mead_pdf

defmodule Mead.Style do
  @moduledoc """
  Visual and layout styling for a node.

  Lengths are in PDF points. Colors are `{r, g, b}` tuples of 0-255 integers.

  Text properties (`color`, `font_size`, `line_height`, `font_family`,
  `font_weight`, `italic`, `text_align`) are inheritable: `nil` means "inherit from the
  parent", with document defaults of black 14pt/1.2 regular in the default
  family at the root.

  `orphans`/`widows` (also inheritable, default 2 like CSS) set the minimum
  number of text lines kept before / carried after a page break inside a
  text node; a paragraph that cannot satisfy them moves to the next page.
  At the top of a page an unsatisfiable rule breaks geometrically instead
  (progress is never sacrificed). `1` disables the constraint.
  """

  defstruct flex_direction: :column,
            width: nil,
            height: nil,
            min_width: nil,
            min_height: nil,
            max_width: nil,
            max_height: nil,
            flex_grow: nil,
            flex_shrink: nil,
            flex_basis: nil,
            padding: 0.0,
            margin: 0.0,
            gap: 0.0,
            align_items: nil,
            justify_content: nil,
            align_self: nil,
            border: 0.0,
            border_color: nil,
            border_radius: 0.0,
            background: nil,
            font_size: nil,
            line_height: nil,
            font_family: nil,
            font_weight: nil,
            italic: nil,
            text_align: nil,
            color: nil,
            orphans: nil,
            widows: nil

  @type color :: {0..255, 0..255, 0..255}
  @typedoc """
  A length in points, or `{:percent, n}` with CSS-style `n` (50 = 50%).
  """
  @type dimension :: number() | {:percent, number()}
  @typedoc "Uniform, or per-side in CSS order {top, right, bottom, left}."
  @type sides :: number() | {number(), number(), number(), number()}
  @type alignment :: :start | :end | :center | :stretch | :baseline
  @type justify :: :start | :end | :center | :space_between | :space_around | :space_evenly

  @type t :: %__MODULE__{
          flex_direction: :row | :column,
          width: dimension() | nil,
          height: dimension() | nil,
          min_width: dimension() | nil,
          min_height: dimension() | nil,
          max_width: dimension() | nil,
          max_height: dimension() | nil,
          flex_grow: number() | nil,
          flex_shrink: number() | nil,
          flex_basis: number() | nil,
          align_items: alignment() | nil,
          justify_content: justify() | nil,
          align_self: alignment() | nil,
          border: sides(),
          border_color: color() | nil,
          border_radius: number(),
          padding: sides(),
          margin: sides(),
          gap: number(),
          background: color() | nil,
          font_size: number() | nil,
          line_height: number() | nil,
          font_family: String.t() | nil,
          font_weight: number() | :normal | :bold | nil,
          italic: boolean() | nil,
          text_align: :left | :center | :right | :justify | nil,
          color: color() | nil,
          orphans: pos_integer() | nil,
          widows: non_neg_integer() | nil
        }
end