Source Code for Module conduit.modules.PhotoConverterModule

  1  import logging 
  2  log = logging.getLogger("modules.PhotoConverter") 
  3   
  4  import conduit 
  5  import conduit.utils as Utils 
  6  import conduit.TypeConverter as TypeConverter 
  7  import conduit.datatypes.File as File 
  8  import conduit.datatypes.Photo as Photo 
  9   
 10  MODULES = { 
 11          "PixbufPhotoConverter" :  { "type": "converter" } 
 12  } 
 13   
 14  NO_RESIZE = "None" 
 15   
 16 -class PixbufPhotoConverter(TypeConverter.Converter): 
 17 -    def __init__(self): 
 18          self.conversions =  { 
 19                              "file/photo,file/photo"     :   self.transcode,     
 20                              "file,file/photo"           :   self.file_to_photo 
 21                              } 
 22          self._image_types = None 
 23                               
 24 -    def _get_pixbuf_capabilities(self): 
 25          """ 
 26          Returns a dict mapping image mimetypes to extensions to  
 27          be used when converting image formats 
 28          """ 
 29          if self._image_types == None: 
 30              import gtk.gdk 
 31              types = {} 
 32              for f in gtk.gdk.pixbuf_get_formats(): 
 33                  for t in f["mime_types"]: 
 34                      if f["is_writable"] == True: 
 35                          types[t] = f["extensions"][0] 
 36                      else: 
 37                          types[t] = None 
 38              self._image_types = types 
 39          return self._image_types 
 40           
 41 -    def _convert(self, photo, format, width, height, doResize, doReformat): 
 42          """ 
 43          Basically we defer the conversion until as late as possible, or  
 44          not at all. 
 45          """ 
 46          import gtk.gdk 
 47   
 48          pb = photo.get_photo_pixbuf() 
 49          out_file = photo.to_tempfile() 
 50   
 51          if doResize: 
 52              try: 
 53                  log.debug("Photo: Scaling to %sx%s" % (width,height)) 
 54                  pb = pb.scale_simple(width,height,gtk.gdk.INTERP_HYPER) 
 55              except Exception, err: 
 56                  log.debug("Photo: Error scaling photo\n%s" % err) 
 57           
 58          #save to new format. gdk.Pixbuf needs the type argument 
 59          if doResize or doReformat: 
 60              log.debug("Photo: Saving photo:%s Format:%s" % (out_file,format)) 
 61              pb.save(out_file, format) 
 62              #can safely rename the file here because its defintately a tempfile 
 63              photo.force_new_file_extension(".%s" % format) 
 64   
 65 -    def transcode(self, photo, **kwargs): 
 66          log.info("Transcode Photo: %s" % kwargs) 
 67           
 68          #default format is the current format, and default is no resize 
 69          formats = kwargs.get("formats",photo.get_mimetype()).split(',') 
 70          newSize = kwargs.get("size",NO_RESIZE) 
 71   
 72          #resize if necessary 
 73          if newSize != NO_RESIZE: 
 74              w,h = photo.get_photo_size() 
 75              width,height = Utils.get_proportional_resize( 
 76                                  desiredW=int(newSize.split('x')[0]), 
 77                                  desiredH=int(newSize.split('x')[1]), 
 78                                  currentW=int(w), 
 79                                  currentH=int(h) 
 80                                  ) 
 81              doResize = True 
 82          else: 
 83              width = None 
 84              height = None 
 85              doResize = False 
 86   
 87          #check if the photo is in the allowed format, otherwise we must convert it 
 88          mimeType = photo.get_mimetype() 
 89          doReformat = False 
 90          if mimeType not in formats: 
 91              #convert photo to default format 
 92              mimeType = kwargs.get("default-format","image/jpeg") 
 93              doReformat = True 
 94   
 95          #convert the mimetype to the image type for gdk pixbuf save method 
 96          format = self._get_pixbuf_capabilities()[mimeType] 
 97               
 98          self._convert( 
 99                  photo, 
100                  format, 
101                  width, 
102                  height, 
103                  doResize, 
104                  doReformat 
105                  ) 
106                   
107          return photo 
108   
109 -    def file_to_photo(self, f, **kwargs): 
110          t = f.get_mimetype() 
111          if t in self._get_pixbuf_capabilities().keys(): 
112              p = Photo.Photo( 
113                          URI=f._get_text_uri() 
114                          ) 
115              p.set_from_instance(f) 
116              return self.transcode(p,**kwargs) 
117          else: 
118              return None 
119