Excel has both form controls and ActiveX controls, and tdf#106181 XLSX export: output form controls last year started adding support for form control export to XLSX.

Hoping that this will be mostly shared drawingML export code fixing (benefiting DOCX and PPTX as well), it seemed reasonable to assume that we can improve button handling from the "it’s lost" state to "it’s good enough" with some effort.

Now Excel shows the button and you can click on it:

While it used to just refuse our export result:

If you would like to know a bit more about how this works, continue reading… :-)

As usual, the end goal was reached via a set of incremental commits:

Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release (7.3).

Once you insert an image to a Writer document, you can customize its anchor type. The as-char anchor type is handy if you don’t want text to flow around the image. This has the side effect that a large image significantly increases the nominal height of a line. The problematic document had an image height of 118.9 cm (46.81 inch), so the unsigned integer used to represent its height wrapped around, leading to an incorrect layout.

Now it looks like the way you would expect it:

If you would like to know a bit more about how this works, continue reading… :-)

As usual, the end goal was reached via a set of incremental commits:

Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release (7.2).

The same feature in normal HTML linking / citation is well-known: you can place anchors in your document and then links can refer to not only to your page, but also can set the fragment part of the URL to jump to a specific section directly. E.g. this link will jump to the "Motivation" section of the above referred previous post.

Wouldn’t it be nice if you could also jump to a specific page of a scientific PDF?

You can add such references by choosing the Insert → Table of Contents and Index → Bibliography Entry menu item. Set Bibliography Source to Document Content and press the New button. The appearing dialog now has widgets to set a specific page number:

This is then stored in the URL by setting its fragment to page=..., and typically PDF readers understand this syntax, so when you click on the URL, the PDF will open exactly on the cited page.

This also works the other way around: URLs with such syntax are presented to the user with the dedicated widget to see, edit or delete the page number of the URL.

Finally, if you refer to different pages of the same source, the bibliography text generator detects this and lists the source in the bibliography only once.

If you would like to know a bit more about how this works, continue reading… :-)

As usual, the high-level problem was addressed by a series of incremental development steps:

Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release (7.2).

Both Word and Writer allow specifying borders for any kind of table cells. When the user creates a vertically merged cell, there is a covering cell and there is one or more covered table cells.

The Writer approach is to render the cell borders according to the properties of the covering cell. This has the benefit that each edge of the table cell has a single border style (e.g. dashed or hairline).

The Word approach is to render the cell borders as if there would be no vertical merge, according to the properties of the covered cell. This has the benefit that merging the content of cells vertically doesn’t change the border rendering, but it also requires more complex code for painting.

Writer can now detect that your tables originate from Word formats and render table borders the Word way in that case.

Here is how the new rendering result look like:

And here is how it used to look like:

And finally the reference rendering is:

You can see that the B4 and B5 cells are covered, they had some unwanted border on their left side and this is now gone.

If you would like to know a bit more about how this works, continue reading… :-)

Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release (7.2).

I posted about Writer gutter margin in general back in February, and two follow-up requests accumulated around this new feature since then.

First, the gutter margin could be on the left or at the top for non-mirrored documents, which initially sounded like a complete solution, but later it turned out that right-to-left (RTL) documents want it on the right.

Second, there was a request from the OASIS TC to to implement the ODF filter differently for gutter margin.

Neither of these is simple to do, so this hackweek was a good opportunity to address these problems.

Here is the layout and user interface for RTL gutter looks like:

You can see how the gutter is on the right (not the left) and you can alter this behavior with a dedicated checkbox on the UI.

If you would like to know a bit more about how this works, continue reading… :-)

Finally I had a little bit of remaining time, so I addressed a request from the OASIS ODF TC:

Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release (7.2).

Generating a bibliography (table) for a document is a two-step process: first the user inserts bibliography entry fields to refer to sources, then later the bibliography can be auto-generated. It was not great that details of a source was only visible in the Writer edit window after generating the bibliography table. A somewhat related shortcoming was that URLs of sources were handled as plain text, while users expect that references are also clickable, similar to e.g. table of contents.

This is how a tooltip looks like, available even if there is no bibliography table yet:

And URLs in the bibliography table are now clickable:

If you would like to know a bit more about how this works, continue reading… :-)

As usual, the high-level problem was addressed by a series of incremental development steps:

Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release (7.2).

Word has a gutter margin feature, and we saw that some UI-level workaround appeared to have something similar based on the LibreOffice technology. We thought it’s much better to impelement this properly, so that the result is interoperable with Word, and also available both in Online and on the desktop.

This is how the UI looks like in Online:

This is how the new render result looks like:

Matching the reference rendering:

While the gutter was just missing previously:

You can see that the gutter margin is now handled properly.

If you would like to know a bit more about how this works, continue reading… :-)

As usual, the high-level problem was addressed by a series of incremental development steps:

With these, it’s now possible to add, modify, render and delete gutter margins for your documents, while preserving them during ODT and DOCX import/export, without introducing any weird fake line shapes.

You can get a snapshot / demo of Collabora Office and try it out yourself right now: try unstable snapshot. Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release too (7.2).

You can get a snapshot / demo of Collabora Office and try it out yourself right now: try unstable snapshot. Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release too (7.2).

We got a PPTX document, which has a table shape with blurry shadow. The shadow was completely missing in Impress. It was discovered that in case you configure the default shape style to have shadow, then there is some initial table shadow support in Impress, but that was not used in the PPTX case.

The request was to improve the shadow rendering to be PowerPoint-compatible and in general support table shadows as direct formatting as a new feature.

The table shadow now looks like this:

Matching the reference rendering:

While shadow was just missing previously:

You can see that not only the shadow is there, but also the cell backgrounds and the blurry shadow is rendered properly.

If you would like to know a bit more about how this works, continue reading… :-)

As usual, the high-level problem was addressed by a series of small fixes:

With these, it’s now possible to add, edit, render and delete these table shadows, while preserving them during ODP and PPTX import/export.

You can get a snapshot / demo of Collabora Office and try it out yourself right now: try unstable snapshot. Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release too (7.2).

There has been a recent evaluation of PDF signature verification, which included Draw. While we got a checkmark on their Shadow Hide test, their Shadow Replace test found conditional problems and their Shadow Hide-and-Replace test was not happy, either.

So time to look at what are those corner-cases and how the situation can be improved, so people keep trusting that if Draw says a signature is valid, it’s indeed valid.

There were 4 incremental improvements in this area:

These were enough so that talking to the authors of that evaluation now confirmed that these problems are all gone.

If you would like to know a bit more about how this works, continue reading… :-)

PDF signature verification works by using a custom PDF tokenizer. You can read about that code in the PDF tokenizer section of this post. The bottom line is that we now have both PDFium and this custom tokenizer, somewhat duplicating the functionality.

After talking to the PDFium developers (see the relevant mailing list thread), there were open regarding adding all the high level API to allow PDF signature verification based on PDFium, and not via our own tokenizer. See this header file for the set of relevant APIs added. A combinations of those allowed to adapt the code on our side and use PDFium for signature verification, not the own tokanizer.

You can get a snapshot / demo of Collabora Office and try it out yourself right now: try unstable snapshot. Collabora intends to continue supporting and contributing to LibreOffice, the code is merged so we expect all of this work will be available in TDF’s next release too (7.1).