Introduction
The List class represents a list of text items. The list can be configured that users can choose either one item or multiple items.
Class declaration
Following is the declaration for java.awt.List class:
public class List extends Component implements ItemSelectable, Accessible
Class constructors
S.N. | Constructor & Description |
---|---|
1 | List()Creates a new scrolling list class. |
2 | List(int rows)Creates a new scrolling list initialized with the specified number of visible lines. |
3 | List(int rows, boolean multipleMode)Creates a new scrolling list initialized to display the specified number of rows. |
Class methods
<T extends EventListener> T[] getListeners(Class<T> listenerType)
Returns an array of all the objects currently registered as FooListeners upon this List class.
S.N. | Method & Description |
---|---|
1 | void add(String item)Adds the specified item to the end of scrolling list. |
2 | void add(String item, int index)Adds the specified item to the the scrolling list at the position indicated by the index. |
3 | void addActionListener(ActionListener l)Adds the specified action listener to receive action events from this list. |
4 | void addItem(String item)Deprecated. replaced by add(String). |
5 | void addItem(String item, int index)Deprecated. replaced by add(String, int). |
6 | void addItemListener(ItemListener l)Adds the specified item listener to receive item events from this list. |
7 | void addNotify()Creates the peer for the list. |
8 | boolean allowsMultipleSelections()Deprecated. As of JDK version 1.1, replaced by isMultipleMode(). |
9 | void clear()Deprecated. As of JDK version 1.1, replaced by removeAll(). |
10 | int countItems()Deprecated. As of JDK version 1.1, replaced by getItemCount(). |
11 | void delItem(int position)Deprecated. replaced by remove(String) and remove(int). |
12 | void delItems(int start, int end)Deprecated. As of JDK version 1.1, Not for public use in the future. This method is expected to be retained only as a package private method. |
13 | void deselect(int index)Deselects the item at the specified index. |
14 | AccessibleContext getAccessibleContext()Gets the AccessibleContext associated with this List. |
15 | ActionListener[] getActionListeners()Returns an array of all the action listeners registered on this list. |
16 | String getItem(int index)Gets the item associated with the specified index. |
17 | int getItemCount()Gets the number of items in the list. |
18 | ItemListener[] getItemListeners()Returns an array of all the item listeners registered on this list. |
19 | String[] getItems()Gets the items in the list. |
20 | Dimension getMinimumSize()Determines the minimum size of this scrolling list. |
21 | Dimension getMinimumSize(int rows)Gets the minumum dimensions for a list with the specified number of rows. |
22 | Dimension getPreferredSize()Gets the preferred size of this scrolling list. |
23 | Dimension getPreferredSize(int rows)Gets the preferred dimensions for a list with the specified number of rows. |
24 | int getRows()Gets the number of visible lines in this list. |
25 | int getSelectedIndex()Gets the index of the selected item on the list, |
26 | int[] getSelectedIndexes()Gets the selected indexes on the list. |
27 | String getSelectedItem()Gets the selected item on this scrolling list. |
28 | String[] getSelectedItems()Gets the selected items on this scrolling list. |
29 | Object[] getSelectedObjects()Gets the selected items on this scrolling list in an array of Objects. |
30 | int getVisibleIndex()Gets the index of the item that was last made visible by the method makeVisible. |
31 | boolean isIndexSelected(int index)Determines if the specified item in this scrolling list is selected. |
32 | boolean isMultipleMode()Determines whether this list allows multiple selections. |
33 | boolean isSelected(int index)Deprecated. As of JDK version 1.1, replaced by isIndexSelected(int). |
34 | void makeVisible(int index)Makes the item at the specified index visible. |
35 | Dimension minimumSize()Deprecated. As of JDK version 1.1, replaced by getMinimumSize(). |
36 | Dimension minimumSize(int rows)Deprecated. As of JDK version 1.1, replaced by getMinimumSize(int). |
37 | protected String paramString()Returns the parameter string representing the state of this scrolling list. |
38 | Dimension preferredSize()Deprecated. As of JDK version 1.1, replaced by getPreferredSize(). |
39 | Dimension preferredSize(int rows)Deprecated. As of JDK version 1.1, replaced by getPreferredSize(int). |
40 | protected void processActionEvent(ActionEvent e)Processes action events occurring on this component by dispatching them to any registered ActionListener objects. |
41 | protected void processEvent(AWTEvent e)Processes events on this scrolling list. |
42 | protected void processItemEvent(ItemEvent e)Processes item events occurring on this list by dispatching them to any registered ItemListener objects. |
43 | void remove(int position)Removes the item at the specified position from this scrolling list. |
44 | void remove(String item)Removes the first occurrence of an item from the list. |
45 | void removeActionListener(ActionListener l)Removes the specified action listener so that it no longer receives action events from this list. |
46 | void removeAll()Removes all items from this list. |
47 | void removeItemListener(ItemListener l)Removes the specified item listener so that it no longer receives item events from this list. |
48 | void removeNotify()Removes the peer for this list. |
49 | void replaceItem(String newValue, int index)Replaces the item at the specified index in the scrolling list with the new string. |
50 | void select(int index)Selects the item at the specified index in the scrolling list. |
51 | void setMultipleMode(boolean b)Sets the flag that determines whether this list allows multiple selections. |
52 | void setMultipleSelections(boolean b)Deprecated. As of JDK version 1.1, replaced by setMultipleMode(boolean). |
Methods inherited
This class inherits methods from the following classes:
- java.awt.Component
- java.lang.Object
List Example
Create the following java program using any editor of your choice in say D:/ > AWT > com > adglob > gui >AwtControlDemo.java
package com.adglob.gui; import java.awt.*; import java.awt.event.*; public class AwtControlDemo { private Frame mainFrame; private Label headerLabel; private Label statusLabel; private Panel controlPanel; public AwtControlDemo(){ prepareGUI(); } public static void main(String[] args){ AwtControlDemo awtControlDemo = new AwtControlDemo(); awtControlDemo.showListDemo(); } private void prepareGUI(){ mainFrame = new Frame("Java AWT Examples"); mainFrame.setSize(400,400); mainFrame.setLayout(new GridLayout(3, 1)); mainFrame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent windowEvent){ System.exit(0); } }); headerLabel = new Label(); headerLabel.setAlignment(Label.CENTER); statusLabel = new Label(); statusLabel.setAlignment(Label.CENTER); statusLabel.setSize(350,100); controlPanel = new Panel(); controlPanel.setLayout(new FlowLayout()); mainFrame.add(headerLabel); mainFrame.add(controlPanel); mainFrame.add(statusLabel); mainFrame.setVisible(true); } private void showListDemo(){ headerLabel.setText("Control in action: List"); final List fruitList = new List(4,false); fruitList.add("Apple"); fruitList.add("Grapes"); fruitList.add("Mango"); fruitList.add("Peer"); final List vegetableList = new List(4,true); vegetableList.add("Lady Finger"); vegetableList.add("Onion"); vegetableList.add("Potato"); vegetableList.add("Tomato"); Button showButton = new Button("Show"); showButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { String data = "Fruits Selected: " + fruitList.getItem(fruitList.getSelectedIndex()); data += ", Vegetables selected: "; for(String vegetable:vegetableList.getSelectedItems()){ data += vegetable + " "; } statusLabel.setText(data); } }); controlPanel.add(fruitList); controlPanel.add(vegetableList); controlPanel.add(showButton); mainFrame.setVisible(true); } }
Compile the program using the command prompt. Go to D:/ > AWT and type the following command.
D:\AWT>javac com\adglob\gui\AwtControlDemo.java
If no error comes that means compilation is successful. Run the program using following command.
D:\AWT>java com.adglob.gui.AwtControlDemo
Verify the following output
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