CoordinatesDemo.java Source code

Introduction

Here is the source code for CoordinatesDemo.java

Source

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Point;
import java.awt.event.MouseEvent;

import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.event.MouseInputListener;

public class CoordinatesDemo {
    private JLabel label;

    private Point clickPoint, cursorPoint;

    private void buildUI(Container container) {
        container.setLayout(new BoxLayout(container, BoxLayout.PAGE_AXIS));

        CoordinateArea coordinateArea = new CoordinateArea(this);
        container.add(coordinateArea);

        label = new JLabel();
        resetLabel();
        container.add(label);

        coordinateArea.setAlignmentX(Component.LEFT_ALIGNMENT);
        label.setAlignmentX(Component.LEFT_ALIGNMENT); // redundant
    }

    public void updateCursorLocation(int x, int y) {
        if (x < 0 || y < 0) {
            cursorPoint = null;
            updateLabel();
            return;
        }

        if (cursorPoint == null) {
            cursorPoint = new Point();
        }

        cursorPoint.x = x;
        cursorPoint.y = y;
        updateLabel();
    }

    public void updateClickPoint(Point p) {
        clickPoint = p;
        updateLabel();
    }

    public void resetLabel() {
        cursorPoint = null;
        updateLabel();
    }

    protected void updateLabel() {
        String text = "";

        if ((clickPoint == null) && (cursorPoint == null)) {
            text = "Click or move the cursor within the framed area.";
        } else {

            if (clickPoint != null) {
                text += "The last click was at (" + clickPoint.x + ", " + clickPoint.y + "). ";
            }

            if (cursorPoint != null) {
                text += "The cursor is at (" + cursorPoint.x + ", " + cursorPoint.y + "). ";
            }
        }

        label.setText(text);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("CoordinatesDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        CoordinatesDemo controller = new CoordinatesDemo();
        controller.buildUI(frame.getContentPane());

        frame.pack();
        frame.setVisible(true);
    }

    public static class CoordinateArea extends JComponent implements MouseInputListener {
        Point point = null;

        CoordinatesDemo controller;

        Dimension preferredSize = new Dimension(400, 75);

        Color gridColor;

        public CoordinateArea(CoordinatesDemo controller) {
            this.controller = controller;

            // Add a border of 5 pixels at the left and bottom,
            // and 1 pixel at the top and right.
            setBorder(BorderFactory.createMatteBorder(1, 5, 5, 1, Color.RED));

            addMouseListener(this);
            addMouseMotionListener(this);
            setBackground(Color.WHITE);
            setOpaque(true);
        }

        public Dimension getPreferredSize() {
            return preferredSize;
        }

        protected void paintComponent(Graphics g) {
            // Paint background if we're opaque.
            if (isOpaque()) {
                g.setColor(getBackground());
                g.fillRect(0, 0, getWidth(), getHeight());
            }

            // Paint 20x20 grid.
            g.setColor(Color.GRAY);
            drawGrid(g, 20);

            // If user has chosen a point, paint a small dot on top.
            if (point != null) {
                g.setColor(getForeground());
                g.fillRect(point.x - 3, point.y - 3, 7, 7);
            }
        }

        // Draws a 20x20 grid using the current color.
        private void drawGrid(Graphics g, int gridSpace) {
            Insets insets = getInsets();
            int firstX = insets.left;
            int firstY = insets.top;
            int lastX = getWidth() - insets.right;
            int lastY = getHeight() - insets.bottom;

            // Draw vertical lines.
            int x = firstX;
            while (x < lastX) {
                g.drawLine(x, firstY, x, lastY);
                x += gridSpace;
            }

            // Draw horizontal lines.
            int y = firstY;
            while (y < lastY) {
                g.drawLine(firstX, y, lastX, y);
                y += gridSpace;
            }
        }

        // Methods required by the MouseInputListener interface.
        public void mouseClicked(MouseEvent e) {
            int x = e.getX();
            int y = e.getY();
            if (point == null) {
                point = new Point(x, y);
            } else {
                point.x = x;
                point.y = y;
            }
            controller.updateClickPoint(point);
            repaint();
        }

        public void mouseMoved(MouseEvent e) {
            controller.updateCursorLocation(e.getX(), e.getY());
        }

        public void mouseExited(MouseEvent e) {
            controller.resetLabel();
        }

        public void mouseReleased(MouseEvent e) {
        }

        public void mouseEntered(MouseEvent e) {
        }

        public void mousePressed(MouseEvent e) {
        }

        public void mouseDragged(MouseEvent e) {
        }
    }
}