Java Tutorial/2D Graphics/Mouse Draw
Содержание
Draws a small dot where the user clicks the mouse
Also reports the x, y location of the cursor and of the most recent mouse click.
<source lang="java">
/*
*
* 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
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import java.awt.Color; import java.awt.ruponent; 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) {
}
}
}</source>
Mouse drag and draw
<source lang="java">
import java.awt.AlphaComposite; import java.awt.BasicStroke; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Point; import java.awt.RenderingHints; import java.awt.Shape; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionAdapter; import java.awt.geom.Line2D; import java.awt.geom.Rectangle2D; import java.util.ArrayList; import javax.swing.JComponent; import javax.swing.JFrame; public class DrawingBoardWithMatrix extends JFrame {
public static void main(String[] args) {
new DrawingBoardWithMatrix();
}
public DrawingBoardWithMatrix() {
this.setSize(300, 300);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(new PaintSurface(), BorderLayout.CENTER);
this.setVisible(true);
}
private class PaintSurface extends JComponent {
ArrayList<Shape> shapes = new ArrayList<Shape>();
Point startDrag, endDrag;
public PaintSurface() {
this.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
startDrag = new Point(e.getX(), e.getY());
endDrag = startDrag;
repaint();
}
public void mouseReleased(MouseEvent e) {
Shape r = makeRectangle(startDrag.x, startDrag.y, e.getX(), e.getY());
shapes.add(r);
startDrag = null;
endDrag = null;
repaint();
}
});
this.addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
endDrag = new Point(e.getX(), e.getY());
repaint();
}
});
}
private void paintBackground(Graphics2D g2){
g2.setPaint(Color.LIGHT_GRAY);
for (int i = 0; i < getSize().width; i += 10) {
Shape line = new Line2D.Float(i, 0, i, getSize().height);
g2.draw(line);
}
for (int i = 0; i < getSize().height; i += 10) {
Shape line = new Line2D.Float(0, i, getSize().width, i);
g2.draw(line);
}
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
paintBackground(g2);
Color[] colors = { Color.YELLOW, Color.MAGENTA, Color.CYAN , Color.RED, Color.BLUE, Color.PINK};
int colorIndex = 0;
g2.setStroke(new BasicStroke(2));
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.50f));
for (Shape s : shapes) {
g2.setPaint(Color.BLACK);
g2.draw(s);
g2.setPaint(colors[(colorIndex++) % 6]);
g2.fill(s);
}
if (startDrag != null && endDrag != null) {
g2.setPaint(Color.LIGHT_GRAY);
Shape r = makeRectangle(startDrag.x, startDrag.y, endDrag.x, endDrag.y);
g2.draw(r);
}
}
private Rectangle2D.Float makeRectangle(int x1, int y1, int x2, int y2) {
return new Rectangle2D.Float(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));
}
}
}</source>
Save Your Drawing To a File
<source lang="java">
import java.awt.BorderLayout; import java.awt.Color; import java.awt.Graphics; import java.awt.Panel; import java.awt.Point; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.util.ArrayList; import java.util.List; import java.util.Vector; import javax.swing.JButton; import javax.swing.JFrame; public class SaveYourDrawingToFile extends JFrame implements MouseListener, ActionListener {
List<Point> displayList = new ArrayList<Point>();
String pathname = "data.dat";
JButton clearBtn = new JButton("Clear");
JButton saveBtn = new JButton("Save");
JButton restoreBtn = new JButton("Restore");
JButton quitBtn = new JButton("Quit");
public static void main(String args[]) {
SaveYourDrawingToFile that = new SaveYourDrawingToFile();
that.setVisible(true);
}
public SaveYourDrawingToFile() {
addMouseListener(this);
setLayout(new BorderLayout());
Panel pan = new Panel();
clearBtn.addActionListener(this);
pan.add(clearBtn);
saveBtn.addActionListener(this);
pan.add(saveBtn);
restoreBtn.addActionListener(this);
pan.add(restoreBtn);
quitBtn.addActionListener(this);
pan.add(quitBtn);
add("North", pan);
setSize(350, 200);
}
public void paint(Graphics g) {
g.setColor(Color.white);
g.fillRect(0, 0, getSize().width, getSize().height);
g.setColor(Color.black);
int i = 0;
while (i < displayList.size()) {
Point p0 = (Point) (displayList.get(i++));
Point p1 = (Point) (displayList.get(i++));
int x = Math.min(p0.x, p1.x);
int y = Math.min(p0.y, p1.y);
int w = Math.abs(p0.x - p1.x);
int h = Math.abs(p0.y - p1.y);
g.drawRect(x, y, w, h);
}
}
public void mousePressed(MouseEvent e) {
Point p = new Point(e.getX(), e.getY());
displayList.add(p);
}
public void mouseReleased(MouseEvent e) {
Point p = new Point(e.getX(), e.getY());
displayList.add(p);
repaint();
}
public void mouseClicked(MouseEvent e) {
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == clearBtn) {
displayList = new Vector();
repaint();
} else if (e.getSource() == saveBtn) {
try {
FileOutputStream fos = new FileOutputStream(pathname);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(displayList);
oos.flush();
oos.close();
fos.close();
} catch (Exception ex) {
System.out.println("Trouble writing display list vector");
}
} else if (e.getSource() == restoreBtn) {
try {
FileInputStream fis = new FileInputStream(pathname);
ObjectInputStream ois = new ObjectInputStream(fis);
displayList = (Vector) (ois.readObject());
ois.close();
fis.close();
repaint();
} catch (Exception ex) {
System.out.println("Trouble reading display list vector");
}
} else if (e.getSource() == quitBtn) {
setVisible(false);
dispose();
System.exit(0);
}
}
}</source>
Select the Ellipse to Move It in the Canvas
<source lang="java">
import java.awt.Canvas; import java.awt.Color; import java.awt.Cursor; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionAdapter; import java.awt.geom.Ellipse2D; import java.awt.geom.Rectangle2D; import javax.swing.JFrame; public class CircleWithHandles extends JFrame {
DrawingCanvas canvas = new DrawingCanvas();
public CircleWithHandles() {
getContentPane().add(canvas);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setVisible(true);
}
public static void main(String arg[]) {
new CircleWithHandles();
}
class DrawingCanvas extends Canvas {
double x = 20, y = 20, w = 50, h = 50;
int x1, y1, x2, y2;
Ellipse2D ellipse;
Ellipse2D selectedShape;
Rectangle2D handleRectangle;
Cursor curCursor;
public DrawingCanvas() {
setBackground(Color.white);
addMouseListener(new MyMouseListener());
addMouseMotionListener(new MyMouseMotionListener());
setSize(400, 300);
}
public void paint(Graphics g) {
Graphics2D g2D = (Graphics2D) g;
ellipse = new Ellipse2D.Double(x, y, w, h);
g2D.draw(ellipse);
if (handleRectangle != null) {
drawHighlightSquares(g2D, handleRectangle);
}
if (curCursor != null)
setCursor(curCursor);
}
public void drawHighlightSquares(Graphics2D g2D, Rectangle2D r) {
double x = r.getX();
double y = r.getY();
double w = r.getWidth();
double h = r.getHeight();
g2D.setColor(Color.black);
g2D.fill(new Rectangle.Double(x - 3.0, y - 3.0, 6.0, 6.0));
g2D.fill(new Rectangle.Double(x + w * 0.5 - 3.0, y - 3.0, 6.0, 6.0));
g2D.fill(new Rectangle.Double(x + w - 3.0, y - 3.0, 6.0, 6.0));
g2D.fill(new Rectangle.Double(x - 3.0, y + h * 0.5 - 3.0, 6.0, 6.0));
g2D.fill(new Rectangle.Double(x + w - 3.0, y + h * 0.5 - 3.0, 6.0, 6.0));
g2D.fill(new Rectangle.Double(x - 3.0, y + h - 3.0, 6.0, 6.0));
g2D.fill(new Rectangle.Double(x + w * 0.5 - 3.0, y + h - 3.0, 6.0, 6.0));
g2D.fill(new Rectangle.Double(x + w - 3.0, y + h - 3.0, 6.0, 6.0));
}
class MyMouseListener extends MouseAdapter {
public void mousePressed(MouseEvent e) {
if (ellipse.contains(e.getX(), e.getY())) {
selectedShape = ellipse;
if (handleRectangle != null)
handleRectangle = ellipse.getBounds2D();
} else {
handleRectangle = null;
}
canvas.repaint();
x1 = e.getX();
y1 = e.getY();
}
public void mouseReleased(MouseEvent e) {
if (ellipse.contains(e.getX(), e.getY())) {
handleRectangle = ellipse.getBounds2D();
selectedShape = ellipse;
}
canvas.repaint();
}
public void mouseClicked(MouseEvent e) {
if (ellipse.contains(e.getX(), e.getY())) {
selectedShape = ellipse;
handleRectangle = ellipse.getBounds2D();
} else {
if (handleRectangle != null)
handleRectangle = null;
}
canvas.repaint();
}
}
class MyMouseMotionListener extends MouseMotionAdapter {
public void mouseDragged(MouseEvent e) {
if (ellipse.contains(e.getX(), e.getY())) {
handleRectangle = null;
selectedShape = ellipse;
x2 = e.getX();
y2 = e.getY();
x = x + x2 - x1;
y = y + y2 - y1;
x1 = x2;
y1 = y2;
}
canvas.repaint();
}
public void mouseMoved(MouseEvent e) {
if (ellipse != null) {
if (ellipse.contains(e.getX(), e.getY())) {
curCursor = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
} else {
curCursor = Cursor.getDefaultCursor();
}
}
canvas.repaint();
}
}
}
}</source>
The SimpleDraw application
<source lang="java">
import java.awt.BorderLayout; import java.awt.FlowLayout; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import java.awt.Shape; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.util.ArrayList; import javax.swing.ButtonGroup; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JRadioButton; public class SimpleDraw extends JFrame
implements ActionListener, MouseListener {
// (x1,y1) = coordinate of mouse pressed
// (x2,y2) = coordinate of mouse released
int x1;
int y1;
int x2;
int y2;
ArrayList<Shape> shapes = new ArrayList<Shape>();
String shapeType = "Rectangle";
public SimpleDraw() {
this.setTitle("Simple DRAW");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// add check box group
ButtonGroup cbg = new ButtonGroup();
JRadioButton lineButton = new JRadioButton("Line");
JRadioButton ovalButton = new JRadioButton("Oval");
JRadioButton rectangleButton =
new JRadioButton("Rectangle");
cbg.add(lineButton);
cbg.add(ovalButton);
cbg.add(rectangleButton);
lineButton.addActionListener(this);
ovalButton.addActionListener(this);
rectangleButton.addActionListener(this);
rectangleButton.setSelected(true);
JPanel radioPanel = new JPanel(new FlowLayout());
radioPanel.add(lineButton);
radioPanel.add(ovalButton);
radioPanel.add(rectangleButton);
this.addMouseListener(this);
this.setLayout(new BorderLayout());
this.add(radioPanel, BorderLayout.NORTH);
}
public void paint(Graphics g) {
paintComponents(g);
for (Shape shape : shapes) {
Graphics2D g2 = (Graphics2D)g;
g2.draw(shape);
}
}
public void actionPerformed(ActionEvent ae) {
shapeType = ae.getActionCommand().toString();
}
public void mouseClicked(MouseEvent me) {
}
public void mouseEntered(MouseEvent me) {
}
public void mouseExited(MouseEvent me) {
}
public void mousePressed(MouseEvent me) {
x1 = me.getX();
y1 = me.getY();
}
public void mouseReleased(MouseEvent me) {
x2 = me.getX();
y2 = me.getY();
Shape shape = null;
if (shapeType.equals("Rectangle")) {
// a Rectangle cannot have a zero width or height
if (x1 != x2 || y1 != y2) {
shape = new Rectangle(x1, y1, x2, y2);
}
}
if (shape != null) {
this.shapes.add(shape);
this.repaint();
}
}
public static void main(String[] args) {
JFrame.setDefaultLookAndFeelDecorated(true);
SimpleDraw frame = new SimpleDraw();
frame.pack();
frame.setVisible(true);
}
}</source>
