Rich text documents combine text with formatting information in a way that allow

Rich text documents combine text with formatting information in a way that allows the text in those documents to use a mixture of fonts, font sizes, font styles (bold, italics, etc), and paragraph styles. Rich text documents may also contain non-text content such as images. This is contrast to plain text documents that contain only plain, unformatted text.
Different programs are designed to display a text document correctly depending on the type of formatting that is contained in the file. The type of a file is usually indicated by the file extension. For example, an ″.html″ document contains markup that can be interpreted by your web browser; a ″.md″ document can be displayed by a markdown editor; a ″.docx″ document contains markup that can be interpreted by a word processor, etc. The list goes on ..
Many forms of rich text documents have similar types of formatting:
Basic text refers to the regular text found in the document.
Bold text refers to text that is emphasized through darkening.
Italic text refers to text that is emphasized through using a slightly slanted font.
Hypertext represents hyperlinks that usually include a ″url″ in addition to the describing text.
Groups of text are usually organized into paragraphs consisting of one or more text elements.
Headings are used to represent titles in our text and can usually be created at several levels.
What to do
Package: document
To start this assignment, download this provided starter code zip file Download provided starter code zip filedownloadthat contains several different types of text elements. Take a moment to familiarize yourself with the classes in the document.element package. Each class, implementing the TextElement interface, represents a different type of text formatting. Finally, the Document class in the document package is used to represent a generic document.
In this lab, we will be using the visitor design pattern to add new capabilities to the Document class.
To do this you need to add a method to the TextElement interface. Start by making the elements of the document ″visitable″ by adding the following method to the TextElement interface, and implementing it in the implementing classes:
public ˂R˃ R accept(TextElementVisitor˂R˃ visitor)
Next, implement each of the following visitors, in the document package:
WordCountVisitor: counts the number of words that are in a document.
BasicStringVisitor generates a simple string representation of the document. In a simple string representation, the text of each element is added one at a time using a space between each element. Additional information (e.g., the level of a heading) is ignored.
HtmlStringVisitor generates an HTML version of the document. In HTML, white space is not important so each element of the document should be separated by a newline (″n″). In addition, formatting tags should be added according to basic html syntax (Links to an external site.).
MarkdownStringVisitor generates a Markdown version of the document. Similar to HTML, white space is less important to the document so each element of the document should be separated by a newline (″n″). In addition, formatting tags should be added according to basic markdown syntax (Links to an external site.).
Now, you should add two methods to the Document class that use these visitors:
countWords that returns the number of words in the document.
toText that takes one of these ″string visitors″ as a parameter and returns a String as per the above desсrіption. String visitors should accumulate their result and return it when toString is called on the visitor.