Add bin and edit workflow

bin/gems/pdf-reader-2.14.1/lib/pdf/reader/page_text_receiver.rb

@@ -0,0 +1,198 @@
+# coding: utf-8
+# typed: true
+# frozen_string_literal: true
+
+require 'forwardable'
+require 'pdf/reader/page_layout'
+
+module PDF
+  class Reader
+
+    # Builds a UTF-8 string of all the text on a single page by processing all
+    # the operaters in a content stream.
+    #
+    class PageTextReceiver
+      extend Forwardable
+
+      SPACE = " "
+
+      attr_reader :state, :options
+
+      ########## BEGIN FORWARDERS ##########
+      # Graphics State Operators
+      def_delegators :@state, :save_graphics_state, :restore_graphics_state
+
+      # Matrix Operators
+      def_delegators :@state, :concatenate_matrix
+
+      # Text Object Operators
+      def_delegators :@state, :begin_text_object, :end_text_object
+
+      # Text State Operators
+      def_delegators :@state, :set_character_spacing, :set_horizontal_text_scaling
+      def_delegators :@state, :set_text_font_and_size, :font_size
+      def_delegators :@state, :set_text_leading, :set_text_rendering_mode
+      def_delegators :@state, :set_text_rise, :set_word_spacing
+
+      # Text Positioning Operators
+      def_delegators :@state, :move_text_position, :move_text_position_and_set_leading
+      def_delegators :@state, :set_text_matrix_and_text_line_matrix, :move_to_start_of_next_line
+      ##########  END FORWARDERS  ##########
+
+      # starting a new page
+      def page=(page)
+        @state = PageState.new(page)
+        @page = page
+        @content = []
+        @characters = []
+      end
+
+      def runs(opts = {})
+        runs = @characters
+
+        if rect = opts.fetch(:rect, @page.rectangles[:CropBox])
+          runs = BoundingRectangleRunsFilter.runs_within_rect(runs, rect)
+        end
+
+        if opts.fetch(:skip_zero_width, true)
+          runs = ZeroWidthRunsFilter.exclude_zero_width_runs(runs)
+        end
+
+        if opts.fetch(:skip_overlapping, true)
+          runs = OverlappingRunsFilter.exclude_redundant_runs(runs)
+        end
+
+        runs = NoTextFilter.exclude_empty_strings(runs)
+
+        if opts.fetch(:merge, true)
+          runs = merge_runs(runs)
+        end
+
+        if (only_filter = opts.fetch(:only, nil))
+          runs = AdvancedTextRunFilter.only(runs, only_filter)
+        end
+
+        if (exclude_filter = opts.fetch(:exclude, nil))
+          runs = AdvancedTextRunFilter.exclude(runs, exclude_filter)
+        end
+
+        runs
+      end
+
+      # deprecated
+      def content
+        mediabox = @page.rectangles[:MediaBox]
+        PageLayout.new(runs, mediabox).to_s
+      end
+
+      #####################################################
+      # Text Showing Operators
+      #####################################################
+      # record text that is drawn on the page
+      def show_text(string) # Tj (AWAY)
+        internal_show_text(string)
+      end
+
+      def show_text_with_positioning(params) # TJ [(A) 120 (WA) 20 (Y)]
+        params.each do |arg|
+          if arg.is_a?(String)
+            internal_show_text(arg)
+          elsif arg.is_a?(Numeric)
+            @state.process_glyph_displacement(0, arg, false)
+          else
+            # skip it
+          end
+        end
+      end
+
+      def move_to_next_line_and_show_text(str) # '
+        @state.move_to_start_of_next_line
+        show_text(str)
+      end
+
+      def set_spacing_next_line_show_text(aw, ac, string) # "
+        @state.set_word_spacing(aw)
+        @state.set_character_spacing(ac)
+        move_to_next_line_and_show_text(string)
+      end
+
+      #####################################################
+      # XObjects
+      #####################################################
+      def invoke_xobject(label)
+        @state.invoke_xobject(label) do |xobj|
+          case xobj
+          when PDF::Reader::FormXObject then
+            xobj.walk(self)
+          end
+        end
+      end
+
+      private
+
+      def internal_show_text(string)
+        PDF::Reader::Error.validate_type_as_malformed(string, "string", String)
+        if @state.current_font.nil?
+          raise PDF::Reader::MalformedPDFError, "current font is invalid"
+        end
+        glyphs = @state.current_font.unpack(string)
+        glyphs.each_with_index do |glyph_code, index|
+          # paint the current glyph
+          newx, newy = @state.trm_transform(0,0)
+          newx, newy = apply_rotation(newx, newy)
+
+          utf8_chars = @state.current_font.to_utf8(glyph_code)
+
+          # apply to glyph displacment for the current glyph so the next
+          # glyph will appear in the correct position
+          glyph_width = @state.current_font.glyph_width_in_text_space(glyph_code)
+          th = 1
+          scaled_glyph_width = glyph_width * @state.font_size * th
+          unless utf8_chars == SPACE
+            @characters << TextRun.new(newx, newy, scaled_glyph_width, @state.font_size, utf8_chars)
+          end
+          @state.process_glyph_displacement(glyph_width, 0, utf8_chars == SPACE)
+        end
+      end
+
+      def apply_rotation(x, y)
+        if @page.rotate == 90
+          tmp = x
+          x = y
+          y = tmp * -1
+        elsif @page.rotate == 180
+          y *= -1
+          x *= -1
+        elsif @page.rotate == 270
+          tmp = y
+          y = x
+          x = tmp * -1
+        end
+        return x, y
+      end
+
+      # take a collection of TextRun objects and merge any that are in close
+      # proximity
+      def merge_runs(runs)
+        runs.group_by { |char|
+          char.y.to_i
+        }.map { |y, chars|
+          group_chars_into_runs(chars.sort)
+        }.flatten.sort
+      end
+
+      def group_chars_into_runs(chars)
+        chars.each_with_object([]) do |char, runs|
+          if runs.empty?
+            runs << char
+          elsif runs.last.mergable?(char)
+            runs[-1] = runs.last + char
+          else
+            runs << char
+          end
+        end
+      end
+
+    end
+  end
+end