some work on the new Python binding

TODO

@@ -1,3 +1,11 @@
+- python/* is too old, keep for reference, but we need to use the
+  introspection stuff to get current gobject bindings
+
+  look at that brancg again
+
+
+
+
 - foreign docs come up as "VipsForeignSave", annoying, why?
 
 - we can no longer have round brackets in filenames, argh

python/README

@@ -2,7 +2,7 @@ Experimental Python binding using ctypes
 
 The current Python binding uses swig to wrap the C++ interface. This causes
 problems on Windows, since compiling all of the DLLs correctly to work with
-the various python binaries is painful, and makes the bainding very large.
+the various python binaries is painful, and makes the binding very large.
 
 The idea here is to use ctypes to make a binding that's just Python and which
 directly wraps the C API. The new vips8 C API is much more wrapper-friendly,

python/test.py

@@ -5,6 +5,7 @@ import gc
 
 import gobject
 
+import vipsobject
 import vipsimage
 
 logging.basicConfig(level = logging.DEBUG)
@@ -21,22 +22,34 @@ a = vipsimage.VipsImage('/home/john/pics/healthygirl.jpg')
 print 'width =', a.width()
 print 'height =', a.height()
 print 'bands =', a.bands()
-print 'format =', vipsimage.VipsBandFormat.name(a.format())
-print 'coding =', vipsimage.VipsCoding.name(a.coding())
-print 'interpretation =', vipsimage.VipsInterpretation.name(a.interpretation())
+print 'format = %d - %s' % (a.format(), 
+        vipsimage.VipsBandFormat.name(a.format()))
+print 'coding = %d - %s' % (a.coding(), 
+        vipsimage.VipsCoding.name(a.coding()))
+print 'interpretation = %d - %s' % (a.interpretation(),
+        vipsimage.VipsInterpretation.name(a.interpretation()))
 print 'xres =', a.xres()
 print 'yres =', a.yres()
 print 'xoffset =', a.xoffset()
 print 'yoffset =', a.yoffset()
 
 # should raise an error
-a = vipsimage.VipsImage('banana')
+try:
+    a = vipsimage.VipsImage('banana')
+except vipsobject.VipsError, e:
+    print 'caught VipsError'
+    print '\tmessage =', e.message
+    print '\tdetail =', e.detail
 
 # try calling a vips8 method
 a = vipsimage.VipsImage('/home/john/pics/healthygirl.jpg')
 b = vipsimage.VipsImage('/home/john/pics/babe.jpg')
 c = a.add(b)
 
+print 'c = ', c
+
+c.write('/home/john/pics/x.v')
+
 print 'starting shutdown ...'
 del a
 del b

python/vipsimage.py

@@ -9,6 +9,8 @@ GNU LESSER GENERAL PUBLIC LICENSE
 import logging
 import ctypes
 
+import gobject
+
 import vipsobject
 
 # image enums
@@ -45,7 +47,6 @@ class VipsInterpretation:
 
     @staticmethod
     def name(value):
-        print currentclass
         return vipsobject.class_value(VipsInterpretation, value)
 
 class VipsBandFormat:
@@ -102,15 +103,14 @@ vips_image_get_xres.restype = ctypes.c_double;
 vips_image_get_yres = libvips.vips_image_get_yres
 vips_image_get_yres.restype = ctypes.c_double;
 
-vips_operation_new = libvips.vips_operation_new
-vips_operation_new.argtypes = [ctypes.c_char_p]
-vips_operation_new.restype = ctypes.c_void_p
-vips_operation_new.errcheck = vipsobject.check_pointer_return
-
 def vips_call_instance(self, name, args):
     logging.debug('vipsimage: vips_call_instance name=%s, self=%s, args=%s' % 
                   (name, self, args))
+    operation = vipsoperation.VipsOperation(name)
     operation = vips_operation_new(name)
+    vipsobject.vips_object_print(operation)
+    vipsobject.vips_argument_map(operation, 
+            vipsobject.VipsArgumentMapFn(show_args),None, None)
 
 class VipsImage(vipsobject.VipsObject):
     """Manipulate a libvips image."""

python/vipsobject.py

@@ -20,6 +20,26 @@ import finalizable
 libvips = ctypes.CDLL('libvips.so.15')
 libvips.vips_init(sys.argv[0])
 
+vips_object_print = libvips.vips_object_print
+vips_object_print.argtypes = [ctypes.c_void_p]
+vips_object_print.restype = None
+
+# in C:
+# typedef void *(*VipsArgumentMapFn)( VipsObject *, 
+#   GParamSpec *, VipsArgumentClass *, VipsArgumentInstance *, 
+#   void *a, void *b );
+VipsArgumentMapFn = ctypes.CFUNCTYPE(ctypes.c_void_p, ctypes.c_void_p,
+        ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, 
+        ctypes.c_void_p, ctypes.c_void_p)
+vips_argument_map = libvips.vips_argument_map
+vips_argument_map.argtypes = [ctypes.c_void_p, VipsArgumentMapFn,
+        ctypes.c_void_p, ctypes.c_void_p]
+vips_argument_map.restype = ctypes.c_void_p
+
+g_param_spec_get_name = libvips.g_param_spec_get_name
+g_param_spec_get_name.argtypes = [ctypes.c_void_p]
+g_param_spec_get_name.restype = ctypes.c_char_p
+
 # given a class and value, search for a class member with that value
 # handy for enum classes, use to turn numbers to strings
 def class_value(classobject, value):
@@ -45,7 +65,7 @@ class VipsError(Exception):
         logging.debug('vipsobject: Error: %s %s', self.message, self.detail)
 
     def __str__(self):
-        return '%s %s' %(self.message, self.detail)
+        return '%s %s' % (self.message, self.detail)
 
 # handy checkers, assign to errcheck
 def check_int_return(result, func, args):

python/vipsoperation.py

@@ -0,0 +1,46 @@
+#!/usr/bin/python
+
+"""This module wraps up libvips in a less awful interface.
+
+Author: J.Cupitt
+GNU LESSER GENERAL PUBLIC LICENSE
+"""
+
+import logging
+import ctypes
+
+import gobject
+
+import vipsobject
+
+libvips = vipsobject.libvips
+
+vips_operation_new = libvips.vips_operation_new
+vips_operation_new.argtypes = [ctypes.c_char_p]
+vips_operation_new.restype = ctypes.c_void_p
+vips_operation_new.errcheck = vipsobject.check_pointer_return
+
+def show_args(operation, pspec, arg_class, arg_instance, a, b):
+    name = vipsobject.g_param_spec_get_name(pspec)
+
+def vips_call_instance(self, name, args):
+    logging.debug('vipsimage: vips_call_instance name=%s, self=%s, args=%s' % 
+                  (name, self, args))
+    operation = vips_operation_new(name)
+    vipsobject.vips_object_print(operation)
+    vipsobject.vips_argument_map(operation, 
+            vipsobject.VipsArgumentMapFn(show_args),None, None)
+
+class VipsOperation(vipsobject.VipsObject):
+    """Call a libvips operation."""
+
+    def __init__(self, name):
+        logging.debug('vipsoperation: init %s', name)
+
+        vipsobject.VipsObject.__init__(self)
+
+        self.vipsobject = vips_operation_new(name)
+
+        self.enable_finalize()
+
+    def call