Source Code for Module zeroinstall.gtkui.icon

 1  """Loading icons.""" 
 2  # Copyright (C) 2009, Thomas Leonard 
 3  # See the README file for details, or visit http://0install.net. 
 4   
 5  from zeroinstall import _, logger 
 6  import gtk 
 7  import math 
 8   
 9 -def load_icon(icon_path, icon_width=None, icon_height=None): 
10          """Load icon from path. Icon MUST be in PNG format. 
11          @param icon_path: pathname of icon, or None to load nothing 
12          @return: a GdkPixbuf, or None on failure""" 
13          if not icon_path: 
14                  return None 
15   
16          def size_prepared_cb(loader, width, height): 
17                  dest_width = icon_width or width 
18                  dest_height = icon_height or height 
19   
20                  if dest_width == width and dest_height == height: 
21                          return 
22   
23                  ratio_width = float(dest_width) / width 
24                  ratio_height = float(dest_height) / height 
25                  ratio = min(ratio_width, ratio_height) 
26   
27                  # preserve original ration 
28                  if ratio_width != ratio: 
29                          dest_width = int(math.ceil(width * ratio)) 
30                  elif ratio_height != ratio: 
31                          dest_height = int(math.ceil(height * ratio)) 
32   
33                  loader.set_size(int(dest_width), int(dest_height)) 
34   
35          # Restrict icon formats to avoid attacks 
36          try: 
37                  loader = gtk.gdk.PixbufLoader('png') 
38                  if icon_width or icon_height: 
39                          loader.connect('size-prepared', size_prepared_cb) 
40                  try: 
41                          with open(icon_path, 'rb') as stream: 
42                                  loader.write(stream.read()) 
43                  finally: 
44                          loader.close() 
45                  return loader.get_pixbuf() 
46          except Exception as ex: 
47                  logger.warning(_("Failed to load cached PNG icon: %s") % ex) 
48                  return None 
49