Nevron Rich Text Editor DOM (Document Object Model) is very close to the HTML DOM model with the exception that it extends it so that it can also accommodate Word specific features such as sections, headers and footers, fields, advanced fillings and borders, etc. which are missing in HTML.

Conceptually there are two types of elements in the Nevron Rich Text Editor DOM:

• Inline elements – inline elements are elements that can participate in line formatting and are layout horizontally. An inline element is generally represented on the screen as one or more runs positioned on one or more lines.
• Block elements – block elements are boxes which are layout by the control and can contain either inline elements or other block elements. There are only two block elements that can contain inlines - the paragraph block (NParagraph) and the shape block (NShapeBlock). All other blocks can contain block elements only.

To model this all objects that you add to the Nevron Text DOM derive directly or indirectly from the NTextElement base class as shown on the following class diagram:

In turn all objects can be classified as either inline or block, with the exception of the NTableColumn element. From the above class hierarchy you can see that both inline and block elements derive from the range text element base class. This is because each element in the Nevron Text document tree has a property called Range that is used for selection purposes.