Description
A browser window consists of a many tabs. On each tab a user can enter a new web address (url) to go to, press the
back button to go a url that was just visited, or press the forward button to go the url that was visited before the back
button was pressed. A list of urls corresponding to a particular tab is kept in an array of characters. The goal of this
project is to create appropriate classes and simulate the actions of a user on a web browser. When a user chooses
forward or backward we need to just print the urls and do not have to write complex code to actually go to a website.
Given the above, we will first start with the description of the input. All input lines will be stored in a text file (file with
txt extension) and we will use redirected input to read the contents of the file. Each line of input consists of three items
(each separated by a single space): tab number (integer), action (single character), and the url (depending on the action).
The possible actions that needs to be implemented for this project are N (for adding a url), B (pressing the backward
button), and F (pressing the forward button), and P (for printing the urls).
For each action, print the action that is invoked, followed by the tab number, and followed by the result of the action.
Both forward and backward actions should print the url that they go to. Add should provide the url that being added.
The print P should print all the urls in the current tab.
Here is an example of the input file.
1 N http://www.msn.com/?ocid=iehp
1 N http://www.microsoftstore.com/store/msusa/en_US/home
1 B
1 F
1 P
3 N https://www.udacity.com/course/front-end-web-developer-nanodegree–nd001
1 N http://www.cnn.com/2016/01/24/us/weather-winter-snowstorm/index.html
1 P
1 B
1 B
1 P
2 N http://www.cnn.com/2016/01/24/us/weather-winter-snowstorm/index.html
2 N http://www.sas.com/en_us/software/university-edition.html
2 B
2 F
2 P
We will assume that the number of commands in the input file is unknown. Additionally, we will assume that the
maximum number of tabs is 20 and the number of characters in each url is limited to 200.
In this project, you will write a C++ program that allows the users to perform all the actions described above. You will
implement the C++ classes as described in this section and as well as the main() method which will read and execute
the commands from standard I/O.
webAddressInfo Class
The webAddressInfo class is used to store the information on the urls in a particular tab, it is defined as follows:
class webAddressInfo
{
private:
char url[201]; //allow a maximum of 200 characters
// other private methods if necessary for this class
public:
webAddressInfo ();
webAddressInfo (char* inputString);
void setWebAddressInfo(char* inputString);
char* getWebAddressInfo();
void display();
// and other public methods if necessary
};
browserTab
The browserTab class is used to store the web address information for each tab, it is defined as follows:
class browserTab {
protected:
int numAddress; //Current number of web addresses in this tab
webAddressInfo webAddresses [20]; //Web addreses in this tab
int currentAddress; //index of current location in webAddresses
// other private methods if necessary for this class
public:
browserTab();
browserTab(char* inputString); //creates a new tab with the inputString
webAddressInfo& forward();
webAddressInfo& backward();
void addAddress(char* inputString);
void display();
// and other public methods if necessary
};
main() method
The main() method reads different user actions from standard I/O as described earlier.
You will implement the main() method as the code provided below.
#include
using namespace std;
// define and implement the required classes or functions here,
// or in separate files, you will need to include the headers
/ for these classes in the latter case.
int main()
{
char buffer[256];
browserTab myTabs[20];
// other local variables used to store data temporally
int tabNumber;
char blank;
while( !cin.eof()) // while end of line is not reached
{
while (!cin.eof()) {
cin >> tabNumber;
cin.get(blank);
cin.get(action);
switch (action) {
case ‘N’: { //New url
break;
}
case ‘F’: { //Forward
break;
}
case ‘B’: { //Backward
break;
}
case ‘P’: { //Print current
break;
}
default: { //illeagal action}
}
}
}
return 0;
}
Redirected Input
Redirected input provides you a way to send a file to the standard input of a program without typing it using the
keyboard. To use redirected input in Visual Studio environment, follow these steps: After you have opened or created a
new project, on the menu go to project, project properties, expand configuration properties until you see Debugging, on
the right you will see a set of options, and in the command arguments type “< input filename”. The < sign is for
redirected input and the input filename is the name of the input file (including the path if not in the working directory).
A simple program that reads character by character until it reaches enf-of-file can be found below.
#include
using namespace std;
//The character for end-of-line is ‘\n’ and you can compare c below with this
//character to check if end-of-line is reached.
int main () {
char c;
cin.get(c);
while (!cin.eof()) {
i = c;
cout << c;
cin.get(c);
}
return 0;
}
C String
A string in the C Programming Language is an array of characters ends with ‘\0’ (NULL) character. The NULL character
denotes the end of the C string. For example, you can declare a C string like this:
char aCString[9];
Then you will be able to store up to 8 characters in this string. You can use cout to print out the string and the characters
stored in a C string will be displayed one by one until ‘\0’ is reached. Here are some examples:
0 1 2 3 4 5 6 7 8 cout result Length
u s e r n a m e \0 username 8
n a m e \0 name 4
n a m e \0 1 2 3 4 name 4
\0 (nothing) 0
Similarly, you can use a for loop to determine the length of a string (NULL is NOT included). We show this in the
following and also show how you can dynamically create a string using a pointer
char aCString[] = “This is a C String.”; // you don’t need to provide
// the size of the array
// if the content is provided
char* anotherCString; // a pointer to an array of
// characters
unsigned int length = 0;
while( aCString[length] != ‘\0’)
{
length++;
}
// the length of the string is now known
anotherCString = new char[length+1]; // need space for NULL character
// copy the string
for( int i=0; i< length+1; i++)
anotherCString[i] = aCString[i];
cout << aCString << endl; // print out the two strings
cout << anotherCSring << endl;
delete [] anotherCString; // release the memory after use
You check http://www.cs.bu.edu/teaching/cpp/string/array-vs-ptr/, other online sources or textbooks to learn more
about this.
Constraints
1. In this project, the only header you will use is #include .
2. None of the projects is a group project. Consulting with other members of this class on programming projects is
strictly not allowed and plagiarism charges will be imposed on students who do not follow this.
