For sheets, once again Excel 2016, I cannot hide the last visible sheet. So it appears that Excel handles Sheets and workbooks differently. One potential reason to have hidden workbooks is if you have a workbook with just macros in it, and you have that in your XLSTART library [User library]/AppData/Roaming/Microsoft/Excel/XLSTART, then that workbook will open every time you open Excel, and you really want that workbook to be hidden, but open with no visible window views.
-----Original Message----- From: Javen O'Neal [mailto:[email protected]] Sent: Monday, October 30, 2017 10:46 PM To: POI Users List <[email protected]> Subject: Re: XSSFWorkbook isHidden implementation Yudai Yamaguchi-san, How are you planning on using workbook visibility? My understanding of workbook visibility, using Excel 2013 (no longer a multiple document interface) is that at least one workbook view must be visible (Excel disallows saving an all-hidden workbook), and each sheet defines a sheetviews list with one entry per workbook view. There are quite a few gotchas to getting book views working in POI without creating xlsx files that Excel will declare are corrupt. If your use case is a workbook that already contains multiple workbook views and you need to change the visibility of the first workbook view, then we can skip adding and removing workbook views to a workbook. Otherwise, some research is needed to implement the dependent features before implementing boolean isHidden(int) and void setHidden(int, boolean), or possibly Enum WorbookViewVisibility { visible, hidden, very_hidden }.
