Java project question:

You are given two separate JPanels, DrawArcs.java(Fan) and StillClock.java(clock)

Use your own thread to give them a life, that means make the clock to work in realtime, and Fan

To start. Use your own GUI to start and stop as you wish.

DrawArcs.java:

import javax.swing.JFrame; import javax.swing.JPanel; import java.awt.Graphics;

public class DrawArcs extends JFrame { public DrawArcs() { setTitle("DrawArcs"); add(new ArcsPanel()); }

/** Main method */ public static void main(String[] args) { DrawArcs frame = new DrawArcs(); frame.setLocationRelativeTo(null); // Center the frame frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(250, 300); frame.setVisible(true); } }

// The class for drawing arcs on a panel class ArcsPanel extends JPanel { @Override protected void paintComponent(Graphics g) { super.paintComponent(g);

int xCenter = getWidth() / 2; int yCenter = getHeight() / 2; int radius = (int)(Math.min(getWidth(), getHeight()) * 0.4);

int x = xCenter - radius; int y = yCenter - radius;

g.fillArc(x, y, 2 * radius, 2 * radius, 0, 30); g.fillArc(x, y, 2 * radius, 2 * radius, 90, 30); g.fillArc(x, y, 2 * radius, 2 * radius, 180, 30); g.fillArc(x, y, 2 * radius, 2 * radius, 270, 30); } }

StillClock.java:

import java.awt.*; import javax.swing.*; import java.util.*;

public class StillClock extends JPanel { private int hour; private int minute; private int second;

/** Construct a default clock with the current time*/ public StillClock() { setCurrentTime(); }

/** Construct a clock with specified hour, minute, and second */ public StillClock(int hour, int minute, int second) { this.hour = hour; this.minute = minute; this.second = second; }

/** Return hour */ public int getHour() { return hour; }

/** Set a new hour */ public void setHour(int hour) { this.hour = hour; repaint(); }

/** Return minute */ public int getMinute() { return minute; }

/** Set a new minute */ public void setMinute(int minute) { this.minute = minute; repaint(); }

/** Return second */ public int getSecond() { return second; }

/** Set a new second */ public void setSecond(int second) { this.second = second; repaint(); }

@Override /** Draw the clock */ protected void paintComponent(Graphics g) { super.paintComponent(g);

// Initialize clock parameters int clockRadius = (int)(Math.min(getWidth(), getHeight()) * 0.8 * 0.5); int xCenter = getWidth() / 2; int yCenter = getHeight() / 2;

// Draw circle g.setColor(Color.black); g.drawOval(xCenter - clockRadius, yCenter - clockRadius, 2 * clockRadius, 2 * clockRadius); g.drawString("12", xCenter - 5, yCenter - clockRadius + 12); g.drawString("9", xCenter - clockRadius + 3, yCenter + 5); g.drawString("3", xCenter + clockRadius - 10, yCenter + 3); g.drawString("6", xCenter - 3, yCenter + clockRadius - 3);

// Draw second hand int sLength = (int)(clockRadius * 0.8); int xSecond = (int)(xCenter + sLength * Math.sin(second * (2 * Math.PI / 60))); int ySecond = (int)(yCenter - sLength * Math.cos(second * (2 * Math.PI / 60))); g.setColor(Color.red); g.drawLine(xCenter, yCenter, xSecond, ySecond);

// Draw minute hand int mLength = (int)(clockRadius * 0.65); int xMinute = (int)(xCenter + mLength * Math.sin(minute * (2 * Math.PI / 60))); int yMinute = (int)(yCenter - mLength * Math.cos(minute * (2 * Math.PI / 60))); g.setColor(Color.blue); g.drawLine(xCenter, yCenter, xMinute, yMinute);

// Draw hour hand int hLength = (int)(clockRadius * 0.5); int xHour = (int)(xCenter + hLength * Math.sin((hour % 12 + minute / 60.0) * (2 * Math.PI / 12))); int yHour = (int)(yCenter - hLength * Math.cos((hour % 12 + minute / 60.0) * (2 * Math.PI / 12))); g.setColor(Color.green); g.drawLine(xCenter, yCenter, xHour, yHour); }

public void setCurrentTime() { // Construct a calendar for the current date and time Calendar calendar = new GregorianCalendar();

// Set current hour, minute and second this.hour = calendar.get(Calendar.HOUR_OF_DAY); this.minute = calendar.get(Calendar.MINUTE); this.second = calendar.get(Calendar.SECOND); }

@Override public Dimension getPreferredSize() { return new Dimension(200, 200); } }