Web browsers can do amazing things, but some of their functionality is as simple as maintaining a list.

In this lab, you will build a mock web browser, read commands from a file that let you know what buttons are being pushed and what URLs are being navigated to, and you will track a List of Tabs. Each Tab will have its own browser history.

This is still a terminal program! You don't need to know any networking or actually write code for a web browser!

Updating LinkedList class

You can use your old LinkedList for this lab, but you'll need to update it be templated. That means you'll also have to update your Node to be templated as well. Both your Tab class and WebBrowser class will use Lists, but they'll need Lists of different types.

Tab class

Below is a header file for your Tab class. You can add constructors, destructors, operator overloads, and private helper methods. You may not add any other type of public method.

#include "LinkedList.h" #include  class Tab { public: /** * @pre none * @post the browser navigate to the given url * @param url, a string representing a URL */ void navigateTo(std::string url); /** * @pre none * @post if possible, the browser navigates forward in the history otherwise it keeps focus * on the current URL */ void forward(); /** * @pre none * @post if possible, the browser navigates backwards in the history otherwise it keeps focus * on the current URL */ void back(); /** * @return the URL currently open in the tab */ std::string currentURL() const; /** * @pre The list being passed in is empty * @post The current browser history is copied into the given list * @param destination, an empty list of strings * @return the position in the list with focus (zero if there is no history) */ int copyCurrentHistory(LinkedList& destination); }; 

WebBrowser Class

You will also need design and implement a Browser class, which can manage several tabs. How many tabs? That's up to the file.

What can a browser do?

• Open new tab
• Close existing tab
• Switch focus to a particular tab
• Move a tab left or right in the List of tabs
  • Note, when you move a tab, no tabs are lost, they only rearrange in order

Reading the from file

Commands to interact with your browser will come from a file. The file name will come in on the command line.

Any given line of the file will contain one of the following entries. Some commands pertain to the browser and some pertain to a tab. I've separated them into two tables, but a single file will contains commands from both tables.

Browser Command	Description
NEW_TAB	Creates a new tab at the end of the list of tab and immediately gives it focus.
FOCUS	Switches focus to the tab at position 1 to total_num_tabs.
CLOSE	Closes the tab at the indicated position. with focus
MOVE_LEFT	Moves the tab with focus left amount times. If it reaches the front of the list it stops there. Focus remains on the moved tab.
MOVE_RIGHT	Moves the tab with focus right amount times. If it reaches the back of the list it stops there. Focus remains on the moved tab.
HISTORY	Prints the tab number and current URL history to the screen using the following format: Tab # =========== <==current (assuming this is the current URL) =========== Newest
EXIT	End the simulation. No more commands need to be read in.

Tab Command	Description
NAVIGATE	Navigates the browser to the given URL. NOTE navigating to a URL retains all URLs accessible from going BACK, but any URLs that would have accessible from going FORWARD are now lost
BACK	A command indicating the web browser is redirected to the previous URL in the history. If there is no URL further back, then the browser stays on the current URL.
FORWARD	A command indicating the web browser is redirected to the next URL in the history. If there is no URL that is next, then the browser stays on the current URL.

Sample input file

NEW_TAB NAVIGATE http://google.com NAVIGATE http://reddit.com NAVIGATE http://facebook.com NAVIGATE http://myspace.com HISTORY NEW_TAB NAVIGATE http://ku.edu NAVIGATE http://youtube.com NAVIGATE http://bing.com BACK HISTORY MOVE_LEFT 1 FOCUS 2 BACK NAVIGATE http://amazon.com HISTORY EXIT 

Output to screen:

Tab 1 =========== http://google.com http://reddit.com http://facebook.com http://myspace.com <==current =========== Newest Tab 2 =========== http://ku.edu http://youtube.com <===current http://bing.com =========== Newest Tab 2 =========== http://google.com http://reddit.com http://facebook.com http://amazon.com <==current =========== Newest