Major cleanup of ffi abstraction layer

[clg] / glib / genums.lisp

;; Common Lisp bindings for GTK+ v2.0
;; Copyright (C) 2000-2001 Espen S. Johnsen <esj@stud.cs.uit.no>
;;
;; 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.
;;
;; 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

;; $Id: genums.lisp,v 1.4 2004-11-06 21:39:58 espen Exp $

(in-package "GLIB")


(defun %map-enum (args op)
  (let ((current-value 0))
    (mapcar
     #'(lambda (mapping)
         (destructuring-bind (symbol &optional (value current-value))
             (mklist mapping)
           (setf current-value (1+ value))
           (case op
             (:enum-int (list symbol value))
             (:flags-int (list symbol value))
             (:int-enum (list value symbol))
             (:int-flags (list value symbol))
             (:symbols symbol))))
     args)))

(defun %query-enum-or-flags-values (query-function class type)
  (multiple-value-bind (sap length)
      (funcall query-function (type-class-ref type))
    (let ((values nil)
          (size (proxy-instance-size (find-class class)))
          (proxy (make-instance class :location sap)))
      (dotimes (i length)
        (with-slots (location nickname value) proxy
          (setf location sap)
          (setq sap (sap+ sap size))
          (push
           (list
            (intern (substitute #\- #\_ (string-upcase nickname)) "KEYWORD")
            value)
           values)))
      values)))
   
  
;;;; Generic enum type

(deftype enum (&rest args)
  `(member ,@(%map-enum args :symbols)))

(defmethod alien-type ((type (eql 'enum)) &rest args)
  (declare (ignore type args))
  (alien-type 'signed))

(defmethod size-of ((type (eql 'enum)) &rest args)
  (declare (ignore type args))
  (size-of 'signed))

(defmethod to-alien-form (form (type (eql 'enum)) &rest args)
  (declare (ignore type))
  `(ecase ,form
    ,@(%map-enum args :enum-int)))

(defmethod from-alien-form (form (type (eql 'enum)) &rest args)
  (declare (ignore type))
  `(ecase ,form
    ,@(%map-enum args :int-enum)))

(defmethod to-alien-function ((type (eql 'enum)) &rest args)
  (let ((mappings (%map-enum args :enum-int)))
    #'(lambda (enum)
        (or
         (second (assoc enum mappings))
         (error "~S is not of type ~S" enum (cons type args))))))

(defmethod from-alien-function ((type (eql 'enum)) &rest args)
  (declare (ignore type))
  (let ((mappings (%map-enum args :int-enum)))
    #'(lambda (int)
        (second (assoc int mappings)))))

(defmethod writer-function ((type (eql 'enum)) &rest args)
  (declare (ignore type))
  (let ((writer (writer-function 'signed))
        (function (apply #'to-alien-function 'enum args)))
    #'(lambda (enum location &optional (offset 0))
        (funcall writer (funcall function enum) location offset))))
    
(defmethod reader-function ((type (eql 'enum)) &rest args)
  (declare (ignore type))
  (let ((reader (reader-function 'signed))
        (function (apply #'from-alien-function 'enum args)))
    #'(lambda (location &optional (offset 0))
        (funcall function (funcall reader location offset)))))



(defclass %enum-value (struct)
  ((value :allocation :alien :type int)
   (name :allocation :alien :type string)
   (nickname :allocation :alien :type string))
  (:metaclass static-struct-class))

(defbinding %enum-class-values () pointer
  (class pointer)
  (n-values unsigned-int :out))

(defun query-enum-values (type)
  (%query-enum-or-flags-values #'%enum-class-values '%enum-value type))



;;;;  Generic flags type

(deftype flags (&rest args)
  `(or null (cons (member ,@(%map-enum args :symbols)) list)))

(defmethod alien-type ((type (eql 'flags)) &rest args)
  (declare (ignore type args))
  (alien-type 'unsigned))

(defmethod size-of ((type (eql 'flags)) &rest args)
  (declare (ignore type args))
  (size-of 'unsigned))

(defmethod to-alien-form (flags (type (eql 'flags)) &rest args)
  `(loop
    with value = 0
    with flags = ,flags
    for flag in (mklist flags)
    do (let ((flagval
              (or
               (second (assoc flag ',(%map-enum args :flags-int)))
               (error "~S is not of type ~S" flags '(,type ,@args)))))
         (setq value (logior value flagval)))
    finally (return value)))

(defmethod from-alien-form (int (type (eql 'flags)) &rest args)
  (declare (ignore type))
  `(loop
    for mapping in ',(%map-enum args :int-flags)
    unless (zerop (logand int (first mapping)))
    collect (second mapping)))

(defmethod to-alien-function ((type (eql 'flags)) &rest args)
  (let ((mappings (%map-enum args :flags-int)))
    #'(lambda (flags)   
        (loop
         with value = 0
         for flag in (mklist flags)
         do (let ((flagval (or
                    (second (assoc flag mappings))
                    (error "~S is not of type ~S" flags (cons type args)))))
              (setq value (logior value flagval)))
         finally (return value)))))

(defmethod from-alien-function ((type (eql 'flags)) &rest args)
  (declare (ignore type))
  (let ((mappings (%map-enum args :int-flags)))
    #'(lambda (int)
        (loop
         for mapping in mappings
         unless (zerop (logand int (first mapping)))
         collect (second mapping)))))

(defmethod writer-function ((type (eql 'flags)) &rest args)
  (declare (ignore type))
  (let ((writer (writer-function 'unsigned))
        (function (apply #'to-alien-function 'flags args)))
    #'(lambda (flags location &optional (offset 0))
        (funcall writer (funcall function flags) location offset))))
    
(defmethod reader-function ((type (eql 'flags)) &rest args)
  (declare (ignore type))
  (let ((reader (reader-function 'unsigned))
        (function (apply #'from-alien-function 'flags args)))
    #'(lambda (location &optional (offset 0))
        (funcall function (funcall reader location offset)))))



(defclass %flags-value (struct)
  ((value :allocation :alien :type unsigned-int)
   (name :allocation :alien :type string)
   (nickname :allocation :alien :type string))
  (:metaclass static-struct-class))

(defbinding %flags-class-values () pointer
  (class pointer)
  (n-values unsigned-int :out))

(defun query-flags-values (type)
  (%query-enum-or-flags-values #'%flags-class-values '%flags-value type))



;;;;

(defun expand-enum-type (type-number &optional options)
  (let* ((super (supertype type-number))
         (type (type-from-number type-number))
         (mappings (getf options :mappings))
         (expanded-mappings
          (append
           (delete-if
            #'(lambda (mapping)
                (or
                 (assoc (first mapping) mappings)
                 (rassoc (cdr mapping) mappings :test #'equal)))
            (if (eq super 'enum)
                (query-enum-values type-number)
              (query-flags-values type-number)))
           (remove-if
            #'(lambda (mapping) (eq (second mapping) nil)) mappings))))
    `(progn
       (register-type ',type ,(find-type-name type-number))
       (deftype ,type () '(,super ,@expanded-mappings)))))


(register-derivable-type 'enum "GEnum" 'expand-enum-type)
(register-derivable-type 'flags "GFlags" 'expand-enum-type)