public PageInfo GetPreviousPage(int firstTokenID, string stopText)
{
string startText = string.Empty;
var tokenLines = new List<TokenBlockBase>();
int stopTokenID = firstTokenID;
LineBuilder lineBuilder = CreateLineParser();
foreach (int blockStartId in FindBlockTokenID(firstTokenID))
{
List<TokenBlockBase> linesInBlock = lineBuilder
.GetLines(_bookTokens, string.Empty, blockStartId, stopTokenID, stopText)
.ToList();
EndTokenBlock(linesInBlock);
InsertTokenBlocks(linesInBlock, tokenLines);
// Remove all page breaks at the end
TokenBlockBase pageBreak;
while ((pageBreak = tokenLines.LastOrDefault()) != null && pageBreak is PageBreakBlock)
{
tokenLines.RemoveAt(tokenLines.Count - 1);
}
if (RemovePageBreaks(tokenLines, ref stopTokenID, ref startText))
break;
stopTokenID = blockStartId;
stopText = string.Empty;
}
if (!tokenLines.Any())
return null;
PageInfo pageInfo = new PageBuilder(_pageSize, _images).GetPage(tokenLines);
if (pageInfo == null)
return null;
pageInfo.StartText = startText;
pageInfo.FirstTokenID = stopTokenID;
return pageInfo;
}
public PageInfo GetPage(int firstTokenID, string lastText)
{
if (firstTokenID >= _bookTokens.Count)
return null;
LineBuilder lineBuilder = CreateLineParser();
IEnumerable<TokenBlockBase> lines = lineBuilder.GetLines(_bookTokens, lastText, firstTokenID);
var pageParser = new PageBuilder(_pageSize, _images);
string startText = lastText;
PageInfo pageInfo = pageParser.GetPage(lines);
if (pageInfo == null)
return null;
pageInfo.StartText = startText;
return pageInfo;
}