sdk/fidl/fuchsia.fonts/styles.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.fonts;

using Weight = uint16;

// Commonly used constants for font weight.
const uint16 WEIGHT_THIN = 100;
const uint16 WEIGHT_EXTRA_LIGHT = 200;
const uint16 WEIGHT_LIGHT = 300;
const uint16 WEIGHT_NORMAL = 400;
const uint16 WEIGHT_MEDIUM = 500;
const uint16 WEIGHT_SEMI_BOLD = 600;
const uint16 WEIGHT_BOLD = 700;
const uint16 WEIGHT_EXTRA_BOLD = 800;
const uint16 WEIGHT_BLACK = 900;

/// The type of slant of a type face.
enum Slant {
    /// The default; upright glyphs.
    UPRIGHT = 1;
    /// Specially designed, slanted and slightly calligraphic glyphs.
    ITALIC = 2;
    /// Skewed glyphs. Oblique usually means an geometric transformation of the upright variant,
    /// rather than a custom-designed variant.
    OBLIQUE = 3;
};

/// Horizontal width class of the glyphs.
///
/// See https://docs.microsoft.com/en-us/typography/opentype/spec/os2#uswidthclass.
enum Width {
    /// 50% of normal width
    ULTRA_CONDENSED = 1;
    /// 62.5% of normal width
    EXTRA_CONDENSED = 2;
    /// 75% of normal width
    CONDENSED = 3;
    /// 87.5% of normal width
    SEMI_CONDENSED = 4;
    /// Normal width
    NORMAL = 5;
    /// 112.5% of normal width
    SEMI_EXPANDED = 6;
    /// 125% of normal width
    EXPANDED = 7;
    /// 150% of normal width
    EXTRA_EXPANDED = 8;
    /// 200% of normal width
    ULTRA_EXPANDED = 9;
};

/// Style properties that can be used when requesting or describing a type face.
table Style2 {
    /// See |Slant|.
    1: Slant slant;
    /// Weight or thickness of the glyphs. Allowed values are integers in the range [1, 1000], but
    /// most real-world font families only support some integer multiples of 100:
    /// {100, 200, ..., 900}. Normal text (|WEIGHT_NORMAL|) is 400; |WEIGHT_BOLD| is 700.
    ///
    /// See:
    /// https://developer.mozilla.org/en-US/docs/Web/CSS/font-weight#Common_weight_name_mapping
    /// https://docs.microsoft.com/en-us/typography/opentype/spec/os2#usweightclass
    2: Weight weight;
    /// See |Width|.
    3: Width width;
};

/// Generic groups of font families that can serve as fallbacks for a specific family.
///
/// Every font family belongs to some _generic_ font family (see examples below).
///
/// If an exact requested family is unavailable but a fallback group is specified in the request,
/// the provider may return some other family that belongs to the fallback group. For example, if
/// the client requests the "Arial" family with a |SANS_SERIF| fallback, and "Arial" is unavailable,
/// the provider may return another available sans serif family, such as "Roboto Regular", instead.
///
/// See also:
/// https://www.w3.org/Style/Examples/007/fonts.en.html
/// https://developer.mozilla.org/en-US/docs/Web/CSS/font-family#Values
enum GenericFontFamily {
    /// Glyphs have little "serifs", hooks, or notches at the ends of most strokes.
    /// Examples: Georgia, Noto Serif, Times New Roman.
    SERIF = 1;
    /// Glyphs that have no serifs at the ends of most strokes.
    /// Examples: Arial, Noto Sans, Roboto, Tahoma.
    SANS_SERIF = 2;
    /// Fixed-width fonts.
    /// Examples: Consolas, Courier New, Inconsolata.
    MONOSPACE = 3;
    /// Handwritten or cursive fonts.
    /// Examples: Brush Script, Comic Sans, Lucida Calligraphy.
    CURSIVE = 4;
    /// Decorative fonts.
    /// Examples: Impact, Papyrus.
    FANTASY = 5;
};