document.rb in prawn-2.3.0

- old
+ new

@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 # document.rb : Implements PDF document generation for Prawn
 #
 # Copyright April 2008, Gregory Brown.  All Rights Reserved.
 #
 # This is free software. Please see the LICENSE and COPYING files for details.
@@ -60,15 +62,15 @@
     # @group Extension API
 
     # NOTE: We probably need to rethink the options validation system, but this
     # constant temporarily allows for extensions to modify the list.
 
-    VALID_OPTIONS = [
-      :page_size, :page_layout, :margin, :left_margin,
-      :right_margin, :top_margin, :bottom_margin, :skip_page_creation,
-      :compress, :background, :info,
-      :text_formatter, :print_scaling
+    VALID_OPTIONS = %i[
+      page_size page_layout margin left_margin
+      right_margin top_margin bottom_margin skip_page_creation
+      compress background info
+      text_formatter print_scaling
     ].freeze
 
     # Any module added to this array will be included into instances of
     # Prawn::Document at the per-object level.  These will also be inherited by
     # any subclasses.
@@ -267,11 +269,11 @@
           new_graphic_state = last_page.graphic_state.dup
         end
 
         # erase the color space so that it gets reset on new page for fussy
         # pdf-readers
-        new_graphic_state.color_space = {} if new_graphic_state
+        new_graphic_state&.color_space = {}
 
         page_options[:graphic_state] = new_graphic_state
       end
 
       state.page = PDF::Core::Page.new(self, page_options)
@@ -302,10 +304,30 @@
           state.on_page_create_action(self)
         end
       end
     end
 
+    # Remove page of the document by index
+    #
+    #   pdf = Prawn::Document.new
+    #   pdf.page_count #=> 1
+    #   3.times { pdf.start_new_page }
+    #   pdf.page_count #=> 4
+    #   pdf.delete_page(-1)
+    #   pdf.page_count #=> 3
+    #
+    def delete_page(index)
+      return false if index.abs > (state.pages.count - 1)
+
+      state.pages.delete_at(index)
+
+      state.store.pages.data[:Kids].delete_at(index)
+      state.store.pages.data[:Count] -= 1
+      @page_number -= 1
+      true
+    end
+
     # Returns the number of pages in the document
     #
     #   pdf = Prawn::Document.new
     #   pdf.page_count #=> 1
     #   3.times { pdf.start_new_page }
@@ -318,13 +340,13 @@
     # Re-opens the page with the given (1-based) page number so that you can
     # draw on it.
     #
     # See Prawn::Document#number_pages for a sample usage of this capability.
     #
-    def go_to_page(k)
-      @page_number = k
-      state.page = state.pages[k - 1]
+    def go_to_page(page_number)
+      @page_number = page_number
+      state.page = state.pages[page_number - 1]
       generate_margin_box
       @y = @bounding_box.absolute_top
     end
 
     def y=(new_y)
@@ -367,17 +389,17 @@
     end
 
     # Renders the PDF document to string.
     # Pass an open file descriptor to render to file.
     #
-    def render(*a, &b)
+    def render(*arguments, &block)
       (1..page_count).each do |i|
         go_to_page i
         repeaters.each { |r| r.run(i) }
       end
 
-      renderer.render(*a, &b)
+      renderer.render(*arguments, &block)
     end
 
     # Renders the PDF document to file.
     #
     #   pdf.render_file "foo.pdf"
@@ -435,19 +457,19 @@
     end
 
     # Moves up the document by n points relative to the current position inside
     # the current bounding box.
     #
-    def move_up(n)
-      self.y += n
+    def move_up(amount)
+      self.y += amount
     end
 
     # Moves down the document by n points relative to the current position
     # inside the current bounding box.
     #
-    def move_down(n)
-      self.y -= n
+    def move_down(amount)
+      self.y -= amount
     end
 
     # Moves down the document and then executes a block.
     #
     #   pdf.text "some text"
@@ -595,11 +617,11 @@
     #
     # Raises CannotGroup if the provided content is too large to fit alone in
     # the current page or column.
     #
     # @private
-    def group(*_a)
+    def group(*_arguments)
       raise NotImplementedError,
         'Document#group has been disabled because its implementation ' \
         'lead to corrupted documents whenever a page boundary was ' \
         'crossed. We will try to work on reimplementing it in a ' \
         'future release'
@@ -704,14 +726,14 @@
         @margin_box.add_right_padding(old_margin_box.total_right_padding)
       end
 
       # we must update bounding box if not flowing from the previous page
       #
-      @bounding_box = @margin_box unless @bounding_box && @bounding_box.parent
+      @bounding_box = @margin_box unless @bounding_box&.parent
     end
 
     def apply_margin_options(options)
-      sides = [:top, :right, :bottom, :left]
+      sides = %i[top right bottom left]
       margin = Array(options[:margin])
 
       # Treat :margin as CSS shorthand with 1-4 values.
       positions = {
         4 => [0, 1, 2, 3], 3 => [0, 1, 2, 1],