Siegmann epublib calculate page number for table of content

Question

I use "Siegmann epublib" library to extract the contents of epub files in an android project. I can show total content of the book and paginate that; but how should I find a correlation between table of contents and these pages? as table of contents has a tree structure but resources (content of the book) is a list without any depth.

this is my code to get total content:

List<Resource> resources = book.getContents();
StringBuilder total = new StringBuilder();
for(int i = 0;i < resources.size();i++){
    Resource resource = resources.get(i);
    String htmlData = new String(resource.getData());
    total.append(TextTools.htmlToText(htmlData));
}

And this is how I get the table of contents:

List<TOCReference> tocReferences = book.getTableOfContents().getTocReferences();
for(int i = 0;i < tocReferences.size();i++){
    // Get tree structure of table of contents
    // If has children use a nested loop to get them...
}