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

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 @@ module Paperclip
     # 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