How can I centralize figure caption in Quarto with docx output?

[mjdzr]

Description

I have created a new template document, which is essentially a totally new document with the "Image Caption" style changed to Arial 9 and making sure it's center aligned:

But when I create the caption, it's still left-aligned. Is it anyway to make figure caption centered? Also, I understand that "Image Caption" style is used on both figure and table captions. Is there any way to bypass this so that ONLY figure captions are centralized?

---
format:
  docx:
    reference-doc: "templates/template.docx"
---

```{r}
#| label: fig-figure1
#| fig-cap: "Cars!"
plot(cars)

Interesting enough, in the output word file, if we change the caption to another type and then back to "Image Caption", we can see that the caption gets centralized:

[mcanouil]

The issue is because the alignment does not come from the style but seems to be added/hardcoded on top of it.

Let's modify the Image Caption style in obvious ways in addition to make it centred.

Generate the Word document

Input	Output
--- title: "Quarto Playground" format: docx: reference-doc: centre-caption.docx --- {#fig-placeholder}

If you look at the style of the caption, it get "+ Left"

Now, if you use standard figure (not cross-referenceable):

Input	Output
--- title: "Quarto Playground" format: docx: reference-doc: centre-caption.docx --- 

@cscheid Is it on purpose that the alignment is set this way for Word? This means you no longer can change caption alignment via reference document which is the only way for this format. (known behaviour in the feature matrix)
I believe for Word (and Powerpoint), it should only use the default style with nothing hardcoded unless fig-align is explicitly provided.

[mcanouil]

Alignment is hardcoded by Quarto

• quarto-cli/src/resources/filters/layout/docx.lua

  Lines 97 to 110 in 39baf40

  	function docxParaStyles(align)
  	local styles = "<w:pPr>\n"
  	local captionAlign = docxAlign(align)
  	if captionAlign then
  	styles = styles ..
  	"<w:jc w:val=\"" .. captionAlign .. "\"/>\n"
  	end
  	styles = styles ..
  	"<w:spacing w:before=\"200\" />\n" ..
  	"<w:pStyle w:val=\"ImageCaption\" />\n" ..
  	"</w:pPr>\n"
  	return styles
  	end

In theory, fig-align is supposed to control caption but it's not the case (maybe related to the cross-reference system refactoring/improvement)

Input	Output
--- title: "Quarto Playground" format: docx: reference-doc: centre-caption.docx fig-align: center --- {#fig-placeholder-1} {#fig-placeholder-2 fig-align="right"}

Now, if I remove the alignment hardcoded/added, in addition to get fig-align working, you also get the reference document works by default as one might expect.

function docxParaStyles(align)
  local styles = "<w:pPr>\n"
- local captionAlign = docxAlign(align)
- if captionAlign then
-   styles = styles .. 
-       "<w:jc w:val=\"" .. captionAlign .. "\"/>\n"
- end  
  styles = styles ..
    "<w:spacing w:before=\"200\" />\n" ..
    "<w:pStyle w:val=\"ImageCaption\" />\n" ..
    "</w:pPr>\n"
  return styles
end

Input	Output
--- title: "Quarto Playground" format: docx: reference-doc: centre-caption.docx fig-align: center --- {#fig-placeholder-1} {#fig-placeholder-2 fig-align="right"}
--- title: "Quarto Playground" format: docx: reference-doc: centre-caption.docx --- {#fig-placeholder-1} {#fig-placeholder-2 fig-align="right"}

Unfortunately, the code which adds the alignment is needed for table caption to be aligned according to the document level tbl-align.

For short, the current implementation is in conflict with itself resulting in more bad results than good.

Quarto document

---
title: "Quarto Playground"
format:
  docx:
    reference-doc: centre-caption.docx
    tbl-align: left
---

![An image 1]({{< placeholder 600 400 >}}){#fig-placeholder-1}

| A | B | C |
|---|---|---|
| 1 | 2 | 3 |
| 4 | 5 | 6 |

: A table 1 {#tbl-table-1}

![An image 2]({{< placeholder 600 400 >}}){#fig-placeholder-2 fig-align="right"}

| A | B | C |
|---|---|---|
| 1 | 2 | 3 |
| 4 | 5 | 6 |

: A table 2 {#tbl-table-2 tbl-align="right"}

Version	Output
v1.7		"Figure 1" should be centred "Figure 2" should be right-aligned "Table 1" is correctly left-aligned "Table 2" should be right-aligned Results: 1 correct out of 4 cases
No alignment added in `docxDivCaption`		"Figure 1" is correctly centred "Figure 2" is correctly right-aligned "Table 1" should be left-aligned "Table 2" is correctly right-aligned Results: 3 correct out of 4 cases

[mcanouil]

I've opened an issue as I do believe this to be a bug in the codebase that needs fixing.

• Wrong alignment for table/figure in docx (fig-align not working) #11589