resolves #403 advance table to next page if rowspan in first row does…

… not fit in space remaining on current page

CHANGELOG.adoc

@@ -5,6 +5,12 @@
 This document provides a high-level view of the changes to the {project-name} by release.
 For a detailed view of what has changed, refer to the {url-repo}/commits/main[commit history] on GitHub.
 
+== Unreleased
+
+Bug Fixes::
+
+* advance table to next page if rowspan in first row does not fit in space remaining on current page (#403)
+
 == 2.0.1 (2022-05-21) - @mojavelinux
 
 Bug Fixes::

docs/modules/ROOT/pages/features.adoc

@@ -37,6 +37,7 @@
 * Footnotes are always displayed as endnotes (at the bottom of the last page of a chapter for books; at the bottom of the last page of the document for all other doctypes).
 *Footnotes cannot be displayed at the current bottom of the page because the PDF generator does not support content reflows* (see {url-project-issues}/85#issuecomment-577412975[#85^] for reasoning).
 * Table cells that exceed the height of a single page are truncated with a warning (see https://github.com/prawnpdf/prawn-table/issues/41[prawn-table#41^]).
+* A rowspan in a table that exceeds the height of a single page will be orphaned and the remaining columns will be truncated (see {url-project-issues}/403#issuecomment-1133840210[#403^]).
 * A column can't be assigned a `width` of `0%` or a `width` less than the width of a single character.
 The converter will skip the table and emit a warning if such a case occurs.
 * A column can't be set to `autowidth` if the width of all the other columns in the table meets or exceeds 100%.

lib/asciidoctor/pdf/ext/prawn-table.rb

@@ -1,6 +1,17 @@
 # frozen_string_literal: true
 
 require 'prawn/table'
+
+Prawn::Table.prepend (Module.new do
+  def initial_row_on_initial_page
+    return 0 if fits_on_page? @pdf.bounds.height
+    height_required = (row (0..number_of_header_rows)).height_with_span
+    return -1 if fits_on_page? height_required, true
+    @pdf.bounds.move_past_bottom
+    0
+  end
+end)
+
 require_relative 'prawn-table/cell'
 require_relative 'prawn-table/cell/asciidoc'
 require_relative 'prawn-table/cell/text'

spec/table_spec.rb

@@ -2853,6 +2853,27 @@
       (expect big_cell_text[:y]).to be < top_cell_text[:y]
       (expect big_cell_text[:y]).to be > bottom_cell_text[:y]
     end
+
+    it 'should advance table to next page if rowspan in first row does not fit on current page' do
+      input = <<~EOS
+      #{(['filler'] * 5).join %(\n\n)}
+
+      [cols=2*]
+      |===
+      .30+|Group A |Member 1
+      #{29.times.map {|idx| '|Member ' + idx.next.to_s }.join ?\n}
+
+      .30+|Group B |Member 1
+      #{29.times.map {|idx| '|Member ' + idx.next.to_s }.join ?\n}
+      |===
+      EOS
+
+      pdf = to_pdf input, analyze: true
+      (expect pdf.pages).to have_size 3
+      (expect (pdf.find_text 'filler').map {|it| it[:page_number] }.uniq).to eql [1]
+      (expect (pdf.find_unique_text 'Group A')[:page_number]).to eql 2
+      (expect (pdf.find_unique_text 'Group B')[:page_number]).to eql 3
+    end
   end
 
   context 'Arrange block' do