Abstract out the file geometry parser within Thumbnail. This makes it…

… possible to have different cropping and scaling controls, as the papermill gem does.

gemfiles/rails2.gemfile

@@ -2,19 +2,19 @@
 
 source "http://rubygems.org"
 
+gem "sqlite3", "~>1.3.4"
+gem "rails", "~> 2.3.12"
 gem "activerecord", :require=>"active_record"
-gem "appraisal"
-gem "aws-s3", :require=>"aws/s3"
-gem "bundler"
 gem "cocaine", "~>0.2"
-gem "fog"
-gem "jruby-openssl", :platform=>:jruby
+gem "rake"
+gem "sprockets", "~> 2.0.0.beta.13", :require=>false
+gem "shoulda"
 gem "mime-types"
+gem "jruby-openssl", :platform=>:jruby
 gem "mocha"
-gem "rake"
+gem "bundler"
+gem "fog"
+gem "appraisal"
+gem "aws-s3", :require=>"aws/s3"
 gem "rdoc", :require=>false
-gem "shoulda"
-gem "sqlite3", "~>1.3.4"
-gem "sprockets", "~> 2.0.0.beta.13", :require=>false
-gem "rails", "~> 2.3.12"
 

gemfiles/rails3.gemfile

@@ -2,19 +2,19 @@
 
 source "http://rubygems.org"
 
+gem "sqlite3", "~>1.3.4"
+gem "rails", "~> 3.0.9"
 gem "activerecord", :require=>"active_record"
-gem "appraisal"
-gem "aws-s3", :require=>"aws/s3"
-gem "bundler"
 gem "cocaine", "~>0.2"
-gem "fog"
-gem "jruby-openssl", :platform=>:jruby
+gem "rake"
+gem "sprockets", "~> 2.0.0.beta.13", :require=>false
+gem "shoulda"
 gem "mime-types"
+gem "jruby-openssl", :platform=>:jruby
 gem "mocha"
-gem "rake"
+gem "bundler"
+gem "fog"
+gem "appraisal"
+gem "aws-s3", :require=>"aws/s3"
 gem "rdoc", :require=>false
-gem "shoulda"
-gem "sqlite3", "~>1.3.4"
-gem "sprockets", "~> 2.0.0.beta.13", :require=>false
-gem "rails", "~> 3.0.9"
 

gemfiles/rails3_1.gemfile

@@ -2,19 +2,19 @@
 
 source "http://rubygems.org"
 
+gem "sqlite3", "~>1.3.4"
+gem "rails", "~> 3.1.0.rc5"
 gem "activerecord", :require=>"active_record"
-gem "appraisal"
-gem "aws-s3", :require=>"aws/s3"
-gem "bundler"
 gem "cocaine", "~>0.2"
-gem "fog"
-gem "jruby-openssl", :platform=>:jruby
+gem "rake"
+gem "sprockets", "~> 2.0.0.beta.13", :require=>false
+gem "shoulda"
 gem "mime-types"
+gem "jruby-openssl", :platform=>:jruby
 gem "mocha"
-gem "rake"
+gem "bundler"
+gem "fog"
+gem "appraisal"
+gem "aws-s3", :require=>"aws/s3"
 gem "rdoc", :require=>false
-gem "shoulda"
-gem "sqlite3", "~>1.3.4"
-gem "sprockets", "~> 2.0.0.beta.13", :require=>false
-gem "rails", "~> 3.1.0.rc5"
 

lib/paperclip/thumbnail.rb

@@ -14,14 +14,24 @@ class Thumbnail < Processor
     # unless specified. Thumbnail creation will raise no errors unless
     # +whiny+ is true (which it is, by default. If +convert_options+ is
     # set, the options will be appended to the convert command upon image conversion
-    def initialize file, options = {}, attachment = nil
+    #
+    # Options include:
+    #
+    #   +geometry+ - the desired width and height of the thumbnail
+    #   +file_geometry_parser+ - an object with a method named +from_file+ that takes an image file and produces its geometry. Defaults to Paperclip::Geometry
+    #   +source_file_options+ - flags passed to the +convert+ command that influence how the source file is read
+    #   +convert_options+ - flags passed to the +convert+ command that influence how the image is processed
+    #   +whiny+ - whether to raise an error when processing fails. Defaults to true.
+    #   +format+ - the desired filename extension
+    #   +animated+ - whether to merge all the layers in the image. Defaults to true.
+    def initialize(file, options = {}, attachment = nil)
       super
 
       geometry             = options[:geometry]
       @file                = file
       @crop                = geometry[-1,1] == '#'
-      @target_geometry     = Geometry.parse geometry
-      @current_geometry    = Geometry.from_file @file
+      @target_geometry     = Geometry.parse(geometry)
+      @current_geometry    = (options[:file_geometry_parser] || Geometry).from_file(@file)
       @source_file_options = options[:source_file_options]
       @convert_options     = options[:convert_options]
       @whiny               = options[:whiny].nil? ? true : options[:whiny]

test/thumbnail_test.rb

@@ -224,6 +224,32 @@ class ThumbnailTest < Test::Unit::TestCase
         assert !@thumb.transformation_command.include?("-resize")
       end
     end
+
+    context "passing a custom geometry parser" do
+      should "produce the appropriate transformation_command" do
+        GeoParser = Class.new do
+          def self.from_file(file)
+            new
+          end
+          def transformation_to(target, should_crop)
+            ["SCALE", "CROP"]
+          end
+        end
+
+        thumb = Paperclip::Thumbnail.new(@file, :geometry => "50x50", :file_geometry_parser => GeoParser)
+
+        transformation_command = thumb.transformation_command
+
+        assert transformation_command.include?('-crop'),
+          %{expected #{transformation_command.inspect} to include '-crop'}
+        assert transformation_command.include?('"CROP"'),
+          %{expected #{transformation_command.inspect} to include '"CROP"'}
+        assert transformation_command.include?('-resize'),
+          %{expected #{transformation_command.inspect} to include '-resize'}
+        assert transformation_command.include?('"SCALE"'),
+          %{expected #{transformation_command.inspect} to include '"SCALE"'}
+      end
+    end
   end
 
   context "A multipage PDF" do