Frames may break between pages in text documents

Developer contact: Miklos Vajna

= Rationale =

Use cases:

A table inside a text document may be inside a frame, so that content can wrap around it. A table can be also directly in the text document ("inline"), so it can span over multiple pages if there is enough content in it. The proposal is to allow the two use-cases at the same time: a frame containing a table and also spanning over multiple pages.

Alternatives considered:

• Don't split tables in frames over multiple pages. This has the downside that it looks like some content is not in the document, while it's just not visible.

• Never put tables inside frames. This has the downside that content can't wrap around the table, even if there would be space for it. This can lead to more pages than necessary.

Regina:

• Use a chain of linked frames. This has the downside that it needs several individual frames each with its own anchor, size and position. It would not allow the author to start with the table because following pages has no text content to anchor a frame to.
• Limit the new feature to a <table:table> element as child of a <draw:frame> element. This has the downside, that it does not allow additional text to the table like a caption, for example, or allow the page break if a frame has long <draw:object> and <draw:object-ole> child elements.

Regina: Addition for interoperability:

When a floating table spreads over a page break in MS Office, the text content beside the table only starts at the last page. MS Office has the compatSetting extension allowTextAfterFloatingTableBreak to enable that text content beside table is already possible on the first page of the floating table. Such layout is usesful for long smalll tables. Therefore the requested attribute has to be complemented by an attribute to allow such wrap behavior. 

= Requested changes to the ODF Standard =

see attachment

= Impacts =

Conformance:

This proposal will not add any mandatory features or behaviors.

Backwards compatibility:

This change will not impact existing ODF processors, the usage of the new attributes is optional.

Accessibility impact:

This change will not impact accessibility.

Interoperability:

OOXML's wordprocessingML has a <w:tblpPr> markup [17.4.57 tblpPr (Floating Table Positioning), page 443, ISO/IEC 29500-1:2016(E)] to describe a similar feature (multi-page floating table). This proposal allows round-tripping that feature in ODF. LibreOffice 7.6 implements this layout feature in its ODF extension namespace.

Regina: The attribute allowTextAfterFloatingTableBreak is a document setting in MS Office. I prefer a style attribute for ODF because it is more flexible and therefore suggest style:wrap-text-at-frame-start as graphic property. To get it document wide for round-tripping, it can be set at the root of the styles hierarchy.

The topic has been discussed on the LibreOffice mailing list:
https://lists.freedesktop.org/archives/libreoffice/2023-July/090610.html

The initial proposal is by Miklos, see his attachment in the thread sited above.  I have added the attribute style:wrap-text-at-frame-start because otherwise it is not possible to distinguish between a typographically more appealing layout and the way MS Office arrange body text as default.