Changes to ImageFileDescriptor and ImageField to fix a few cases of setting image dimension fields.

* Moved dimension field update logic out of `ImageFileDescriptor.__set__` and into its own method on `ImageField`.
 * New `ImageField.update_dimension_fields` method is attached to model instance's `post_init` signal so that:
   * Dimension fields are set when defined before the ImageField.
   * Dimension fields are set when the field is assigned in the model constructor (fixes #11196), but only if the dimension fields don't already have values, so we avoid updating the dimensions every time an object is loaded from the database (fixes #11084).
 * Clear dimension fields when the ImageField is set to None, which also causes dimension fields to be cleared when `ImageFieldFile.delete()` is used.
 * Added many more tests for ImageField that test edge cases we weren't testing before, and moved the ImageField tests out of `file_storage` and into their own module within `model_fields`.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@10858 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/model_fields/models.py

@@ -1,10 +1,23 @@
-from django.db import models
+import os
+import tempfile
 
 try:
     import decimal
 except ImportError:
     from django.utils import _decimal as decimal    # Python 2.3 fallback
 
+try:
+    # Checking for the existence of Image is enough for CPython, but for PyPy,
+    # you need to check for the underlying modules.
+    from PIL import Image, _imaging
+except ImportError:
+    Image = None
+
+from django.core.files.storage import FileSystemStorage
+from django.db import models
+from django.db.models.fields.files import ImageFieldFile, ImageField
+
+
 class Foo(models.Model):
     a = models.CharField(max_length=10)
     d = models.DecimalField(max_digits=5, decimal_places=3)
@@ -31,9 +44,97 @@ class Whiz(models.Model):
         (0,'Other'),
     )
     c = models.IntegerField(choices=CHOICES, null=True)
-    
+
 class BigD(models.Model):
     d = models.DecimalField(max_digits=38, decimal_places=30)
 
 class BigS(models.Model):
-    s = models.SlugField(max_length=255)
+    s = models.SlugField(max_length=255)
+
+
+###############################################################################
+# ImageField
+
+# If PIL available, do these tests.
+if Image:
+    class TestImageFieldFile(ImageFieldFile):
+        """
+        Custom Field File class that records whether or not the underlying file
+        was opened.
+        """
+        def __init__(self, *args, **kwargs):
+            self.was_opened = False
+            super(TestImageFieldFile, self).__init__(*args,**kwargs)
+        def open(self):
+            self.was_opened = True
+            super(TestImageFieldFile, self).open()
+
+    class TestImageField(ImageField):
+        attr_class = TestImageFieldFile
+
+    # Set up a temp directory for file storage.
+    temp_storage_dir = tempfile.mkdtemp()
+    temp_storage = FileSystemStorage(temp_storage_dir)
+    temp_upload_to_dir = os.path.join(temp_storage.location, 'tests')
+
+    class Person(models.Model):
+        """
+        Model that defines an ImageField with no dimension fields.
+        """
+        name = models.CharField(max_length=50)
+        mugshot = TestImageField(storage=temp_storage, upload_to='tests')
+
+    class PersonWithHeight(models.Model):
+        """
+        Model that defines an ImageField with only one dimension field.
+        """
+        name = models.CharField(max_length=50)
+        mugshot = TestImageField(storage=temp_storage, upload_to='tests',
+                                 height_field='mugshot_height')
+        mugshot_height = models.PositiveSmallIntegerField()
+
+    class PersonWithHeightAndWidth(models.Model):
+        """
+        Model that defines height and width fields after the ImageField.
+        """
+        name = models.CharField(max_length=50)
+        mugshot = TestImageField(storage=temp_storage, upload_to='tests',
+                                 height_field='mugshot_height',
+                                 width_field='mugshot_width')
+        mugshot_height = models.PositiveSmallIntegerField()
+        mugshot_width = models.PositiveSmallIntegerField()
+
+    class PersonDimensionsFirst(models.Model):
+        """
+        Model that defines height and width fields before the ImageField.
+        """
+        name = models.CharField(max_length=50)
+        mugshot_height = models.PositiveSmallIntegerField()
+        mugshot_width = models.PositiveSmallIntegerField()
+        mugshot = TestImageField(storage=temp_storage, upload_to='tests',
+                                 height_field='mugshot_height',
+                                 width_field='mugshot_width')
+
+    class PersonTwoImages(models.Model):
+        """
+        Model that:
+        * Defines two ImageFields
+        * Defines the height/width fields before the ImageFields
+        * Has a nullalble ImageField
+        """
+        name = models.CharField(max_length=50)
+        mugshot_height = models.PositiveSmallIntegerField()
+        mugshot_width = models.PositiveSmallIntegerField()
+        mugshot = TestImageField(storage=temp_storage, upload_to='tests',
+                                 height_field='mugshot_height',
+                                 width_field='mugshot_width')
+        headshot_height = models.PositiveSmallIntegerField(
+                blank=True, null=True)
+        headshot_width = models.PositiveSmallIntegerField(
+                blank=True, null=True)
+        headshot = TestImageField(blank=True, null=True,
+                                  storage=temp_storage, upload_to='tests',
+                                  height_field='headshot_height',
+                                  width_field='headshot_width')
+
+###############################################################################