Java - swing listen an action in a text field of a

2019-01-03 10:57发布

I would like to develop a form with some text field.
example:

Name
SecondName

the idea is that every text field have inside a text like:

Insert your name
Insert your second name

when you click on the first text field to write your name, the text "Insert your name" have to be deleted... the same have to happen for the second text field (SecondName).
The effect have to be this:
enter image description here

I think that i just need an Action on the text field that have to wake up when the user press on the mouse on the text field, it's possible?
Thank you

标签: java forms swing
3条回答
我命由我不由天
2楼-- · 2019-01-03 11:28

Take a look at Text Prompt for a simple solution that allows you to control when the text is displayed/hidden as well as the font/color of the text.

It will work with regular text components. In its simplest form you only need one extra line of code:

JTextField firstName = new JTextField(10);
TextPrompt tp = new TextPrompt("First Name", firstName);
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成全新的幸福
3楼-- · 2019-01-03 11:43

Take a look at PromptSupport in SwingLabs SwingX Library

For Example

Prompt fields

When the fields have focus, the "prompt" will be hidden, but you can control this, making it shown until the user types something or highlight when focus is gained.

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import org.jdesktop.swingx.prompt.BuddySupport;
import org.jdesktop.swingx.prompt.PromptSupport;

public class PromptSupportTest {

    public static void main(String[] args) {
        new PromptSupportTest();
    }

    public PromptSupportTest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            JTextField firstName = new JTextField(10);
            PromptSupport.setPrompt("First Name", firstName);
            PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.HIDE_PROMPT, firstName);

            JTextField lastName = new JTextField(10);
            PromptSupport.setPrompt("Last Name", lastName);
            PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.HIDE_PROMPT, lastName);

            JTextField picture = new JTextField(10);
            PromptSupport.setPrompt("Picture", picture);
            PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.HIDE_PROMPT, picture);

            JButton browse = new JButton("...");
            browse.setMargin(new Insets(0, 0, 0, 0));
            browse.setContentAreaFilled(false);
            browse.setFocusPainted(false);
            browse.setFocusable(false);
            browse.setOpaque(false);
            // Add action listener to brose button to show JFileChooser...

            BuddySupport.addRight(browse, picture);

            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            gbc.weightx = 1;

            add(firstName, gbc);
            add(lastName, gbc);
            add(picture, gbc);

            gbc.anchor = GridBagConstraints.CENTER;
            add(new JButton("Ok"), gbc);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

    }

}

I've also added an example of BuddySupport which is part of the same API, which allows you to "buddy" another component with a text component. Here I've done the classic "file browser" combination, but I do "search" style fields like this all the time...

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小情绪 Triste *
4楼-- · 2019-01-03 11:44

see this example

import java.awt.Color;  
 import java.awt.Font;  
 import java.awt.event.FocusAdapter;  
 import java.awt.event.FocusEvent;  
 import javax.swing.JTextField;  

 public class HintTextField extends JTextField {  

   Font gainFont = new Font("Tahoma", Font.PLAIN, 11);  
   Font lostFont = new Font("Tahoma", Font.ITALIC, 11);  

   public HintTextField(final String hint) {  

     setText(hint);  
     setFont(lostFont);  
     setForeground(Color.GRAY);  

     this.addFocusListener(new FocusAdapter() {  

       @Override  
       public void focusGained(FocusEvent e) {  
         if (getText().equals(hint)) {  
           setText("");  
           setFont(gainFont);  
         } else {  
           setText(getText());  
           setFont(gainFont);  
         }  
       }  

       @Override  
       public void focusLost(FocusEvent e) {  
         if (getText().equals(hint)|| getText().length()==0) {  
           setText(hint);  
           setFont(lostFont);  
           setForeground(Color.GRAY);  
         } else {  
           setText(getText());  
           setFont(gainFont);  
           setForeground(Color.BLACK);  
         }  
       }  
     });  

   }  
 }  
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