Notes on core java

1. Core Java
Debasish Pratihari
Event Handling :

Event : An event describe in sufficient details, a
particular user action

Instead the program takes care of collecting the
event, the java run-time notifies the program
about the event.

Program that handles user action in this fashion
is called event-driven programming.
System View of Event Handling
Key Strokes, Mouse Actions
Operating System
Java Run-Time
Event
Handlers
Lecture/core/event/18
Event
Handlers
Event
Handlers
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Event
Handlers
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2. Core Java
Debasish Pratihari
Event Types

Low-level Events
o These are events that are arises from the
keyboard or from mouse.

Semantic Events
o These are specific component-related
events
Low –level Event :
Event
Description
FocusEvent
MouseEvent
KeyEvent
WindowEvent
ComponenetEvent
ContainerEvent
Generated when a component gets or loses
input focus.
Generated when the mouse is dragged,
moved, clicked, pressed or released ; also
generated when the mouse enters or exits
a component.
Generated when input is received from the
keyboard.
Generated when a window is activated,
closed, deactivated, deiconified, iconified,
opened or quit.
Generated when a component is hidden,
moved, resized, or became visible.
Generated when a component is added to
or removed from a container.
Relationship Among classes
EventObject
java.util
AWTEvent
java.awt
ContainerEvent
ComponentEvent
WindowEvent
MouseEvent
Lecture/core/event/18
InputEvent
FocusEvent
KeyEvent
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3. Core Java
Debasish Pratihari
Semantic Events :
Event
ActionEvent
ItemEvent
AdjustEvent
Description
Generated when a button is pressed, a
list item is double-clicked, or a menu
item is selected.
Generated when a check box or list item
is clicked, choice selection is made or a
checkable menu item is selected or
deselected.
Generated on actions on a scrollbar.
Relationship among classes :
EventObject
AWTEvent
ActionEvent
ItemEvent
java.util
java.awt
TextEvent
AdjustmentObject
Listener Interfaces and their Methods:


ActionListener interface:
public abstract void actionPerformed(ActionEvent
e)
AdjustmentListener interface:
public abstract void adjustmentValueChanged(AdjustmentEvent e)


FocusListener interface:
public abstract void focusGained(FocusEvent e)
public abstract void focusLost(FocusEvent e)
ItemListener interface:
public abstract void itemStateChanged(ItemEvent e)
Lecture/core/event/18
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4. Core Java

Debasish Pratihari
KeyListener interface:
public abstract void keyPressed(KeyEvent e)
public abstract void keyReleased(KeyEvent e)
public abstract void keyTyped(KeyEvent e)

MouseListener interface:
public abstract void mouseClicked(MouseEvent e)
public abstract void mouseEntered(MouseEvent e)
public abstract void mouseExited(MouseEvent e)
public abstract void mousePressed(MouseEvent e)
public abstract void mouseReleased(MouseEvent e)

MouseMotionListener interface
public abstract void mouseDragged(MouseMotionEvent e)
public abstract void mouseMoved(MouseMotionEvent e)

WindowListener interface:
25%
public abstract void windowActivated(WindowEvent
public
public
public
public
public
public

abstract
abstract
abstract
abstract
abstract
abstract
void
void
void
void
void
void
e)
windowClosed(WindowEvent e)
windowClosing(WindowEvent e)
windowDeactivated(WindowEvent e)
windowDeiconified(WindowEvent e)
windowIconified(WindowEvent e)
windowOpened(WindowEvent e)
TextListener interface:
public abstract void textValueChanged(TextEvent

e)
ComponentListener interface:
public abstract void componentHidden(ComponentEvent e)
public abstract void componentMoved(ComponentEvent e)
public abstract void componentResizes(ComponentEvent e)
public abstract void componentShown(ComponentEvent e)

ContainerListener interface:
public abstract void componentAdded(ContainerEvent e)
public abstract void componentRemoved(ContainerEvent e)
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