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Source code for above classes

Frame2.java

package view; import java.awt.*; // to use Container.import java.awt.event.*; // to use WindowAdpater and WindowEvent. import javax.swing.*; // to use JFrame./** * A subclass of AFrame containing two JButtons that have event handler called* "commands" to dynamically switch layout managers when the buttons are clicked * upon.* @author D.X. Nguyen */public class Frame2 extends AFrame { public Frame2(String title) {super(title); }protected void initialize() { Container cp = getContentPane();cp.setLayout(new FlowLayout());JButton jb1 = new JButton("Grid Layout"); JButton jb2 = new JButton("Flow Layout");cp.add(jb1); cp.add(jb2);pack(); /*** Registers an anonymous event handler for the clicking of button jb1. * When jb1 is clicked upon, this event handler will respond by* executing its actionPerformed(...) method. */jb1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) {jb1Clicked(e); }}); /*** Same as the above. */jb2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) {jb2Clicked(e); }}); }/** * Dynamically changes to a GridLayout with 2 rows and 1 column.*/ protected void jb1Clicked(ActionEvent e) {System.out.println("Set GridLayout..."); getContentPane().setLayout(new GridLayout(2,1));validate(); // forces this frame to re-layout. }/** * Dynamically changes to FlowLayout.*/ protected void jb2Clicked(ActionEvent e) {System.out.println("Set FlowLayout..."); getContentPane().setLayout(new FlowLayout());validate(); // forces this frame to re-layout. }}

Frame2app.java

package app; import javax.swing.*;import view.*; public class Frame2App {public static void main(String[] args) {JFrame f = new Frame2("A JFrame with 2 JButtons with event listeners"); f.setVisible(true);f.setSize(300, 100); // Guess what this does! f.setLocation(200, 200); // Guess what this does!// Forces the frame to re-layout its components: f.validate();} }

Frame3.java

package view; import java.awt.*;import java.awt.event.*; import javax.swing.*;/** * Same functionality as Frame2 but uses an adapter interface to communicate* with the outside world instead. This design allows varying the communication * with the outside world. How the outside world reacts to the events that* happen to the view is a variant behavior! * Uses the Null-Object Pattern to initialize the adapter avoiding checking for* null. * @author DXN*/ public class Frame3 extends Frame2 {// Initializes the adapter to a null object: private IView2World _v2wAdapter = new IView2World() {public Object button1Clicked (ActionEvent e) { return null; // does nothing!} public Object button2Clicked (ActionEvent e) {return null; // does nothing! }}; public Frame3(String title) {super(title); }public void setV2WAdapter(IView2World v2w) { if (null == v2w) {throw new IllegalArgumentException("Argument cannot be null!"); }_v2wAdapter = v2w; }/** * Tells _v2wAdapter the button click event happens on jb1.*/ protected void jb1Clicked(ActionEvent e) {_v2wAdapter.button1Clicked(e); }/** * Tells _v2wAdapter the button click event happens on jb2.*/ protected void jb2Clicked(ActionEvent e) {_v2wAdapter.button2Clicked(e); }}

Iview2world.java

package view; import java.awt.event.*;/** * Adapter connecting Frame3 (the View) to the outside world.*/ public interface IView2World {/** * Called by Frame3 when its button 1 is clicked.*/ public Object button1Clicked (ActionEvent e);/** * Called by Frame3 when its button 2 is clicked.*/ public Object button2Clicked (ActionEvent e);}

Frame3controller.java

package controller; import view.*;import java.awt.event.*; import javax.swing.JFrame;import java.awt.*; // For layout managers. /*** The controller that instantiates a concrete IView2World object and connects * the world outside of Frame3 (the view) to Frame3.* The concrete adapter is implemented as an anonymous inner classe. */public class Frame3Controller { public JFrame constructFrame() {// Local variable needs to be final so that the local inner class // can access it:final Frame3 frame = new Frame3("View and Controller"); /*** Install as concrete anonymous IView2World adapter in frame, without * frame knowing what the adapter does.*/ frame.setV2WAdapter(new IView2World() {public Object button1Clicked (ActionEvent e) { frame.getContentPane().setLayout(new GridLayout(2,1));frame.validate(); return null;} public Object button2Clicked (ActionEvent e) {frame.getContentPane().setLayout(new FlowLayout()); frame.validate();return null; }}); frame.setVisible(true);return frame; }}

Frame3app.java

package app; import view.*;import controller.*; /*** Instantiates the controller and builds the frame! */public class Frame3App { public static void main(String[]args) { new Frame3Controller().constructFrame().validate();} }

Questions & Answers

the diagram of the digestive system
Assiatu Reply
How does twins formed
William Reply
They formed in two ways first when one sperm and one egg are splited by mitosis or two sperm and two eggs join together
Oluwatobi
what is genetics
Josephine Reply
Genetics is the study of heredity
Misack
how does twins formed?
Misack
What is manual
Hassan Reply
discuss biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles
Joseph Reply
what is biology
Yousuf Reply
the study of living organisms and their interactions with one another and their environments
AI-Robot
the study of living organisms and their interactions with one another and their environment.
Wine
discuss the biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles in an essay form
Joseph Reply
what is the blood cells
Shaker Reply
list any five characteristics of the blood cells
Shaker
lack electricity and its more savely than electronic microscope because its naturally by using of light
Abdullahi Reply
advantage of electronic microscope is easily and clearly while disadvantage is dangerous because its electronic. advantage of light microscope is savely and naturally by sun while disadvantage is not easily,means its not sharp and not clear
Abdullahi
cell theory state that every organisms composed of one or more cell,cell is the basic unit of life
Abdullahi
is like gone fail us
DENG
cells is the basic structure and functions of all living things
Ramadan
What is classification
ISCONT Reply
is organisms that are similar into groups called tara
Yamosa
in what situation (s) would be the use of a scanning electron microscope be ideal and why?
Kenna Reply
A scanning electron microscope (SEM) is ideal for situations requiring high-resolution imaging of surfaces. It is commonly used in materials science, biology, and geology to examine the topography and composition of samples at a nanoscale level. SEM is particularly useful for studying fine details,
Hilary
cell is the building block of life.
Condoleezza Reply
what is cell divisoin?
Aron Reply
Diversity of living thing
ISCONT
what is cell division
Aron Reply
Cell division is the process by which a single cell divides into two or more daughter cells. It is a fundamental process in all living organisms and is essential for growth, development, and reproduction. Cell division can occur through either mitosis or meiosis.
AI-Robot
What is life?
Allison Reply
life is defined as any system capable of performing functions such as eating, metabolizing,excreting,breathing,moving,Growing,reproducing,and responding to external stimuli.
Mohamed
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Source:  OpenStax, Principles of object-oriented programming. OpenStax CNX. May 10, 2013 Download for free at http://legacy.cnx.org/content/col10213/1.37
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