resolves #1346 allow elements on title page to be disabled from theme…

… (PR #1347)

CHANGELOG.adoc

@@ -9,6 +9,7 @@ For a detailed view of what has changed, refer to the {uri-repo}/commits/master[
 
 * fix value of implicit page-count attribute when page numbering and running content don't start on same page (#1334)
 * fix value of implicit chapter-title attribute on preface pages (#1340)
+* allow elements on title page to be disabled from theme using display: none (#1346)
 * set chapter-title attribute to value of toc-title attribute on toc pages in book (#1338)
 * set section-title attribute to value of toc-title attribute on toc pages in article if page has no other sections (#1338)
 * set default footer content in base theme; remove logic to process `footer_<side>_content: none` key (#1320)

docs/theming-guide.adoc

@@ -1705,6 +1705,13 @@ TIP: The title page can be disabled for the book doctype by setting the `notitle
 
 3+|[#key-prefix-title-page-title]*Key Prefix:* <<key-prefix-title-page-title,title-page-title>>
 
+|display
+|none +
+(default: _not set_)
+|title-page:
+  title:
+    display: none
+
 |font-color
 |<<colors,Color>> +
 (default: _inherit_)
@@ -1770,6 +1777,13 @@ TIP: The title page can be disabled for the book doctype by setting the `notitle
 
 3+|[#key-prefix-title-page-subtitle]*Key Prefix:* <<key-prefix-title-page-subtitle,title-page-subtitle>>
 
+|display
+|none +
+(default: _not set_)
+|title-page:
+  subtitle:
+    display: none
+
 |font-color
 |<<colors,Color>> +
 (default: _inherit_)
@@ -1828,6 +1842,13 @@ TIP: The title page can be disabled for the book doctype by setting the `notitle
 
 3+|[#key-prefix-authors]*Key Prefix:* <<key-prefix-authors,title-page-authors>>
 
+|display
+|none +
+(default: _not set_)
+|title-page:
+  authors:
+    display: none
+
 |delimiter
 |<<quoted-string,Quoted string>> +
 (default: ', ')
@@ -1886,6 +1907,13 @@ TIP: The title page can be disabled for the book doctype by setting the `notitle
 
 3+|[#key-prefix-revision]*Key Prefix:* <<key-prefix-revision,title-page-revision>>
 
+|display
+|none +
+(default: _not set_)
+|title-page:
+  revision:
+    display: none
+
 |delimiter
 |<<quoted-string,Quoted string>> +
 (default: ', ')

lib/asciidoctor/pdf/converter.rb

@@ -2615,7 +2615,7 @@ def layout_title_page doc
     title_align = (@theme.title_page_align || @base_align).to_sym
 
     # TODO disallow .pdf as image type
-    if (logo_image_path = (doc.attr 'title-logo-image') || (logo_image_from_theme = @theme.title_page_logo_image))
+    if @theme.title_page_logo_display != 'none' && (logo_image_path = (doc.attr 'title-logo-image') || (logo_image_from_theme = @theme.title_page_logo_image))
       if (logo_image_path.include? ':') && logo_image_path =~ ImageAttributeValueRx
         logo_image_attrs = (AttributeList.new $2).parse ['alt', 'width', 'height']
         relative_to_imagesdir = true
@@ -2647,7 +2647,6 @@ def layout_title_page doc
 
     # TODO prevent content from spilling to next page
     theme_font :title_page do
-      doctitle = doc.doctitle partition: true
       if (title_top = @theme.title_page_title_top)
         if title_top.end_with? 'vh'
           title_top = page_height - page_height * title_top.to_f / 100.0
@@ -2657,29 +2656,32 @@ def layout_title_page doc
         # FIXME delegate to method to convert page % to y value
         @y = title_top
       end
-      move_down(@theme.title_page_title_margin_top || 0)
-      indent (@theme.title_page_title_margin_left || 0), (@theme.title_page_title_margin_right || 0) do
-        theme_font :title_page_title do
-          layout_prose doctitle.main,
-            align: title_align,
-            margin: 0,
-            line_height: @theme.title_page_title_line_height
+      unless @theme.title_page_title_display == 'none'
+        doctitle = doc.doctitle partition: true
+        move_down(@theme.title_page_title_margin_top || 0)
+        indent (@theme.title_page_title_margin_left || 0), (@theme.title_page_title_margin_right || 0) do
+          theme_font :title_page_title do
+            layout_prose doctitle.main,
+              align: title_align,
+              margin: 0,
+              line_height: @theme.title_page_title_line_height
+          end
         end
+        move_down(@theme.title_page_title_margin_bottom || 0)
       end
-      move_down(@theme.title_page_title_margin_bottom || 0)
-      if doctitle.subtitle
+      if @theme.title_page_subtitle_display != 'none' && (subtitle = (doctitle || (doc.doctitle partition: true)).subtitle)
         move_down(@theme.title_page_subtitle_margin_top || 0)
         indent (@theme.title_page_subtitle_margin_left || 0), (@theme.title_page_subtitle_margin_right || 0) do
           theme_font :title_page_subtitle do
-            layout_prose doctitle.subtitle,
+            layout_prose subtitle,
               align: title_align,
               margin: 0,
               line_height: @theme.title_page_subtitle_line_height
           end
         end
         move_down(@theme.title_page_subtitle_margin_bottom || 0)
       end
-      if doc.attr? 'authors'
+      if @theme.title_page_authors_display != 'none' && (doc.attr? 'authors')
         move_down(@theme.title_page_authors_margin_top || 0)
         indent (@theme.title_page_authors_margin_left || 0), (@theme.title_page_authors_margin_right || 0) do
           # TODO provide an API in core to get authors as an array
@@ -2695,8 +2697,7 @@ def layout_title_page doc
         end
         move_down(@theme.title_page_authors_margin_bottom || 0)
       end
-      revision_info = [(doc.attr? 'revnumber') ? %(#{doc.attr 'version-label'} #{doc.attr 'revnumber'}) : nil, (doc.attr 'revdate')].compact
-      unless revision_info.empty?
+      unless @theme.title_page_revision_display == 'none' || (revision_info = [(doc.attr? 'revnumber') ? %(#{doc.attr 'version-label'} #{doc.attr 'revnumber'}) : nil, (doc.attr 'revdate')].compact).empty?
         move_down(@theme.title_page_revision_margin_top || 0)
         revision_text = revision_info.join (@theme.title_page_revision_delimiter || ', ')
         if (revremark = doc.attr 'revremark')
@@ -2713,6 +2714,8 @@ def layout_title_page doc
         move_down(@theme.title_page_revision_margin_bottom || 0)
       end
     end
+
+    layout_prose DummyText, margin: 0, line_height: 1, normalize: false if page.empty?
   end
 
   def layout_cover_page doc, face

spec/document_title_spec.rb

@@ -321,6 +321,56 @@
       (expect get_images pdf, 2).to have_size 1
       (expect get_images pdf, 3).to have_size 1
     end
+
+    it 'should allow theme to disable elements on title page' do
+      pdf_theme = {
+        title_page_subtitle_display: 'none',
+        title_page_authors_display: 'none',
+        title_page_revision_display: 'none',
+      }
+
+      pdf = to_pdf <<~'EOS', pdf_theme: pdf_theme, analyze: true
+      = Document Title: Subtitle
+      :doctype: book
+      Author Name
+      v1.0, 2020-01-01
+
+      first page of content
+      EOS
+
+      (expect pdf.pages).to have_size 2
+      title_page_texts = pdf.find_text page_number: 1
+      (expect title_page_texts).to have_size 1
+      (expect title_page_texts[0][:string]).to eql 'Document Title'
+    end
+
+    it 'should not remove title page if all elements are disabled' do
+      pdf_theme = {
+        title_page_title_display: 'none',
+        title_page_subtitle_display: 'none',
+        title_page_authors_display: 'none',
+        title_page_revision_display: 'none',
+      }
+
+      pdf = to_pdf <<~'EOS', pdf_theme: pdf_theme
+      = Document Title: Subtitle
+      :doctype: book
+      :title-page-background-image: image:cover.jpg[]
+      Author Name
+      v1.0, 2020-01-01
+
+      first page of content
+      EOS
+
+      (expect pdf.pages).to have_size 2
+      title_page_text = (pdf.page 1).text
+      (expect title_page_text).to be_empty
+
+      image_data = File.binread fixture_file 'cover.jpg'
+      title_page_images = get_images pdf, 1
+      (expect title_page_images).to have_size 1
+      (expect title_page_images[0].data).to eql image_data
+    end
   end
 
   context 'article' do