get ready for class methods

TODO

@@ -1,8 +1,32 @@
 
 - python:
 
+	- can we override __getattr__ on a type object?
+
+		Vips.Image.black
+		AttributeError: type object 'Image' has no attribute 'black'
+
+	  we'd like to attack black as a class method, or override __getattr__
+	  to let us patch class methods in
+
+	  looks like defining a metaclass might do it, but 
+
+ 	  	Vips.Image.__metaclass__ = ImageType
+		setattr(Vips.Image, '__metaclass__', ImageType)
+		setattr(Vips.Image, '__metaclass__', classmethod(ImageType))
+
+	  don't work, nor any other obvious variations
+
+	  we could walk all vips operators and paste in ones without an
+	  image instance arg as class methods, but that would be very slow and
+	  wouldn't work for loading plugins
+
+
 	- how about the in-place things? draw a circle?
 
+	- try getting / setting / deleting metadata such as an ICC profile or
+	  an exif tag
+
 	- try vips benchmark in vips8 python, how much slower?
 
 	- could import like this:

python/try9.py

@@ -2,16 +2,15 @@
 
 import sys
 
-#import logging
+import logging
-#logging.basicConfig(level = logging.DEBUG)
+logging.basicConfig(level = logging.DEBUG)
 
+from gi.repository import GLib
+from gi.repository import GObject
 from gi.repository import Vips 
+
 from vips8 import vips
 
 a = Vips.Image.black(100, 100)
 
-b = Vips.Image.new_memory()
+a.write_to_file("x.v")
-
-a.write(b)
-
-b.write_to_file("x.v")

python/vips8/vips.py

@@ -4,12 +4,10 @@ import sys
 
 import logging
 
-from gi.repository import GLib
-from gi.repository import GObject
-
 # you might need this in your .bashrc
 # export GI_TYPELIB_PATH=$VIPSHOME/lib/girepository-1.0
-from gi.repository import Vips 
+
+from gi.repository import GLib, GObject, Vips
 
 # start up vips!
 Vips.init(sys.argv[0])
@@ -19,6 +17,8 @@ vips_type_array_int = GObject.GType.from_name("VipsArrayInt")
 vips_type_array_double = GObject.GType.from_name("VipsArrayDouble")
 vips_type_array_image = GObject.GType.from_name("VipsArrayImage")
 vips_type_blob = GObject.GType.from_name("VipsBlob")
+vips_type_image = GObject.GType.from_name("VipsImage")
+vips_type_operation = GObject.GType.from_name("VipsOperation")
 
 class Error(Exception):
 
@@ -83,8 +83,8 @@ class Argument:
         # turn VipsBlobs into strings 
         # FIXME ... this will involve a copy, we should use
         # buffer() instead
-#        if isinstance(value, Vips.Blob):
+        if isinstance(value, Vips.Blob):
-#            value = value.get()
+            value = value.get()
 
         return value
 
@@ -244,6 +244,10 @@ def vips_image_new_from_array(cls, array, scale = 1, offset = 0):
 
     return image
 
+# this is a class method
+def vips_black(cls, width, height, **kwargs):
+    return _call_base("black", [width, height], kwargs)
+
 def vips_image_getattr(self, name):
     logging.debug('Image.__getattr__ %s' % name)
 
@@ -392,6 +396,39 @@ setattr(Vips.Image, 'new_from_file', classmethod(vips_image_new_from_file))
 setattr(Vips.Image, 'new_from_buffer', classmethod(vips_image_new_from_buffer))
 setattr(Vips.Image, 'new_from_array', classmethod(vips_image_new_from_array))
 
+# yuk, we should run these via a metaclass somehow
+setattr(Vips.Image, 'black', classmethod(vips_black))
+
+# Search for all VipsOperation which don't have an input image object ... these
+# become class methods
+
+def vips_image_class_method(name, args, kwargs):
+    logging.debug('vips_image_class_method %s' % name)
+
+    return _call_instance(None, name, args, kwargs)
+
+def define_class_methods(cls):
+    if len(cls.children) > 0:
+        for child in cls.children:
+            # not easy to get at the deprecated flag in an abtract type?
+            if cls.name != 'VipsWrap7':
+                define_class_methods(child)
+    elif cls.is_instantiatable():
+        op = Vips.Operation.new(cls.name)
+        found = False
+        for prop in op.props:
+            flags = op.get_argument_flags(prop.name)
+            if flags & Vips.ArgumentFlags.INPUT and flags & Vips.ArgumentFlags.REQUIRED:
+                if GObject.type_is_a(vips_type_image, prop.value_type):
+                    found = True
+                    break
+
+        if not found:
+            print 'operation %s has no input image args' % cls.name
+            setattr(Vips.Image, cls.name, classmethod(lambda *args, **kwargs: vips_image_class_method(cls.name, args, kwargs)))
+
+define_class_methods(vips_type_operation)
+
 # instance methods
 Vips.Image.write_to_file = vips_image_write_to_file
 Vips.Image.write_to_buffer = vips_image_write_to_buffer