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Creating text nodes#

What are nodes?#

Text data structure#

  • Hierarchical structure
func NewText() *Text
type Text struct {
    Settings TypesettingSettings
    Items    []any

Text can be a nested structure. Think of

<em>this is <u>emphasized and underlined</u></em>

where you can consider the underlined part as a child of the emphasized part.

ul := NewText()
ul.Items = append(ul.Items,"emphasized and underlined")

em := NewText()
em.Items = append(em.Items, "this is ")
em.Items = append(em.Items, ul

Format a paragraph#

  • font family needed

This breaks a paragraph into lines:

func (fe *Document) FormatParagraph(te *Text, hsize bag.ScaledPoint, opts ...TypesettingOption) (*node.VList, []*node.Breakpoint, error)

hsize is the desired horizontal size.

format paragraph calls mknodes

func (fe *Document) Mknodes(ts *Text) (head node.Node, tail node.Node, err error)

which creates a list of nodes from a nested Text data structure.

Typesetting options#

The FormatParagraph() method takes a typesetting options as the last argument.

type TypesettingOption func(*Options)
Option Description
Leading(leading bag.ScaledPoint) Set the vertical distance between two baselines
Language(language *lang.Lang) Set the language used for hyphenation
FontSize(size bag.ScaledPoint) Set the font size for the paragraph
IndentLeft(size bag.ScaledPoint, rows int) Set the text indent
HorizontalAlign(a HorizontalAlignment) Sets the horizontal alignment for a paragraph