Java Swing | JList with examples
JList is part of Java Swing package . JList is a component that displays a set of Objects and allows the user to select one or more items . JList inherits JComponent class. JList is a easy way to display an array of Vectors .
Constructor for JList are :
- JList(): creates an empty blank list
- JList(E [ ] l) : creates an new list with the elements of the array.
- JList(ListModel d): creates a new list with the specified List Model
- JList(Vector l) : creates a new list with the elements of the vector
Commonly used methods are :
| method | explanation |
|---|---|
| getSelectedIndex() | returns the index of selected item of the list |
| getSelectedValue() | returns the selected value of the element of the list |
| setSelectedIndex(int i) | sets the selected index of the list to i |
| setSelectionBackground(Color c) | sets the background Color of the list |
| setSelectionForeground(Color c) | Changes the foreground color of the list |
| setListData(E [ ] l) | Changes the elements of the list to the elements of l . |
| setVisibleRowCount(int v) | Changes the visibleRowCount property |
| setSelectedValue(Object a, boolean s) | selects the specified object from the list. |
| setSelectedIndices(int[] i) | changes the selection to be the set of indices specified by the given array. |
| setListData(Vector l) | constructs a read-only ListModel from a Vector specified. |
| setLayoutOrientation(int l) | defines the orientation of the list |
| setFixedCellWidth(int w) | Changes the cell width of list to the value passed as parameter. |
| setFixedCellHeight(int h) | Changes the cell height of the list to the value passed as parameter. |
| isSelectedIndex(int i) | returns true if the specified index is selected, else false. |
| indexToLocation(int i) | returns the origin of the specified item in the list’s coordinate system. |
| getToolTipText(MouseEvent e) | returns the tooltip text to be used for the given event. |
| getSelectedValuesList() | returns a list of all the selected items. |
| getSelectedIndices() | returns an array of all of the selected indices, in increasing order |
| getMinSelectionIndex() | returns the smallest selected cell index, or -1 if the selection is empty. |
| getMaxSelectionIndex() | returns the largest selected cell index, or -1 if the selection is empty. |
| getListSelectionListeners() | returns the listeners of list |
| getLastVisibleIndex() | returns the largest list index that is currently visible. |
| getDragEnabled() | returns whether or not automatic drag handling is enable |
| addListSelectionListener(ListSelectionListener l) | adds a listSelectionlistener to the list |
The Following programs will illustrate the use of JLists
1. Program to create a simple JList
// java Program to create a simple JListimport java.awt.event.*;import java.awt.*;import javax.swing.*;class solve extends JFrame { //frame static JFrame f; //lists static JList b; //main class public static void main(String[] args) { //create a new frame f = new JFrame("frame"); //create a object solve s=new solve(); //create a panel JPanel p =new JPanel(); //create a new label JLabel l= new JLabel("select the day of the week"); //String array to store weekdays String week[]= { "Monday","Tuesday","Wednesday", "Thursday","Friday","Saturday","Sunday"}; //create list b= new JList(week); //set a selected index b.setSelectedIndex(2); //add list to panel p.add(b); f.add(p); //set the size of frame f.setSize(400,400); f.show(); } } |
Output :
2. Program to create a list and add itemListener to it (program to select your birthday using lists) .
// java Program to create a list and add itemListener to it// (program to select your birthday using lists) .import javax.swing.event.*;import java.awt.*;import javax.swing.*;class solve extends JFrame implements ListSelectionListener{ //frame static JFrame f; //lists static JList b,b1,b2; //label static JLabel l1; //main class public static void main(String[] args) { //create a new frame f = new JFrame("frame"); //create a object solve s=new solve(); //create a panel JPanel p =new JPanel(); //create a new label JLabel l= new JLabel("select your bithday"); l1= new JLabel(); //String array to store weekdays String month[]= { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}; //create a array for months and year String date[]=new String[31],year[]=new String[31]; //add month number and year to list for(int i=0;i<31;i++) { date[i]=""+(int)(i+1); year[i]=""+(int)(2018-i); } //create lists b= new JList(date); b1= new JList(month); b2= new JList(year); //set a selected index b.setSelectedIndex(2); b1.setSelectedIndex(1); b2.setSelectedIndex(2); l1.setText(b.getSelectedValue()+" "+b1.getSelectedValue() +" "+b2.getSelectedValue()); //add item listener b.addListSelectionListener(s); b1.addListSelectionListener(s); b2.addListSelectionListener(s); //add list to panel p.add(l); p.add(b); p.add(b1); p.add(b2); p.add(l1); f.add(p); //set the size of frame f.setSize(500,600); f.show(); } public void valueChanged(ListSelectionEvent e) { //set the text of the label to the selected value of lists l1.setText(b.getSelectedValue()+" "+b1.getSelectedValue() +" "+b2.getSelectedValue()); } } |
Output :
Note : The above programs might not run in an Online compiler please use an Offline IDE
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