COMP 274
Week 5 Homework Questions
Answer the following questions:

1. Describe the graphical coordinate system in Java. Where is the origin? What units apply to the x,y coordinates? The horizontal axis is the x coordinate and the vertical axis is the y coordinate. The origin is the upper left corner of the display area. Moving to the right increases the x value, moving down increases the y value. The units are pixels.

2. How would you use the Graphics class to draw a line between 2 specific points? Give an example. public void paint(Graphics g) { Graphics2D g2 = (Graphics2D) g; Line2D lin = new Line2D.Float(5, 30, 380, 30); g2.draw(lin); }

3. How do you specify a particular color to be used as fill when using the Graphics class? g2.setPaint(Color.BLACK);

4. How would you create a SanSerif font of point size 14 that is bold and italic? Give an example. JButton b = new JButton("OK"); b.setFont(new Font("sansserif", Font.BOLD, 32));

5. Given a graphics object g, write a few lines of code to have that graphics object draw a green circle (filled in) that has a diameter of 100 pixels. import java.awt.*; import java.applet.*;

public class FirstApplet extends Applet { public void paint (Graphics g) { g.drawRect(40,20,200,100); g.drawOval(40,20,200,100); }

6. Given a graphics object g, write a few lines of code to draw a red rectangle (not filled in) with its upper left corner at position 25, 25 with a width of 100 and a height of 50. import java.awt.*; import java.applet.Applet; public class redRectangle extends Applet { public void paint(Graphics g) { g.setColor(Color.red); g.drawRect(25,25,100,50); } }

7. What is the paintComponent method? How is it used in