Use contents settings for size in EssencePicture#picture_url

Without we would need to pass the settings into the method as options
although the essence always knows its content and therefore can read
the size value from it.

app/models/alchemy/essence_picture.rb

@@ -79,7 +79,8 @@ def picture_url_options
       {
         format: picture.default_render_format,
         crop_from: crop_from.presence,
-        crop_size: crop_size.presence
+        crop_size: crop_size.presence,
+        size: content.settings[:size]
       }.with_indifferent_access
     end
 

lib/alchemy/test_support/factories/essence_picture_factory.rb

@@ -1,10 +1,15 @@
 # frozen_string_literal: true
 
 require 'factory_bot'
+require 'alchemy/test_support/factories/content_factory'
 require 'alchemy/test_support/factories/picture_factory'
 
 FactoryBot.define do
   factory :alchemy_essence_picture, class: 'Alchemy::EssencePicture' do
     picture factory: :alchemy_picture
+
+    trait :with_content do
+      association :content, factory: :alchemy_content
+    end
   end
 end

spec/dummy/app/views/alchemy/elements/_gallery_picture.html.erb

@@ -1,5 +1,5 @@
 <%- cache(gallery_picture) do -%>
   <%= element_view_for(gallery_picture) do |el| -%>
-    <%= el.render :picture, size: '160x120' %>
+    <%= el.render :picture %>
   <%- end -%>
 <%- end -%>

spec/dummy/config/alchemy/elements.yml

@@ -140,6 +140,8 @@
   contents:
     - name: picture
       type: EssencePicture
+      settings:
+        size: 160x120
 
 - name: right_column
   fixed: true

spec/models/alchemy/essence_picture_spec.rb

@@ -54,7 +54,7 @@ module Alchemy
 
       let(:options) { {} }
       let(:picture) { create(:alchemy_picture) }
-      let(:essence) { create(:alchemy_essence_picture, picture: picture) }
+      let(:essence) { create(:alchemy_essence_picture, :with_content, picture: picture) }
 
       context 'with no format in the options' do
         it "includes the image's default render format." do
@@ -116,7 +116,7 @@ module Alchemy
       subject(:picture_url_options) { essence.picture_url_options }
 
       let(:picture) { build_stubbed(:alchemy_picture) }
-      let(:essence) { build_stubbed(:alchemy_essence_picture, picture: picture) }
+      let(:essence) { build_stubbed(:alchemy_essence_picture, :with_content, picture: picture) }
 
       it { is_expected.to be_a(HashWithIndifferentAccess) }
 
@@ -150,6 +150,16 @@ module Alchemy
         end
       end
 
+      context 'with content having size setting' do
+        before do
+          expect(essence.content).to receive(:settings) { {size: '30x70'} }
+        end
+
+        it "includes this size." do
+          expect(picture_url_options[:size]).to eq '30x70'
+        end
+      end
+
       context 'without picture assigned' do
         let(:picture) { nil }