Description
Swing event classes play a major role in Swing applications and indicate the event. While developing an application based on the Swing technology developer can use more Swing classes depends on the requirement because Swing consists of more classes so it is a little bit hard to use all the classes in applications. Splessons will teach about commonly used classes.
EventObject class is base class and it can derive the exact behavior and state of the instance(object). It is available in java.util package. So, the syntax of the above class(java.util.EventObject) can be shown as follows.
[java]public class EventObject
extends Object
implements Serializable[/java]
Protected Object Source is the field of java.util.EventObject, and on which the only event will happen initially.This class consists of methods also and these methods will be inherited from the java.util.object.
It is the base of the AWTEvent and i can be derived from the java.awt package.The syntax declaration of the java.awt.AWTEvent can be indicated as follows.
[java]public class AWTEvent
extends EventObject[/java]
- static int ACTION_FIRST
- static long FOCUS_EVENT_MASK
- static long HIERARCHY_EVENT_MASK
- static long INVOCATION_EVENT_MASK
- static long PAINT_EVENT_MASK
- static int RESERVED_ID_MAX
When user click on the button it will be performed.
The syntax of the above class(java.awt.event.ActionEvent) can be shown as follows.
[java]public class ActionEvent
extends AWTEvent[/java]
Above methods will be inherited from the package such as
- static int ACTION_FIRST
- static int ACTION_LAST
- static int ACTION_PERFORMED
- java.lang.String getActionCommand()---->Command String will be returned
- int getModifiers()------->Modifier keys will be returned if ActionEvent happened
- long getWhen()----->Encoded data will be returned
- java.lang.String paramString()---->Parameters of the String will be returned.
java.awt.AWTEvent and java.lang.Object
The instance of WindowEvent will be activated when window is open or closed or terminated.
The package of this class can be declared as java.awt.event.WindowEvent.
The syntax of java.awt.event.WindowEvent can be written as follows.
[java]public class WindowEvent
extends ComponentEvent[/java]
The above methods will be inherited from the java.lang.object , java.awt.AWTEvent .
- static int WINDOW_ACTIVATED
- static int WINDOW_CLOSED
- static int WINDOW_GAINED_FOCUS
- static int WINDOW_LOST_FOCUS
- int getNewState()---->If user change the window state
- int getOldState()------->To get the previous state of window
- Window getWindow()----->Crucial element of the event will be returned
- String paramString()---->Arguments of the string will be retuned
This event will be useful when the mouse is dragged or moved. This class will be available in java.awt.event.MouseMotionEvent . The syntax of this class can be written as follows.
[java]public class MouseMotionEvent
extends InputEvent[/java]
The above all the methods inherited from java.awt.event.InputEvent , java.awt.event.ComponentEvent .
- void mouseDRAGGED(MouseEvent e)--->When button is pressed it will be invoked.
- void mouseMOVED(MouseEvent e)----->When cursor is moved it will be invoked.
This class will be use full to update or paint the methods and it will be available in the package of java.awt.event and can be declare as
java.awt.event.PaintEvent .The syntax can be written as follows.
[java]public class PaintEvent
extends ComponentEvent[/java]
The above methods will be inherited from the java.awt.ComponentEvent , java.awt.AWTEvent, java.lang.Object
- static int PAINT
- static int PAINT_FIRST
- static int PAINT_LAST
- static int UPDATE
- Rectangle getUpdateRect()---->Returns the area that needs to be updated.
- String paramString()--->Returns the arguments of the String.
Points
- java.io.Serializable interface needs to be implemented by the class.
- int getID() is a method of AWTEvent i.e indicates the type of the event.