Spreadsheets calculate some chart sizes incorrectly

Sometimes Excel stores a chart with an anchor referencing two cells, creating a rectangular range, plus EMU offsets. This is a CTTwoCellAnchor POI type. Vaadin handles these correctly.

However, SpreadsheetFactory.getAnchorFromParent(XmlObject) copies incorrect code from the POI XSSFDrawing class, which fails to account properly for CTOneCellAnchor and CTAbsoluteAnchor types.

A starting point on their definitions is found in the MS documentation for their common sizing element.

POI bug 61203 has been opened to enhance POI to support these additional anchor types. That should include a public interface to get what Vaadin needs to avoid copying code (which can then persist bugs like this of course).

The current result is a workbook rendered with huge charts incorrectly sized. I have not figured out yet exactly what one must do in Excel to produce a file with these types of anchors, but one of my users did it somehow. I think it is the shape properties:

• Move and size with cells == CTTwoCellAnchor
• Move but don't size with cells == CTOneCellAnchor
• Don't move or size with cells == CTAbsoluteAnchor

Start at SpreadsheetFactory.getAnchorFromParent(XmlObject) and compare its anchor handling with POI's XSSFDrawing implementation and the CTOneCellAnchor, CTTwoCellAnchor, and CTAbsoluteAnchor definitions. Use the linked Microsoft sizing documentation and POI bug 61203 as context; done means workbooks with these anchor types render charts at their correct sizes.