Question: Need help writing Java Code. Some codes are given to assist. use JComponent. The Graphics2D class provides the draw method for drawing Shape objects, as
Need help writing Java Code. Some codes are given to assist. use JComponent.
The Graphics2D class provides the draw method for drawing Shape objects, as in this simple example:
g2d.draw( new Rectangle( x, y, w, h ) );
public void paintComponent( Graphics g ) { super.paintComponent( g ); Graphics2D g2d = (Graphics2D) g; }
public class GraphicView extends JPanel {
/**
* Informs the Easel of what type of shape to generate.
*/
private class ShapeListener implements ActionListener {
@Override
public void actionPerformed(final ActionEvent e) {
final String type = ((JButton) e.getSource()).getText();
GraphicView.this.easel.defineShape(type);
}
}
/**
* @param args
*/
public static void main(final String[] args) {
final Model model = new Model();
final GraphicView view = new GraphicView(model);
final JFrame f = new JFrame("Draw Test");
f.setContentPane(view);
f.setSize(500, 300);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
private final JButton circle = new JButton("Circle");
private final Easel easel;
private final JButton line = new JButton("Line");
private Model model = null;
private final JButton rectangle = new JButton("Rectangle");
/**
* Lays out the view and registers the button listeners.
*
* @param newModel
* the model to view.
*/
public GraphicView(final Model model) {
this.model = model;
this.easel = new Easel(this.model);
this.layoutView();
this.registerListeners();
}
/**
* Lays out the graphic components.
*/
private void layoutView() {
final JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new GridLayout(3, 1));
buttonPanel.add(this.line);
buttonPanel.add(this.circle);
buttonPanel.add(this.rectangle);
this.setLayout(new BorderLayout());
this.add(buttonPanel, BorderLayout.WEST);
this.add(this.easel, BorderLayout.CENTER);
}
/**
* Registers the button listeners.
*/
private void registerListeners() {
this.line.addActionListener(new ShapeListener());
this.circle.addActionListener(new ShapeListener());
this.rectangle.addActionListener(new ShapeListener());
}
}
public class Easel extends JComponent {
/**
* Repaints the easel whenever the model is updated.
*/
private class ModelListener implements PropertyChangeListener {
@Override
public void propertyChange(final PropertyChangeEvent evt) {
Easel.this.repaint();
}
}
private Model model = null;
/**
* The Easel needs direct access to the Model.
*
* @param newModel
* the Model to access.
*/
public Easel(final Model model) {
this.model = model;
this.registerListeners();
}
/**
* Randomly defines a shape based upon the current size of the easel. The
* new shape is passed back to the model to be stored.
*
* @param t
* the type of shape to define.
*/
public void defineShape(final String t) {
final int x1 = (int) (Math.random() * this.getWidth());
final int y1 = (int) (Math.random() * this.getHeight());
final int x2 = (int) (Math.random() * this.getWidth());
final int y2 = (int) (Math.random() * this.getHeight());
if (t.equals("Rectangle")) {
this.model.addShape(new Rectangle(x1, y1, x2, y2));
} else if (t.equals("Line")) {
this.model.addShape(new Line2D.Double(x1, y1, x2, y2));
} else if (t.equals("Circle")) {
this.model.addShape(new Circle(x1, y1, x2));
}
}
/*
* (non-Javadoc)
*
* @see javax.swing.JComponent#paintComponent(java.awt.Graphics)
*/
@Override
public void paintComponent(final Graphics g) {
final Graphics2D g2d = (Graphics2D) g;
// Get a snapshot of the list of shapes in the model. Draw each in turn.
final Iterator i = this.model.getShapesIterator();
while (i.hasNext()) {
g2d.draw(i.next());
}
}
/**
* Registers the model listener.
*/
private void registerListeners() {
this.model.addPropertyChangeListener(new ModelListener());
}
}
class Circle extends Ellipse2D.Double {
public Circle(final double centerX, final double centerY, final double radius) {
// Call the Ellipse constructure with major and minor axes the same
// size.
super(centerX - radius, centerY - radius, 2.0 * radius, 2.0 * radius);
}
}
Fill every shape with a random color when it is displayed Add another button that allows polygons of 3 to 8 sides (choose randomly) to be added to the model and canvas. Add a textfield that allows the user to add text at random positions on the canvas. (Hint:strings are not shapes- you'll need a list of strings
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