Use "display" width in HTML image links

Gemfile

@@ -33,6 +33,7 @@ gem 'rack-rewrite',         '~> 1.5.0'
 gem 'oj',                   '~> 2.11'
 gem 'oj_mimic_json',        '~> 1.0'
 gem 'foreigner',            '~> 1.7'
+gem 'chunky_png',           '~> 1.3'
 
 group :development do
   gem 'quiet_assets',   '~> 1.0.1'
@@ -64,7 +65,6 @@ group :test do
   gem 'shoulda-matchers'
   gem 'coveralls',          require: false
   gem 'rspec-activemodel-mocks'
-  gem 'chunky_png'
 end
 
 group :production do

Gemfile.lock

@@ -350,7 +350,7 @@ DEPENDENCIES
   capistrano-ext (~> 1.2)
   capybara (~> 2.4.1)
   carrierwave (~> 0.8.0)
-  chunky_png
+  chunky_png (~> 1.3)
   coffee-rails (~> 4.0.1)
   coveralls
   dalli (~> 2.6.2)

app/models/asciicast.rb

@@ -94,7 +94,7 @@ class Asciicast < ActiveRecord::Base
   end
 
   def image_hash
-    version = 1 # version of screenshot, increment to force regeneration
+    version = 2 # version of screenshot, increment to force regeneration
     input = "#{version}/#{id}/#{snapshot_at}"
     Digest::SHA1.hexdigest(input)
   end

app/presenters/asciicast_page_presenter.rb

@@ -58,7 +58,7 @@ class AsciicastPagePresenter
   def embed_html_link(routes)
     img_src = routes.asciicast_url(asciicast, format: :png)
     url = routes.asciicast_url(asciicast)
-    %(<a href="#{url}"><img src="#{img_src}"/></a>)
+    %(<a href="#{url}"><img src="#{img_src}" width="#{asciicast.image_width}" /></a>)
   end
 
   def embed_markdown_link(routes)

app/services/asciicast_image_updater.rb

@@ -16,6 +16,11 @@ class AsciicastImageUpdater
         asciicast.image = f
       end
 
+      image = ChunkyPNG::Image.from_file(png_path)
+      # image has double density so "display" size is half the actual one
+      asciicast.image_width = image.width / 2
+      asciicast.image_height = image.height / 2
+
       asciicast.save!
     end
   end

db/migrate/20150327171201_add_image_width_and_height_to_asciicasts.rb

@@ -0,0 +1,6 @@
+class AddImageWidthAndHeightToAsciicasts < ActiveRecord::Migration
+  def change
+    add_column :asciicasts, :image_width, :integer
+    add_column :asciicasts, :image_height, :integer
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20150324103607) do
+ActiveRecord::Schema.define(version: 20150327171201) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -56,6 +56,8 @@ ActiveRecord::Schema.define(version: 20150324103607) do
     t.integer  "version",                          null: false
     t.string   "file"
     t.string   "image"
+    t.integer  "image_width"
+    t.integer  "image_height"
   end
 
   add_index "asciicasts", ["created_at"], name: "index_asciicasts_on_created_at", using: :btree