Question

Help with StringAnalysis

Write a WidgetViewer application. Create a class StringAnalysis.

This class has an event handler inner that extends WidgetViewerActionEvent

it has instance variables

• StringSet sSet
• JTextField inputStr
• JLabel numStr
• JLabel numChar

In the constructor,

• create a WidgetViewer object
• create sSet
• create a local variable JLabel prompt initialized to "Enter a String"
• create inputStr with some number of columns
• create a local variable JButton pushMe initialized to "Push to include String"
• create numStr initialized to "Number of Strings: 0"
• create numChar initalized to "Number of Characters: 0"
• create an event handler object and add it as a listener to pushMe
• add prompt, inputStr, pushMe, numStr and numChar to your WidgetView object.

Your event handler should add inputStr's contents to sSet and set inputStr to "". It should update numStr and numChar labels to contain sSet's current information.

Note: the same event handler that handles button pushes can, with no modification, handle the <enter> key for a JTextField. For the adventurous, use inputStr's addActionEvent method to add your event handler. (You can use the same object you added to pushMe--you don't even have to create a new one). Then run your program, enter text in the inputStr field, and press the enter key.

Grading Elements

• Program is a WidgetViewer program that displays a GUI with the specified widgets
• Program allows a user to enter Strings and adds them to a StringSet object
• Program uses a StringSet object to maintain its String information
• Program uses a StringSet object to provide information for display
• Program uses an event handler to detect user action and update the display

****************************

StringSet.java -

*****************************

public class StringSet {

private String[] stringArray;

private int stringCount;

public StringSet() {

stringArray = new String[10];

stringCount = 0;

}

public boolean add(String newStr) {

if (stringCount < 10) {

stringArray[stringCount] = newStr;

stringCount++;

}else if (stringCount == 0) {

return false;

}

return true;

}

public int size() {

return stringCount;

}

public int numChars() {

int amount = 0;

for(int i = 0; i < stringArray.length; i++) {

amount = amount + stringArray[i].length();

}

return amount;

}

public int countString(int len) {

int amount = 0;

for(int i = 0; i < stringCount; i++) {

if(stringArray[i].length() == len) {

amount++;

}

}

return amount;

}

}

Answer 1

PROGRAM:

• Assume WidgetViewer is a custom class for swing frame acc to question

import javax.swing.*;

import java.awt.event.*;

public class StringAnalysis{

StringSet sSet;

JTextField inputStr;

JLabel numStr;

JLabel numChar;

StringAnalysis()

{

sSet=new StringSet();

JFrame f= new JFrame("String Analysis"); //replace this with WidgetViewer

JLabel en=new JLabel("Enter a String:");

en.setBounds(50, 10, 100, 100);

numStr=new JLabel("Number of Strings: 0");

numStr.setBounds(50, 200, 400, 100);

numChar=new JLabel("Number of Characters: 0");

numChar.setBounds(50, 250, 400, 100);

inputStr=new JTextField();

inputStr.setBounds(50, 100, 400, 50);

JButton pushMe=new JButton("Push to include String");

pushMe.setBounds(50, 150, 400, 50);

pushMe.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e){

String s=inputStr.getText();

sSet.add(s);

String ns=numStr.getText();

ns=ns.substring(0, ns.length() - 1)+sSet.size();

numStr.setText(ns);

String nc=numChar.getText();

nc=nc.substring(0, nc.length() - 1)+sSet.numChars();

numChar.setText(nc);

inputStr.setText("");

}

});

f.add(en);f.add(inputStr);f.add(pushMe);

f.add(numStr);f.add(numChar);

f.setSize(300,300);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String[] args) {

new StringAnalysis();

}

}