Merge pull request #413 from yob/skip-characters-outside-crobox

Skip text drawn outside the MediaBox

lib/pdf/reader.rb

@@ -273,6 +273,7 @@ def root
 
 require 'pdf/reader/resource_methods'
 require 'pdf/reader/buffer'
+require 'pdf/reader/bounding_rectangle_runs_filter'
 require 'pdf/reader/cid_widths'
 require 'pdf/reader/cmap'
 require 'pdf/reader/encoding'

lib/pdf/reader/bounding_rectangle_runs_filter.rb

@@ -0,0 +1,16 @@
+# coding: utf-8
+# typed: strict
+# frozen_string_literal: true
+
+class PDF::Reader
+
+  # Filter our text/characters that are positioned outside a rectangle. Usually the page
+  # MediaBox or CropBox, but could be a user specified rectangle too
+  class BoundingRectangleRunsFilter
+
+    def self.runs_within_rect(runs, rect)
+      runs.select { |run| rect.contains?(run.origin) }
+    end
+  end
+end
+

lib/pdf/reader/page_layout.rb

@@ -21,9 +21,10 @@ def initialize(runs, mediabox)
       # PDF::Reader::Rectangle at some point
       PDF::Reader::Error.validate_not_nil(mediabox, "mediabox")
 
+      @mediabox = process_mediabox(mediabox)
       runs = ZeroWidthRunsFilter.exclude_zero_width_runs(runs)
       runs = OverlappingRunsFilter.exclude_redundant_runs(runs)
-      @mediabox = process_mediabox(mediabox)
+      runs = BoundingRectangleRunsFilter.runs_within_rect(runs, @mediabox)
       @runs = merge_runs(runs)
       @mean_font_size   = mean(@runs.map(&:font_size)) || DEFAULT_FONT_SIZE
       @mean_font_size = DEFAULT_FONT_SIZE if @mean_font_size == 0

lib/pdf/reader/rectangle.rb

@@ -51,6 +51,11 @@ def width
         bottom_right.x - bottom_left.x
       end
 
+      def contains?(point)
+        point.x >= bottom_left.x && point.x <= top_right.x &&
+          point.y >= bottom_left.y && point.y <= top_right.y
+      end
+
       # A pdf-style 4-number array
       def to_a
         [

lib/pdf/reader/text_run.rb

@@ -7,13 +7,12 @@ class PDF::Reader
   class TextRun
     include Comparable
 
-    attr_reader :x, :y, :width, :font_size, :text
+    attr_reader :origin, :width, :font_size, :text
 
     alias :to_s :text
 
     def initialize(x, y, width, font_size, text)
-      @x = x
-      @y = y
+      @origin = PDF::Reader::Point.new(x, y)
       @width = width
       @font_size = font_size
       @text = text
@@ -35,12 +34,20 @@ def <=>(other)
       end
     end
 
+    def x
+      @origin.x
+    end
+
+    def y
+      @origin.y
+    end
+
     def endx
-      @endx ||= x + width
+      @endx ||= @origin.x + width
     end
 
     def endy
-      @endy ||= y + font_size
+      @endy ||= @origin.y + font_size
     end
 
     def mean_character_width

rbi/pdf-reader.rbi

@@ -43,6 +43,13 @@ module PDF
     sig { returns(T::Hash[Symbol, T.untyped]) }
     def root; end
 
+    class BoundingRectangleRunsFilter
+      extend T::Sig
+
+      sig { params(runs: T::Array[PDF::Reader::TextRun], rect: PDF::Reader::Rectangle).returns(T::Array[PDF::Reader::TextRun]) }
+      def self.runs_within_rect(runs, rect); end
+    end
+
     class Buffer
       TOKEN_WHITESPACE = [0x00, 0x09, 0x0A, 0x0C, 0x0D, 0x20]
       TOKEN_DELIMITER = [0x25, 0x3C, 0x3E, 0x28, 0x5B, 0x7B, 0x29, 0x5D, 0x7D, 0x2F]

spec/integration_spec.rb

@@ -1514,4 +1514,8 @@
       end
     end
   end
+
+  context "PDF with glyphs positioned outside the MediaBox" do
+    it "skips the characteers off the page"
+  end
 end