X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/clg/blobdiff_plain/c8c48a4c0afa3a32f381c3f5662e34ae1874ea2c..e59b159786355b542f5036b1b40247666fe195f2:/glib/gobject.lisp

diff --git a/glib/gobject.lisp b/glib/gobject.lisp
index ee61f96..68ee82c 100644
--- a/glib/gobject.lisp
+++ b/glib/gobject.lisp
@@ -1,130 +1,635 @@
-;; Common Lisp bindings for GTK+ v2.0
-;; Copyright (C) 2000 Espen S. Johnsen <esj@stud.cs.uit.no>
+;; Common Lisp bindings for GTK+ v2.x
+;; Copyright 2000-2006 Espen S. Johnsen <espen@users.sf.net>
 ;;
-;; 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 of the License, or (at your option) any later version.
+;; Permission is hereby granted, free of charge, to any person obtaining
+;; a copy of this software and associated documentation files (the
+;; "Software"), to deal in the Software without restriction, including
+;; without limitation the rights to use, copy, modify, merge, publish,
+;; distribute, sublicense, and/or sell copies of the Software, and to
+;; permit persons to whom the Software is furnished to do so, subject to
+;; the following conditions:
 ;;
-;; 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.
+;; The above copyright notice and this permission notice shall be
+;; included in all copies or substantial portions of the Software.
 ;;
-;; 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
+;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+;; IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+;; CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+;; TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+;; SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-;; $Id: gobject.lisp,v 1.3 2000-11-09 20:29:19 espen Exp $
+;; $Id: gobject.lisp,v 1.59 2008-11-04 03:22:23 espen Exp $
 
 (in-package "GLIB")
 
 
-(eval-when (:compile-toplevel :load-toplevel :execute)
-  (defclass gobject (ginstance)
-    ()
-    (:metaclass ginstance-class)
-    (:alien-name "GObject"))
-
-  (defclass gobject-class (ginstance-class)))
-
+;;;; Metaclass used for subclasses of gobject
 
-;;;; Reference counting for gobject
-
-;; Specializing reference-instance and unreference-instance on gobject
-;; is not really necessary but done for efficiency
+(eval-when (:compile-toplevel :load-toplevel :execute)
+;;   (push :debug-ref-counting *features*)
+  (defclass gobject-class (ginstance-class)
+    ((instance-slots-p :initform nil :reader instance-slots-p
+      :documentation "Non NIL if the class has slots with instance allocation")))
+
+  (defmethod validate-superclass ((class gobject-class) (super standard-class))
+;  (subtypep (class-name super) 'gobject)
+    t))
+
+(defmethod slot-unbound (metaclass (class gobject-class) (slot (eql 'ref)))
+  (assert (class-direct-superclasses class))
+  (setf (slot-value class 'ref) 
+   #?-(pkg-exists-p "glib-2.0" :atleast-version "2.10.0") '%object-ref
+   #?(pkg-exists-p "glib-2.0" :atleast-version "2.10.0")
+   ;; We do this hack instead of creating a new metaclass to avoid
+   ;; breaking backward compatibility
+   (if (subtypep (class-name class) 'initially-unowned)
+       '%object-ref-sink
+     '%object-ref)))
+
+(defmethod slot-unbound (metaclass (class gobject-class) (slot (eql 'unref)))
+  (setf (slot-value class 'unref) '%object-unref))
+
+
+(defclass direct-property-slot-definition (direct-virtual-slot-definition)
+  ((pname :reader slot-definition-pname :initarg :pname)
+   (readable :reader slot-readable-p :initarg :readable)
+   (writable :reader slot-writable-p :initarg :writable)
+   (construct-only :initarg :construct-only :reader construct-only-property-p)))
+
+(defclass effective-property-slot-definition (effective-virtual-slot-definition)
+  ((pname :reader slot-definition-pname :initarg :pname)
+   (readable :initform t :reader slot-readable-p :initarg :readable)
+   (writable :initform t :reader slot-writable-p :initarg :writable)
+   (construct-only :initform nil :initarg :construct-only :reader construct-only-property-p)))
+
+(defclass direct-user-data-slot-definition (direct-virtual-slot-definition)
+  ())
+
+(defclass effective-user-data-slot-definition (effective-virtual-slot-definition)
+  ())
+
+
+(defbinding %object-ref () pointer
+  (location pointer))
+
+(defbinding %object-unref () nil
+  (location pointer))
+
+#?(pkg-exists-p "glib-2.0" :atleast-version "2.8.0")
+(progn
+  (define-callback toggle-ref-callback nil
+      ((data pointer) (location pointer) (last-ref-p boolean))
+    (declare (ignore data))
+    #+debug-ref-counting
+    (if last-ref-p
+	(format t "Object at 0x~8,'0X has no foreign references~%" (pointer-address location))
+      (format t "Foreign reference added to object at 0x~8,'0X~%" (pointer-address location)))
+    (if last-ref-p
+	(cache-instance (find-cached-instance location) t)
+      (cache-instance (find-cached-instance location) nil)))
+
+  (defbinding %object-add-toggle-ref (location) pointer
+    (location pointer)
+    (toggle-ref-callback callback)
+    (nil null))
+
+  (defbinding %object-remove-toggle-ref (location) pointer
+    (location pointer)
+    (toggle-ref-callback callback)
+    (nil null)))
+
+#+debug-ref-counting
+(progn
+  (define-callback weak-ref-callback nil ((data pointer) (location pointer))
+    (format t "Object at 0x~8,'0X (~A) being finalized~%" (pointer-address location) (type-from-number (%type-number-of-ginstance location))))
+  
+  (defbinding %object-weak-ref (location) pointer
+    (location pointer)
+    (weak-ref-callback callback)
+    (nil null)))
+
+
+; (defbinding object-class-install-param () nil
+;   (class pointer)
+;   (id unsigned-int)
+;   (parameter parameter))
 
-(defmethod reference-instance ((object gobject))
-  (%object-ref object)
-  object)
+; (defbinding object-class-find-param-spec () parameter
+;   (class pointer)
+;   (name string))
 
-(defmethod unreference-instance ((object gobject))
-  (%object-unref object))
+(defun signal-name-to-string (name)
+  (substitute #\_ #\- (string-downcase (string name))))
+
+
+(defmethod direct-slot-definition-class ((class gobject-class) &rest initargs)
+  (case (getf initargs :allocation)
+    (:property (find-class 'direct-property-slot-definition))
+    (:user-data (find-class 'direct-user-data-slot-definition))
+    (t (call-next-method))))
+
+(defmethod effective-slot-definition-class ((class gobject-class) &rest initargs)
+  (case (getf initargs :allocation)
+    (:property (find-class 'effective-property-slot-definition))
+    (:user-data (find-class 'effective-user-data-slot-definition))
+    (t (call-next-method))))
+
+(defmethod compute-effective-slot-definition-initargs ((class gobject-class) direct-slotds)
+  (if (eq (slot-definition-allocation (first direct-slotds)) :property)
+      (nconc
+       (compute-most-specific-initargs direct-slotds
+        '(pname construct-only readable writable))
+       (call-next-method))
+    (call-next-method)))
+
+
+(defvar *ignore-setting-construct-only-property* nil)
+(declaim (special *ignore-setting-construct-only-property*))
+
+(defmethod compute-slot-reader-function ((slotd effective-property-slot-definition) &optional signal-unbound-p)
+  (declare (ignore signal-unbound-p))
+  (let* ((type (slot-definition-type slotd))
+	 (pname (slot-definition-pname slotd))
+	 (get-reader (reader-function type :ref :get))
+	 (peek-reader (reader-function type :ref :peek)))
+    #'(lambda (object)
+	(with-memory (gvalue +gvalue-size+)
+	  (%gvalue-init gvalue (find-type-number type))
+	  (%object-get-property object pname gvalue)
+	  (if (gvalue-static-p gvalue)
+	      (funcall peek-reader gvalue +gvalue-value-offset+)
+	    (funcall get-reader gvalue +gvalue-value-offset+))))))
+
+(defmethod compute-slot-writer-function :around ((slotd effective-property-slot-definition))
+  (if (construct-only-property-p slotd)
+      #'(lambda (value object)
+	  (declare (ignore value))
+	  (unless *ignore-setting-construct-only-property*
+	    (error 'unwritable-slot :name (slot-definition-name slotd) :instance object)))
+    (call-next-method)))
+
+(defmethod compute-slot-writer-function ((slotd effective-property-slot-definition))
+  (let* ((type (slot-definition-type slotd))
+	 (pname (slot-definition-pname slotd))
+	 (writer (writer-function type :temp t))
+	 (destroy (destroy-function type :temp t)))
+    #'(lambda (value object)
+	(with-memory (gvalue +gvalue-size+)
+	  (%gvalue-init gvalue (find-type-number type))
+	  (funcall writer value gvalue +gvalue-value-offset+)
+	  (%object-set-property object pname gvalue)
+	  (funcall destroy gvalue +gvalue-value-offset+))
+	value)))
+
+(defmethod slot-readable-p ((slotd effective-user-data-slot-definition))
+  (declare (ignore slotd))
+  t)
+
+(defmethod compute-slot-reader-function ((slotd effective-user-data-slot-definition) &optional signal-unbound-p)
+  (declare (ignore signal-unbound-p))
+  (let ((slot-name (slot-definition-name slotd)))
+    #'(lambda (object)
+	(user-data object slot-name))))
+
+(defmethod compute-slot-boundp-function ((slotd effective-user-data-slot-definition))
+  (let ((slot-name (slot-definition-name slotd)))
+    #'(lambda (object)
+	(user-data-p object slot-name))))
+
+(defmethod slot-writable-p ((slotd effective-user-data-slot-definition))
+  (declare (ignore slotd))
+  t)
+
+(defmethod compute-slot-writer-function ((slotd effective-user-data-slot-definition))
+  (let ((slot-name (slot-definition-name slotd)))
+    #'(lambda (value object)
+	(setf (user-data object slot-name) value))))
+
+(defmethod compute-slot-makunbound-function ((slotd effective-user-data-slot-definition))
+  (let ((slot-name (slot-definition-name slotd)))
+    #'(lambda (object)
+	(unset-user-data object slot-name))))
+
+(defmethod compute-slots :around ((class gobject-class))
+  (let ((slots (call-next-method)))
+    (when (some #'(lambda (slotd)
+		    (and
+		     (eq (slot-definition-allocation slotd) :instance)
+		     (not (typep slotd 'effective-special-slot-definition))))
+		slots)
+      (setf (slot-value class 'instance-slots-p) t))
+    slots))
+
+
+;;;; Super class for all classes in the GObject type hierarchy
 
-(deftype-method alien-ref gobject (type-spec)
-  (declare (ignore type-spec))
-  '%object-ref)
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (defclass gobject (ginstance)
+    (#+debug-ref-counting
+     (ref-count :allocation :alien :type int :reader ref-count))
+    (:metaclass gobject-class)
+    (:gtype "GObject")))
+
+#+debug-ref-counting
+(defmethod print-object ((instance gobject) stream)
+  (print-unreadable-object (instance stream :type t :identity nil)
+    (if (proxy-valid-p instance)
+	(format stream "at 0x~X (~D)" (pointer-address (foreign-location instance)) (ref-count instance))
+      (write-string "at \"unbound\"" stream))))
+
+
+(define-type-method reader-function ((type gobject) &key (ref :read) inlined)
+  (assert-not-inlined type inlined)
+  (ecase ref
+    ((:read :peek) (call-next-method type :ref :read))
+    (:get
+     #'(lambda (location &optional (offset 0))
+	 (let ((instance (ref-pointer location offset)))
+	   (unless (null-pointer-p instance)
+	     (multiple-value-bind (gobject new-p)
+		 (ensure-proxy-instance 'gobject instance :reference nil)
+	       (unless new-p
+		 (%object-unref instance))
+	       (setf (ref-pointer location offset) (make-pointer 0))
+	       gobject)))))))
+
+(define-type-method callback-wrapper ((type gobject) var arg form)
+  (let ((class (type-expand type)))
+    `(let ((,var (ensure-proxy-instance ',class ,arg)))
+       ,form)))
+
+(defun initial-add (object function initargs key pkey)
+  (loop 
+   as (initarg value . rest) = initargs then rest
+   do (cond
+       ((eq initarg key) (funcall function object value))
+       ((eq initarg pkey) (mapc #'(lambda (value)
+				    (funcall function object value))
+				value)))
+       while rest))
+
+(defun initial-apply-add (object function initargs key pkey)
+  (initial-add object #'(lambda (object value)
+			  (apply function object (mklist value)))
+	       initargs key pkey))
+
+
+(defmethod make-proxy-instance ((class gobject-class) location &rest initargs)
+  (declare (ignore location initargs))
+  (if (slot-value class 'instance-slots-p)
+      (error "Objects of class ~A has instance slots and should only be created with MAKE-INSTANCE" class)
+    (call-next-method)))
+
+(defparameter +gparameter-gvalue-offset+
+  (max (size-of 'pointer) (type-alignment '(unsigned-byte 64))))
+(defparameter +gparameter-size+
+  (+ +gparameter-gvalue-offset+ +gvalue-size+))
+
+(defmethod allocate-foreign ((object gobject) &rest initargs)
+  (let ((init-slots ())) 
+    (flet ((value-from-initargs (slotd)
+	     (loop
+	      with slot-initargs = (slot-definition-initargs slotd)
+	      for (initarg value) on initargs by #'cddr
+	      when (find initarg slot-initargs)
+	      do (return (values value t)))))
+
+    (loop 
+     for slotd in (class-slots (class-of object))
+     when (and 
+	   (eq (slot-definition-allocation slotd) :property)
+	   (construct-only-property-p slotd))
+     do (multiple-value-bind (value initarg-p) (value-from-initargs slotd)
+	  (cond
+	   (initarg-p (push (cons slotd value) init-slots))
+	   ((slot-definition-initfunction slotd)
+	    (push 
+	     (cons slotd (funcall (slot-definition-initfunction slotd)))
+	     init-slots))))))
+
+    (cond
+     (init-slots
+      (let* ((num-slots (length init-slots)))
+	(with-memory (params (* num-slots +gparameter-size+))
+          (loop
+	   with string-writer = (writer-function 'string)
+	   for (slotd . value) in init-slots
+	   as param = params then (pointer+ param +gparameter-size+)
+	   as type = (slot-definition-type slotd)
+	   as pname = (slot-definition-pname slotd)
+	   do (funcall string-writer pname param)
+	      (gvalue-init 
+	       (pointer+ param +gparameter-gvalue-offset+) type value))
+
+	  (unwind-protect
+	      (%gobject-newv (type-number-of object) num-slots params)
+	
+	    (loop
+	     with string-destroy = (destroy-function 'string)
+	     repeat num-slots
+	     as param = params then (pointer+ param +gparameter-size+)
+	     do (funcall string-destroy param)
+	        (gvalue-unset (pointer+ param +gparameter-gvalue-offset+)))))))
+     
+     (t (%gobject-new (type-number-of object))))))
+
+
+(defmethod shared-initialize ((object gobject) names &rest initargs)
+  (declare (ignore names initargs))
+  (let ((*ignore-setting-construct-only-property* t))
+    (call-next-method)))
+
+(defmethod initialize-instance :around ((object gobject) &rest initargs)
+  (declare (ignore initargs))
+  (prog1
+      (call-next-method)
+    (let ((location (foreign-location object)))
+      #+debug-ref-counting(%object-weak-ref location)
+      #?(pkg-exists-p "glib-2.0" :atleast-version "2.8.0")
+      (when (slot-value (class-of object) 'instance-slots-p)
+	(%object-add-toggle-ref location)
+	(%object-unref location)))))
+
+
+(defmethod instance-finalizer ((instance gobject))
+  (let ((location (foreign-location instance)))
+    #?(pkg-exists-p "glib-2.0" :atleast-version "2.8.0")
+    (if (slot-value (class-of instance) 'instance-slots-p)
+	#'(lambda ()
+	    #+debug-ref-counting
+	    (format t "Finalizing proxy for 0x~8,'0X (~A)~%" 
+	     (pointer-address location) 
+	     (find-foreign-type-name (%type-number-of-ginstance location)))
+	    (%object-remove-toggle-ref location))
+      #'(lambda ()
+	  #+debug-ref-counting
+	  (format t "Finalizing proxy for 0x~8,'0X (~A)~%" 
+	   (pointer-address location)
+	   (find-foreign-type-name (%type-number-of-ginstance location)))
+	  (%object-unref location)))
+    #?-(pkg-exists-p "glib-2.0" :atleast-version "2.8.0")
+    #'(lambda ()
+	(%object-unref location))))
+
+
+(defbinding (%gobject-new "g_object_new") () pointer
+  (type type-number)
+  (nil null))
+
+(defbinding (%gobject-newv "g_object_newv") () pointer
+  (type type-number)
+  (n-parameters unsigned-int)
+  (params pointer))
+
+
+;;;; Floating references
+
+#?(pkg-exists-p "glib-2.0" :atleast-version "2.10.0")
+(progn
+  (defclass initially-unowned (gobject)
+    ()
+    (:metaclass gobject-class)
+    (:gtype "GInitiallyUnowned"))
 
-(deftype-method alien-unref gobject (type-spec)
-  (declare (ignore type-spec))
-  '%object-unref)
+  (defbinding %object-ref-sink () pointer
+    (location pointer))
 
-(define-foreign %object-ref () pointer
-  (object (or gobject pointer)))
+  (defbinding %object-is-floating () boolean
+    (location pointer))
 
-(define-foreign %object-unref () nil
-  (object (or gobject pointer)))
+  (defmethod initialize-instance :before ((object initially-unowned) &rest initargs)
+    (declare (ignore initargs))
+    (%object-ref-sink (foreign-location object))))
 
 
-;;;; Parameter stuff
+;;;; Property stuff
 
-(define-foreign %object-set-param () nil
+(defbinding %object-set-property () nil
   (object gobject)
   (name string)
   (value gvalue))
 
-(define-foreign %object-get-param () nil
+(defbinding %object-get-property () nil
   (object gobject)
   (name string)
-  (value gvalue :out))
+  (value gvalue))
 
-(define-foreign object-queue-param-changed () nil
+(defbinding %object-notify () nil
   (object gobject)
   (name string))
 
+(defbinding object-freeze-notify () nil
+  (object gobject))
+
+(defbinding object-thaw-notify () nil
+  (object gobject))
 
 
+;;;; User data
 
-(define-foreign %object-set-qdata-full () nil
+(defgeneric (setf user-data) (data object key))
+(defgeneric user-data (object key))
+(defgeneric user-data-p (object key))
+(defgeneric unset-user-data (object key))
+
+(defbinding %object-set-qdata-full () nil
   (object gobject)
   (id quark)
-  (data unsigned-long)
-  (destroy-marshal pointer))
+  (data pointer-data)
+  (destroy-marshal callback))
+
+(define-callback user-data-destroy-callback nil ((id pointer-data))
+  (destroy-user-data id))
 
-(defun (setf object-data) (data object key &key (test #'eq))
-  (%object-set-qdata-full
-   object (quark-from-object key :test test)
-   (register-user-data data) *destroy-notify*)
+(defmethod (setf user-data) (data (object gobject) key)
+  (%object-set-qdata-full object (quark-intern key)
+   (register-user-data data) user-data-destroy-callback)
   data)
 
-(define-foreign %object-get-qdata () unsigned-long
+(defbinding %object-get-qdata () pointer-data
   (object gobject)		 
   (id quark))
 
-(defun object-data (object key &key (test #'eq))
-  (find-user-data
-   (%object-get-qdata object (quark-from-object key :test test))))
-
-
-
-
-
-
-;;;; Methods for gobject-class
-
-(defmethod shared-initialize ((class gobject-class) names &rest initargs
-			      &key type-init name)
-  (declare (ignore initargs names))
-  (let ((alien
-	 (alien::%heap-alien
-	  (alien::make-heap-alien-info
-	   :type (alien::parse-alien-type '(function (unsigned 32)))
-	   :sap-form (system:foreign-symbol-address
-		      (or
-		       (first type-init)
-		       (default-alien-func-name
-			 (format
-			  nil "~A_get_type" (or name (class-name class))))))))))
-    (alien:alien-funcall alien))
-  (call-next-method))
+(defmethod user-data ((object gobject) key)
+  (find-user-data (%object-get-qdata object (quark-intern key))))
 
+(defmethod user-data-p ((object gobject) key)
+  (user-data-exists-p (%object-get-qdata object (quark-intern key))))
 
-; (define-foreign object-class-install-param () nil
-;   (class pointer)
-;   (id unsigned-int)
-;   (parameter parameter))
-
-; (define-foreign object-class-find-param-spec () parameter
-;   (class pointer)
-;   (name string))
+(defbinding %object-steal-qdata () pointer-data
+  (object gobject)		 
+  (id quark))
 
+(defmethod unset-user-data ((object gobject) key)
+  (destroy-user-data (%object-steal-qdata object (quark-intern key))))
+
+
+;;;;
+
+(defbinding %object-class-list-properties () pointer
+  (class pointer)
+  (n-properties unsigned-int :out))
+
+
+(defun %map-params (params length type inherited-p)
+  (if inherited-p
+      (map-c-vector 'list #'identity params 'param length)
+    (let ((properties ()))
+      (map-c-vector 'list 
+       #'(lambda (param)
+	   (when (eql (param-owner-type param) type)
+	     (push param properties)))
+       params 'param length)
+      (nreverse properties))))
+
+(defun query-object-class-properties (type &optional inherited-p)
+  (let* ((type-number (find-type-number type t))
+	 (class (type-class-ref type-number)))
+    (unwind-protect
+	 (multiple-value-bind (array length)
+	     (%object-class-list-properties class)
+	   (unless (null-pointer-p array)
+	     (unwind-protect
+		 (%map-params array length type-number inherited-p)
+	       (deallocate-memory array))))
+;      (type-class-unref type-number)
+      )))
+
+
+(defun default-slot-name (name)
+  (let ((prefix-len (length (package-prefix))))
+    (intern (substitute #\- #\_
+	     (string-upcase
+	      (if (and
+		   (string-prefix-p (package-prefix) name)
+		   (char= #\- (char name prefix-len)))
+		  (subseq name (1+ prefix-len))
+		name))))))
+
+(defun default-slot-accessor (class-name slot-name type)
+  (intern
+   (format
+    nil "~A-~A~A" class-name slot-name
+    (if (eq type 'boolean) "-P" ""))))
+
+
+(defun slot-definition-from-property (class property &optional slot-name args)
+  (with-slots (name flags value-type documentation) property
+    (let* ((slot-name (or slot-name (default-slot-name name)))
+	   (slot-type (or (getf args :type) (type-from-number value-type) 'pointer))
+	   (accessor (default-slot-accessor class slot-name slot-type)))
+      
+      `(,slot-name
+	:allocation :property :pname ,name
+
+	,@(when (find :unbound args) (list :unbound (getf args :unbound)))
+	,@(when (find :getter args) (list :getter (getf args :getter)))
+	,@(when (find :setter args) (list :setter (getf args :setter)))
+	
+	;; accessors
+	,@(cond
+	   ((and
+	     (member :writable flags) (member :readable flags)
+	     (not (member :construct-only flags)))
+	    (list :accessor accessor))
+	   ((and (member :writable flags) (not (member :construct-only flags)))
+	    (list :writer `(setf ,accessor)))
+	   ((member :readable flags)
+	    (list :reader accessor)))
+
+	;; readable/writable/construct
+	,@(when (or (not (member :writable flags))
+		    (member :construct-only flags))
+	    '(:writable nil))
+	,@(when (not (member :readable flags))
+	    '(:readable nil))
+	,@(when (member :construct-only flags)
+	    '(:construct-only t))
+	
+	;; initargs
+	,@(if (find :initarg args)
+	      (let ((initarg (getf args :initarg)))
+		(etypecase initarg
+		  (null ())
+		  (symbol `(:initarg ,initarg))))
+	    (when (or (member :construct flags)
+		      (member :construct-only flags)
+		      (member :writable flags))
+	      (list :initarg (intern (string slot-name) "KEYWORD"))))
+	
+	:type ,slot-type
+	:documentation ,documentation))))
+
+
+(defun slot-definitions (class properties slots)
+  (loop 
+   for property in properties
+   as slot = (or
+	      (find (param-name property) slots 
+	       :key #'(lambda (slot) (getf (rest slot) :pname)) 
+	       :test #'string=)
+	      (find (param-name property) slots 
+	       :key #'first :test #'string-equal))
+   do (cond
+       ((not slot) 
+	(push (slot-definition-from-property class property) slots))
+       ((getf (rest slot) :merge)
+	(setf 
+	 (rest slot) 
+	 (rest (slot-definition-from-property class property (first slot) (rest slot)))))))
+  (delete-if #'(lambda (slot) (getf (rest slot) :ignore)) slots))
+
+
+(defun expand-gobject-type (type forward-p options &optional (metaclass 'gobject-class))
+  (let ((supers (cons (supertype type) (implements type)))
+	(class  (type-from-number type))
+	(slots (getf options :slots)))
+    (when (member nil supers)
+      (error "Got NIL as a supertype for ~A (full list: ~A).~%~
+              This shouldn't happen - is the parent type correctly registered?"
+             (find-foreign-type-name type) supers))
+    `(defclass ,class ,supers
+	 ,(unless forward-p
+	    (slot-definitions class (query-object-class-properties type) slots))
+	 (:metaclass ,metaclass)
+	 (:gtype ,(register-type-as type)))))
+
+(defun gobject-dependencies (type options)
+  (delete-duplicates 
+   (cons
+    (supertype type)
+    (append 
+     (type-interfaces type)
+     (mapcar #'param-value-type (query-object-class-properties type))
+     (getf options :dependencies)
+     (loop
+      for slot in (getf options :slots)
+      as type = (getf (rest slot) :type)
+      when (and type (symbolp type) (find-type-number type))
+      collect (find-type-number type))))))
+
+
+(register-derivable-type 'gobject "GObject" 'expand-gobject-type 'gobject-dependencies)
+
+
+;;; Pseudo type for gobject instances which have their reference count
+;;; increased by the returning function
+
+(deftype referenced (type) type)
+
+(define-type-method from-alien-form ((type referenced) form &key (ref :free))
+  (cond
+   ((not (eq ref :free))
+    (error "Keyword arg :REF to FROM-ALIEN-FORM should be :FREE for type ~A. It was give ~A" type ref))
+   ((subtypep type 'gobject)
+    (from-alien-form (second (type-expand-to 'referenced type)) form :ref ref))))
+
+(define-type-method from-alien-function ((type referenced) &key (ref :free))
+  (cond
+   ((not (eq ref :free))
+    (error "Keyword arg :REF to FROM-ALIEN-FUNCTION should be :FREE for type ~A. It was give ~A" type ref))
+;   ((subtypep type 'gobject) (call-next-method type ref :free))))
+   ((subtypep type 'gobject) 
+    (from-alien-function (second (type-expand-to 'referenced type)) :ref ref))))