Please help: validate() function is taking 2 sec.

Question

Hi,
My application creates a new panel with different components frequently.
The problem is one JComboBox which most of the panels have in common holds 1lakh string objects.
Creating the panel with all the required components is taking 100ms.
I remove the old panel and add the newly created one to the parent panel. After that when i invoke validate() or invalidate() it is taking 1.5-2 sec to show.
This is seen only in the case of panel that have these 1lakh object component. Why should validate() ever depend on the model?
I tried invalidate() this was return quickly but it took the same time to render.
Could any one please please tell me what validate() internally?
I mean which fun. does the validate invoke.
Thanks
Shilpa

Answer 1

Hello,
I am posting an example with few button and a side panel with a combo box. Clicking any of the buttons removes the side panel and validates it with the new panel. I found that it is taking around 1900ms to validate .Here is the example.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Collection;
import javax.swing.BorderFactory;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
public class GridLay extends JFrame
JPanel panel = new JPanel();
JPanel panel2 = new JPanel();
JPanel panel3 = new JPanel();
public GridLay()
GridBagLayout gridbag = new GridBagLayout();
setFont(new Font("SansSerif", Font.PLAIN, 14));
// setLayout(gridbag);
panel.setLayout(gridbag);
panel3.setLayout(new GridLayout(1, 2));
makeCombo();
makeText("Button1", gridbag, getScriptDescGridConstraints2());
makebutton("Button2", gridbag, getCenterLabelGridConstraints2());
makebutton("Button3", gridbag, getRightEditorGridConstraints2());
makebutton("Button4", gridbag, getCenterLabelGridConstraints2());
makebutton("Button5", gridbag, getRightEditorGridConstraints2());
makebutton("Button6", gridbag, getCenterLabelGridConstraints2());
makebutton("Button7", gridbag, getRightEditorGridConstraints2());
makebutton("Button8", gridbag, getCenterLabelGridConstraints2());
makebutton("Button9", gridbag, getRightEditorGridConstraints2());
makebutton("Button2", gridbag, getCenterLabelGridConstraints2());
makebutton("Button3", gridbag, getRightEditorGridConstraints2());
makebutton("Button4", gridbag, getCenterLabelGridConstraints2());
makebutton("Button5", gridbag, getRightEditorGridConstraints2());
makebutton("Button6", gridbag, getCenterLabelGridConstraints2());
makebutton("Button7", gridbag, getRightEditorGridConstraints2());
makebutton("Button8", gridbag, getCenterLabelGridConstraints2());
makebutton("Button9", gridbag, getRightEditorGridConstraints2());
JScrollPane scroll = new JScrollPane(panel);
scroll.setHorizontalScrollBarPolicy(
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scroll.setVerticalScrollBarPolicy(
JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
panel3.add(scroll);
panel3.add(panel2);
getContentPane().add(panel3);
setSize(400, 400);
// pack();
// setSize(getPreferredSize());
setVisible(true);
setSize(300, 100);
protected void makebutton(
String name,
GridBagLayout gridbag,
GridBagConstraints c)
Button button = new Button(name);
gridbag.setConstraints(button, c);
panel.add(button);
button.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e)
panel3.remove(panel2);
panel2 = new JPanel();
makeCombo();
panel3.add(panel2);
System.out.println("Validating");
long start = System.currentTimeMillis();
validate();
System.out.println(
"Time taken to validate =" + (System.currentTimeMillis() - start));
protected void makeCombo()
JComboBox button = new JComboBox();
button.setModel(getMod());
panel2.add(button);
private DefaultComboBoxModel getMod()
String a = "22222222222222222222222222222222";
Collection<String> list = new ArrayList<String>();
for (int i = 0; i < 100000; i++) {
list.add(a);
DefaultComboBoxModel mod = new DefaultComboBoxModel(list.toArray());
return mod;
protected void makeText(
String name,
GridBagLayout gridbag,
GridBagConstraints c)
final JTextArea scriptDescription = new JTextArea(2, 10);
scriptDescription.setLineWrap(true);
scriptDescription.setWrapStyleWord(true);
scriptDescription.setEditable(false);
scriptDescription.setBackground(
UIManager.getColor("Panel.Background"));
scriptDescription.setFont(new Font("", Font.ITALIC, 12));
scriptDescription.setText(
"Jane was born in Steventon, Hampshire, where her father was a rector. "
+ "She was the second daughter and seventh child in a family of eight."
+ " The first 25 years of her life Austen spent in Hampshire. "
+ "She was mostly tutored at home. ");
gridbag.setConstraints(scriptDescription, c);
scriptDescription.setBorder(
BorderFactory.createCompoundBorder(
BorderFactory.createLineBorder(Color.gray, 1),
BorderFactory.createEmptyBorder(1, 15, 1, 10)));
panel.add(scriptDescription);
* Returns the grid bag constraints for the script description text area.
private GridBagConstraints getScriptDescGridConstraints2()
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
c.weightx = 1.0;
c.anchor = GridBagConstraints.EAST;
c.fill = GridBagConstraints.HORIZONTAL;
c.gridwidth = 3;
return c;
* Returns the grid bag constraints for the label.
* @return gridBagConstraints.
private GridBagConstraints getCenterLabelGridConstraints2()
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = GridBagConstraints.RELATIVE;
c.weightx = 0.0;
c.gridwidth = 1;
c.anchor = GridBagConstraints.WEST;
c.insets = new Insets(1, 10, 1, 0);
return c;
* Returns the grid bag constraints for the editor.
* @return gridBagConstraints.
private GridBagConstraints getRightEditorGridConstraints2()
GridBagConstraints c = new GridBagConstraints();
c.weightx = 1.0;
c.gridx = 1;
c.gridy = GridBagConstraints.RELATIVE;
c.gridwidth = GridBagConstraints.RELATIVE;
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.EAST;
c.insets = new Insets(1, 2, 1, 1);
c.weighty = 1.0;
return c;
public static void main(String[] args)
GridLay gr = new GridLay();
And i found that if I set the model after i validate it takes around 8 ms.
I was of the opinion that validate() only renders!!!
Thanks
Shilpa