no output from drawstring method

Hi, below is part of a program that outputs a string when the user enters text into a text box and hits the enter button. The program compiles but when I press enter nothing is outputted. The button gets clicked and nothing happens. Ive commented the area where I think the problem is.
Cheers


//public class
  Label prompt;
       TextField input;
       String name;

//init class
prompt = new Label("Enter your name: ");
                 input = new TextField(20);
                 add(prompt);
                 add(input);
                 enter = new Button(" Enter ");
                 add(enter);


   public boolean action(Event e, Object o){
name = (input.getText());
if(e.target == enter){
           
            name = (input.getText()); //i think its do to with this line?
                  Graphics g = null;
                  g.drawString("Welcome" + name , 100 , 100);
                  }
     
     return true;
}
eire_irelandAsked:
Who is Participating?
 
CEHJConnect With a Mentor Commented:
Yes, that's because you'd have to write the setStringtoDraw method! If you want to make it easier and more direct, just use a String variable instead

stringToDraw = input.getText();
repaint();

your paint method would do

if (stringToDraw != null) {
  // draw the String
}

stringToDraw should be an instance variable
0
 
CEHJCommented:
You need to add a proper listener to your button

enter.addActionListener(new ActionListener() {
  public void actionPerformed(ActionEvent e) {
       setStringToDraw(input.getTexT());
        
  }
});

and your paint/paintComponent should then be flagged to draw the String set in setStringToDraw and repaint to call. It would be easier to use a text-oriented component than doing painting
0
 
CEHJCommented:

>>setStringToDraw(input.getTexT());

should have been


       setStringToDraw(input.getText());

0
Cloud Class® Course: Microsoft Azure 2017

Azure has a changed a lot since it was originally introduce by adding new services and features. Do you know everything you need to about Azure? This course will teach you about the Azure App Service, monitoring and application insights, DevOps, and Team Services.

 
eire_irelandAuthor Commented:
Cheers for the help, I tried that but its giving an error, what other way could I go about it?

enter.addActionListener(new ActionListener() {
                       ^
C:\r.c.p\c.java:110: package enter does not exist
enter.addActionListener(new ActionListener() {
     ^
Note: Some input files use or override a deprecated API.
Note: Recompile with -deprecation for details.
2 errors

Process completed.

0
 
CEHJCommented:
'enter' is your button variable referred to here:

>>enter = new Button(" Enter ");

just add the code immediately after that
0
 
eire_irelandAuthor Commented:
Its not recognising the setStringtoDraw method. This is the code im using and the error is underneath.

import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
import javax.swing.*;
import java.lang.*;
import java.applet.*;

     public void init()
     {
prompt = new Label("Enter your name: ");
                 input = new TextField(20);
                 add(prompt);
                 add(input);
                 enter = new Button(" Enter ");
                 enter.addActionListener(new ActionListener() {
  public void actionPerformed(ActionEvent e) {
        setStringToDraw(input.getText());
       
  }
});

C:\r.c.p\c.java:36: cannot resolve symbol
symbol: method setStringToDraw  (java.lang.String)
        setStringToDraw(input.getText());
        ^
Note: Some input files use or override a deprecated API.
Note: Recompile with -deprecation for details.
1 error

Process completed.

                 add(enter);

0
 
objectsConnect With a Mentor Commented:
add a paint method to do your painting:

public void paint(Graphics g)
{
   super.paint(g);
   g.drawString("Welcome" + name , 100 , 100);
}

And change your existing method to:

   public boolean action(Event e, Object o){
name = (input.getText());
if(e.target == enter){
         
           name = (input.getText()); //i think its do to with this line?
           repaint();
               }
     
     return true;
}
0
 
objectsCommented:
If you want to use an ActionListener on your button it would be:

enter = new Button(" Enter ");
enter.addActionListener(new ActionListener() {
  public void actionPerformed(ActionEvent e) {
       name = input.getText();
       repaint();
  }
});
0
 
eire_irelandAuthor Commented:
Cheers for the help fellas, both your answers helped me so im stuck, can they be divided?
0
 
objectsCommented:
there should be a split points button
0
 
CEHJCommented:
Yep, just go for the 'Split points' link
0
 
eire_irelandAuthor Commented:
Objects: how does your action method call the paint method?
0
 
objectsCommented:
paint() gets called automatically whenever the component needs repainting.
Calling repaint() notifies that the component needs repainting and will result in paint() being called.
0
 
eire_irelandAuthor Commented:
ok, thats sound
0
 
objectsCommented:
From the code you have posted, you don't actually need a stringToDraw member var.
0
 
eire_irelandAuthor Commented:
oh ya, even better
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.