MouseDrag.java Source code

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Here is the source code for MouseDrag.java

Source

/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
 * All rights reserved. Software written by Ian F. Darwin and others.
 * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
 * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
 * pioneering role in inventing and promulgating (and standardizing) the Java 
 * language and environment is gratefully acknowledged.
 * 
 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
 * inventing predecessor languages C and C++ is also gratefully acknowledged.
 */

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Label;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.JFrame;

/**
 * MouseDrag -- implement simple mouse drag in a window.
 */
public class MouseDrag extends Component implements MouseListener, MouseMotionListener {
    /** The Image we are to paint */
    Image curImage;

    /** Kludge for showStatus */
    static Label status;

    /** true if we are in drag */
    boolean inDrag = false;

    /** starting location of a drag */
    int startX = -1, startY = -1;

    /** current location of a drag */
    int curX = -1, curY = -1;

    // "main" method
    public static void main(String[] av) {
        JFrame f = new JFrame("Mouse Dragger");
        Container cp = f.getContentPane();

        if (av.length < 1) {
            System.err.println("Usage: MouseDrag imagefile");
            System.exit(1);
        }
        Image im = Toolkit.getDefaultToolkit().getImage(av[0]);

        // create a MouseDrag object
        MouseDrag j = new MouseDrag(im);

        cp.setLayout(new BorderLayout());
        cp.add(BorderLayout.NORTH, new Label("Hello, and welcome to the world of Java"));
        cp.add(BorderLayout.CENTER, j);
        cp.add(BorderLayout.SOUTH, status = new Label());
        status.setSize(f.getSize().width, status.getSize().height);
        f.pack();
        f.setVisible(true);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    // "Constructor" - creates the object
    public MouseDrag(Image i) {
        super();
        curImage = i;
        setSize(300, 200);
        addMouseListener(this);
        addMouseMotionListener(this);
    }

    public void showStatus(String s) {
        status.setText(s);
    }

    // Five methods from MouseListener:
    /** Called when the mouse has been clicked on a component. */
    public void mouseClicked(MouseEvent e) {
    }

    /** Called when the mouse enters a component. */
    public void mouseEntered(MouseEvent e) {
    }

    /** Called when the mouse exits a component. */
    public void mouseExited(MouseEvent e) {
    }

    /** Called when the mouse has been pressed. */
    public void mousePressed(MouseEvent e) {
        Point p = e.getPoint();
        System.err.println("mousePressed at " + p);
        startX = p.x;
        startY = p.y;
        inDrag = true;
    }

    /** Called when the mouse has been released. */
    public void mouseReleased(MouseEvent e) {
        inDrag = false;
        System.err.println("SELECTION IS " + startX + "," + startY + " to " + curX + "," + curY);
    }

    // And two methods from MouseMotionListener:
    public void mouseDragged(MouseEvent e) {
        Point p = e.getPoint();
        // System.err.println("mouse drag to " + p);
        showStatus("mouse Dragged to " + p);
        curX = p.x;
        curY = p.y;
        if (inDrag) {
            repaint();
        }
    }

    public void paint(Graphics g) {
        int w = curX - startX, h = curY - startY;
        Dimension d = getSize();
        g.drawImage(curImage, 0, 0, d.width, d.height, this);
        if (startX < 0 || startY < 0)
            return;
        System.err.println("paint:drawRect @[" + startX + "," + startY + "] size " + w + "x" + h);
        g.setColor(Color.red);
        g.fillRect(startX, startY, w, h);
    }

    public void mouseMoved(MouseEvent e) {
        showStatus("mouse Moved to " + e.getPoint());
    }

}