TextArea replacement

Networking & Multiplayer
#1

Can anyone recommend a lightweight replacement for TextArea? The
most common complaint about TextArea used as a chat window is that
it auto-scrolls inappropriately, but it would also be nice to have access
to fonts and color.

I would prefer something lightweight and not tied to some other
massive package.

#2

You can programatically make it scroll how you want. How is it not scrolling how you need it to?

#3

the big complaint is that when the text is updated, the window auto-scrolls to the bottom.
I haven’t seen a way to prevent this.

#4

It took some experimenting, but here is a solution.


import java.awt.Adjustable;
import java.awt.BorderLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;

import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JScrollBar;
import javax.swing.JScrollPane; 
import javax.swing.JTextArea; 

/** 
 * 
 */ 
public class Test extends JFrame implements ActionListener, AdjustmentListener { 
    private JTextArea text; 
    private JScrollPane scroll; 
    private JButton addText;
    private int value;
    private int appended = 0;
    private boolean max = false;
    
    public Test() { 
        JPanel panel = new JPanel(new BorderLayout()); 
        setContentPane(panel); 
        text = new JTextArea(); 
        scroll = new JScrollPane(text); 
        panel.add(scroll, BorderLayout.CENTER);
        scroll.getVerticalScrollBar().addAdjustmentListener(this);
        addText = new JButton("Add Text"); 
        panel.add(addText, BorderLayout.SOUTH); 
        addText.addActionListener(this); 
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        setSize(400, 200); 
        setVisible(true); 
    } 
    public void actionPerformed(ActionEvent e) { 
        if(e.getSource().equals(addText)) {
            JScrollBar bar = scroll.getVerticalScrollBar(); 
            value = bar.getValue();
            if(value + bar.getVisibleAmount() >= bar.getMaximum()) {
                max = true;
            }
            else {
                max = false;
            }
            //value needs to be set to 2 because the adjustmentValueChanged gets called twice for some reason
            appended = 2;
            text.append("This is a test string to add\r\n"); 
        }
    }
    public void adjustmentValueChanged(AdjustmentEvent arg0) {
        Adjustable adj = arg0.getAdjustable();
        if(appended > 0) {
            if(max) {
                adj.setValue(adj.getMaximum());
            }
            else {
                adj.setValue(value);
            }
        }
        appended--;
    }
    public static void main(String[] args) { 
        Test t = new Test(); 
    } 
}
#5

Thanks for trying, but this isn’t completely satisfactory. It glitches funny sometimes, and
I’d rather avoid swing components - my applet is still compatible with Java 1.1 and I’d
prefer to keep it that way.

… Still hoping for a nice class specifically designed as a chat area.

#6

Hrm? JTextArea doesn’t automatically scroll to the bottom. I had to make it do that myself.

#7

I think he’s talking about java.awt.TextArea

#8

No idea if it works, but maybe this is something for you?
http://jabberapplet.jabberstudio.org/doxygen/ChatTextArea_8java-source.html

#9

That looks promising, but the big missing feature is cut and paste - there is none.
Textarea somehow manages to implement access to the clipboard without tickling
the security manager, but ordinary java applets have to be signed.