terom@51: """
terom@51:     Rendering images as thumbnails/previews.
terom@51: """
terom@51: 
terom@51: import PIL.Image
terom@51: 
terom@51: class RenderMachine (object) :
terom@51:     """
terom@51:         RAWR! I'm the render machine!
terom@51: 
terom@51:         TODO: use multithreaded rendering (PIL supports it)
terom@51:     """
terom@51: 
terom@51:     def __init__ (self, config) :
terom@51:         """
terom@51:             Use the given Configuration object's settings for rendering
terom@51:         """
terom@51: 
terom@51:         self.config = config
terom@51: 
terom@57:     def render_out (self, image, size, file) :
terom@51:         """
terom@57:             Creates a thumbnail from the given Image of the given `size`, and saves it at `out`.
terom@57: 
terom@57:             Returns the file for convenience
terom@51:         """
terom@51: 
terom@57:         # load the PIL.Image
terom@77:         img = image.image
terom@57: 
terom@51:         # we need to create a copy, as .thumbnail mutates the Image
terom@51:         img_out = img.copy()
terom@51: 
terom@51:         # then resample to given size
terom@51:         img_out.thumbnail(size, resample=True)
terom@51: 
terom@51:         # and write out
terom@57:         img_out.save(file.path)
terom@51: 
terom@57:         return file
terom@57:    
terom@57:     def render_lazy (self, image, size, out) :
terom@51:         """
terom@57:             Renders the given image with render_out if `out` does not yet exist or is older than image.
terom@51:         """
terom@51: 
terom@57:         # stat the output file
terom@57:         out_stat = out.stat(soft=True)
terom@51: 
terom@57:         # compare
terom@77:         if not out_stat or out_stat.st_mtime < image.stat.st_mtime :
terom@57:             # render anew
terom@77:             return self.render_out(image, size, out)
terom@57: 
terom@57:         else :
terom@57:             # already rendered
terom@77:             return out