Yard: Add in lots of @api private directives

lib/squib/api/text_embed.rb

@@ -1,7 +1,11 @@
 module Squib
   class TextEmbed
+    # :nodoc:
+    # @api private
     attr_reader :rules
 
+    # :nodoc:
+    # @api private
     def initialize
       @rules = {} # store an array of options for later usage
     end
@@ -17,6 +21,7 @@ module Squib
     # @option opts alpha [Decimal] (1.0) the alpha-transparency percentage used to blend this image. Supports Arrays, see {file:README.md#Arrays_and_Singleton_Expansion Arrays and Singleon Expansion}
     # @option opts blend [:none, :multiply, :screen, :overlay, :darken, :lighten, :color_dodge, :color_burn, :hard_light, :soft_light, :difference, :exclusion, :hsl_hue, :hsl_saturation, :hsl_color, :hsl_luminosity] (:none) the composite blend operator used when applying this image. See Blend Modes at http://cairographics.org/operators. Supports Arrays, see {file:README.md#Arrays_and_Singleton_Expansion Arrays and Singleon Expansion}
     # @option opts angle [FixNum] (0) Rotation of the in radians. Note that this rotates around the upper-left corner, making the placement of x-y coordinates slightly tricky. Supports Arrays, see {file:README.md#Arrays_and_Singleton_Expansion Arrays and Singleon Expansion}
+    # @api public
     def svg(opts)
       opts = Squib::SYSTEM_DEFAULTS.merge(opts)
       # TODO: add input validation here. We need the key for example.

lib/squib/args/unit_conversion.rb

@@ -2,8 +2,12 @@ require 'squib/constants'
 
 module Squib
   module Args
+    # :nodoc:
+    # @api private
     module UnitConversion
 
+      # :nodoc:
+      # @api private
       module_function
       def parse(arg, dpi=300)
         case arg.to_s.rstrip

lib/squib/card.rb

@@ -27,6 +27,8 @@ module Squib
       @cairo_context.antialias = ANTIALIAS_OPTS[(@deck.antialias.downcase)] || 'subpixel'
     end
 
+    # :nodoc:
+    # @api private
     def make_surface(svgfile, backend)
       case backend
       when :memory

lib/squib/graphics/cairo_context_wrapper.rb

@@ -3,10 +3,16 @@ require 'squib/graphics/gradient_regex'
 
 module Squib
   module Graphics
+    # Wrapper class for the Cairo context. Private.
     class CairoContextWrapper
       extend Forwardable
+
+      # :nodoc:
+      # @api private
       attr_accessor :cairo_cxt
 
+      # :nodoc:
+      # @api private
       def initialize(cairo_cxt)
         @cairo_cxt = cairo_cxt
       end
@@ -18,6 +24,8 @@ module Squib
         :operator=, :show_page, :clip, :transform, :mask, :create_pango_layout,
         :antialias=
 
+      # :nodoc:
+      # @api private
       def set_source_squibcolor(arg)
         if match = arg.match(LINEAR_GRADIENT)
           x1, y1, x2, y2 = match.captures

lib/squib/graphics/showcase.rb

@@ -60,6 +60,8 @@ module Squib
       return tmp_cc.target
     end
 
+    # :nodoc:
+    # @api private
     def perspective(src, scale, face_right)
       dest_cxt = Cairo::Context.new(Cairo::ImageSurface.new(src.width * scale, src.height))
       in_thickness = 1 # Take strip 1 pixel-width at a time

lib/squib/graphics/text.rb

@@ -82,6 +82,8 @@ module Squib
       layout
     end
 
+    # :nodoc:
+    # @api private
     def next_embed(keys, str)
       ret     = nil
       ret_key = nil