attachment_fu cropping

rubyonrails-talk
1

attachment_fu doesn't have cropping, I'm trying to bake some in using ImageScience.

Firstly this requires the enabling of the '!' modifier in the geometry.rb file. However in the to_s method I don't think it's passing out the flags correctly. So I changed 'FLAGS[@flag.to_i]' to 'RFLAGS.index(@flag)' on line 47.

However now I need to change the logic in the image_science_processor.rb file to recognise the "!" aspect flag and then execute the crop and resize.

My issue is in doing two transformations, I don't really understand what the &grab_dimensions argument passed to the with_crop and resize methods is doing... please excuse my noob-ness.

I post my modified resize_image method to see if anyone can help...

def resize_image(img, size)   # create a dummy temp file to write to   self.temp_path = write_to_temp_file(filename)   grab_dimensions = lambda do |img|     self.width = img.width if respond_to?(:width)     self.height = img.height if respond_to?(:height)     img.save temp_path     callback_with_args :after_resize, img   end

  size = size.first if size.is_a?(Array) && size.length == 1   if size.is_a?(Fixnum) || (size.is_a?(Array) && size.first.is_a? (Fixnum))     if size.is_a?(Fixnum)       img.thumbnail(size, &grab_dimensions)     else       img.resize(size[0], size[1], &grab_dimensions)     end   else     new_size = [img.width, img.height] / size.to_s     # Added logic here     if size.ends_with? "!"       aspect = new_size[0].to_f / new_size[1].to_f       ih, iw = img.height, img.width       w, h = (ih * aspect), (iw / aspect)       w = [iw, w].min.to_i       h = [ih, h].min.to_i

      # THIS IS WHERE THE ISSUE IS!       img.with_crop( iw/2-w/2, ih/2-h/2, iw/2+w/2, ih/2+h/2, &grab_dimensions )       img.resize(new_size[0], new_size[1], &grab_dimensions )

    else       img.resize(new_size[0], new_size[1], &grab_dimensions)     end   end end

2

andycroll@deepcalm.com wrote:

attachment_fu doesn't have cropping, I'm trying to bake some in using ImageScience.

Firstly this requires the enabling of the '!' modifier in the geometry.rb file. However in the to_s method I don't think it's passing out the flags correctly. So I changed 'FLAGS[@flag.to_i]' to 'RFLAGS.index(@flag)' on line 47.

However now I need to change the logic in the image_science_processor.rb file to recognise the "!" aspect flag and then execute the crop and resize.

My issue is in doing two transformations, I don't really understand what the &grab_dimensions argument passed to the with_crop and resize methods is doing... please excuse my noob-ness.

I post my modified resize_image method to see if anyone can help...

def resize_image(img, size)   # create a dummy temp file to write to   self.temp_path = write_to_temp_file(filename)   grab_dimensions = lambda do |img|     self.width = img.width if respond_to?(:width)     self.height = img.height if respond_to?(:height)     img.save temp_path     callback_with_args :after_resize, img   end

  size = size.first if size.is_a?(Array) && size.length == 1   if size.is_a?(Fixnum) || (size.is_a?(Array) && size.first.is_a? (Fixnum))     if size.is_a?(Fixnum)       img.thumbnail(size, &grab_dimensions)     else       img.resize(size[0], size[1], &grab_dimensions)     end   else     new_size = [img.width, img.height] / size.to_s     # Added logic here     if size.ends_with? "!"       aspect = new_size[0].to_f / new_size[1].to_f       ih, iw = img.height, img.width       w, h = (ih * aspect), (iw / aspect)       w = [iw, w].min.to_i       h = [ih, h].min.to_i

      # THIS IS WHERE THE ISSUE IS!       img.with_crop( iw/2-w/2, ih/2-h/2, iw/2+w/2, ih/2+h/2, &grab_dimensions )       img.resize(new_size[0], new_size[1], &grab_dimensions )

    else       img.resize(new_size[0], new_size[1], &grab_dimensions)     end   end end

>

I posted a way to do this on railsweenie (with the diff on pastie). It's a little bit hackish (works on ImageScience and RMagick), but works for me. Here's the relevant post:

and the diff is at: http://pastie.caboo.se/48191

Hope this helps, Chris

3

I did see your solution Chris, it helped a lot in translating what the methods were doing. However the ImageScience cropped thumbnail function provides only a square image, my solution requires a cropped thumbnail to the width and height that it is passed...

Or at least it would if I could do two transformations on it!

Can anyone explain what I'm doing wrong?

4

I'm getting a 'Bitmap has already been freed' error, in case that helps.

5

Blogged the answer. http://www.deepcalm.com/writing/cropped-thumbnails-in-attachment_fu-using-imagescience

6

Hi Chris, thanks for that. I applied the patch, but didn't seem to see any
difference to my results. If I do :square => "100!" I get w=100 &
h=original-height. could I have missed something?

dorian

7

Dorian Mcfarland wrote:

Hi Chris, thanks for that. I applied the patch, but didn't seem to see any
difference to my results. If I do :square => "100!" I get w=100 &
h=original-height. could I have missed something?

dorian

I posted a way to do this on railsweenie (with the diff on pastie).
It's a little bit hackish (works on ImageScience and RMagick), but works
for me. Here's the relevant post: RailsNotes, the Ruby on Rails guides you wished you had. and the diff is at: Parked at Loopia

Hope this helps, Chris ------------------------------- http://autopendium.co.uk stuff about old cars

~~~ I do things for love or money

this one's for love: http://www.marseillefigs.org (and money)

>

Do the tests pass OK? Also, just to check you restarted the server after making the change...

Chris