Add support for images

lib/ezdoc/document.rb

@@ -21,6 +21,7 @@ module Ezdoc
       @current_table = nil
       @current_row = nil
       @num_id_counter = 0
+      @images = {}
     end
 
     def save(path)
@@ -30,5 +31,26 @@ module Ezdoc
     def lists
       @nodes.select { |n| n.is_a?(Nodes::List) }
     end
+
+    def images
+      @images.values
+    end
+
+    def register_image(path, width: nil, height: nil)
+      return @images[path] if @images[path]
+
+      rid = next_image_rid
+      width_emu, height_emu = ImageDimensions.calculate_emus(path, width: width, height: height)
+      image = Nodes::Image.new(path, rid: rid, width_emu: width_emu, height_emu: height_emu)
+      @images[path] = image
+      image
+    end
+
+    private
+
+    def next_image_rid
+      base = lists.any? ? 2 : 1
+      "rId#{base + @images.size}"
+    end
   end
 end