Module: Fatty::Themes::Resolver

Defined in:
lib/fatty/themes/resolver.rb

Overview

The Resolver module is responsible for transforming a raw theme loaded by the Loader into a fully-resolved "theme_spec".

Resolution includes:

  • applying inheritance between themes
  • applying inheritance between roles
  • filling in default attributes
  • synthesizing "composite" roles used by the alert panel

Composite alert roles (e.g., :alert_info, :alert_warn, etc.) combine the background and structural properties of the :alert role with the foreground and attributes of the semantic roles (:good, :info, :warn, :error).

The result of resolution is a Hash keyed by role names, where each value is a symbolic color specification (typically using color names and attrs). We refer to this Hash as a "theme_spec".

A theme_spec is not directly renderable. Before rendering, it must be "compiled" into a palette by Fatty::Colors::Palette.apply!. The palette maps each role to concrete rendering data (RGB values for truecolor or Curses color pairs, along with attributes).

Renderer classes consume only the compiled palette and never operate directly on the theme_spec. module Resolver

Constant Summary collapse

DEFAULT_ROLE_SPECS = 
{
  region: { attrs: [:reverse] },
  cursor: { attrs: [:reverse] },
  input_suggestion: { attrs: [:dim] },
  pager_status: { attrs: [:reverse] },
  search_input: { attrs: [:reverse] },
  match_current: { attrs: [:reverse] },
  match_other: { attrs: [:underline] },
  popup_counts: { attrs: [:bold] },
  alert: { attrs: [:bold] },
  markdown_table_cell: {},
  markdown_underline: { attrs: [:underline] },
  markdown_hrule: { attrs: [:dim] },
}.freeze
ROLE_PARENTS = 
{
  input: :output,
  input_suggestion: :input,

  region: :output,
  cursor: :input,

  popup: :output,
  popup_frame: :popup,
  popup_input: :input,
  popup_selection: :region,
  popup_counts: :popup,

  search_input: :popup,

  match_current: :region,
  match_other: :region,

  status: :output,
  alert: :output,
  info: :output,
  good: :info,
  warn: :info,
  error: :warn,

  pager_status: :status,

  markdown_h1: :output,
  markdown_h2: :markdown_h1,
  markdown_h3: :markdown_h2,

  markdown_code: :output,
  markdown_code_gutter: :markdown_code,

  markdown_strong: :output,
  markdown_emphasis: :output,

  markdown_link: :output,
  markdown_url: :markdown_link,

  markdown_quote_gutter: :output,
  markdown_highlight: :output,
  markdown_table_header: :markdown_strong,
  markdown_table_cell: :output,
  markdown_underline: :output,
  markdown_hrule: :output,
}.freeze

Class Method Summary collapse

Class Method Details

.deep_merge(parent, child) ⇒ Object 



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# File 'lib/fatty/themes/resolver.rb', line 179

def self.deep_merge(parent, child)
  out = parent.dup

  out[:roles] = deep_merge_hash(parent[:roles] || {}, child[:roles] || {})

  child.each do |key, value|
    next if key == :roles

    out[key] = value
  end

  out
end

.deep_merge_hash(parent, child) ⇒ Object 



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# File 'lib/fatty/themes/resolver.rb', line 193

def self.deep_merge_hash(parent, child)
  parent.merge(child) do |_key, old_value, new_value|
    if old_value.is_a?(Hash) && new_value.is_a?(Hash)
      deep_merge_hash(old_value, new_value)
    else
      new_value
    end
  end
end

.empty_theme ⇒ Object 



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# File 'lib/fatty/themes/resolver.rb', line 98

def self.empty_theme
  {
    name: nil,
    inherit: nil,
    roles: {},
    source: nil,
  }
end

.merge_theme_chain(registry, name, stack:) ⇒ Object

Raises:



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# File 'lib/fatty/themes/resolver.rb', line 115

def self.merge_theme_chain(registry, name, stack:)
  defn = registry.fetch(name)
  raise MissingThemeError, "Theme not found: #{name}" unless defn

  if stack.include?(name)
    cycle = (stack + [name]).join(" -> ")
    raise InheritanceCycleError, "Theme inheritance cycle: #{cycle}"
  end

  parent =
    if defn[:inherit]
      merge_theme_chain(registry, defn[:inherit], stack: stack + [name])
    else
      empty_theme
    end

  merged = deep_merge(parent, defn)
  merged[:name] = name
  merged[:inherit] = defn[:inherit]
  merged[:source] = defn[:source]
  merged
end

.resolve(registry, name) ⇒ Object 



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# File 'lib/fatty/themes/resolver.rb', line 107

def self.resolve(registry, name)
  raw = merge_theme_chain(registry, name.to_sym, stack: [])
  raw[:roles] = resolve_role_inheritance(raw[:roles])
  raw[:roles] = add_composite_roles(raw[:roles])
  raw[:name] = name.to_sym
  raw
end

.resolve_role(name, roles, resolved, stack:) ⇒ Object 



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# File 'lib/fatty/themes/resolver.rb', line 154

def self.resolve_role(name, roles, resolved, stack:)
  return resolved[name] if resolved.key?(name)

  if stack.include?(name)
    raise InheritanceCycleError, "Role inheritance cycle: #{(stack + [name]).join(' -> ')}"
  end

  spec = roles[name] || DEFAULT_ROLE_SPECS.fetch(name, {})
  parent_name =
    if spec.key?(:inherit)
      spec[:inherit]&.to_sym
    else
      ROLE_PARENTS[name]
    end

  parent_spec =
    if parent_name
      resolve_role(parent_name, roles, resolved, stack: stack + [name])
    else
      {}
    end

  resolved[name] = deep_merge_hash(parent_spec, spec.reject { |k, _| k == :inherit })
end

.resolve_role_inheritance(roles) ⇒ Object 



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# File 'lib/fatty/themes/resolver.rb', line 138

def self.resolve_role_inheritance(roles)
  resolved = {}
  names = (
    ROLE_PARENTS.keys +
    ROLE_PARENTS.values +
    DEFAULT_ROLE_SPECS.keys +
    roles.keys
  ).compact.uniq

  names.each do |name|
    resolve_role(name, roles, resolved, stack: [])
  end

  resolved
end