source/blender/python/intern/bpy_app_handlers.c

   1 /*
   2  * ***** BEGIN GPL LICENSE BLOCK *****
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  17  *
  18  * Contributor(s): Campbell Barton
  19  *
  20  * ***** END GPL LICENSE BLOCK *****
  21  */
  22
  23 /** \file blender/python/intern/bpy_app_handlers.c
  24  *  \ingroup pythonintern
  25  *
  26  * This file defines a 'PyStructSequence' accessed via 'bpy.app.handlers',
  27  * which exposes various lists that the script author can add callback
  28  * functions into (called via blenders generic BLI_cb api)
  29  */
  30
  31 #include <Python.h>
  32 #include "BLI_utildefines.h"
  33 #include "BLI_callbacks.h"
  34
  35 #include "RNA_types.h"
  36 #include "RNA_access.h"
  37 #include "bpy_rna.h"
  38 #include "bpy_app_handlers.h"
  39
  40 void bpy_app_generic_callback(struct Main *main, struct ID *id, void *arg);
  41
  42 static PyTypeObject BlenderAppCbType;
  43
  44 static PyStructSequence_Field app_cb_info_fields[]= {
  45         {(char *)"frame_change_pre",  (char *)"Callback list - on frame change for playback and rendering (before)"},
  46         {(char *)"frame_change_post", (char *)"Callback list - on frame change for playback and rendering (after)"},
  47         {(char *)"render_pre",        (char *)"Callback list - on render (before)"},
  48         {(char *)"render_post",       (char *)"Callback list - on render (after)"},
  49         {(char *)"render_stats",      (char *)"Callback list - on printing render statistics"},
  50         {(char *)"load_pre",          (char *)"Callback list - on loading a new blend file (before)"},
  51         {(char *)"load_post",         (char *)"Callback list - on loading a new blend file (after)"},
  52         {(char *)"save_pre",          (char *)"Callback list - on saving a blend file (before)"},
  53         {(char *)"save_post",         (char *)"Callback list - on saving a blend file (after)"},
  54         {(char *)"scene_update_pre",  (char *)"Callback list - on updating the scenes data (before)"},
  55         {(char *)"scene_update_post", (char *)"Callback list - on updating the scenes data (after)"},
  56
  57         /* sets the permanent tag */
  58 #   define APP_CB_OTHER_FIELDS 1
  59         {(char *)"persistent",        (char *)"Function decorator for callback functions not to be removed when loading new files"},
  60
  61         {NULL}
  62 };
  63
  64 static PyStructSequence_Desc app_cb_info_desc= {
  65         (char *)"bpy.app.handlers",     /* name */
  66         (char *)"This module contains callbacks",    /* doc */
  67         app_cb_info_fields,    /* fields */
  68         (sizeof(app_cb_info_fields)/sizeof(PyStructSequence_Field)) - 1
  69 };
  70
  71 /*
  72 #if (BLI_CB_EVT_TOT != ((sizeof(app_cb_info_fields)/sizeof(PyStructSequence_Field))))
  73 #  error "Callbacks are out of sync"
  74 #endif
  75 */
  76
  77 /* --------------------------------------------------------------------------*/
  78 /* permanent tagging code */
  79 #define PERMINENT_CB_ID "_bpy_persistent"
  80
  81 static PyObject *bpy_app_handlers_persistent_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *UNUSED(kwds))
  82 {
  83         PyObject *value;
  84
  85         if(!PyArg_ParseTuple(args, "O:bpy.app.handlers.persistent", &value))
  86                 return NULL;
  87
  88         if (PyFunction_Check(value)) {
  89                 PyObject **dict_ptr= _PyObject_GetDictPtr(value);
  90                 if (dict_ptr == NULL) {
  91                         PyErr_SetString(PyExc_ValueError,
  92                                         "bpy.app.handlers.persistent wasn't able to "
  93                                         "get the dictionary from the function passed");
  94                         return NULL;
  95                 }
  96                 else {
  97                         /* set id */
  98                         if (*dict_ptr == NULL) {
  99                                 *dict_ptr= PyDict_New();
 100                         }
 101
 102                         PyDict_SetItemString(*dict_ptr, PERMINENT_CB_ID, Py_None);
 103                 }
 104
 105                 Py_INCREF(value);
 106                 return value;
 107         }
 108         else {
 109                 PyErr_SetString(PyExc_ValueError,
 110                                 "bpy.app.handlers.persistent expected a function");
 111                 return NULL;
 112         }
 113 }
 114
 115 /* dummy type because decorators can't be PyCFunctions */
 116 static PyTypeObject BPyPersistent_Type = {
 117
 118 #if defined(_MSC_VER) || defined(FREE_WINDOWS)
 119     PyVarObject_HEAD_INIT(NULL, 0)
 120 #else
 121     PyVarObject_HEAD_INIT(&PyType_Type, 0)
 122 #endif
 123
 124     "persistent",                               /* tp_name */
 125     0,                                          /* tp_basicsize */
 126     0,                                          /* tp_itemsize */
 127     /* methods */
 128     0,                                          /* tp_dealloc */
 129     0,                                          /* tp_print */
 130     0,                                          /* tp_getattr */
 131     0,                                          /* tp_setattr */
 132     0,                                          /* tp_reserved */
 133     0,                                          /* tp_repr */
 134     0,                                          /* tp_as_number */
 135     0,                                          /* tp_as_sequence */
 136     0,                                          /* tp_as_mapping */
 137     0,                                          /* tp_hash */
 138     0,                                          /* tp_call */
 139     0,                                          /* tp_str */
 140     0,                                          /* tp_getattro */
 141     0,                                          /* tp_setattro */
 142     0,                                          /* tp_as_buffer */
 143     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
 144         Py_TPFLAGS_BASETYPE,                    /* tp_flags */
 145     0,                                          /* tp_doc */
 146     0,                                          /* tp_traverse */
 147     0,                                          /* tp_clear */
 148     0,                                          /* tp_richcompare */
 149     0,                                          /* tp_weaklistoffset */
 150     0,                                          /* tp_iter */
 151     0,                                          /* tp_iternext */
 152     0,                                          /* tp_methods */
 153     0,                                          /* tp_members */
 154     0,                                          /* tp_getset */
 155     0,                                          /* tp_base */
 156     0,                                          /* tp_dict */
 157     0,                                          /* tp_descr_get */
 158     0,                                          /* tp_descr_set */
 159     0,                                          /* tp_dictoffset */
 160     0,                                          /* tp_init */
 161     0,                                          /* tp_alloc */
 162     bpy_app_handlers_persistent_new,            /* tp_new */
 163     0,                                          /* tp_free */
 164 };
 165
 166 static PyObject *py_cb_array[BLI_CB_EVT_TOT]= {NULL};
 167
 168 static PyObject *make_app_cb_info(void)
 169 {
 170         PyObject *app_cb_info;
 171         int pos= 0;
 172
 173         app_cb_info= PyStructSequence_New(&BlenderAppCbType);
 174         if (app_cb_info == NULL) {
 175                 return NULL;
 176         }
 177
 178         for (pos= 0; pos < BLI_CB_EVT_TOT; pos++) {
 179                 if (app_cb_info_fields[pos].name == NULL) {
 180                         Py_FatalError("invalid callback slots 1");
 181                 }
 182                 PyStructSequence_SET_ITEM(app_cb_info, pos, (py_cb_array[pos]= PyList_New(0)));
 183         }
 184         if (app_cb_info_fields[pos + APP_CB_OTHER_FIELDS].name != NULL) {
 185                 Py_FatalError("invalid callback slots 2");
 186         }
 187
 188         /* custom function */
 189         PyStructSequence_SET_ITEM(app_cb_info, pos++, (PyObject *)&BPyPersistent_Type);
 190
 191         return app_cb_info;
 192 }
 193
 194 PyObject *BPY_app_handlers_struct(void)
 195 {
 196         PyObject *ret;
 197
 198 #if defined(_MSC_VER) || defined(FREE_WINDOWS)
 199         BPyPersistent_Type.ob_base.ob_base.ob_type= &PyType_Type;
 200 #endif
 201
 202         if (PyType_Ready(&BPyPersistent_Type) < 0) {
 203                 BLI_assert(!"error initializing 'bpy.app.handlers.persistent'");
 204         }
 205
 206         PyStructSequence_InitType(&BlenderAppCbType, &app_cb_info_desc);
 207
 208         ret= make_app_cb_info();
 209
 210         /* prevent user from creating new instances */
 211         BlenderAppCbType.tp_init= NULL;
 212         BlenderAppCbType.tp_new= NULL;
 213         BlenderAppCbType.tp_hash= (hashfunc)_Py_HashPointer; /* without this we can't do set(sys.modules) [#29635] */
 214
 215         /* assign the C callbacks */
 216         if (ret) {
 217                 static bCallbackFuncStore funcstore_array[BLI_CB_EVT_TOT]= {{NULL}};
 218                 bCallbackFuncStore *funcstore;
 219                 int pos= 0;
 220
 221                 for (pos= 0; pos < BLI_CB_EVT_TOT; pos++) {
 222                         funcstore= &funcstore_array[pos];
 223                         funcstore->func= bpy_app_generic_callback;
 224                         funcstore->alloc= 0;
 225                         funcstore->arg= SET_INT_IN_POINTER(pos);
 226                         BLI_add_cb(funcstore, pos);
 227                 }
 228         }
 229
 230         return ret;
 231 }
 232
 233 void BPY_app_handlers_reset(const short do_all)
 234 {
 235         int pos= 0;
 236
 237         if (do_all) {
 238         for (pos= 0; pos < BLI_CB_EVT_TOT; pos++) {
 239                         /* clear list */
 240                         PyList_SetSlice(py_cb_array[pos], 0, PY_SSIZE_T_MAX, NULL);
 241                 }
 242         }
 243         else {
 244                 /* save string conversion thrashing */
 245                 PyObject *perm_id_str= PyUnicode_FromString(PERMINENT_CB_ID);
 246
 247                 for (pos= 0; pos < BLI_CB_EVT_TOT; pos++) {
 248                         /* clear only items without PERMINENT_CB_ID */
 249                         PyObject *ls= py_cb_array[pos];
 250                         Py_ssize_t i;
 251
 252                         PyObject *item;
 253                         PyObject **dict_ptr;
 254
 255                         for(i= PyList_GET_SIZE(ls) - 1; i >= 0; i--) {
 256
 257                                 if (    (PyFunction_Check((item= PyList_GET_ITEM(ls, i)))) &&
 258                                         (dict_ptr= _PyObject_GetDictPtr(item)) &&
 259                                         (*dict_ptr) &&
 260                                         (PyDict_GetItem(*dict_ptr, perm_id_str) != NULL))
 261                                 {
 262                                         /* keep */
 263                                 }
 264                                 else {
 265                                         /* remove */
 266                                         /* PySequence_DelItem(ls, i); */ /* more obvious buw slower */
 267                                         PyList_SetSlice(ls, i, i + 1, NULL);
 268                                 }
 269                         }
 270                 }
 271
 272                 Py_DECREF(perm_id_str);
 273         }
 274 }
 275
 276 /* the actual callback - not necessarily called from py */
 277 void bpy_app_generic_callback(struct Main *UNUSED(main), struct ID *id, void *arg)
 278 {
 279         PyObject *cb_list= py_cb_array[GET_INT_FROM_POINTER(arg)];
 280         Py_ssize_t cb_list_len;
 281         if ((cb_list_len= PyList_GET_SIZE(cb_list)) > 0) {
 282                 PyGILState_STATE gilstate= PyGILState_Ensure();
 283
 284                 PyObject* args= PyTuple_New(1); // save python creating each call
 285                 PyObject* func;
 286                 PyObject* ret;
 287                 Py_ssize_t pos;
 288
 289                 /* setup arguments */
 290                 if (id) {
 291                         PointerRNA id_ptr;
 292                         RNA_id_pointer_create(id, &id_ptr);
 293                         PyTuple_SET_ITEM(args, 0, pyrna_struct_CreatePyObject(&id_ptr));
 294                 }
 295                 else {
 296                         PyTuple_SET_ITEM(args, 0, Py_None);
 297                         Py_INCREF(Py_None);
 298                 }
 299
 300                 // Iterate the list and run the callbacks
 301                 for (pos=0; pos < cb_list_len; pos++) {
 302                         func= PyList_GET_ITEM(cb_list, pos);
 303                         ret= PyObject_Call(func, args, NULL);
 304                         if (ret==NULL) {
 305                                 PyErr_Print();
 306                                 PyErr_Clear();
 307                         }
 308                         else {
 309                                 Py_DECREF(ret);
 310                         }
 311                 }
 312
 313                 Py_DECREF(args);
 314
 315                 PyGILState_Release(gilstate);
 316         }
 317 }