picture tags, areas overhaul #1

[wolnelektury.git] / apps / picture / templatetags / picture_tags.py

diff --git a/apps/picture/templatetags/picture_tags.py b/apps/picture/templatetags/picture_tags.py
index ef297c9..38e7a66 100644 (file)
--- a/apps/picture/templatetags/picture_tags.py
+++ b/apps/picture/templatetags/picture_tags.py
@@ -1,9 +1,15 @@
 from django import template
 from django.template import Node, Variable, Template, Context
 from catalogue.utils import split_tags
+from itertools import chain
+from ..engine import CustomCroppingEngine
+import sorl.thumbnail.default
+import logging 
 
 register = template.Library()
 
+cropper = CustomCroppingEngine()
+
 @register.inclusion_tag('picture/picture_short.html', takes_context=True)
 def picture_short(context, picture):
     context.update({
@@ -26,3 +32,39 @@ def picture_wide(context, picture):
         })
     return context
 
+
+@register.simple_tag()
+def area_thumbnail_url(area, geometry):
+    def to_square(coords):
+        w = coords[1][0] - coords[0][0]
+        h = coords[1][1] - coords[0][1]
+        if w == h:
+            return coords
+        elif w > h:
+            return [[coords[0][0] + w/2 - h/2, coords[0][1]],
+                    [coords[1][0] - w/2 + h/2, coords[1][1]]]
+        else:
+            return [[coords[0][0], coords[0][1] + h/2 - w/2],
+                    [coords[1][0], coords[1][1] - h/2 + w/2, ]]            
+
+    # so much for sorl extensibility. 
+    # what to do about this?
+    _engine = sorl.thumbnail.default.engine
+    sorl.thumbnail.default.engine = cropper
+    coords = to_square(area.area)
+    logging.debug("coords: %s, %s" % (unicode(coords), geometry))
+    try:
+        th = sorl.thumbnail.default.backend.get_thumbnail(
+            area.picture.image_file,
+            geometry,
+            crop="%dpx %dpx %dpx %dpx" % tuple(coords[0] + coords[1]))
+    except Exception, e:
+        logging.exception("Error creating a thumbnail for PictureArea")
+
+    sorl.thumbnail.default.engine = _engine
+    
+    return th.url
+            
+
+                                            
+