Action Listener

Question 1

Action Listener

Answer 1

Event handlers, what should be done when a user performs certain operations

Question 2

Action Event Examples

Answer 2

User clicks a button
Chooses a menu item
Presses Enter in a text field

Question 3

Write Action Listener Steps

Answer 3

Declare event handler class either implements ActionListener interface or extends class that implements ActionListener interface
Register instance of event handler class as a listener on component
Include code that reacts to the action

Question 4

Write Action Listener Code

Answer 4

public class MyClass implements ActionListener
{
someComponent.addActionListener(instanceOfMyClass);
public void actionPerformed(ActionEvent e)
{
//reaction code
}
}

Question 5

addActionListener method

Answer 5

Program registers object as action listener on button or event source

Question 6

ActionEvent argument

Answer 6

Single argument gives information about event and its source

Question 7

Action Listener Interface

actionPerformed(actionEvent)

Answer 7

Called just after the user performs an action

Question 8

Action Event Class
String getActionCommand()

Answer 8

Return string associated with this action

Question 9

Action Event Class
int getModifiers()

Answer 9

Returns integer represent modifier keys user was pressing on keyboard

Question 10

Action Event Class
Object getSource()

Answer 10

Returns obj that fired the event