set hint to reader to fit document to window

2 files changed, 11 insertions, 3 deletions

diff --git a/lib/asciidoctor/pdf_renderer.rb b/lib/asciidoctor/pdf_renderer.rb
index aca9d5af..52fa8aee 100644
--- a/lib/asciidoctor/pdf_renderer.rb
+++ b/lib/asciidoctor/pdf_renderer.rb
@@ -171,6 +171,7 @@ class PDFRenderer < ::Prawn::Document
     add_page_numbers skip: (toc_page_nums.size + 1)
 
     add_outline doc, num_toc_levels, toc_page_nums
+    catalog.data[:ViewerPreferences] = [:FitWindow]
   end
 
   def render_title_page doc
@@ -936,9 +937,8 @@ class PDFRenderer < ::Prawn::Document
       document.outline_level self, doc.sections, num_levels, page_num_labels, numbering_offset
     end
 
-    catalog = state.store.root.data
-    catalog[:PageLabels] = state.store.ref Nums: page_num_labels.flatten
-    catalog[:PageMode] = :UseOutlines
+    catalog.data[:PageLabels] = state.store.ref Nums: page_num_labels.flatten
+    catalog.data[:PageMode] = :UseOutlines
     nil
   end
 
diff --git a/lib/asciidoctor/prawn/extensions.rb b/lib/asciidoctor/prawn/extensions.rb
index a465a48d..8e7d8b7c 100644
--- a/lib/asciidoctor/prawn/extensions.rb
+++ b/lib/asciidoctor/prawn/extensions.rb
@@ -3,6 +3,14 @@ module Prawn
   module Extensions
     LineMetrics = ::Struct.new :leading, :shift, :height, :final_gap
 
+    # Core
+
+    # Retrieves the catalog reference data for the PDF.
+    #
+    def catalog
+      state.store.root
+    end
+
     # Measurements
 
     # Returns the width of the current page from edge-to-edge