What I am looking to do is a similar principle to adding attachments to emails, you can click a button and a new browse box would open increasing the number of separate attachments you can have.
I'm fairly new so if someone could point me towards an example?
Sample code to add Buttons on the fly dynamically.
panel.add(new JButton("Button"));
validate();
Full code:
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JPanel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.FlowLayout;
import java.awt.BorderLayout;
public class AddComponentOnJFrameAtRuntime extends JFrame implements ActionListener {
JPanel panel;
public AddComponentOnJFrameAtRuntime() {
super("Add component on JFrame at runtime");
setLayout(new BorderLayout());
this.panel = new JPanel();
this.panel.setLayout(new FlowLayout());
add(panel, BorderLayout.CENTER);
JButton button = new JButton("CLICK HERE");
add(button, BorderLayout.SOUTH);
button.addActionListener(this);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 500);
setVisible(true);
}
public void actionPerformed(ActionEvent evt) {
this.panel.add(new JButton("Button"));
this.panel.revalidate();
validate();
}
public static void main(String[] args) {
AddComponentOnJFrameAtRuntime acojfar = new AddComponentOnJFrameAtRuntime();
}
}
revalidate() and/or validate() should be followed by repaint() (or changes wont be refelcted) also using validate() is redundant as revalidate() calls validate()
repaint() after validate() or revalidate() is not always necessary. Though I do not know the conditions for when it is required... I have a case in my app where without validate(), revalidate(), and repaint() the window does not redraw when a component is added. Just adding validate() causes the new component to be displayed.
actionPerformed method. But if i have some other task to perform, firstly its performing those task and at last moment Button is adding to the panel. I was expecting in the reverse case. First it should add Button in the Panel and perform other task for that actionperformed method.public static void main(String[] args) {
final JFrame frame = new JFrame("Test");
frame.setLayout(new GridLayout(0, 1));
frame.add(new JButton(new AbstractAction("Click to add") {
@Override
public void actionPerformed(ActionEvent e) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
frame.add(new JLabel("Bla"));
frame.validate();
frame.repaint();
}
});
}
}));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 300);
frame.setVisible(true);
}
Component was not visible until setSize() was called:
component.setSize(100,200);
jPanel.add(component);
jPanel.revalidate();
jPanel.repaint();
panel.add(button);
panel.revalidate();
panel.repaint();
Java : Dynamically add swing components
for Example : count=3
//Java Swing: Add Component above method
public void dya_addcomp(int count)
{
//Dynamicaly Delete Image_icon
BufferedImage Drop_Tablefield = null;
try {
Drop_Tablefield = ImageIO.read(this.getClass().getResource("/images/drop.png"));
} catch (IOException ex) {
msg(" Error: drop and edit icon on Table, "+ex);
}
//count Items: 3 times for loop executed..
for(int i=0;i<count;i++)
{
//cnt++;
//lblcount.setText("Count : "+cnt);
JTextField txtcolnm=new JTextField("",20);
JComboBox cmbtype=new JComboBox();
JTextField txtcolsize=new JTextField("",20);
JButton Drop_Table_Field = new JButton(new ImageIcon(Drop_Tablefield));
cmbtype.addItem("INTEGER"); cmbtype.addItem("FLOAT");
cmbtype.addItem("STRING"); cmbtype.addItem("BOOLEAN");
colnamepanel.add(txtcolnm); colnamepanel.add(cmbtype);
colnamepanel.add(txtcolsize); colnamepanel.add(Drop_Table_Field);
colnamepanel.setAutoscrolls(true);
//refresh panel
colnamepanel.revalidate();
colnamepanel.repaint();
//set the layout on Jpanel
colnamepanel.setLayout(new FlowLayout(FlowLayout.LEFT,5,0));
}//end for loop
}//end method
