以下是代码:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
/**
* Winter Assignment for Java 2012/13
*/
// Class definition
public class Main extends JPanel implements ActionListener {
private JSlider sizeslider;
private int startX, startY, endX, endY, val;
private Color shapeColor = Color.black;
private JComboBox shapeChoice, colorChoice;
private Point firstPoint;
private Circle firstCircle;
private Square firstSquare;
private Doughnut firstDoughnut;
private Triangle firstTriangle;
private Pentagon firstPentagon;
private Point aShape;
static final int SlideMin = 10;
static final int SlideMax = 110;
static final int SlideInit = 50;
// Constructor method declaration
public Main() {
//Create the slider.
sizeslider = new JSlider(JSlider.HORIZONTAL, SlideMin, SlideMax, SlideInit);
add(sizeslider, BorderLayout.NORTH);
shapeChoice = new JComboBox();
shapeChoice.addItem("Point");
shapeChoice.addItem("Square");
shapeChoice.addItem("Circle");
shapeChoice.addItem("Doughnut");
shapeChoice.addItem("Triangle");
shapeChoice.addItem("Pentagon");
add(shapeChoice);
shapeChoice.addActionListener(this);
colorChoice = new JComboBox();
colorChoice.addItem("Black");
colorChoice.addItem("Red");
colorChoice.addItem("Green");
colorChoice.addItem("Blue");
colorChoice.addItem("Yellow");
colorChoice.addItem("Purple");
colorChoice.addItem("Turquoise");
add(colorChoice);
colorChoice.addActionListener(this);
this.addMouseListener(new MouseAdapter() {
public void mouseReleased(MouseEvent me) {
repaint();
}
public void mouseDragged(MouseEvent me) {
aShape.moveXY(me.getX(), me.getY());
repaint();
}
});
this.addMouseMotionListener(new MouseAdapter() {
public void mouseReleased(MouseEvent me) {
repaint();
}
public void mouseDragged(MouseEvent me) {
aShape.moveXY(me.getX(), me.getY());
repaint();
}
});
sizeslider.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider)e.getSource(); // get the slider
if (!source.getValueIsAdjusting()) {
val = source.getValue(); // get slider value
aShape.reSize(val);
repaint();
}
}
});
// Instantiate shape classes
firstPoint = new Point();
firstCircle = new Circle();
firstSquare = new Square();
firstDoughnut = new Doughnut();
firstTriangle = new Triangle();
firstPentagon = new Pentagon();
// Initially assign aShape a Point object
aShape = firstPoint;
// Create a new window using the Swing class JFrame and add this panel
makeFrame();
}
public void actionPerformed(ActionEvent e) {
// Manipulate respective object when buttons pressed
// checkbox assigns object to aShape
if (e.getSource() == shapeChoice) {
if (shapeChoice.getSelectedItem().equals("Circle"))
aShape = firstCircle;
else if (shapeChoice.getSelectedItem().equals("Square"))
aShape = firstSquare;
else if (shapeChoice.getSelectedItem().equals("Point"))
aShape = firstPoint;
else if (shapeChoice.getSelectedItem().equals("Doughnut"))
aShape = firstDoughnut;
else if (shapeChoice.getSelectedItem().equals("Triangle"))
aShape = firstTriangle;
else if (shapeChoice.getSelectedItem().equals("Pentagon"))
aShape = firstPentagon;
}
// Assigns color to shape
else if (e.getSource() == colorChoice) {
if (colorChoice.getSelectedItem().equals("Black")) {
shapeColor = Color.black;
repaint();
}
else if (colorChoice.getSelectedItem().equals("Red")) {
shapeColor = Color.red;
repaint();
}
else if (colorChoice.getSelectedItem().equals("Green")) {
shapeColor = Color.green;
repaint();
}
else if (colorChoice.getSelectedItem().equals("Blue")) {
shapeColor = Color.blue;
repaint();
}
else if (colorChoice.getSelectedItem().equals("Yellow")) {
shapeColor = Color.yellow;
repaint();
}
else if (colorChoice.getSelectedItem().equals("Purple")) {
shapeColor = Color.decode("#9B30FF"); //Assignment said purple, but purple isn't defined in the Java api, so I used the hex code. The closest color in the API is Magenta.
repaint();
}
else if (colorChoice.getSelectedItem().equals("Turquoise")) {
shapeColor = Color.decode("#40E0D0"); //Turquoise hex code
repaint();
}
}
// Ask Java to repaint the window to reflect the updates made
repaint();
}
// Provide this method to instruct Java what to do when repainting the window
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(shapeColor);
// Call the respective methods from respective class to print the new co-ordinate values
aShape.outputXYCoords(g);
// Call the respective methods from respective class to redraw the shape
aShape.display(g);
}
// Create a window frame
public void makeFrame() {
// Instantiate a window frame using Swing class JFrame
JFrame frame = new JFrame("Winter Assignment");
// When the window is closed terminate the application
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
// set initial size of window
frame.setSize(800, 600);
// add the current object to the centre of the frame and make visible
frame.getContentPane().add(this, BorderLayout.CENTER);
frame.setVisible(true);
}
}
其中一个形状文件,它们都具有相同的结构:
Triangle.java
import java.awt.*;
public class Triangle extends Point {
protected int size;
private int p1x, p2x, p3x, p1y, p2y, p3y;
//Create a new triangle
public Triangle()
{
super();
size = 50;
yPos = 100;
}
public void reSize(int newSize) {
size = size + newSize;
}
//Draw the triangle with current specifications on screen.
public void display(Graphics g) {
p1x = xPos;
p2x = xPos + size/2;
p3x = xPos + size;
p1y = yPos + size;
p2y = yPos;
p3y = yPos + size;
int[] xPoints = { p1x, p2x, p3x };
int[] yPoints = { p1y, p2y, p3y };
int npoints = 3;
g.fillPolygon(xPoints, yPoints, npoints);
}
}
aShape.reSize(val);
通过增加滑块的值来增加形状的大小。我不确定如何解决它。还有一些垃圾代码,但我只是用它来引用发生的事情。
答案 0 :(得分:5)
我希望会发生什么:滑块会将形状调整为 它所带来的价值。
这是我做的一个简短的例子,它将广场的宽度和高度增加/减少到滑块上的数量,即在50处,正方形的宽度和高度为50,在60处它们是60,依此类推。 / p>
这是通过 getters and setters 来完成的,它允许访问实例字段,我们向ChangeListener
添加JSlider
以检测值的变化,并在那里我们使用设置器设置实例的值,然后调用repaint()
调用paintComponent
的{{1}},JPanel
将调用形状的draw(Graphcis2D g2d)
以反映容器上的更改:< / p>
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class ShapeAndSliderTest {
public ShapeAndSliderTest() {
createAndShowGui();
}
private void createAndShowGui() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
final MyRectangle myRectangle = new MyRectangle(10, 10, 50,50, Color.RED);
JSlider jslider = new JSlider();
jslider.setValue(50);
jslider.setMaximum(250);
jslider.setMinorTickSpacing(5);
jslider.setMajorTickSpacing(10);
jslider.setPaintTicks(true);
jslider.setPaintLabels(true);
// We'll just use the standard numeric labels for now...
jslider.setLabelTable(jslider.createStandardLabels(50));
final JPanel panel = new JPanel() {
@Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
Graphics2D g2d = (Graphics2D) grphcs;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
myRectangle.draw(g2d);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
};
jslider.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent ce) {
JSlider slider = (JSlider) ce.getSource();
if (!slider.getValueIsAdjusting()) {
int newW = slider.getValue();
int newH = slider.getValue();
myRectangle.setWidth(newW);
myRectangle.setHeight(newH);
System.out.println(newW + "," + newH);
panel.repaint();
}
}
});
frame.add(jslider, BorderLayout.SOUTH);
frame.add(panel, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new ShapeAndSliderTest();
}
});
}
}
class MyRectangle {
private int x, y, width, height;
private final Color color;
public MyRectangle(int x, int y, int w, int h, Color color) {
this.x = x;
this.y = y;
this.width = w;
this.height = h;
this.color = color;
}
void draw(Graphics2D g2d) {
Color prevState = g2d.getColor();
g2d.setColor(color);
g2d.drawRect(x, y, width, height);
g2d.setColor(prevState);
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
public void setWidth(int w) {
this.width = w;
}
public void setHeight(int h) {
this.height = h;
}
public int getHeight() {
return height;
}
public int getWidth() {
return width;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
}