信息协助范例 : 数据验证 « Swing组件




/*

Code revised from Desktop Java Live:

http://www.sourcebeat.com/downloads/

*/



import java.awt.Component;

import java.awt.KeyboardFocusManager;

import java.beans.PropertyChangeEvent;

import java.beans.PropertyChangeListener;



import javax.swing.JComponent;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JTextField;



import com.jgoodies.forms.builder.DefaultFormBuilder;

import com.jgoodies.forms.layout.FormLayout;

import com.jgoodies.validation.view.ValidationComponentUtils;

import com.jgoodies.validation.view.ValidationResultViewFactory;



public class InfoAssistExample extends JPanel {

    private JLabel infoLabel;



    public InfoAssistExample() {

        DefaultFormBuilder formBuilder = new DefaultFormBuilder(new FormLayout("right:pref, 3dlu, p:g"));

        formBuilder.setDefaultDialogBorder();



        JTextField nameField = new JTextField();

        JTextField feedField = new JTextField();

        JTextField siteField = new JTextField();



        ValidationComponentUtils.setInputHint(nameField, "Enter a name.");

        ValidationComponentUtils.setInputHint(feedField, "Enter a valid rss feed url.");

        ValidationComponentUtils.setInputHint(siteField, "Enter a site url.");



        this.infoLabel = new JLabel();

        this.infoLabel.setIcon(ValidationResultViewFactory.getInfoIcon());

        this.infoLabel.setVisible(false);



        KeyboardFocusManager.getCurrentKeyboardFocusManager().addPropertyChangeListener(new FocusChangeHandler());



        formBuilder.append(this.infoLabel, 3);

        formBuilder.append("Name:", nameField);

        formBuilder.append("Site Url:", siteField);

        formBuilder.append("Feed Url:", feedField);



        add(formBuilder.getPanel());

    }



    private class FocusChangeHandler implements PropertyChangeListener {

        public void propertyChange(PropertyChangeEvent evt) {

            String propertyName = evt.getPropertyName();

            if (!"permanentFocusOwner".equals(propertyName))

                return;



            Component focusOwner = KeyboardFocusManager

                    .getCurrentKeyboardFocusManager().getFocusOwner();



            String focusHint = (focusOwner instanceof JComponent)

                    ? (String) ValidationComponentUtils

                    .getInputHint((JComponent) focusOwner)

                    : null;



            infoLabel.setText(focusHint);

            infoLabel.setVisible(focusHint != null);

        }

    }



    public static void main(String[] a){

      JFrame f = new JFrame("Info Assist Example");

      f.setDefaultCloseOperation(2);

      f.add(new InfoAssistExample());

      f.pack();

      f.setVisible(true);

    }

}
信息协助范例 : 数据验证 « Swing组件 « Java
