vectorcraft/crates/doc/src/text/area.rs

use super::para_style::FirstBaseline;
use super::{Deserialize, PathData, Serialize};

/// Area Type Options "Align" (vertical): where the lines of each row/column sit in it.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum VerticalAlign {
    /// Lines start at the top of the cell (the default).
    #[default]
    Top,
    /// The block of lines is centred in the cell.
    Center,
    /// The last line's descent touches the cell bottom.
    Bottom,
    /// The first line stays at the top, the last one moves to the bottom and the space left over
    /// is shared equally between the lines (no paragraph spacing limit).
    Justify,
}

impl VerticalAlign {
    pub const ALL: [VerticalAlign; 4] = [VerticalAlign::Top, VerticalAlign::Center, VerticalAlign::Bottom, VerticalAlign::Justify];
    pub fn id(self) -> &'static str {
        match self {
            VerticalAlign::Top => "top",
            VerticalAlign::Center => "center",
            VerticalAlign::Bottom => "bottom",
            VerticalAlign::Justify => "justify",
        }
    }
}

/// Area Type Options › Text Flow: the order text fills the cells of area type with several rows
/// and columns.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum TextFlow {
    /// Down each column's rows, then on to the next column (the default, and what a document
    /// from before the option reads as).
    #[default]
    Columns,
    /// Across each row's columns, then on to the next row.
    Rows,
}

/// Text Wrap Options of a wrap object (Object → Text Wrap).
#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
#[serde(default)]
pub struct TextWrap {
    /// Distance kept between the text and the object, in points (Illustrator's default 6 pt).
    pub offset: f64,
    /// Invert Wrap: text flows inside the object instead of around it.
    pub invert: bool,
}

impl Default for TextWrap {
    fn default() -> Self {
        Self { offset: 6.0, invert: false }
    }
}

/// A resolved wrap shape on an area text object: the outline of a wrap object in text space.
#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
pub struct WrapShape {
    pub path: PathData,
    #[serde(flatten)]
    pub wrap: TextWrap,
}

/// Type on a Path effect: how each glyph is oriented on the path (Type → Type on a Path).
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum PathEffect {
    /// Glyphs rotate with the path (the default).
    #[default]
    Rainbow,
    /// Vertical edges stay vertical; the baseline follows the path.
    Skew,
    /// Horizontal edges stay horizontal; vertical edges are perpendicular to the path.
    #[serde(rename = "3dRibbon")]
    Ribbon3d,
    /// No rotation: the left end of each glyph's baseline sits on the path.
    StairStep,
    /// The baseline centre sits on the path and glyphs point away from the path's centre.
    Gravity,
}

impl PathEffect {
    pub const ALL: [PathEffect; 5] = [PathEffect::Rainbow, PathEffect::Skew, PathEffect::Ribbon3d, PathEffect::StairStep, PathEffect::Gravity];
    pub fn id(self) -> &'static str {
        match self {
            PathEffect::Rainbow => "rainbow",
            PathEffect::Skew => "skew",
            PathEffect::Ribbon3d => "3dRibbon",
            PathEffect::StairStep => "stairStep",
            PathEffect::Gravity => "gravity",
        }
    }
    pub fn parse(s: &str) -> Option<Self> {
        let k = s.to_ascii_lowercase().replace([' ', '-', '_'], "");
        Self::ALL.into_iter().find(|e| e.id().to_ascii_lowercase() == k || (k == "ribbon3d" && *e == PathEffect::Ribbon3d))
    }
}

/// Type on a Path Options › Align to Path: which height of the type runs along the path. Each
/// character is measured by its own font, size and vertical scale, and in vertical type by its own
/// size and horizontal scale. An inline graphic moves as a character of its run would, by its
/// run's vertical scale in vertical type too. These distances are VectorCraft's own values.
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum PathAlign {
    /// The top of the font's em box: the type hangs below the path. The em box is the font's
    /// ideographic em box (from its `BASE` table, its typographic or `hhea` box, or its
    /// ideographs), else an em box centered on the cap height, else a box whose top is 0.88 em
    /// above the baseline. In vertical type the characters move half an em.
    Ascender,
    /// The bottom of the font's bounding box, else the font's descent: the type stands above the
    /// path. In vertical type the characters move half an em the other way.
    Descender,
    /// A line at half the height of the top of the font's H above the baseline, else at half its
    /// cap height, else at the middle of its em box. In vertical type the characters stay on the
    /// path.
    Center,
    /// The baseline (the default).
    #[default]
    Baseline,
}

impl PathAlign {
    pub const ALL: [PathAlign; 4] = [PathAlign::Ascender, PathAlign::Descender, PathAlign::Center, PathAlign::Baseline];
    pub fn id(self) -> &'static str {
        match self {
            PathAlign::Ascender => "ascender",
            PathAlign::Descender => "descender",
            PathAlign::Center => "center",
            PathAlign::Baseline => "baseline",
        }
    }
    pub fn parse(s: &str) -> Option<Self> {
        Self::ALL.into_iter().find(|a| a.id().eq_ignore_ascii_case(s.trim()))
    }
}

/// Area Type Options: rows and columns, gutters, inset and first baseline of area type.
#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
#[serde(default, rename_all = "camelCase")]
pub struct AreaOptions {
    #[serde(deserialize_with = "de_rows_or_columns")]
    pub rows: usize,
    #[serde(deserialize_with = "de_rows_or_columns")]
    pub columns: usize,
    /// Gutter between rows/columns in points.
    pub gutter: f64,
    /// Gutter between rows in points when it differs from [`Self::gutter`], which is then the
    /// gutter between columns (left out when saved while unset).
    #[serde(skip_serializing_if = "Option::is_none")]
    pub row_gutter: Option<f64>,
    /// Inset from the frame edges in points.
    pub inset: f64,
    pub first_baseline: FirstBaseline,
    /// Minimum first-baseline offset in points.
    pub first_baseline_min: f64,
    /// Vertical alignment of the lines in each row/column.
    pub vertical_align: VerticalAlign,
    /// Text Flow: by columns (the default, left out when saved) or by rows.
    #[serde(skip_serializing_if = "crate::skip::is_default")]
    pub flow: TextFlow,
    /// How the frame and its text fit each other (Auto Size, Shrink Text to Fit).
    #[serde(skip_serializing_if = "crate::skip::is_default")]
    pub fit: AreaFit,
    /// Dynamic Text's Block ([`super::TextObject::dynamic_text`] on area type): the Desired word
    /// spacing the layout sets every paragraph with ([`super::TextObject::layout_justification`]), in
    /// percent of a word space (100, the default, is left out when saved).
    #[serde(skip_serializing_if = "AreaOptions::is_default_word_gap")]
    pub word_gap: f64,
    /// Dynamic Text's Block: the points added to each character's size to give its leading (0, the
    /// default, is left out when saved).
    #[serde(skip_serializing_if = "crate::skip::is_default")]
    pub line_gap: f64,
}

impl Default for AreaOptions {
    fn default() -> Self {
        Self {
            rows: 1,
            columns: 1,
            gutter: 18.0,
            row_gutter: None,
            inset: 0.0,
            first_baseline: FirstBaseline::Ascent,
            first_baseline_min: 0.0,
            vertical_align: VerticalAlign::Top,
            flow: TextFlow::Columns,
            fit: AreaFit::None,
            word_gap: Self::DEFAULT_WORD_GAP,
            line_gap: 0.0,
        }
    }
}

impl AreaOptions {
    /// The most rows, and the most columns, area type can have.
    pub const MAX_ROWS_COLUMNS: usize = 100;
    /// Block's word gap range (percent of a word space), the Justification word spacing range.
    pub const WORD_GAP: (f64, f64) = (0.0, 1000.0);
    /// Block's word gap new type starts with: the font's own word space.
    pub const DEFAULT_WORD_GAP: f64 = 100.0;
    /// Block's line gap range in points.
    pub const LINE_GAP: (f64, f64) = (-1296.0, 1296.0);
    fn is_default_word_gap(v: &f64) -> bool {
        *v == Self::DEFAULT_WORD_GAP
    }
    /// Block's gaps kept within their ranges; a gap that is not a number gives its default.
    pub fn block_gaps(&self) -> (f64, f64) {
        let word = if self.word_gap.is_finite() { self.word_gap.clamp(Self::WORD_GAP.0, Self::WORD_GAP.1) } else { Self::DEFAULT_WORD_GAP };
        let line = if self.line_gap.is_finite() { self.line_gap.clamp(Self::LINE_GAP.0, Self::LINE_GAP.1) } else { 0.0 };
        (word, line)
    }
}

/// [`AreaOptions::rows`] or [`AreaOptions::columns`], read as a `u64` and clamped to
/// 1..=[`AreaOptions::MAX_ROWS_COLUMNS`].
fn de_rows_or_columns<'de, D: serde::Deserializer<'de>>(d: D) -> Result<usize, D::Error> {
    let n = usize::try_from(u64::deserialize(d)?).unwrap_or(usize::MAX);
    Ok(n.clamp(1, AreaOptions::MAX_ROWS_COLUMNS))
}

/// How area type and its frame fit each other. Serialized as `"none"`, `"autoHeight"` or
/// `{"shrinkText": {"minPercent": 50}}`.
#[derive(Clone, Copy, Debug, Default, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub enum AreaFit {
    /// The frame keeps its size; text that doesn't fit overflows.
    #[default]
    None,
    /// The frame's height follows the text (Illustrator's Auto Size): resolved by the engine after
    /// each edit, for rectangular frames of horizontal type in one row.
    AutoHeight,
    /// Text that overflows is scaled down (size, leading and baseline shift; not paragraph
    /// spacing) by the largest factor down to `min_percent` % that makes it fit, at layout time.
    ShrinkText {
        #[serde(rename = "minPercent", default = "AreaFit::default_min_percent")]
        min_percent: f64,
    },
}

impl AreaFit {
    /// The smallest Shrink Text to Fit percentage allowed.
    pub const MIN_PERCENT: f64 = 10.0;
    /// The Shrink Text to Fit percentage new settings start with.
    pub const DEFAULT_MIN_PERCENT: f64 = 50.0;
    fn default_min_percent() -> f64 {
        Self::DEFAULT_MIN_PERCENT
    }
    /// Its id: `none`, `autoHeight` or `shrinkText`.
    pub fn id(self) -> &'static str {
        match self {
            AreaFit::None => "none",
            AreaFit::AutoHeight => "autoHeight",
            AreaFit::ShrinkText { .. } => "shrinkText",
        }
    }
    /// The fit an id names (case, spaces, dashes and underscores ignored), with `min_percent`
    /// for Shrink Text (clamped to 10..100; a non-finite value gives the default).
    pub fn parse(id: &str, min_percent: Option<f64>) -> Option<Self> {
        match id.to_ascii_lowercase().replace([' ', '-', '_'], "").as_str() {
            "none" | "off" => Some(AreaFit::None),
            "autoheight" | "autosize" => Some(AreaFit::AutoHeight),
            "shrinktext" | "shrinktexttofit" | "shrink" => {
                Some(AreaFit::ShrinkText { min_percent: Self::clamp_percent(min_percent.unwrap_or(Self::DEFAULT_MIN_PERCENT)) })
            }
            _ => None,
        }
    }
    /// A Shrink Text minimum percentage within 10..100 (the default when not finite).
    pub fn clamp_percent(p: f64) -> f64 {
        if p.is_finite() { p.clamp(Self::MIN_PERCENT, 100.0) } else { Self::DEFAULT_MIN_PERCENT }
    }
    /// Shrink Text's minimum scale factor (0.1..1), if this is Shrink Text.
    pub fn min_scale(self) -> Option<f64> {
        match self {
            AreaFit::ShrinkText { min_percent } => Some(Self::clamp_percent(min_percent) / 100.0),
            _ => None,
        }
    }
}