Package java'awt

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Package java.awt
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Abstract Windowing Toolkit (AWT)

• Graphical User Interfaces (GUIs)
• Component (control)
• Event
• Font
• Graphics
• . . .

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Small Piece of Java AWT Class Hierarchy

• class java.lang.Object
• class java.awt.Component
• class java.awt.Button
• class java.awt.Checkbox
• class java.awt.Container
• class java.awt.Panel
• 
  java.applet.Applet
• class java.awt.Window
• class java.awt.Dialog
• class java.awt.Frame
• class java.awt.Label
• class java.awt.List
• class java.awt.TextComponent
• class java.awt.TextArea
• class java.awt.TextField
• class java.awt.Event
• class java.awt.Graphics
• class java.awt.Font

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Component

• Abstract superclass of the non-menu-related AWT
  components
• Interacts with the user
• Has graphical representation, displayed on the
  screen
• Examples buttons, checkboxes, text fields
• Methods
• setSize
• setLocation
• paint
• repaint

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TextField

• Single line of text
• Subclass of AWT Component
• import java.awt.
• Methods
• getString
• setString

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List

• List of Strings
• Subclass of AWT Component
• import java.awt.
• Methods
• add
• remove
• getSelectedIndex

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Container

• Can contain other AWT components
• Subclass of Component
• import java.awt.
• It has some subclasses
• Panel
• Window
• Dialog
• Frame

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Graphics

• Allow an application to draw onto components
• Abstract base class for all graphics contexts
• import java.awt.
• Encapsulates state information
• color, font, object on which to draw,
  etc.
• Methods
• public void drawLine(int x1, int y1, int x2,
  int y2)
• void drawString(String str, int x, int y)
• void drawOval(int x, int y, int width,
  int height) // x,y upper-left
• void setColor(Color c)
  // set current drawing color
• void setFont(Font font)

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Timer

• Fires action events after a specified delay
• Not AWT
• import javax.swing.Timer
• Methods
• start
• stop
• Change timeout time

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Event

• GUI Programs
• Event Driven
• Event Examples
• Clicking on a button
• Selecting Yes or No
• Moving the mouse
• Pressing a key
• Resizing a window
• Closing a window

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Events Handling

• Exceptions Handling
• defining exception class
• throw / throws
• try-catch
• statements to handle exceptions
• Defining an event
• Raising an event
• Receiving an event
• Responding to an event

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Events Handling

• Defining an event
• Class ActionEvent
• import java.awt.event.
• Raising an event
• inside a class
• Receiving an event
• Interface ActionListener
• import java.awt.event.
• Responding to an event
• actionPerformed
• method of ActionListener

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Events Handling

• NetBeans generates all necessary code for us
• Responding to an event
• In NetBeans
• InsertCode
• Implement Method
• actionPerformed
• Double click
• NetBeans does almost all the work for us!

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Java Applet

• Subclass of Panel (which was a subclass of
  Container)
• Embedded in another application (not run on its
  own)
• Calling an Applet from an HTML file
• ltapplet codebase"classes code"MyApplet.class"
  width800 height600gt lt/appletgt
• NetBeans does almost all the work for us!

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Prog5
Lab 5
Quiz4