Java subclass of JButton overriding setEnabled method problem
I have a custom button class called ImageButton that extends JButton. In it i have a setEnabled method that I want to be called rather than the JButton's setEnabled method.
My code is below. In my other class I create a new instance of ImageButton, but when I try to use the setEnabled method, it goes straight to the JButton's setEnabled method. Even before I run the code, my IDE is telling me that the ImageButton's setEnabled method is never used. If I change the method to "SetOn" it works fine. So why is it that I can't use the same name as that of the super class? I开发者_Go百科 thought it's supposed to hide the superclass method if it's the same name?
public class ImageButton extends JButton{
public ImageButton(ImageIcon icon){
setSize(icon.getImage().getWidth(null),icon.getImage().getHeight(null));
setIcon(icon);
setMargin(new Insets(0,0,0,0));
setIconTextGap(0);
setBorderPainted(true);
setBackground(Color.black);
setText(null);
}
public void setEnabled(Boolean b){
if (b){
setBackground(Color.black);
} else {
setBackground(Color.gray);
}
super.setEnabled(b);
}
}
You need to change
public void setEnabled(Boolean b){
to
public void setEnabled(boolean b){
^
(By using Boolean
instead of boolean
you're overloading the method instead of overriding it.)
I encourage you to always annotate methods intended to override another method with @Override
. If you had done it in this case, the compiler would have complained and said something like
The method
setEnabled(Boolean)
of typeImageButton
must override or implement a supertype method.
Try without the capital letter in Boolean: there is difference between Boolean and boolean, so the signature is different:
public void setEnabled(boolean b)
Boolean with the capital letter is a Class. boolean is a primitive type of the language. (The same is for int vs Integer, double vs Double, etc)
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