Add Document#font_style and Document#font_family

lib/prawn/document.rb

@@ -218,6 +218,7 @@ def initialize(options = {}, &block)
 
       @background = options[:background]
       @background_scale = options[:background_scale] || 1
+      @font = nil
       @font_size = 12
 
       @bounding_box = nil

lib/prawn/font.rb

@@ -47,14 +47,15 @@ class Document
     # font files.
     # See font_families for more information.
     #
-    def font(name = nil, options = DEFAULT_OPTS)
-      return((defined?(@font) && @font) || font('Helvetica')) if name.nil?
+    def font(name = nil, options = nil)
+      return @font || font('Helvetica') if name.nil? && options.nil?
 
       if state.pages.empty? && !state.page.in_stamp_stream?
         raise Prawn::Errors::NotOnPage
       end
 
-      new_font = find_font(name.to_s, options)
+      options ||= DEFAULT_OPTS
+      new_font = find_font(name, options)
 
       if block_given?
         save_font do
@@ -68,6 +69,54 @@ def font(name = nil, options = DEFAULT_OPTS)
       @font
     end
 
+    # Returns the family name of the current font, if the font was selected using
+    # a font family name, or nil, if the font was specified as a specific built-in
+    # font or a TTF file.
+    def font_family
+      @font ? @font.family : 'Helvetica'
+    end
+
+    # @method font_style(points=nil)
+    #
+    # When called with no argument, returns the current font style.
+    #
+    # When called with a single argument but no block, sets the current font
+    # style.  When a block is used, the font style is applied transactionally and
+    # is rolled back when the block exits.  You may still change the font style
+    # within a transactional block for individual text segments, or nested calls
+    # to font_style.
+    #
+    #   Prawn::Document.generate("font_style.pdf") do
+    #     font_style :bold
+    #     text "Bold text"
+    #
+    #     font_style(:italic) do
+    #       text "Italic text"
+    #       text "Bold text", :style => :bold
+    #       text "Italic text"
+    #     end
+    #
+    #     text "Bold text"
+    #   end
+    #
+    # Font styles are not additive, i.e. if the current style is :bold, setting
+    # the style to :italic results in italic, not bold-italic text. Use
+    # :bold_italic instead.
+    #
+    # Font style can only be applied, if the current font is specified using a
+    # font family name, not a specific built-in font or TTF file.
+    #
+    def font_style(style = nil, &block)
+      return @font ? @font.style : :normal if style.nil?
+
+      font(nil, style: style, &block)
+    end
+
+    # Sets the font style
+    def font_style=(style = nil)
+      font_style(style)
+    end
+
     # @method font_size(points=nil)
     #
     # When called with no argument, returns the current font size.
@@ -91,9 +140,6 @@ def font(name = nil, options = DEFAULT_OPTS)
     #     text "At size 16"
     #   end
     #
-    # When called without an argument, this method returns the current font
-    # size.
-    #
     def font_size(points = nil)
       return @font_size unless points
 
@@ -237,13 +283,22 @@ def save_font
     #
     # @private
     def find_font(name, options = {}) #:nodoc:
+      name ||= font_family || font.name
+      style = options[:style] || :normal
       if font_families.key?(name)
         family = name
-        name = font_families[name][options[:style] || :normal]
+        if !font_families[family].key?(style)
+          raise Prawn::Errors::UnknownFont,
+            "Font family `#{family}` has no `:#{style}` style."
+        end
+        name = font_families[family][style]
         if name.is_a?(::Hash)
           options = options.merge(name)
           name = options[:file]
         end
+      elsif style != :normal
+        options[:style] = :normal
+        warn "Style not supported for `#{name}`."
       end
       key = "#{name}:#{options[:font] || 0}"
 
@@ -299,6 +354,9 @@ class Font
     # The current font family
     attr_reader :family
 
+    # The current font style
+    attr_reader :style
+
     # The options hash used to initialize the font
     attr_reader :options
 
@@ -334,6 +392,7 @@ def initialize(document, name, options = {}) #:nodoc:
       @options = options
 
       @family = options[:family]
+      @style = options[:style] || :normal
 
       @identifier = generate_unique_id
 

lib/prawn/font_metric_cache.rb

@@ -25,7 +25,7 @@ def width_of(string, options)
       f =
         if options[:style]
           # override style with :style => :bold
-          @document.find_font(@document.font.family, style: options[:style])
+          @document.find_font(nil, style: options[:style])
         else
           @document.font
         end

lib/prawn/fonts/afm.rb

@@ -55,7 +55,7 @@ def initialize(document, name, options = {}) #:nodoc:
         name ||= options[:family]
         unless BUILT_INS.include?(name)
           raise Prawn::Errors::UnknownFont,
-            "#{name} (#{options[:style] || 'normal'}) is not a known font."
+            "`#{name}` is not a known font."
         end
 
         super

manual/text/font.rb

@@ -5,11 +5,12 @@
 # If we don't pass it any arguments it will return the current font being used
 # to render text.
 #
-# If we just pass it a font name it will use that font for rendering text
-# through the rest of the document.
+# If we just pass it a font name and an options hash, it will use that font for
+# rendering text through the rest of the document. Both the font name and
+# the options can be omitted. Valid option keys are :style and :size.
 #
-# It can also be used by passing a font name and a block. In this case the
-# specified font will only be used to render text inside the block.
+# It can also be used by passing a font name, an options hash and a block. In this
+# case the specified font will only be used to render text inside the block.
 #
 # The default font is Helvetica.
 
@@ -18,6 +19,7 @@
 filename = File.basename(__FILE__).gsub('.rb', '.pdf')
 Prawn::ManualBuilder::Example.generate(filename) do
   text "Let's see which font we are using: #{font.inspect}"
+  text "Family is #{font_family}, style is #{font_style}, and size is #{font_size}"
 
   move_down 20
   font 'Times-Roman'
@@ -31,6 +33,11 @@
   move_down 20
   text 'Written in Times again as we left the previous block.'
 
+  move_down 20
+  font nil, size: 16, style: :bold do
+    text 'Written in 16pt bold, still Times.'
+  end
+
   move_down 20
   text "Let's see which font we are using again: #{font.inspect}"
 

manual/text/font_style.rb

@@ -1,25 +1,51 @@
 # frozen_string_literal: true
 
+# The <code>font_style</code> method works just like the <code>font</code>
+# method.
+#
+# In fact we can even use <code>font</code> with the <code>:style</code> option
+# to declare which size we want.
+#
+# Another way to change the font size is by supplying the <code>:style</code>
+# option to the text methods.
+#
 # Most font families come with some styles other than normal. Most common are
 # <code>bold</code>, <code>italic</code> and <code>bold_italic</code>.
-#
-# The style can be set the using the <code>:style</code> option, with either the
-# <code>font</code> method which will set the font and style for rest of the
-# document, or with the inline text methods.
 
 require_relative '../example_helper'
 
 filename = File.basename(__FILE__).gsub('.rb', '.pdf')
 Prawn::ManualBuilder::Example.generate(filename) do
-  fonts = %w[Courier Helvetica Times-Roman]
-  styles = %i[bold bold_italic italic normal]
+  text "The default style is normal"
+
+  move_down 10
+  font_style :bold
+  text 'This is bold'
 
-  fonts.each do |example_font|
-    move_down 20
+  move_down 10
+  font_style :italic
+  text 'This is italic (not bold, i.e. existing style is overwritten)'
 
-    styles.each do |style|
-      font example_font, style: style
-      text "I'm writing in #{example_font} (#{style})"
-    end
+  move_down 10
+  font_style :bold_italic
+  text 'This is bold italic'
+
+  move_down 10
+  font_style :normal
+  text 'Back to normal'
+
+  move_down 10
+  text 'A single line of italic', style: :italic
+
+  move_down 10
+  font_style :bold do
+    text 'A single line of bold'
   end
+
+  move_down 10
+  font 'Courier', style: :bold_italic
+  text 'This is Courier bold italic'
+
+  font 'Courier'
+  text 'This is Courier normal (style is reset when changing font)'
 end