Add a property helper, fixes #338098

    * examples/properties.py:
    * gobject/Makefile.am:
    * gobject/__init__.py:
    * gobject/constants.py.in:
    * gobject/generate-constants.c: (main):
    * gobject/propertyhelper.py:
    * tests/Makefile.am:
    * tests/test_enum.py:
    * tests/test_interface.py:
    * tests/test_properties.py:

    Add a property helper, fixes #338098

svn path=/trunk/; revision=662

5 files changed, 417 insertions, 27 deletions

diff --git a/gobject/Makefile.am b/gobject/Makefile.am
index 6c4f242..32b4305 100644
--- a/gobject/Makefile.am
+++ b/gobject/Makefile.am
@@ -9,15 +9,29 @@ pkgpyexecdir = $(pyexecdir)/gtk-2.0
 
 # gobject python scripts
 pygobjectdir = $(pkgpyexecdir)/gobject
-pygobject_PYTHON = __init__.py option.py
+pygobject_PYTHON = 	\
+	__init__.py 	\
+	option.py	\
+	propertyhelper.py
 pygobject_LTLIBRARIES = _gobject.la 
-
+nodist_pygobject_PYTHON = constants.py
 
 common_ldflags = -module -avoid-version
 if PLATFORM_WIN32
 common_ldflags += -no-undefined
 endif
 
+constants.py: generate-constants constants.py.in
+	rm -f constants.py
+	cp $(srcdir)/constants.py.in constants.py
+	chmod 644 constants.py
+	$(top_builddir)/gobject/generate-constants >> constants.py
+	chmod 444 constants.py
+
+generate_constants_CFLAGS = $(GLIB_CFLAGS)
+noinst_PROGRAMS = generate-constants
+CLEANFILES = constants.py
+EXTRA_DIST = constants.py.in
 
 _gobject_la_CFLAGS = $(GLIB_CFLAGS)
 _gobject_la_LDFLAGS = $(common_ldflags) -export-symbols-regex init_gobject
@@ -39,9 +53,10 @@ _gobject_la_SOURCES = \
 	pygtype.c \
 	pygoptioncontext.c \
 	pygoptiongroup.c
+_gobject_la_DEPENDENCIES = constants.py
 
 if HAVE_LIBFFI
-_gobject_la_SOURCES += ffi-marshaller.c
+_gobject_la_SOURCES += ffi-marshaller.c ffi-marshaller.h
 endif
 
 if PLATFORM_WIN32
diff --git a/gobject/__init__.py b/gobject/__init__.py
index 43a2cfd..d251d31 100644
--- a/gobject/__init__.py
+++ b/gobject/__init__.py
@@ -27,15 +27,61 @@ try:
 except ImportError:
     pass
 
+from gobject.constants import *
 from _gobject import *
 _PyGObject_API = _gobject._PyGObject_API
 
+from propertyhelper import property
+
 class GObjectMeta(type):
     "Metaclass for automatically registering GObject classes"
     def __init__(cls, name, bases, dict_):
         type.__init__(cls, name, bases, dict_)
+        cls._install_properties()
         cls._type_register(cls.__dict__)
 
+    def _install_properties(cls):
+        gproperties = getattr(cls, '__gproperties__', {})
+        props = {}
+        for name, prop in cls.__dict__.items():
+            if isinstance(prop, property): # not same as the built-in
+                if name in gproperties:
+                    raise ValueError
+                prop.name = name
+                props[name] = prop.get_pspec_args()
+
+        if not props:
+            return
+
+        if not gproperties:
+            cls.__gproperties__ = props
+        else:
+            gproperties.update(props)
+
+        if (hasattr(cls, 'do_get_property') or
+            hasattr(cls, 'do_set_property')):
+            for prop in props:
+                if (prop.getter != prop.default_getter or
+                    prop.setter != prop.default_setter):
+                    raise TypeError(
+                        "GObject subclass %r defines do_get/set_property"
+                        " and it also uses a property which a custom setter"
+                        " or getter. This is not allowed" % (cls,))
+
+        def obj_get_property(self, pspec):
+            name = pspec.name.replace('-', '_')
+            prop = getattr(cls, name, None)
+            if prop:
+                return prop.getter(self)
+        cls.do_get_property = obj_get_property
+
+        def obj_set_property(self, pspec, value):
+            name = pspec.name.replace('-', '_')
+            prop = getattr(cls, name, None)
+            if prop:
+                prop.setter(self, value)
+        cls.do_set_property = obj_set_property
+
     def _type_register(cls, namespace):
         ## don't register the class if already registered
         if '__gtype__' in namespace:
@@ -50,28 +96,4 @@ class GObjectMeta(type):
 
 _gobject._install_metaclass(GObjectMeta)
 
-# TYPE_INVALID defined in gobjectmodule.c
-TYPE_NONE = type_from_name('void')
-TYPE_INTERFACE = type_from_name('GInterface')
-TYPE_CHAR = type_from_name('gchar')
-TYPE_UCHAR = type_from_name('guchar')
-TYPE_BOOLEAN = type_from_name('gboolean')
-TYPE_INT = type_from_name('gint')
-TYPE_UINT = type_from_name('guint')
-TYPE_LONG = type_from_name('glong')
-TYPE_ULONG = type_from_name('gulong')
-TYPE_INT64 = type_from_name('gint64')
-TYPE_UINT64 = type_from_name('guint64')
-TYPE_ENUM = type_from_name('GEnum')
-TYPE_FLAGS = type_from_name('GFlags')
-TYPE_FLOAT = type_from_name('gfloat')
-TYPE_DOUBLE = type_from_name('gdouble')
-TYPE_STRING = type_from_name('gchararray')
-TYPE_POINTER = type_from_name('gpointer')
-TYPE_BOXED = type_from_name('GBoxed')
-TYPE_PARAM = type_from_name('GParam')
-TYPE_OBJECT = type_from_name('GObject')
-TYPE_PYOBJECT = type_from_name('PyObject')
-TYPE_UNICHAR = TYPE_UINT
-
 del _gobject
diff --git a/gobject/constants.py.in b/gobject/constants.py.in
new file mode 100644
index 0000000..6cb2d4f
--- /dev/null
+++ b/gobject/constants.py.in
@@ -0,0 +1,47 @@
+# -*- Mode: Python; py-indent-offset: 4 -*-
+# pygobject - Python bindings for the GObject library
+# Copyright (C) 2006-2007 Johan Dahlin
+#
+#   gobject/constants.py: GObject type constants
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+# USA
+
+from _gobject import type_from_name
+
+# TYPE_INVALID defined in gobjectmodule.c
+TYPE_NONE = type_from_name('void')
+TYPE_INTERFACE = type_from_name('GInterface')
+TYPE_CHAR = type_from_name('gchar')
+TYPE_UCHAR = type_from_name('guchar')
+TYPE_BOOLEAN = type_from_name('gboolean')
+TYPE_INT = type_from_name('gint')
+TYPE_UINT = type_from_name('guint')
+TYPE_LONG = type_from_name('glong')
+TYPE_ULONG = type_from_name('gulong')
+TYPE_INT64 = type_from_name('gint64')
+TYPE_UINT64 = type_from_name('guint64')
+TYPE_ENUM = type_from_name('GEnum')
+TYPE_FLAGS = type_from_name('GFlags')
+TYPE_FLOAT = type_from_name('gfloat')
+TYPE_DOUBLE = type_from_name('gdouble')
+TYPE_STRING = type_from_name('gchararray')
+TYPE_POINTER = type_from_name('gpointer')
+TYPE_BOXED = type_from_name('GBoxed')
+TYPE_PARAM = type_from_name('GParam')
+TYPE_OBJECT = type_from_name('GObject')
+TYPE_PYOBJECT = type_from_name('PyObject')
+TYPE_UNICHAR = TYPE_UINT
+
diff --git a/gobject/generate-constants.c b/gobject/generate-constants.c
new file mode 100644
index 0000000..ed66a07
--- /dev/null
+++ b/gobject/generate-constants.c
@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <glibconfig.h>
+
+int main(void)
+{
+  printf("# This part is generated by generate-constants.c\n");
+  printf("G_MINFLOAT = %f\n", G_MINFLOAT);
+  printf("G_MINFLOAT = %f\n", G_MINFLOAT);
+  printf("G_MAXFLOAT = %f\n", G_MAXFLOAT);
+  printf("G_MINDOUBLE = %f\n", G_MINDOUBLE);
+  printf("G_MAXDOUBLE = %f\n", G_MAXDOUBLE);
+  printf("G_MINSHORT = %d\n", G_MINSHORT);
+  printf("G_MAXSHORT = %d\n", G_MAXSHORT);
+  printf("G_MAXUSHORT = %u\n", G_MAXUSHORT);
+  printf("G_MININT = %d\n", G_MININT);
+  printf("G_MAXINT = %d\n", G_MAXINT);
+  printf("G_MAXUINT = %u\n", G_MAXUINT);
+  printf("G_MINLONG = %ldL\n", G_MINLONG);
+  printf("G_MAXLONG = %ldL\n", G_MAXLONG);
+  printf("G_MAXULONG = %luL\n", G_MAXULONG);
+}
diff --git a/gobject/propertyhelper.py b/gobject/propertyhelper.py
new file mode 100644
index 0000000..f0c01e4
--- /dev/null
+++ b/gobject/propertyhelper.py
@@ -0,0 +1,285 @@
+# -*- Mode: Python; py-indent-offset: 4 -*-
+# pygobject - Python bindings for the GObject library
+# Copyright (C) 2007 Johan Dahlin
+#
+#   gobject/_property.py: GObject property wrapper/helper
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+# USA
+
+import _gobject
+from gobject.constants import \
+     TYPE_NONE, TYPE_INTERFACE, TYPE_CHAR, TYPE_UCHAR, \
+     TYPE_BOOLEAN, TYPE_INT, TYPE_UINT, TYPE_LONG, \
+     TYPE_ULONG, TYPE_INT64, TYPE_UINT64, TYPE_ENUM, \
+     TYPE_FLAGS, TYPE_FLOAT, TYPE_DOUBLE, TYPE_STRING, \
+     TYPE_POINTER, TYPE_BOXED, TYPE_PARAM, TYPE_OBJECT, \
+     TYPE_PYOBJECT
+from gobject.constants import \
+     G_MINFLOAT, G_MAXFLOAT, G_MINDOUBLE, G_MAXDOUBLE, \
+     G_MININT, G_MAXINT, G_MAXUINT, G_MINLONG, G_MAXLONG, \
+     G_MAXULONG
+
+
+class PropertyMeta(type):
+    def __repr__(self):
+        return "<class 'gobject.property'>"
+
+
+class property(object):
+    """
+    Creates a new property which in conjunction with GObjectMeta will
+    create a GObject property proxy:
+
+    >>> class MyObject(gobject.GObject):
+    >>> ... prop = gobject.property(type=str)
+
+    >>> obj = MyObject()
+    >>> obj.prop = 'value'
+
+    >>> obj.prop
+    'value'
+    """
+
+    __metaclass__ = PropertyMeta
+
+    def __init__(self, getter=None, setter=None, type=None, default=None,
+                 nick='', blurb='', flags=_gobject.PARAM_READWRITE,
+                 minimum=None, maximum=None):
+        """
+        @param  getter: getter to get the value of the property
+        @type   getter: callable
+        @param  setter: setter to set the value of the property
+        @type   setter: callable
+        @param    type: type of property
+        @type     type: type
+        @param default: default value
+        @param    nick: short description
+        @type     bick: string
+        @param   blurb: long description
+        @type    blurb: string
+        @param flags:    parameter flags, one of:
+        - gobject.PARAM_READABLE
+        - gobject.PARAM_READWRITE
+        - gobject.PARAM_WRITABLE
+        - gobject.PARAM_CONSTRUCT
+        - gobject.PARAM_CONSTRUCT_ONLY
+        - gobject.PARAM_LAX_VALIDATION
+        @keyword minimum:  minimum allowed value (int, float, long only)
+        @keyword maximum:  maximum allowed value (int, float, long only)
+        """
+
+        if getter and not setter:
+            setter = self._readonly_setter
+        elif setter and not getter:
+            getter = self._writeonly_getter
+        elif not setter and not getter:
+            getter = self._default_getter
+            setter = self._default_setter
+        self.getter = getter
+        self.setter = setter
+
+        if type is None:
+            type = object
+        self.type = self._type_from_python(type)
+        self.default = self._get_default(default)
+        self._check_default()
+
+        if not isinstance(nick, basestring):
+            raise TypeError("nick must be a string")
+        self.nick = nick
+
+        if not isinstance(blurb, basestring):
+            raise TypeError("blurb must be a string")
+        self.blurb = blurb
+
+        if flags < 0 or flags > 32:
+            raise TypeError("invalid flag value: %r" % (flags,))
+        self.flags = flags
+
+        if minimum is not None:
+            if minimum < self._get_minimum():
+                raise TypeError(
+                    "Minimum for type %s cannot be lower than %d" % (
+                    self.type, self._get_minimum()))
+        else:
+            minimum = self._get_minimum()
+        self.minimum = minimum
+        if maximum is not None:
+            if maximum > self._get_maximum():
+                raise TypeError(
+                    "Maximum for type %s cannot be higher than %d" % (
+                    self.type, self._get_maximum()))
+        else:
+            maximum = self._get_maximum()
+        self.maximum = maximum
+
+        self.name = None
+
+        self._value = self.default
+        self._exc = None
+
+    def __repr__(self):
+        return '<gobject property %s (%s)>' % (
+            self.name or '(uninitialized)',
+            _gobject.type_name(self.type))
+
+    def __get__(self, instance, klass):
+        if instance is None:
+            return self
+
+        self._exc = None
+        value = instance.get_property(self.name)
+        if self._exc:
+            exc = self._exc
+            self._exc = None
+            raise exc
+
+        return value
+
+    def __set__(self, instance, value):
+        if instance is None:
+            raise TypeError
+
+        self._exc = None
+        instance.set_property(self.name, value)
+        if self._exc:
+            exc = self._exc
+            self._exc = None
+            raise exc
+
+    def _type_from_python(self, type):
+        if type == int:
+            return TYPE_INT
+        elif type == bool:
+            return TYPE_BOOLEAN
+        elif type == long:
+            return TYPE_LONG
+        elif type == float:
+            return TYPE_DOUBLE
+        elif type == str:
+            return TYPE_STRING
+        elif type == object:
+            return TYPE_PYOBJECT
+        elif type in [TYPE_NONE, TYPE_INTERFACE, TYPE_CHAR, TYPE_UCHAR,
+                      TYPE_INT, TYPE_UINT, TYPE_BOOLEAN, TYPE_LONG,
+                      TYPE_ULONG, TYPE_INT64, TYPE_UINT64, TYPE_ENUM,
+                      TYPE_FLAGS, TYPE_FLOAT, TYPE_DOUBLE, TYPE_POINTER,
+                      TYPE_BOXED, TYPE_PARAM, TYPE_OBJECT, TYPE_STRING,
+                      TYPE_PYOBJECT]:
+            return type
+        else:
+            raise TypeError("Unsupported type: %r" % (type,))
+
+    def _get_default(self, default):
+        ptype = self.type
+        if default is not None:
+            return default
+
+        if ptype in [TYPE_INT, TYPE_UINT, TYPE_LONG, TYPE_ULONG,
+                     TYPE_INT64, TYPE_UINT64]:
+            return 0
+        elif ptype == TYPE_STRING:
+            return ''
+        elif ptype == TYPE_FLOAT or ptype == TYPE_DOUBLE:
+            return 0.0
+        else:
+            return None
+
+    def _check_default(self):
+        ptype = self.type
+        default = self.default
+        if (ptype == TYPE_BOOLEAN and
+            (default is not True or
+             default is not False)):
+            raise TypeError(
+                "default must be True or False, not %r" % (default,))
+        elif ptype == TYPE_PYOBJECT:
+            if default is not None:
+                raise TypeError("object types does not have default values")
+
+    def _get_minimum(self):
+        ptype = self.type
+        if ptype in [TYPE_UINT, TYPE_ULONG, TYPE_UINT64]:
+            return 0
+        elif ptype == TYPE_FLOAT:
+            return G_MINFLOAT
+        elif ptype == TYPE_DOUBLE:
+            return G_MINDOUBLE
+        elif ptype == TYPE_INT:
+            return G_MININT
+        elif ptype == TYPE_LONG:
+            return G_MINLONG
+        elif ptype == TYPE_INT64:
+            return -2 ** 62 - 1
+
+        return None
+
+    def _get_maximum(self):
+        ptype = self.type
+        if ptype == TYPE_UINT:
+            return G_MAXUINT
+        elif ptype == TYPE_ULONG:
+            return G_MAXULONG
+        elif ptype == TYPE_INT64:
+            return 2 ** 62 - 1
+        elif ptype == TYPE_UINT64:
+            return 2 ** 63 - 1
+        elif ptype == TYPE_FLOAT:
+            return G_MAXFLOAT
+        elif ptype == TYPE_DOUBLE:
+            return G_MAXDOUBLE
+        elif ptype == TYPE_INT:
+            return G_MAXINT
+        elif ptype == TYPE_LONG:
+            return G_MAXLONG
+
+        return None
+
+    #
+    # Getter and Setter
+    #
+
+    def _default_setter(self, instance, value):
+        self._value = value
+
+    def _default_getter(self, instance):
+        return self._value
+
+    def _readonly_setter(self, instance, value):
+        self._exc = TypeError("%s property of %s is read-only" % (
+            self.name, type(instance).__name__))
+
+    def _writeonly_getter(self, instance):
+        self._exc = TypeError("%s property of %s is write-only" % (
+            self.name, type(instance).__name__))
+
+    #
+    # Public API
+    #
+
+    def get_pspec_args(self):
+        ptype = self.type
+        if ptype in [TYPE_INT, TYPE_UINT, TYPE_LONG, TYPE_ULONG,
+                     TYPE_INT64, TYPE_UINT64, TYPE_FLOAT, TYPE_DOUBLE]:
+            args = self._get_minimum(), self._get_maximum(), self.default
+        elif ptype == TYPE_STRING or ptype == TYPE_BOOLEAN:
+            args = (self.default,)
+        elif ptype == TYPE_PYOBJECT:
+            args = ()
+        else:
+            raise NotImplementedError(ptype)
+
+        return (self.type, self.nick, self.blurb) + args + (self.flags,)