A developer is trying populate a GUI window menu from a file that contains a menu hierarchy.

The menu may contain three different types of items as explained below:

Plain text items: These are menu items that only contain a text label. When clicked on$,$

this item performs a programmable simple action such as popping up a new input

window.

Selectable items: Selectable items changes their label when clicked by the user. Each

selectable item is independent from the rest of the menu items, their selection does not

affect other items.

Nested menu items: Nested menu items can be in plain text or in selectable format.

When clicked, it behaves in a different way than both the other item types and pops out

a submenu defined in the hierarchy file. The orientation of the submenu display is also

indicated in the hierarchy file.

A sample menu and its related hierarchy file is provided below $($indentation defines the

hierarchy levels$)$:

MenuBars

JMenu $1[$below$]$

JMenultem $1$

JMenultem $2$

JMenultem $3$

JMenu sub menu $[$right$]$

JMenultem $4$

JMenultem $5$

JMenultem $6$

JCheckBoxMenultem $1[$selectable$]$

JCheckBoxMenultem $2[$selectable$]$

JCheckBoxMenultem $3[$selectable$]$

JMenu $2$

JMenu $3$

Assuming the orientation of the menu bars are done automatically $($horizontal for the first level,

vertical for the rest$),$ you are asked to provide an object oriented design that can handle the

menu hierarchy defined above.

a$.$ State the design pattern$($s$)$ that would be useful in your design

b$.$ Provide a UML class diagram in full $($including properties, functions, relations, etc.$)$ to

support the functionality defined above.

c$.$ Imagine you are asked to support grouping items in the menu. A group of items can

contain any kind of menu item but the group itself is not a new item type $($it is not plain

text, clickable or nested$).$ Modify your design and provide a new class diagram.