THPDFHeadlessTextAppearanceOptions

Options in HPDFHeadlessAppearance for Unicode Form XObjects with measured layout and optional complex shaping

Field	Default and contract
`Width, Height`	200 by 30 PDF units; document filling derives these values from each widget rectangle
`FontSize`	12 PDF units; zero requests auto-fit with a maximum of 12
`Padding`	2 units on each edge, leaving a positive inner clip rectangle
`TextColor[0..2]`	Black RGB components, each from zero through one
`PaintWhiteBackground`	True, painting the complete widget background white
`Alignment`	`htaLeft`; supports center and right, with inherited field Q taking precedence during document filling
`Multiline, WrapText`	False and True; CR/LF paragraph breaks and measured logical-line wrapping, with document filling deriving multiline mode from the field flags
`CombCells`	Zero; a positive value centers direct scalar glyphs in individual cells, derived from MaxLen for comb text fields
`Rotation`	Zero; multiples of 90 degrees normalized modulo 360, derived from widget MK.R during document filling
`LineSpacing`	1.2 times font size, bounded from 1 through 10
`CharacterSpacing, WordSpacing`	Zero PDF points; finite positive or negative spacing bounded by an absolute value of 1000000, with word spacing applied to U+0020 and character spacing applied once after each direct scalar or shaped cluster, including the last cluster
`ShapeComplexText`	True; loads matching HarfBuzz and FriBidi runtimes only when complex text requires shaping
`FallbackFontFamilies`	False; True enables complete-grapheme font fallback across explicitly supplied rich-text families, with original values and authored styles retained; the single-font text builder does not search other families
`HighlightLines`	Empty dynamic integer array; each nonnegative visible line index paints a blue background, with row count bounded by MaxGlyphs and offscreen rows clipped
`HighlightLine`	-1; a nonnegative visible line index paints a blue selection background for list box appearances
`Border`	habNone; habRectangle or habCircle paints a bounded button outline
`MaxFontBytes`	8 MiB across selected programs and candidate programs inspected during supplied-family fallback
`MaxObjectBytes`	16 MiB per dictionary or stream including its payload
`MaxGlyphs`	65535 input scalars and generated glyphs, bounded by the 16-bit CID space
`CancellationToken`	Nil or a caller-owned token that stays alive throughout the operation

Dimensions, padding, and font size must be finite; dimensions and a nonzero font size are bounded from 0.000001 through 1000000 units, and the inner clip rectangle must remain at least 0.000001 units on each axis

Auto-fit that would serialize a zero font size is rejected, while fixed-size text is clipped to the inner widget rectangle

Text spacing participates in measured widths, alignment, wrapping, and auto-fit; generated CID text uses absolute glyph positioning because PDF Tw does not apply to a two-byte Identity-H space code

Document filling further caps object and glyph budgets by document options, caps font size in bytes by the decoded-stream budget, and admits the aggregate new objects against the remaining file budget