How to create and delete JTextArea's dynamically

Question

I am new on using Swings

my requirement is I have to create two buttons "Create" and "Remove" ."Create" button has to create a new JTextArea and "Remove" button has to remove the selected JTextarea .

I have successfully created the "Create" Button but

my problem is "How to remove the selected the JTextArea means if I Clicked a particular JTextArea and pressed the "Remove" button the clicked JTextarea has to be deleted"

Thanks in advance

Answer 1

You need to use some kind of focus listener that is attached to each text area. Basically, you're only interested in the focus gained event.

When this occurs, you need to store a reference to the text area that was focused.

When you click the remove button, you would use this, previously, stored reference and simply remove it from it's parent, for example

if (selectedTextArea != null) {
    selectedTextArea.getParent().remove(selectedTextArea);
}

Have a look at How to write a focus listener for more details

Update

As has being pointed out in the comments, you will need to call revalidate so that the container/layout can be updated, followed by a request for a repaint

Updated with example

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class TestRemover {

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

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

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

    public class TestPane extends JPanel {

        private JTextArea lastFocused;
        private FocusHandler focusHandler;
        private JPanel fields;
        private JPanel buttons;

        public TestPane() {
            setLayout(new BorderLayout());
            focusHandler = new FocusHandler();
            fields = new JPanel(new GridBagLayout());
            buttons = new JPanel();
            JButton add = new JButton("Add");
            JButton remove = new JButton("Remove");
            buttons.add(add);
            buttons.add(remove);
            add(buttons, BorderLayout.SOUTH);
            add(new JScrollPane(fields));

            add.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    JTextArea ta = new JTextArea(10, 10);
                    GridBagConstraints gbc = new GridBagConstraints();
                    gbc.fill = GridBagConstraints.HORIZONTAL;
                    gbc.weightx = 1;
                    gbc.gridwidth = GridBagConstraints.REMAINDER;
                    fields.add(new JScrollPane(ta), gbc);
                    ta.addFocusListener(focusHandler);

                    fields.revalidate();
                    fields.repaint();
                }
            });
            remove.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    if (lastFocused != null) {

                        // ViewPort.ScrollPane
                        Container scollPane = lastFocused.getParent().getParent();
                        Container parent = scollPane.getParent();
                        parent.remove(scollPane);
                        lastFocused = null;
                        parent.revalidate();
                        parent.repaint();

                    }
                }
            });
        }

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

        public class FocusHandler extends FocusAdapter {

            @Override
            public void focusGained(FocusEvent e) {
                if (e.getComponent() instanceof JTextArea) {

                    lastFocused = (JTextArea) e.getComponent();

                }
            }                
        }            
    }        
}