeatDelay() {
		return repeatDelay;
	}

	/**
	 * 
	 * @param repeatDelay
	 *            The new repeat delay in milliseconds.
	 * 
	 */
	public void setRepeatDelay(int repeatDelay) {
		this.repeatDelay = repeatDelay;
	}

	private void buttonPressed(int stateMask, int time) {
		SelectionListener[] listeners = new SelectionListener[selectionListeners.size()];
		selectionListeners.toArray(listeners);
		for (int i = 0; i < listeners.length; i++) {
			SelectionListener l = listeners[i];
			Event event = new Event();
			event.type = SWT.Selection;
			event.display = getDisplay();
			event.widget = this;
			event.stateMask = stateMask;
			event.time = time;
			l.widgetSelected(new SelectionEvent(event));
		}
	}

	private void cancelRepeater() {
		if (repeater != null) {
			repeater.cancel();
			repeater = null;
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.widgets.Widget#checkSubclass()
	 * 
	 */
	protected void checkSubclass() {
	}

	private class Repeater implements Runnable {
		private boolean canceled;

		private int stateMask;

		public Repeater(int stateMask) {
			super();
			this.stateMask = stateMask;
		}

		/*
		 * (non-Javadoc)
		 * 
		 * @see java.lang.Runnable#run()
		 * 
		 */
		public void run() {
			if (!canceled) {
				buttonPressed(stateMask, (int) System.currentTimeMillis());
				getDisplay().timerExec(repeatDelay, this);
			}
		}

		public void cancel() {
			canceled = true;
		}
	}
}