Timer: Generic BLI_timer with Python wrapper

There is a new `bpy.app.timers` api.
For more details, look in the Python API documentation.

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D3994

1 files changed, 199 insertions, 0 deletions

diff --git a/source/blender/python/intern/bpy_app_timers.c b/source/blender/python/intern/bpy_app_timers.c
new file mode 100644
index 00000000000..cd0e57200ec
--- /dev/null
+++ b/source/blender/python/intern/bpy_app_timers.c
@@ -0,0 +1,199 @@
+/*
+ * ***** 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.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/python/intern/bpy_app_timers.c
+ *  \ingroup pythonintern
+ */
+
+#include <Python.h>
+#include "BLI_utildefines.h"
+#include "BLI_timer.h"
+#include "PIL_time.h"
+
+#include "BPY_extern.h"
+#include "bpy_app_timers.h"
+
+#include "../generic/py_capi_utils.h"
+#include "../generic/python_utildefines.h"
+
+
+static double handle_returned_value(PyObject *function, PyObject *ret)
+{
+	if (ret == NULL) {
+		PyErr_PrintEx(0);
+		PyErr_Clear();
+		return -1;
+	}
+
+	if (ret == Py_None) {
+		return -1;
+	}
+
+	double value = PyFloat_AsDouble(ret);
+	if (value == -1.0f && PyErr_Occurred()) {
+		PyErr_Clear();
+		printf("Error: 'bpy.app.timers' callback ");
+		PyObject_Print(function, stdout, Py_PRINT_RAW);
+		printf(" did not return None or float.\n");
+		return -1;
+	}
+
+	if (value < 0.0) {
+		value = 0.0;
+	}
+
+	return value;
+}
+
+static double py_timer_execute(uintptr_t UNUSED(uuid), void *user_data)
+{
+	PyObject *function = user_data;
+
+	PyGILState_STATE gilstate;
+	gilstate = PyGILState_Ensure();
+
+	PyObject *py_ret = PyObject_CallObject(function, NULL);
+	double ret = handle_returned_value(function, py_ret);
+
+	PyGILState_Release(gilstate);
+
+	return ret;
+}
+
+static void py_timer_free(uintptr_t UNUSED(uuid), void *user_data)
+{
+	PyObject *function = user_data;
+
+	PyGILState_STATE gilstate;
+	gilstate = PyGILState_Ensure();
+
+	Py_DECREF(function);
+
+	PyGILState_Release(gilstate);
+}
+
+
+PyDoc_STRVAR(bpy_app_timers_register_doc,
+".. function:: register(function, first_interval=0, persistent=False)\n"
+"\n"
+"   Add a new function that will be called after the specified amount of seconds.\n"
+"   The function gets no arguments and is expected to return either None or a float.\n"
+"   If ``None`` is returned, the timer will be unregistered.\n"
+"   A returned number specifies the delay until the function is called again.\n"
+"   ``functools.partial`` can be used to assign some parameters.\n"
+"\n"
+"   :arg function: The function that should called.\n"
+"   :type function: Callable[[], Union[float, None]]\n"
+"   :arg first_interval: Seconds until the callback should be called the first time.\n"
+"   :type first_interval: float\n"
+"   :arg persistent: Don't remove timer when a new file is loaded.\n"
+"   :type persistent: bool\n"
+);
+static PyObject *bpy_app_timers_register(PyObject *UNUSED(self), PyObject *args, PyObject *kw)
+{
+	PyObject *function;
+	double first_interval = 0;
+	int persistent = false;
+
+	static const char *_keywords[] = {"function", "first_interval", "persistent", NULL};
+	static _PyArg_Parser _parser = {"O|$dp:register", _keywords, 0};
+	if (!_PyArg_ParseTupleAndKeywordsFast(
+	            args, kw, &_parser,
+	            &function, &first_interval, &persistent))
+	{
+		return NULL;
+	}
+
+	if (!PyCallable_Check(function)) {
+		PyErr_SetString(PyExc_TypeError, "function is not callable");
+		return NULL;
+	}
+
+	Py_INCREF(function);
+	BLI_timer_register(
+	        (intptr_t)function,
+	        py_timer_execute, function, py_timer_free,
+	        first_interval, persistent);
+	Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(bpy_app_timers_unregister_doc,
+".. function:: unregister(function)\n"
+"\n"
+"   Unregister timer.\n"
+"\n"
+"   :arg function: Function to unregister.\n"
+"   :type function: function\n"
+);
+static PyObject *bpy_app_timers_unregister(PyObject *UNUSED(self), PyObject *function)
+{
+	if (!BLI_timer_unregister((intptr_t)function)) {
+		PyErr_SetString(PyExc_ValueError, "Error: function is not registered");
+		return NULL;
+	}
+	Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(bpy_app_timers_is_registered_doc,
+".. function:: is_registered(function)\n"
+"\n"
+"   Check if this function is registered as a timer.\n"
+"\n"
+"   :arg function: Function to check.\n"
+"   :type function: int\n"
+"   :return: True when this function is registered, otherwise False.\n"
+"   :rtype: bool\n"
+);
+static PyObject *bpy_app_timers_is_registered(PyObject *UNUSED(self), PyObject *function)
+{
+	bool ret = BLI_timer_is_registered((intptr_t)function);
+	return PyBool_FromLong(ret);
+}
+
+
+static struct PyMethodDef M_AppTimers_methods[] = {
+	{"register", (PyCFunction)bpy_app_timers_register,
+	 METH_VARARGS | METH_KEYWORDS, bpy_app_timers_register_doc},
+	{"unregister", (PyCFunction)bpy_app_timers_unregister,
+	 METH_O, bpy_app_timers_unregister_doc},
+	{"is_registered", (PyCFunction)bpy_app_timers_is_registered,
+	 METH_O, bpy_app_timers_is_registered_doc},
+	{NULL, NULL, 0, NULL}
+};
+
+static struct PyModuleDef M_AppTimers_module_def = {
+	PyModuleDef_HEAD_INIT,
+	"bpy.app.timers", /* m_name */
+	NULL,  /* m_doc */
+	0,     /* m_size */
+	M_AppTimers_methods,  /* m_methods */
+	NULL,  /* m_reload */
+	NULL,  /* m_traverse */
+	NULL,  /* m_clear */
+	NULL,  /* m_free */
+};
+
+PyObject *BPY_app_timers_module(void)
+{
+	PyObject *sys_modules = PyImport_GetModuleDict();
+	PyObject *mod = PyModule_Create(&M_AppTimers_module_def);
+	PyDict_SetItem(sys_modules, PyModule_GetNameObject(mod), mod);
+	return mod;
+}