Im trying to create a program that allows me to change the the variables R,G,B in the Text class. Whenever I try to run the Applet, by clicking the "SubmitR" Button, it gives me a Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException.
public class Main extends JApplet {
private ButtonHandlerR buttonHandlerR;
@Override
public void start() {
super.start();
}
@Override
public void init() {
this.setSize(750, 300);
setLayout(new BorderLayout());
add(new SetTextColour(), BorderLayout.NORTH);
add(new Text(),BorderLayout.CENTER);
}
}
public class SetTextColour extends JPanel {
private JLabel labelR;
private JLabel labelG;
private JLabel labelB;
public JTextField textR;
public JTextField textG;
public JTextField textB;
public JButton submitR;
public JButton submitG;
public JButton submitB;
public SetTextColour() {
labelR = new JLabel("RED: ");
labelG = new JLabel("GREEN: ");
labelB = new JLabel("BLUE: ");
textR = new JTextField(10);
textB = new JTextField(10);
textG = new JTextField(10);
add(textR, BorderLayout.NORTH);
submitR = new JButton("SubmitR");
add(submitR, BorderLayout.NORTH);
add(textB, BorderLayout.NORTH);
submitG = new JButton("SubmitG");
add(submitG, BorderLayout.NORTH);
add(textG, BorderLayout.NORTH);
submitB = new JButton("SubmitB");
add(submitB, BorderLayout.NORTH);
ButtonHandlerB BHB = new ButtonHandlerB();
ButtonHandlerG BHG = new ButtonHandlerG();
ButtonHandlerR BHR = new ButtonHandlerR(this);
submitB.addActionListener(BHB);
submitR.addActionListener(BHR);
submitG.addActionListener(BHG);
}
}
public class ButtonHandlerR implements ActionListener {
private SetTextColour colour;
private Text text;
ButtonHandlerR(Text change){
this.text = change;
}
ButtonHandlerR(SetTextColour set){
this.colour = set;
}
@Override
public void actionPerformed(ActionEvent e) {
JButton Clicked = (JButton) e.getSource();
double tempV;
int tempV2;
if(colour.submitR == Clicked){
tempV = Double.parseDouble(colour.textR.getText());
tempV2 = (int) tempV;
text.R = tempV2;
System.out.println(text.R);
text.repaint();
}
}
}
public class Text extends JApplet {
private String textField = "Welcome to CE203 Assignment 1 - Hassan Khan, 1404460";
public int R=50;
private int G=32;
private int B=54;
public void start(){
}
public void init(){
}
public void paint (Graphics g) {
Color customColor = new Color(R, G, B);
g.setColor(customColor);
g.drawString(textField, 125, 150);
}
}
