gstreamer/gst/arg-types.py

# -*- Mode: Python -*-
# vi:si:et:sw=4:sts=4:ts=4
#
# gst-python
# Copyright (C) 2002 David I. Lehn
#               2004 Johan Dahlin
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Library 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
# Library General Public License for more details.
#
# You should have received a copy of the GNU Library 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.
# 
# Author: David I. Lehn <dlehn@users.sourceforge.net>

from argtypes import UInt64Arg, Int64Arg, PointerArg, ArgMatcher, ArgType, matcher

class XmlNodeArg(ArgType):
	"""libxml2 node generator"""
	
	names = {"xobj":"xmlNode",
			"xptr":"xmlNodePtr",
			"xwrap":"libxml_xmlNodePtrWrap"}
	
	parm = ('    if(xml == NULL) return NULL;\n'
			'    xobj = PyObject_GetAttrString(xml, "%(xobj)s");\n'
			'    if(!PyObject_IsInstance(py%(name)s, xobj)) {\n'
			'        PyErr_Clear();\n'
			'        PyErr_SetString(PyExc_RuntimeError,"%(name)s is not a %(xobj)s instance");\n'
			'        Py_DECREF(xobj);Py_DECREF(xml);\n'
			'        return NULL;\n'
			'    }\n'
			'    o = PyObject_GetAttrString(py%(name)s, "_o");\n'
			'    %(name)s = PyCObject_AsVoidPtr(o);\n')
	parmp = ('    Py_DECREF(o); Py_DECREF(xobj);Py_DECREF(xml);\n')
	
	ret =  ('    if(xml == NULL) return NULL;\n')
	retp = ('    xargs = PyTuple_New(1);\n'
			'    xobj = PyObject_GetAttrString(xml, "%(xobj)s");\n'
			'    o = %(xwrap)s(ret);\n'
			'    PyTuple_SetItem(xargs, 0, o);\n'
			'    return PyInstance_New(xobj, xargs, PyDict_New());\n')
	
	def write_param(self, ptype, pname, pdflt, pnull, keeprefcount, info):
		info.varlist.add('PyObject', '*xml = _gst_get_libxml2_module()')
		info.varlist.add('PyObject', '*o')
		info.varlist.add('PyObject', '*xobj')
		info.varlist.add('PyObject', '*py' + pname)
		info.varlist.add(self.names["xptr"], pname)
		#if pnull:
		info.add_parselist('O', ['&py'+pname], [pname])
		info.arglist.append(pname)
		self.names["name"] = pname
		info.codebefore.append(self.parm % self.names)
		info.codeafter.append(self.parmp % self.names);
	def write_return(self, ptype, ownsreturn, info):
		info.varlist.add('PyObject', '*xml = _gst_get_libxml2_module()')
		info.varlist.add('PyObject', '*xargs')
		info.varlist.add('PyObject', '*xobj')
		info.varlist.add('PyObject', '*o')
		info.varlist.add(self.names["xptr"], 'ret')
		info.codebefore.append(self.ret % self.names)
		info.codeafter.append(self.retp % self.names)
	
class XmlDocArg(XmlNodeArg):
	"""libxml2 doc generator"""
	names = {"xobj":"xmlDoc",
			"xptr":"xmlDocPtr",
			"xwrap":"libxml_xmlDocPtrWrap"}
			
class GstCapsArg(ArgType):
    """GstCaps node generator"""

    before = ('    %(name)s = pygst_caps_from_pyobject (py_%(name)s, %(namecopy)s);\n'
              '    if (PyErr_Occurred())\n'
              '      return NULL;\n')
    beforenull = ('    if (py_%(name)s == Py_None)\n'
                  '        %(name)s = NULL;\n'
                  '    else\n'
                  '  ' + before)
    after = ('    if (%(name)s && %(name)s_is_copy)\n'
             '        gst_caps_unref (%(name)s);\n')

    def write_param(self, ptype, pname, pdflt, pnull, keeprefcount, info):
        if ptype == 'const-GstCaps*':
            self.write_const_param(pname, pdflt, pnull, info)
        elif ptype == 'GstCaps*':
            self.write_normal_param(pname, pdflt, pnull, info)
        else:
            raise RuntimeError, "write_param not implemented for %s" % ptype
    def write_const_param(self, pname, pdflt, pnull, info):
        info.varlist.add('PyObject', '*py_'+pname)
        info.varlist.add('GstCaps', '*'+pname)
        info.varlist.add('gboolean', pname+'_is_copy')
		info.add_parselist('O', ['&py_'+pname], [pname])
        info.arglist.append(pname)
        if pnull:
            info.codebefore.append (self.beforenull % { 'name' : pname, 'namecopy' : '&'+pname+'_is_copy' })
        else:
            info.codebefore.append (self.before % { 'name' : pname, 'namecopy' : '&'+pname+'_is_copy' })
        info.codeafter.append (self.after % { 'name' : pname, 'namecopy' : '&'+pname+'_is_copy' })
    def write_normal_param(self, pname, pdflt, pnull, info):
        info.varlist.add('PyObject', '*py_'+pname)
        info.varlist.add('GstCaps', '*'+pname)
		info.add_parselist('O', ['&py_'+pname], [pname])
        info.arglist.append(pname)
        if pnull:
            info.codebefore.append (self.beforenull % { 'name' : pname, 'namecopy' : 'NULL' })
        else:
            info.codebefore.append (self.before % { 'name' : pname, 'namecopy' : 'NULL' })

	def write_return(self, ptype, ownsreturn, info):
        if ptype == 'GstCaps*':
		    info.varlist.add('GstCaps', '*ret')
            copyval = 'FALSE'
        elif ptype == 'const-GstCaps*':
		    info.varlist.add('const GstCaps', '*ret')
            copyval = 'TRUE'
        else:
            raise RuntimeError, "write_return not implemented for %s" % ptype
		info.codeafter.append('    return pyg_boxed_new (GST_TYPE_CAPS, ret, '+copyval+', TRUE);')
			
matcher.register('GstClockTime', UInt64Arg())
matcher.register('GstClockTimeDiff', Int64Arg())
matcher.register('xmlNodePtr', XmlNodeArg())
matcher.register('xmlDocPtr', XmlDocArg())
matcher.register('GstCaps', GstCapsArg()) #FIXME: does this work?
matcher.register('GstCaps*', GstCapsArg()) #FIXME: does this work?
matcher.register('const-GstCaps*', GstCapsArg())

arg = PointerArg('gpointer', 'G_TYPE_POINTER')
matcher.register('GstClockID', arg)

del arg