Struct BoxModel 

pub struct BoxModel {
    pub width: Option<f64>,
    pub height: Option<f64>,
    pub x: f64,
    pub y: f64,
    pub margins: Insets,
    pub border_width: f64,
    pub min_width: f64,
    pub max_width: f64,
    pub min_height: f64,
    pub max_height: f64,
    pub caption: Option<Caption>,
}

The XFA Box Model for a form element.

XFA Spec 3.3 §2.6 (p49-50) — Nominal extent is w × h. Inside: margins → border inset → caption region → content region. The Nominal Content Region is the area after margins are applied.

§8 Growability (p275-276): a container is growable if it omits h and/or w:

• h=✓ w=✓ → fixed, not growable (minH/maxH/minW/maxW ignored)
• h=✓ w=∅ → growable along X only (minH/maxH ignored)
• h=∅ w=✓ → growable along Y only (minW/maxW ignored)
• h=∅ w=∅ → growable along both axes Default: minH=0, minW=0, maxH=infinity, maxW=infinity.

See spec figure “Relationship between nominal extent and borders, margins, captions, and content” (p50).

TODO(§2.6): border inset not modeled separately — currently merged with margins.

Fields

width: Option<f64>

Nominal width (None = growable).

height: Option<f64>

Nominal height (None = growable).

x: f64

Explicit x position (for positioned layout).

y: f64

Explicit y position (for positioned layout).

margins: Insets

Margins.

border_width: f64

Border thickness (simplified to uniform for now).

min_width: f64

Minimum width constraint.

max_width: f64

Maximum width constraint.

min_height: f64

Minimum height constraint.

max_height: f64

Maximum height constraint.

caption: Option<Caption>

Caption region.

Implementations

impl BoxModel

pub fn content_width(&self) -> f64

The available content width after subtracting margins, borders, and caption.

pub fn content_height(&self) -> f64

The available content height after subtracting margins, borders, and caption.

pub fn outer_size(&self, content: Size) -> Size

The outer extent (total bounding box).

Trait Implementations

impl Clone for BoxModel

fn clone(&self) -> BoxModel

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BoxModel

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for BoxModel

fn default() -> BoxModel

Returns the “default value” for a type.

impl PartialEq for BoxModel

fn eq(&self, other: &BoxModel) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for BoxModel