Update JTextField on property change?

[edbeaty]

Hello all. I am new to using the Instantiations bindings framework, and have a question. I have bound a JTextField to a bean's property, so changes to the JTextField's text are causing the bean's set() method to be called, no problem. My difficulty is in trying to get the JTextField to update its text when the bound bean's property is changed elsewhere.

In the example code, pressing the button calls the bean's setName() method, firing a propertyChangeEvent from the bean, but the JTextField doesn't respond. My guess is that nobody's listening to the fired event, and I'm not sure who should (the JTextField? Or some component of the Binding apparatus?)

Any help you can provide would be greatly appreciated.
Thanks,
Ed

Code: Select all

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import org.jdesktop.beansbinding.BeanProperty;
import org.jdesktop.beansbinding.AutoBinding;
import org.jdesktop.beansbinding.Bindings;
import org.jdesktop.beansbinding.AutoBinding.UpdateStrategy;
import javax.swing.JButton;

public class BindingTest extends JPanel {

    protected JTextField textField;   
    protected Model model = new Model();
   
    public BindingTest() {
       
        JButton button = new JButton("New button");
        add(button);
       
        textField = new JTextField();
        add(textField);
        textField.setColumns(10);
        initDataBindings();
       
        button.addActionListener(new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent e) {
               
                model.setName("foo");
               
            }           
        });
    }

   
    protected void initDataBindings() {
        BeanProperty<Model, String> modelBeanProperty = BeanProperty.create("name");
        BeanProperty<JTextField, String> jTextFieldBeanProperty = BeanProperty.create("text");
        AutoBinding<Model, String, JTextField, String> autoBinding = Bindings.createAutoBinding(UpdateStrategy.READ_WRITE, model, modelBeanProperty, textField, jTextFieldBeanProperty);
        autoBinding.bind();
    }
   
    public static class Model {
       
        protected PropertyChangeSupport support = new PropertyChangeSupport(this);
       
        protected String name;

        public String getName() {
            return name;
        }

        public void setName(String newName) {
            String oldName = this.name;
            this.name = newName;
            System.out.println("setName called: " + newName);
            support.firePropertyChange(new PropertyChangeEvent(this, "name", oldName, newName));
        }
       
        public void addPropertyChangeListener(PropertyChangeListener l){
            support.addPropertyChangeListener(l);
        }
    }
   
   
    public static void main(String[] args){
       
        BindingTest view = new BindingTest();       
        JFrame frame = new JFrame();
        frame.getContentPane().add(view, BorderLayout.CENTER);
        frame.setMinimumSize(new Dimension(500,500));
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);       
    }
}


[edbeaty]

Never mind, I figured it out. Changing the bean to extend PropertyChangeSupport allows the JTextField to respond to the bean's PropertyChangeEvents.
-Ed

[asablin]

See http://www.devx.com/Java/Article/39964/1954

[edbeaty]

Thanks asablin. Here's the project link from the article: http://code.google.com/p/javabuilders/

[Eric Clayberg]

I am new to using the Instantiations bindings framework

BTW, we should point out that it isn't the "Instantiations bindings framework". We are simply offering tooling support for the existing Swing data binding framework (JSR 295)...warts and all.

[edbeaty]

Thanks, Eric. One more question; I'd like to use the @Bindable annotation that asablin pointed out, but I can't seem to find the correct library in the javabuilders code. Is there a different package I should be looking in?

[Eric Clayberg]

Sorry. No idea.

In general, we can help with Swing Designer specific questions in this forum. If you need help with general Swing issues (such as how to best use the JSR 295 framework), you would be much better off asking those questions in one of the general Swing newsgroups/forums available.

[edbeaty]

No problem; I'll try those forums.
I just want to add that I'm really pleased with Instantiations! It's making our GUI creation much simpler than before.
Thanks,
Ed

[Eric Clayberg]

I just want to add that I'm really pleased with Instantiations!

...and now Google

[kseader]

Ed,
I am experiencing the same issues as you were earlier. When you say that you changed the bean to extend PropertyChangeSupport are you talking about the model class? If so, what did you pass the constructor as the source object? Any help would be greatly appreciated.

Thanks,
Kirk

[edbeaty]

Hi, Kirk. Yes, I changed the model class to extend PropertyChangeSupport, and it seemed to work. I defined my model as an inner class to the view, something like:

Code: Select all

public class View extends JPanel implements PropertyChangeListener{
   
   protected Model model = new Model();
   
   public View(){      
   }
      
   public class Model extends PropertyChangeSupport{
      public Model() {
         super(View.this);
      }
      
      //model getters and setters
   }
}



I'm sure this is five ways to non-standard, but it worked as a first pass at getting the bindings to work.
Hope this helps,
Ed

[kseader]

Great, that helps.
Thanks Ed. Much appreciated.

Kirk

[Eric Clayberg]

Thanks for the suggestions, Ed. Those should be helpful to lots of folks.