Problem in Changing size of JComboBox

harshi Sum

Greenhorn

Posts: 5

posted 6 years ago

Hi,

I'm new to java Applets.I'm trying to implement an expert system with the help of jess and java Applets.
My applet have 2 "JComboBox" objects. I have used the grid layout as a layout manager.

I want to set size of the "combobox" , because it appears too large and very ugly. (Actually i want to arrange the things in a proper manner that it would look nice).
I have tried with "setMinimumSize" and "setSize". But it seems the grid layout is ignoring them.

Here is my code.

import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JApplet;
import javax.swing.SwingUtilities;
import jess.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.*;
import javax.swing.JButton;
import javax.swing.JTextField;

public class HelloWorld extends JApplet {
	 private boolean inAnApplet = true;
	  private int count = 0;
	  private int count2 = 0;
	  private String[] description = { "Fred", "Bob", "Pete","George"};
	  private String[] description2 = { "Smith", "Thomas", "Best","Smithson"};
	  
	  private JComboBox c = new JComboBox();
	  private JComboBox c2 = new JComboBox();
	  JLabel lbl = new JLabel();
	  
	  private JTextField t = new JTextField(15);
	  private JButton b = new JButton("Add items");

public String rstl = "";

public String Get(String aa,String bb)throws JessException
    {
		rstl = "";
    	 Rete engine = new Rete();
         engine.batch("query.clp");
         engine.reset();
         String fname =  ((String) c.getSelectedItem());
         String lname =  ((String) c2.getSelectedItem());
      
         QueryResult result =
             engine.runQueryStar("search-by-name", new ValueVector().add(fname).add(lname));
         
         String br = "<br>";

while (result.next()) {
           rstl+= "<html> "+ result.getString("fn") + " " + result.getString("ln")
                                       + ", age" + result.getInt("age") + br; 
               
                }
    	return rstl;
    }
	
	 public HelloWorld() 
	 {
	        setLayout(new GridLayout(0,2));
		 //setLayout(null);
	        setFont(new Font("Helvetica", Font.PLAIN, 14));
	        add(new Label("First Name"));
	        add(c);	  
	        add(new Label("Last Name"));
	        add(c2);	  
	        add(new Label("Results"));
	        add(lbl);
	        add(t);
	     
	    }

public void init() {
    	
		setSize(500, 500);
		int  x = 20, y = 20;
		setLocation (x-5, y-5);

//Execute a job on the event-dispatching thread; creating this applet's GUI.
        try {
            for (int i = 0; i < 4; i++)
                c.addItem(description[count++]);
            c.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                  if (count < description.length)
                    c.addItem(description[count++]);
                }
              });
            
            c.setMinimumSize(new Dimension(1, 1));
            
              c.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                	
                	try
                	{
                	String aa =	Get(  ((String) c.getSelectedItem()), ((String) c2.getSelectedItem()));
                	lbl.setText(aa);
                	}
                	catch (JessException ed)
                    {
                    	// TODO Auto-generated catch block
						//e.printStackTrace();		
                    	 System.err.println("jjjjj");
                    }
                  
                }
              });
              
            
            for (int j = 0; j < 4; j++)
                c2.addItem(description2[count2++]);
            c2.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                  if (count2 < description2.length)
                    c2.addItem(description2[count2++]);
                }
              });
            
            c2.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                	
                	try
                	{
                		 
                		String	lname = Get(  ((String) c.getSelectedItem()), ((String) c2.getSelectedItem()));
                		lbl.setText(lname);
                	}
                	catch (JessException ed)
                    {
                    	// TODO Auto-generated catch block
						//e.printStackTrace();		
                    	 System.err.println("jjjjj");
                    }
                }
              });
       	
            SwingUtilities.invokeAndWait(new Runnable() {
                public void run() {
                	
                	  //Container cp2 = getContentPane();
                	  //cp2.setLayout( new GridLayout( 1, 1)); 
                   
                    String bb = "";
                    try {
                    bb = Get(((String) c.getSelectedItem()), ((String) c2.getSelectedItem()) );
                    lbl.setText(bb);
                  
                    	} 
                    catch (JessException e)
                    {
                    	// TODO Auto-generated catch block
						//e.printStackTrace();		
                    	 System.err.println("jjjjj");
                    }
                }
            });
        } catch (Exception e) {
            System.err.println("createGUI didn't complete successfully");
        }
     
    }
	
	 public static void main(String args[]) {
	        GridWindow window = new GridWindow();
	        window.setTitle("GridWindow Application");
	        window.pack();
	       window.show();
	    }

}

Can someone please help me........ Thanks in advance.

Vidu.

this is the query.clp file (just in case needed)

Rob Spoor

Sheriff

Posts: 21048

I like...

posted 6 years ago

Please UseCodeTags next time. I've added them for you this time.

harshi Sum wrote:I want to set size of the "combobox" , because it appears too large and very ugly. (Actually i want to arrange the things in a proper manner that it would look nice).
I have tried with "setMinimumSize" and "setSize". But it seems the grid layout is ignoring them.

Almost all layout managers ignore the value returned by getSize(). Instead they use the value returned by getPreferredSize(). getMinimumSize() and getMaximumSize() may also be used but only to determine the maximum bounds for components. You'll need to call setPreferredSize instead.

There is a but though. GridLayout uses getPreferredSize() of all the components to calculate the grid cell size. This is then the maximum of all preferred widths by the maximum of all preferred heights. So if you have another component that is longer or higher than your combo box then your combo box will still be stretched. To prevent this, either don't use GridLayout, or put the combo box in a JPanel that you put in your applet. This JPanel can keep its default FlowLayout.

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harshi Sum

Greenhorn

Posts: 5

posted 6 years ago

Rob Spoor wrote:Please UseCodeTags next time. I've added them for you this time.

harshi Sum wrote:I want to set size of the "combobox" , because it appears too large and very ugly. (Actually i want to arrange the things in a proper manner that it would look nice).
I have tried with "setMinimumSize" and "setSize". But it seems the grid layout is ignoring them.

Almost all layout managers ignore the value returned by getSize(). Instead they use the value returned by getPreferredSize(). getMinimumSize() and getMaximumSize() may also be used but only to determine the maximum bounds for components. You'll need to call setPreferredSize instead.

There is a but though. GridLayout uses getPreferredSize() of all the components to calculate the grid cell size. This is then the maximum of all preferred widths by the maximum of all preferred heights. So if you have another component that is longer or higher than your combo box then your combo box will still be stretched. To prevent this, either don't use GridLayout, or put the combo box in a JPanel that you put in your applet. This JPanel can keep its default FlowLayout.

Thanks a lot. My problem solved with GridBagLayout.

Rob Spoor

Sheriff

Posts: 21048

I like...

posted 6 years ago

That's the first time I've ever heard anybody say that

Not that GridBagLayout isn't a good solution, it's just not an easy one. Totally Gridbag

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Problem in Changing size of JComboBox

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