prawnpdf/prawn

View on GitHub
lib/prawn/text/formatted/wrap.rb

Summary

Maintainability
A
1 hr
Test Coverage
# frozen_string_literal: true

# wrap.rb: Handles text wrapping for for formatted text
#
# Contributed by Daniel Nelson
#
# This is free software. Please see the LICENSE and COPYING files for details.

require_relative 'line_wrap'
require_relative 'arranger'

module Prawn
  module Text
    module Formatted #:nodoc:
      # @private

      module Wrap #:nodoc:
        def initialize(_array, options)
          @line_wrap = Prawn::Text::Formatted::LineWrap.new
          @arranger = Prawn::Text::Formatted::Arranger.new(
            @document,
            kerning: options[:kerning]
          )
          @disable_wrap_by_char = options[:disable_wrap_by_char]
        end

        # See the developer documentation for PDF::Core::Text#wrap
        #
        # Formatted#wrap should set the following variables:
        #   <tt>@line_height</tt>::
        #        the height of the tallest fragment in the last printed line
        #   <tt>@descender</tt>::
        #        the descender height of the tallest fragment in the last
        #        printed line
        #   <tt>@ascender</tt>::
        #        the ascender heigth of the tallest fragment in the last
        #        printed line
        #   <tt>@baseline_y</tt>::
        #       the baseline of the current line
        #   <tt>@nothing_printed</tt>::
        #       set to true until something is printed, then false
        #   <tt>@everything_printed</tt>::
        #       set to false until everything printed, then true
        #
        # Returns any formatted text that was not printed
        #
        def wrap(array) #:nodoc:
          initialize_wrap(array)

          stop = false
          until stop
            # wrap before testing if enough height for this line because the
            # height of the highest fragment on this line will be used to
            # determine the line height
            @line_wrap.wrap_line(
              document: @document,
              kerning: @kerning,
              width: available_width,
              arranger: @arranger,
              disable_wrap_by_char: @disable_wrap_by_char
            )

            if enough_height_for_this_line?
              move_baseline_down
              print_line
            else
              stop = true
            end

            stop ||= @single_line || @arranger.finished?
          end
          @text = @printed_lines.join("\n")
          @everything_printed = @arranger.finished?
          @arranger.unconsumed
        end

        private

        def print_line
          @nothing_printed = false
          printed_fragments = []
          fragments_this_line = []

          word_spacing = word_spacing_for_this_line
          @arranger.fragments.each do |fragment|
            fragment.word_spacing = word_spacing
            if fragment.text == "\n"
              printed_fragments << "\n" if @printed_lines.last == ''
              break
            end
            printed_fragments << fragment.text
            fragments_this_line << fragment
          end
          @arranger.fragments.replace []

          accumulated_width = 0
          fragments_this_line.reverse! if @direction == :rtl
          fragments_this_line.each do |fragment_this_line|
            fragment_this_line.default_direction = @direction
            format_and_draw_fragment(
              fragment_this_line, accumulated_width,
              @line_wrap.width, word_spacing
            )
            accumulated_width += fragment_this_line.width
          end

          @printed_lines << printed_fragments.map do |s|
            s.dup.force_encoding(::Encoding::UTF_8)
          end.join
        end

        def word_spacing_for_this_line
          if @align == :justify && @line_wrap.space_count.positive? &&
              !@line_wrap.paragraph_finished?
            (available_width - @line_wrap.width) / @line_wrap.space_count
          else
            0
          end
        end

        def enough_height_for_this_line?
          @line_height = @arranger.max_line_height
          @descender = @arranger.max_descender
          @ascender = @arranger.max_ascender
          diff = if @baseline_y.zero?
                   @ascender + @descender
                 else
                   @descender + @line_height + @leading
                 end
          require_relatived_total_height = @baseline_y.abs + diff
          if require_relatived_total_height > @height + 0.0001
            # no room for the full height of this line
            @arranger.repack_unretrieved
            false
          else
            true
          end
        end

        def initialize_wrap(array)
          @text = nil
          @arranger.format_array = array

          # these values will depend on the maximum value within a given line
          @line_height = 0
          @descender = 0
          @ascender = 0
          @baseline_y = 0

          @printed_lines = []
          @nothing_printed = true
          @everything_printed = false
        end

        def format_and_draw_fragment(fragment, accumulated_width,
          line_width, word_spacing)
          @arranger.apply_color_and_font_settings(fragment) do
            draw_fragment(
              fragment, accumulated_width,
              line_width, word_spacing
            )
          end
        end
      end
    end
  end
end