create favicon overlay on the client

the initial reason for this change was that graphicsmagick does not
support writing to ico files. this fact lead to a chain of changes:

1. use png instead of ico (browser support is good enough)
2. render the overlays on the client using the canvas API. this way we
   only need to store the original favion and generate the overlay versions
   dynamically.
   this change also enables (next step) to simplify the handling of the
   stock favicons as well, as we don't need to generate all the versions
   upfront.

1 files changed, 2 insertions, 35 deletions

diff --git a/app/uploaders/favicon_uploader.rb b/app/uploaders/favicon_uploader.rb
index 7697f5fe885..d7be77477b2 100644
--- a/app/uploaders/favicon_uploader.rb
+++ b/app/uploaders/favicon_uploader.rb
@@ -1,35 +1,12 @@
 class FaviconUploader < AttachmentUploader
   include CarrierWave::MiniMagick
 
-  STATUS_ICON_NAMES = [
-    :favicon_status_canceled,
-    :favicon_status_created,
-    :favicon_status_failed,
-    :favicon_status_manual,
-    :favicon_status_not_found,
-    :favicon_status_pending,
-    :favicon_status_running,
-    :favicon_status_skipped,
-    :favicon_status_success,
-    :favicon_status_warning
-  ].freeze
-
   version :favicon_main do
     process resize_to_fill: [32, 32]
-    process convert: 'ico'
+    process convert: 'png'
 
     def full_filename(filename)
-      filename_for_different_format(super(filename), 'ico')
-    end
-  end
-
-  STATUS_ICON_NAMES.each do |status_name|
-    version status_name, from_version: :favicon_main do
-      process status_favicon: status_name
-
-      def full_filename(filename)
-        filename_for_different_format(super(filename), 'ico')
-      end
+      filename_for_different_format(super(filename), 'png')
     end
   end
 
@@ -39,16 +16,6 @@ class FaviconUploader < AttachmentUploader
 
   private
 
-  def status_favicon(status_name)
-    manipulate! do |img|
-      overlay_path = Rails.root.join("app/assets/images/ci_favicons/overlays/#{status_name}.png")
-      overlay = MiniMagick::Image.open(overlay_path)
-      img.composite(overlay) do |c|
-        c.compose 'over'
-      end
-    end
-  end
-
   def filename_for_different_format(filename, format)
     filename.chomp(File.extname(filename)) + ".#{format}"
   end