Provide classes to operate the content and style of the selected text content.

Abstract class Navigation represent the navigate action on the specified document, and user can iterate all the results of this navigation operation. Abstract class Selection describes one result of navigation.

The instance of derived navigation class will give the match condition so that user can get the corresponding derived Selection class instance. e.g. TextNavigation class is used to search the specified text content in the document, and TextStyleNavigation class can select the text which match the specified style.

TextSelection class which inherits Selection represents a snippet text of the paragraph/heading/header/footer, it can be represent by the belonged element and the text index of this element. User can get delete this result, or replace this text with other content, add href link for this selections, append the italic style for it and paste this selection at the front of or the end of other selction.

CellSelection inherits TextSelection. It provides a new function to not only replace text but also reset the cell values.