Mega Code Archive
Draws a small dot where the user clicks the mouse
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Also reports the x, y location of the cursor and of the most recent mouse click.
/*
*
* 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) {
}
}
}
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