JList issues

**aneesahamedaa** · 09-04-2008, 03:10 PM

Hi all,
In the attached code, I need to have the following options
1) get the name(eg;first.doc) of the selected item/items.
2) When I right click on top of a particular item, I need to have that item alone selected.
3) I need to have no selection for elements once I click outside the list.
I am attaching the code I developed, here.
Kindly help implementing these.
Any help is greatly appreciated.

Java Code:

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Image;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;
import javax.swing.DefaultListCellRenderer;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;
import javax.swing.UIManager;
import javax.swing.filechooser.FileSystemView;

import sun.awt.shell.ShellFolder;
 
public class MainClass {
  public static void main(String args[]) throws Exception {
         
    MainClass mc = new MainClass();
         Object elements[][] = { {"first.doc",mc.getIcone(mc.getExtension("first.doc".toUpperCase()))},
                                                          {"second.pdf",mc.getIcone(mc.getExtension("second.pdf".toUpperCase()))},      
                                                          {"third.txt",mc.getIcone(mc.getExtension("third.txt".toUpperCase()))} ,
                                                          {"first.doc",mc.getIcone(mc.getExtension("first.doc".toUpperCase()))},
                                                          {"second.pdf",mc.getIcone(mc.getExtension("second.pdf".toUpperCase()))},      
                                                          {"third.txt",mc.getIcone(mc.getExtension("third.txt".toUpperCase()))} 
          
          
          };
          

    JFrame frame = new JFrame("Trial");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
    JList jlist = new JList(elements);
    ListCellRenderer renderer = new ComplexCellRenderer();
    jlist.setCellRenderer(renderer);
    jlist.setLayoutOrientation(JList.HORIZONTAL_WRAP);
    jlist.setVisibleRowCount(-1);
    JScrollPane scrollPane = new JScrollPane(jlist);
    frame.add(scrollPane, BorderLayout.CENTER);
 
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
  
  public String getExtension(String name)
        {
                if(name.lastIndexOf(".")!=-1)
                {
                        String extensionPossible = name.substring(name.lastIndexOf(".")+1, name.length());
                        if(extensionPossible.length()>6)
                        {
                                return "";
                        }
                        else 
                        {
                                return extensionPossible;
                        }
                }
                else return "";
        }
        public Icon getIcone(String extension)
        {
                File file;
                String cheminIcone = "";
                if(((System.getProperties().get("os.name").toString()).startsWith("Mac")))
                        cheminIcone = System.getProperties().getProperty("file.separator");
                else if(((System.getProperties().get("os.name").toString()).startsWith("Linux")))
                        cheminIcone = "/"+"tmp"+"/BoooDrive-"+System.getProperty("user.name")+"/";
                else cheminIcone = System.getenv("TEMP") + System.getProperties().getProperty("file.separator");
                
                File repIcone = new File(cheminIcone);
                if(!repIcone.exists()) repIcone.mkdirs();
                
                try
                {
                        if(extension.equals("FOLDER"))
                        {
                                file = new File(cheminIcone + "icon");
                                file.mkdir();
                        }
                        else
                        {
                                file = new File(cheminIcone + "icon." + extension.toLowerCase());
                                file.createNewFile();
                        }
                        
                        Icon icone = getSystemIcon(file);
                        
                        file.delete();
                        return icone;
                } 
                catch (IOException e){ }
                return null;
        }
        public static Icon getSystemIcon(File f) {
            if (f != null) {
                Class fsv = FileSystemView.class;
                try {
                    Method m = fsv.getDeclaredMethod("getShellFolder", new Class[]{File.class});
                    m.setAccessible(true);
                    ShellFolder sf = (ShellFolder) m.invoke(FileSystemView.getFileSystemView(), f);
                    Image img = sf.getIcon(true);
                    if (img != null) {
                        return new ImageIcon(img, sf.getFolderType());
                    } else {
                        return UIManager.getIcon(f.isDirectory() ? "FileView.directoryIcon" : "FileView.fileIcon");
                    }
                } catch (Exception e) {e.printStackTrace();}
            } 
            return null;
        }
 
}
 
class ComplexCellRenderer implements ListCellRenderer {
  protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
 
  public Component getListCellRendererComponent(JList list, Object value, int index,
      boolean isSelected, boolean cellHasFocus) {
    Icon icon = null;
    String theText = null;
 
    JLabel renderer = (JLabel) defaultRenderer.getListCellRendererComponent(list, value, index,
        isSelected, cellHasFocus);
    renderer.setVerticalTextPosition(JLabel.BOTTOM);
    renderer.setHorizontalTextPosition(JLabel.CENTER);

 
    if (value instanceof Object[]) {
      Object values[] = (Object[]) value;
      theText = (String) values[0];
      icon = (Icon) values[1];
    } else {
      
    }
    renderer.setText(theText);
    renderer.setIcon(icon);
    return renderer;
  }
}

**aneesahamedaa** · 09-09-2008, 12:16 PM

Please provide help.

**hardwired** · 09-09-2008, 09:08 PM

Click in the south textField to remove focus from the JList.

Java Code:

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.lang.reflect.Method;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.filechooser.FileSystemView;

import sun.awt.shell.ShellFolder;

public class MC {
    public static void main(String[] args) throws Exception {

        MC mc = new MC();
        Object[][] elements = {
            { "first.doc",
               mc.getIcone(mc.getExtension("first.doc".toUpperCase()))  },
            { "second.pdf",
               mc.getIcone(mc.getExtension("second.pdf".toUpperCase())) },
            {"third.txt",
               mc.getIcone(mc.getExtension("third.txt".toUpperCase()))  },
            {"first.doc",
               mc.getIcone(mc.getExtension("first.doc".toUpperCase()))  },
            {"second.pdf",
               mc.getIcone(mc.getExtension("second.pdf".toUpperCase())) },
            {"third.txt",
               mc.getIcone(mc.getExtension("third.txt".toUpperCase()))  }
        };

        JFrame frame = new JFrame("Trial");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JList jlist = new JList(elements);
        ListCellRenderer renderer = new ComplexCellRenderer();
        jlist.setCellRenderer(renderer);
        jlist.setLayoutOrientation(JList.HORIZONTAL_WRAP);
        jlist.setVisibleRowCount(-1);
        // 2) When I right click on top of a particular item,
        //    I need to have that item alone selected.
        jlist.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        // 1) get the name (eg, first.doc) of the selected item
        jlist.addListSelectionListener(new ListSelectionListener() {
            public void valueChanged(ListSelectionEvent e) {
                if(!e.getValueIsAdjusting()) {
                    Object value = ((JList)e.getSource()).getSelectedValue();
                    if(value != null) {
                        String name = (String)((Object[])value)[0];
                        System.out.println("name = " + name);
                    }
                }
            }
        });
        // 3) I need to have no selection for elements once
        //    I click outside the list.
        jlist.addFocusListener(new FocusAdapter() {
            public void focusLost(FocusEvent e) {
                ((JList)e.getSource()).clearSelection();
            }
        });
        JScrollPane scrollPane = new JScrollPane(jlist);
        frame.add(scrollPane, BorderLayout.CENTER);
        frame.add(new JTextField(), BorderLayout.SOUTH);

        frame.setSize(300, 200);
        frame.setVisible(true);
    }

    public String getExtension(String name) {
        if(name.lastIndexOf(".")!=-1) {
            String extensionPossible =
                name.substring(name.lastIndexOf(".")+1, name.length());
            if(extensionPossible.length()>6) {
                return "";
            } else {
                return extensionPossible;
            }
        }
        else return "";
    }

    public Icon getIcone(String extension) {
        File file;
        String cheminIcone = "";
        if(((System.getProperties().get("os.name")
                    .toString()).startsWith("Mac")))
            cheminIcone = System.getProperties().getProperty("file.separator");
        else if(((System.getProperties().get("os.name")
                    .toString()).startsWith("Linux")))
            cheminIcone = "/"+"tmp"+"/BoooDrive-"+
                System.getProperty("user.name")+"/";
        else
            cheminIcone = System.getenv("TEMP") +
                System.getProperties().getProperty("file.separator");

        File repIcone = new File(cheminIcone);
        if(!repIcone.exists()) repIcone.mkdirs();

        try {
            if(extension.equals("FOLDER")) {
                file = new File(cheminIcone + "icon");
                file.mkdir();
            } else {
                file = new File(cheminIcone + "icon." +
                                extension.toLowerCase());
                file.createNewFile();
            }

            Icon icone = getSystemIcon(file);

            file.delete();
            return icone;
        } catch (IOException e){ }
        return null;
    }

    @SuppressWarnings("unchecked")
    public static Icon getSystemIcon(File f) {
        if (f != null) {
            Class fsv = FileSystemView.class;
            try {
                Method m = fsv.getDeclaredMethod("getShellFolder",
                                                  new Class[] {File.class});
                m.setAccessible(true);
                ShellFolder sf = (ShellFolder) m.invoke(
                    FileSystemView.getFileSystemView(), f);
                Image img = sf.getIcon(true);
                if (img != null) {
                    return new ImageIcon(img, sf.getFolderType());
                } else {
                    return UIManager.getIcon(f.isDirectory() ?
                        "FileView.directoryIcon" : "FileView.fileIcon");
                }
            } catch (Exception e) {e.printStackTrace();}
        }
        return null;
    }
}

class ComplexCellRenderer implements ListCellRenderer {
    protected DefaultListCellRenderer defaultRenderer =
        new DefaultListCellRenderer();

    public Component getListCellRendererComponent(JList list, Object value,
                int index, boolean isSelected, boolean cellHasFocus) {
        Icon icon = null;
        String theText = null;

        JLabel renderer =
            (JLabel) defaultRenderer.getListCellRendererComponent(list,
                         value, index, isSelected, cellHasFocus);
        renderer.setVerticalTextPosition(JLabel.BOTTOM);
        renderer.setHorizontalTextPosition(JLabel.CENTER);

        if (value instanceof Object[]) {
            Object[] values = (Object[]) value;
            theText = (String) values[0];
            icon = (Icon) values[1];
        } else {
            System.out.println("value = " + value.toString());
        }
        renderer.setText(theText);
        renderer.setIcon(icon);
        return renderer;
    }
}

**aneesahamedaa** · 09-10-2008, 01:16 PM

Thanks alot.
That was an awesome work hardwired.
Also,
How can I reduce the width of the selected item.
Just see the link JList Selected Area
I need to somehow reduce the width of the selected area. What should be done?
Anees

**hardwired** · 09-11-2008, 12:27 AM

How can I reduce the width of the selected item.
The JList api has setFixedWidth/Height methods you could use to move the list items closer together.
If you want the selectionColor to cover only the rectangle enclosing the icon and string then you may have to look at some plaf code. You might start with the paintImpl and paintCell methods in the BasicListUI class. You could try calculating the rectangle union of the icon and text rectangles and paint it in the backgroundSelection color.

**Desperado** · 12-15-2009, 04:59 PM

Hello! Could anybody help me with a function of adding(populating) \ removing items from Jlist?
I am selecting some files with Swing File chooser, and setting them to Jlist.

Java Code:

File[] sf;
sf = chooser.getSelectedFiles();
checkBoxList.setListData(sf);

But I need multiple adding of these files, and for now have no idea how to add more items to list.

**Fubarable** · 12-15-2009, 05:08 PM

Hey Desperado -- welcome to the forum!

I think that the answer to your question is to use the right list model, but before we go further, I will ask however that you please create your own question in its own thread rather than hijack an old thread. Then we can discuss this more fully. Thanks for your cooperation!

**Desperado** · 12-15-2009, 05:16 PM

Originally Posted by Fubarable

Hey Desperado -- welcome to the forum!

I think that the answer to your question is to use the right list model, but before we go further, I will ask however that you please create your own question in its own thread rather than hijack an old thread. Then we can discuss this more fully. Thanks for your cooperation!

Thanks, done..