Add a way to change a slide theme displayed in the terminal output

lib/slideck/converter.rb

@@ -30,15 +30,17 @@ def initialize(markdown_parser, color: nil)
     #   the content to convert
     # @param [Hash, String, Symbol] symbols
     #   the converted content symbols
+    # @param [Hash{Symbol => Array, String, Symbol}] theme
+    #   the converted content theme
     # @param [Integer] width
     #   the slide width
     #
     # @return [String]
     #
     # @api public
-    def convert(content, symbols: nil, width: nil)
+    def convert(content, symbols: nil, theme: nil, width: nil)
       @markdown_parser.parse(
-        content, color: @color, symbols: symbols, width: width)
+        content, color: @color, symbols: symbols, theme: theme, width: width)
     end
   end # Converter
 end # Slideck

lib/slideck/metadata.rb

@@ -82,6 +82,11 @@ def self.define_meta(key)
     # @return [Hash, String, Symbol]
     define_meta :symbols
 
+    # The theme configuration
+    #
+    # @return [Hash{Symbol => Array, String, Symbol}]
+    define_meta :theme
+
     # Create a Metadata instance
     #
     # @param [Hash{Symbol => Object}] metadata

lib/slideck/metadata_defaults.rb

@@ -52,7 +52,8 @@ def create_defaults
         footer: default_footer,
         margin: @margin[0, 0, 0, 0],
         pager: default_pager,
-        symbols: :unicode
+        symbols: :unicode,
+        theme: {}
       }.freeze
     end
 

lib/slideck/renderer.rb

@@ -87,9 +87,9 @@ def clear
     #
     # @api private
     def render_content(slide)
-      alignment, margin, symbols =
-        *select_metadata(slide[:metadata], :align, :margin, :symbols)
-      converted = convert_markdown(slide[:content], margin, symbols)
+      alignment, margin, symbols, theme =
+        *select_metadata(slide[:metadata], :align, :margin, :symbols, :theme)
+      converted = convert_markdown(slide[:content], margin, symbols, theme)
 
       render_section(converted.lines, alignment, margin)
     end
@@ -107,8 +107,9 @@ def render_footer(slide_metadata)
       return if (text = footer_metadata[:text]).empty?
 
       alignment = footer_metadata[:align] || @metadata.footer[:align]
-      margin, symbols = *select_metadata(slide_metadata, :margin, :symbols)
-      converted = convert_markdown(text, margin, symbols).chomp
+      margin, symbols, theme =
+        *select_metadata(slide_metadata, :margin, :symbols, :theme)
+      converted = convert_markdown(text, margin, symbols, theme).chomp
 
       render_section(converted.lines, alignment, margin)
     end
@@ -130,9 +131,10 @@ def render_pager(slide_metadata, current_num, num_of_slides)
       return if (text = pager_metadata[:text]).empty?
 
       alignment = pager_metadata[:align] || @metadata.pager[:align]
-      margin, symbols = *select_metadata(slide_metadata, :margin, :symbols)
+      margin, symbols, theme =
+        *select_metadata(slide_metadata, :margin, :symbols, :theme)
       formatted_text = format(text, page: current_num, total: num_of_slides)
-      converted = convert_markdown(formatted_text, margin, symbols).chomp
+      converted = convert_markdown(formatted_text, margin, symbols, theme).chomp
 
       render_section(converted.lines, alignment, margin)
     end
@@ -244,12 +246,15 @@ def find_top_row(alignment, margin, num_of_lines)
     #   the slide margin
     # @param [Hash, String, Symbol] symbols
     #   the converted content symbols
+    # @param [Hash{Symbol => Array, String, Symbol}] theme
+    #   the converted content theme
     #
     # @return [String]
     #
     # @api private
-    def convert_markdown(content, margin, symbols)
-      @converter.convert(content, symbols: symbols, width: slide_width(margin))
+    def convert_markdown(content, margin, symbols, theme)
+      @converter.convert(
+        content, symbols: symbols, theme: theme, width: slide_width(margin))
     end
 
     # Find maximum line length

spec/fixtures/slides.md

@@ -4,6 +4,13 @@ footer: "**footer content**"
 margin: 1 2
 pager: "page %<page>d of %<total>d"
 symbols: ascii
+theme:
+  header:
+    - magenta
+    - underline
+  link: cyan
+  list: green
+  strong: blue
 --- symbols: {base: ascii, override: {arrow: ">>"}}
 
 # [Title](url)

spec/unit/converter_spec.rb

@@ -6,15 +6,17 @@
   it "converts markdown title to terminal output" do
     converter = described_class.new(markdown_parser, color: true)
 
-    converted = converter.convert("# Title", symbols: :unicode, width: 20)
+    converted = converter.convert("# Title", symbols: :unicode, theme: {},
+                                             width: 20)
 
     expect(converted).to eq("\e[36;1;4mTitle\e[0m\n")
   end
 
   it "converts markdown title to terminal output without color" do
     converter = described_class.new(markdown_parser, color: false)
 
-    converted = converter.convert("# Title", symbols: :unicode, width: 20)
+    converted = converter.convert("# Title", symbols: :unicode, theme: {},
+                                             width: 20)
 
     expect(converted).to eq("Title\n")
   end
@@ -23,7 +25,7 @@
     converter = described_class.new(markdown_parser, color: true)
 
     converted = converter.convert("# Very Long Title", symbols: :unicode,
-                                                       width: 10)
+                                                       theme: {}, width: 10)
 
     expect(converted).to eq([
       "\e[36;1;4mVery Long \e[0m\n",
@@ -35,7 +37,7 @@
     converter = described_class.new(markdown_parser, color: false)
 
     converted = converter.convert("# Very Long Title", symbols: :unicode,
-                                                       width: 10)
+                                                       theme: {}, width: 10)
 
     expect(converted).to eq([
       "Very Long \n",
@@ -46,8 +48,19 @@
   it "converts a markdown list to terminal output with ascii symbols" do
     converter = described_class.new(markdown_parser, color: true)
 
-    converted = converter.convert("- list item", symbols: :ascii, width: 20)
+    converted = converter.convert("- list item", symbols: :ascii, theme: {},
+                                                 width: 20)
 
     expect(converted).to eq("\e[33m*\e[0m list item\n")
   end
+
+  it "converts a markdown list to terminal output with a custom theme" do
+    converter = described_class.new(markdown_parser, color: true)
+
+    converted = converter.convert("- list item", symbols: :unicode,
+                                                 theme: {list: :magenta},
+                                                 width: 20)
+
+    expect(converted).to eq("\e[35m●\e[0m list item\n")
+  end
 end

spec/unit/metadata_converter_spec.rb

@@ -102,4 +102,16 @@
       symbols: {base: :ascii, override: {bullet: "x"}}
     })
   end
+
+  it "doesn't convert :theme value" do
+    converter = described_class.new(alignment, margin)
+
+    converted = converter.convert({
+      theme: {list: :magenta, strong: %i[magenta bold]}
+    })
+
+    expect(converted).to eq({
+      theme: {list: :magenta, strong: %i[magenta bold]}
+    })
+  end
 end

spec/unit/metadata_defaults_spec.rb

@@ -20,7 +20,8 @@
         align: alignment["right", "bottom"],
         text: "%<page>d / %<total>d"
       },
-      symbols: :unicode
+      symbols: :unicode,
+      theme: {}
     })
   end
 
@@ -35,7 +36,8 @@
       pager: {
         text: "%<page>d of %<total>d"
       },
-      symbols: :ascii
+      symbols: :ascii,
+      theme: {link: :magenta}
     })
 
     expect(merged).to eq({
@@ -49,7 +51,8 @@
         align: alignment["right", "bottom"],
         text: "%<page>d of %<total>d"
       },
-      symbols: :ascii
+      symbols: :ascii,
+      theme: {link: :magenta}
     })
   end
 
@@ -65,7 +68,8 @@
       pager: {
         align: alignment["right", "top"]
       },
-      symbols: :ascii
+      symbols: :ascii,
+      theme: {link: :magenta}
     })
 
     expect(merged).to eq({
@@ -79,7 +83,8 @@
         align: alignment["right", "top"],
         text: "%<page>d / %<total>d"
       },
-      symbols: :ascii
+      symbols: :ascii,
+      theme: {link: :magenta}
     })
   end
 end

spec/unit/metadata_spec.rb

@@ -244,6 +244,20 @@
     expect(metadata.symbols).to eq(:ascii)
   end
 
+  it "defaults :theme to an empty hash" do
+    metadata = described_class.from(converter, {}, defaults)
+
+    expect(metadata.theme).to eq({})
+  end
+
+  it "creates metadata from :theme with a custom :link value" do
+    config = {theme: {link: :magenta}}
+
+    metadata = described_class.from(converter, config, defaults)
+
+    expect(metadata.theme).to eq({link: :magenta})
+  end
+
   it "raises when invalid metadata key" do
     config = {invalid: ""}
 
@@ -252,6 +266,6 @@
     }.to raise_error(Slideck::InvalidMetadataKeyError,
                      "unknown 'invalid' configuration key\n" \
                      "Available keys are: :align, :footer, :margin, " \
-                     ":pager, :symbols")
+                     ":pager, :symbols, :theme")
   end
 end

spec/unit/parser_spec.rb

@@ -2,8 +2,8 @@
 
 RSpec.describe Slideck::Parser, "#parse" do
   let(:metadata_parser) {
-    Slideck::MetadataParser.new(::YAML, permitted_classes: [Symbol],
-                                        symbolize_names: true)
+    Slideck::MetadataParser.new(YAML, permitted_classes: [Symbol],
+                                      symbolize_names: true)
   }
 
   it "parses empty content" do
@@ -80,6 +80,8 @@
     margin: 2
     pager: "page %<page>d of %<total>d"
     symbols: ascii
+    theme:
+      list: green
     EOS
     parser = described_class.new(StringScanner, metadata_parser)
 
@@ -91,7 +93,8 @@
         footer: "footer content",
         margin: 2,
         pager: "page %<page>d of %<total>d",
-        symbols: "ascii"
+        symbols: "ascii",
+        theme: {list: "green"}
       },
       slides: []
     })
@@ -104,6 +107,8 @@
       :margin: 2
       :pager: "page %<page>d of %<total>d"
       :symbols: ascii
+      :theme:
+        list: green
     EOS
     parser = described_class.new(StringScanner, metadata_parser)
 
@@ -115,7 +120,8 @@
         footer: "footer content",
         margin: 2,
         pager: "page %<page>d of %<total>d",
-        symbols: "ascii"
+        symbols: "ascii",
+        theme: {list: "green"}
       },
       slides: []
     })
@@ -128,6 +134,8 @@
     margin: [1, 2]
     pager: "page %<page>d of %<total>d"
     symbols: ascii
+    theme:
+      list: green
     ---
     # Slide 1
     ---
@@ -145,7 +153,8 @@
         footer: "footer content",
         margin: [1, 2],
         pager: "page %<page>d of %<total>d",
-        symbols: "ascii"
+        symbols: "ascii",
+        theme: {list: "green"}
       },
       slides: [
         {content: "# Slide 1", metadata: {}},
@@ -163,6 +172,8 @@
     margin: {top: 1, left: 2}
     pager: "page %<page>d of %<total>d"
     symbols: ascii
+    theme:
+      list: green
     ---
     # Slide 1
     ---
@@ -181,7 +192,8 @@
         footer: "footer content",
         margin: {top: 1, left: 2},
         pager: "page %<page>d of %<total>d",
-        symbols: "ascii"
+        symbols: "ascii",
+        theme: {list: "green"}
       },
       slides: [
         {content: "# Slide 1", metadata: {}},
@@ -209,7 +221,7 @@
 
     Slide 4
 
-    ---{symbols: {override: {bullet: "x"}}}
+    ---{symbols: {override: {bullet: "x"}}, theme: {list: green}}
 
     Slide 5
     EOS
@@ -229,7 +241,8 @@
         {content: "\nSlide 4\n",
          metadata: {pager: {text: "page %<page>d of %<total>d"}}},
         {content: "\nSlide 5",
-         metadata: {symbols: {override: {bullet: "x"}}}}
+         metadata: {symbols: {override: {bullet: "x"}},
+                    theme: {list: "green"}}}
       ]
     })
   end