Spacing and Indentation

Everything on this page is a paragraph property, set directly on the Paragraph and applying to the whole block. Spacing controls the gap above and below the paragraph; indentation controls how far its edges sit from the page margins. Neither has anything to do with the gap between lines inside the paragraph, which is line spacing.

The setters

Every distance is a measurement.Distance, and the constants in the measurement package are all expressed in points, so measurement.Inch*3, measurement.Point*216 and measurement.Twips*4320 are interchangeable ways of writing the same length. The value is truncated to twips on the way into the file, so a distance built from measurement.Millimeter or measurement.Centimeter can land a twip short of the round number you were aiming at.

For alignment, wml.ST_JcLeft and wml.ST_JcRight are absolute, while wml.ST_JcStart and wml.ST_JcEnd follow the reading direction. Use the second pair if the document has any right-to-left content.

Doing it

para := doc.AddParagraph()
para.AddRun().AddText(lorem)
para.SetAlignment(wml.ST_JcCenter)
para.SetBeforeSpacing(measurement.Inch * 2)
para.SetAfterSpacing(measurement.Inch * 2)
para.SetLeftIndent(measurement.Inch * 3)

Between two paragraphs, the first one’s after spacing and the second one’s before spacing both apply, which is why a run of paragraphs that each set an inch on both sides ends up looking much sparser than expected. IgnoreSpaceBetweenParagraphOfSameStyle sets w:contextualSpacing to suppress that, which is how list items avoid drifting apart. It applies only between neighbors that use the same style, and it takes no argument, so there is no way to switch it back off through this method.

SetFirstLineIndent and SetHangingIndent write different attributes of the same w:ind element and are the two directions of the same idea. Setting both on one paragraph leaves Word to reconcile them; pick one.

Limitations

Passing measurement.Zero to any of the four indent setters deletes the attribute instead of writing zero. A paragraph cannot use SetLeftIndent(0) to cancel an indent inherited from its style. Set the style’s indent, or apply a different style.

SetOutlineLvl subtracts one from the argument before writing it, so SetOutlineLvl(3) produces w:outlineLvl of 2, which is the level Word calls Level 3. The example passes 3 and gets the third level. The style-level equivalent, ParagraphStyleProperties.SetOutlineLevel, writes the value unchanged, so the two are off by one from each other.

SetBeforeSpacing and SetAfterSpacing write an unsigned attribute. Negative distances are not clamped, they wrap, and the result is a document Word may refuse to open.

SetBeforeLineSpacing and SetAfterLineSpacing exist and sound like they take a number of lines, but they convert their argument through measurement.Twips in the same way the point-based setters do, while w:beforeLines and w:afterLines are read by Word in hundredths of a line. The values will not mean what the names suggest. Use SetBeforeSpacing and SetAfterSpacing.

Run the example

The example writes eleven paragraphs of the same lorem ipsum, each one changing a single setting, so the differences are what you read. It also ends with four paragraphs stepping line spacing from single through triple, showing the 12 point baseline the auto rule is measured against.

Note that it never calls doc.Close(). That is fine here, because Close only removes temporary files created by document.Open, and this example builds the document with document.New.

git clone https://github.com/unidoc/unioffice-examples.git
cd unioffice-examples/document/paragraph_spacing_and_indentation
go run main.go

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