Make 3 similar focusListeners into 1 ? 1

[paulbradley]

Hi,

I have 3 very similar FocusListeners and have been trying to find a way of having one and the labels and accesors & mutators accessed chaning depending on who triggered the listener.

There are 3 textFields (tN, tP and tK) and 3 mutators and accessors (getN(), getP() and getK())

The currect code is as follows, how can I have just one of the following and get these little bits of code to relate to where the listener came from, many thanks in advance.


tN.addFocusListener(new FocusListener()
{
public void focusLost(FocusEvent fe)
{
try{
if( (Integer.parseInt(tN.getText())>=0)
&& ( (thedata.getP()!=0) || (thedata.getK()!=0)) ){

thedata.setN(Integer.parseInt(tN.getText()));

}else{
throw new IllegalArgumentException();
}

}catch(IllegalArgumentException e){
tN.setText(""+thedata.getN());
}
}

public void focusGained(FocusEvent fe){}

});



tP.addFocusListener(new FocusListener()
{
public void focusLost(FocusEvent fe)
{
try{
if( (Integer.parseInt(tP.getText())>=0)
&& ( (thedata.getN()!=0) || (thedata.getK()!=0)) ){

thedata.setP(Integer.parseInt(tP.getText()));

}else{
throw new IllegalArgumentException();
}

}catch(IllegalArgumentException e){
tP.setText(""+thedata.getP());
}
}

public void focusGained(FocusEvent fe){}

});

tK.addFocusListener(new FocusListener()
{
public void focusLost(FocusEvent fe)
{
try{
if( (Integer.parseInt(tK.getText())>=0)
&& ( (thedata.getP()!=0) || (thedata.getN()!=0)) ){

thedata.setK(Integer.parseInt(tK.getText()));

}else{
throw new IllegalArgumentException();
}

}catch(IllegalArgumentException e){
tK.setText(""+thedata.getK());
}
}

public void focusGained(FocusEvent fe){}

});

 

[timw]

FocusListener f = new FocusListener(){
  ... your code to do something
};
tN.setFocusListener(f);
tPsetFocusListener(f);
tKsetFocusListener(f);

Tim
---------------------------
"Your morbid fear of losing,
destroys the lives you're using." - Ozzy

 

[paulbradley]

That won't work i'm afraid as the code is slightly different in each listener.

Any other ideas, thanks.

 

[timw]

Yes, but you can interrogate the FocusEvent, find which component generated the event, and perform different logic depending. All within the one bit of code.

FocusListener f = new FocusListener(){
  public void focusGainded(FocusEvent fe){
    Component c = fe.getComponent();
    //check which component we've got in c and do
    //different things depending.
  }
};
tN.setFocusListener(f);
tPsetFocusListener(f);
tKsetFocusListener(f);

Tim
---------------------------
"Your morbid fear of losing,
destroys the lives you're using." - Ozzy

 

[wangdong]

Create you own FocusListener, something likes:

public class MyFocusListener extends FocusListener(){
   private JTextField f1, f2, f3;
   public MyFocusListener(JTextField f1, JTextField f2, JTextField f3,){
      this.f1 = f1;
      this.f2 = f2;
      this.f3 = f3;
   }

   publicvoid focusLost{FocusEvent fe}{
      try{
       if( (Integer.parseInt(f1.getText())>=0)
          && ( (thedata.f2()!=0) ||   (thedata.f3()!=0)) ){
            thedata.setK(Integer.parseInt(f1.getText()));
        }else{
           throw new IllegalArgumentException();
        }
       }catch(IllegalArgumentException e){
              f1.setText(""+thedata.f1.getF1());
       }

   }

When you call it,
tk.setFocusListener(New MyfocusListener(tk, tP, tn));
tn.setFocusListener(New MyfocusListener(tn, tk, tp));
tp.setFocusListener(New MyfocusListener(tp, tn, tk));

 

[paulbradley]

Looks good, cheers guys!