bpy_rna_callback.c

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/*
 * $Id: bpy_rna_callback.c 35624 2011-03-19 11:12:48Z campbellbarton $
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor(s): Campbell Barton
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <Python.h>

#include "RNA_types.h"

#include "bpy_rna.h"
#include "bpy_rna_callback.h"
#include "bpy_util.h"

#include "BLI_utildefines.h"

#include "DNA_screen_types.h"

#include "RNA_access.h"

#include "BKE_context.h"
#include "ED_space_api.h"

/* use this to stop other capsules from being mis-used */
#define RNA_CAPSULE_ID "RNA_HANDLE"
#define RNA_CAPSULE_ID_INVALID "RNA_HANDLE_REMOVED"

static void cb_region_draw(const bContext *C, ARegion *UNUSED(ar), void *customdata)
{
        PyObject *cb_func, *cb_args, *result;
        PyGILState_STATE gilstate;

        bpy_context_set((bContext *)C, &gilstate);

        cb_func= PyTuple_GET_ITEM((PyObject *)customdata, 0);
        cb_args= PyTuple_GET_ITEM((PyObject *)customdata, 1);
        result= PyObject_CallObject(cb_func, cb_args);

        if(result) {
                Py_DECREF(result);
        }
        else {
                PyErr_Print();
                PyErr_Clear();
        }

        bpy_context_clear((bContext *)C, &gilstate);
}

PyObject *pyrna_callback_add(BPy_StructRNA *self, PyObject *args)
{
        void *handle;

        PyObject *cb_func, *cb_args;
        char *cb_event_str= NULL;
        int cb_event;

        if (!PyArg_ParseTuple(args, "OO!|s:bpy_struct.callback_add", &cb_func, &PyTuple_Type, &cb_args, &cb_event_str))
                return NULL;
        
        if(!PyCallable_Check(cb_func)) {
                PyErr_SetString(PyExc_TypeError, "callback_add(): first argument isn't callable");
                return NULL;
        }

        if(RNA_struct_is_a(self->ptr.type, &RNA_Region)) {
                if(cb_event_str) {
                        static EnumPropertyItem region_draw_mode_items[]= {
                                {REGION_DRAW_POST_PIXEL, "POST_PIXEL", 0, "Post Pixel", ""},
                                {REGION_DRAW_POST_VIEW, "POST_VIEW", 0, "Post View", ""},
                                {REGION_DRAW_PRE_VIEW, "PRE_VIEW", 0, "Pre View", ""},
                                {0, NULL, 0, NULL, NULL}};
        
                        if(pyrna_enum_value_from_id(region_draw_mode_items, cb_event_str, &cb_event, "bpy_struct.callback_add()") < 0)
                                return NULL;
                }
                else {
                        cb_event= REGION_DRAW_POST_PIXEL;
                }

                handle= ED_region_draw_cb_activate(((ARegion *)self->ptr.data)->type, cb_region_draw, (void *)args, cb_event);
                Py_INCREF(args);
        }
        else {
                PyErr_SetString(PyExc_TypeError, "callback_add(): type does not suppport callbacks");
                return NULL;
        }

        return PyCapsule_New((void *)handle, RNA_CAPSULE_ID, NULL);
}

PyObject *pyrna_callback_remove(BPy_StructRNA *self, PyObject *args)
{
        PyObject *py_handle;
        void *handle;
        void *customdata;

        if (!PyArg_ParseTuple(args, "O!:callback_remove", &PyCapsule_Type, &py_handle))
                return NULL;

        handle= PyCapsule_GetPointer(py_handle, RNA_CAPSULE_ID);

        if(handle==NULL) {
                PyErr_SetString(PyExc_ValueError, "callback_remove(handle): NULL handle given, invalid or already removed");
                return NULL;
        }

        if(RNA_struct_is_a(self->ptr.type, &RNA_Region)) {
                customdata= ED_region_draw_cb_customdata(handle);
                Py_DECREF((PyObject *)customdata);

                ED_region_draw_cb_exit(((ARegion *)self->ptr.data)->type, handle);
        }

        /* dont allow reuse */
        PyCapsule_SetName(py_handle, RNA_CAPSULE_ID_INVALID);

        Py_RETURN_NONE;
}