c/hooks.c

   1 #include "hooks.h"
   2 #include <Python.h>
   3 #include <glib.h>
   4
   5 /* the 'hooks' module and its dictionary */
   6 static PyObject *hooks = NULL, *hooksdict = NULL;
   7
   8 /*
   9  *
  10  * Define the type 'Hook'
  11  *
  12  */
  13 #define IS_HOOK(v)  ((v)->ob_type == &HookType)
  14
  15 staticforward PyTypeObject HookType;
  16
  17 typedef struct {
  18     PyObject_HEAD
  19     GSList *funcs;
  20 } HookObject;
  21
  22 static PyObject *create_Hook(PyObject *self, PyObject *args)
  23 {
  24     HookObject *hook;
  25     char *name;
  26     int ret;
  27
  28     (void) self;
  29
  30     if (!PyArg_ParseTuple(args, "s:Hook", &name))
  31         return NULL;
  32
  33     hook = PyObject_New(HookObject, &HookType);
  34     hook->funcs = NULL;
  35
  36     /* add it to the hooks module */
  37     ret = PyDict_SetItemString(hooksdict, name, (PyObject*) hook);
  38     Py_DECREF(hook);
  39
  40     if (ret == -1) {
  41         char *s = g_strdup_printf(
  42             "Failed to add the hook '%s' to the 'hooks' module", name);
  43         PyErr_SetString(PyExc_RuntimeError, s);
  44         g_free(s);
  45         return NULL;
  46     }
  47
  48     Py_INCREF(Py_None);
  49     return Py_None;
  50 }
  51
  52 static void hook_dealloc(HookObject *self)
  53 {
  54     GSList *it;
  55
  56     for (it = self->funcs; it != NULL; it = it->next)
  57         Py_DECREF((PyObject*) it->data);
  58
  59     PyObject_Del((PyObject*) self);
  60 }
  61
  62 static PyObject *hook_fire(HookObject *self, PyObject *args)
  63 {
  64     GSList *it;
  65
  66     if (!IS_HOOK(self)) {
  67         PyErr_SetString(PyExc_TypeError,
  68                         "descriptor 'fire' requires a 'Hook' object");
  69         return NULL;
  70     }
  71
  72     for (it = self->funcs; it != NULL; it = it->next) {
  73         PyObject *ret = PyObject_CallObject(it->data, args);
  74         if (ret == NULL)
  75             return NULL;
  76         Py_DECREF(ret);
  77     }
  78
  79     Py_INCREF(Py_None);
  80     return Py_None;
  81 }
  82
  83 static PyObject *hook_add(HookObject *self, PyObject *args)
  84 {
  85     PyObject *func;
  86
  87     if (!IS_HOOK(self)) {
  88         PyErr_SetString(PyExc_TypeError,
  89                         "descriptor 'add' requires a 'Hook' object");
  90         return NULL;
  91     }
  92     if (!PyArg_ParseTuple(args, "O:add", &func))
  93         return NULL;
  94     if (!PyCallable_Check(func)) {
  95         PyErr_SetString(PyExc_TypeError,
  96                         "descriptor 'add' requires a callable argument");
  97         return NULL;
  98     }
  99     self->funcs = g_slist_append(self->funcs, func);
 100     Py_INCREF(func);
 101
 102     Py_INCREF(Py_None);
 103     return Py_None;
 104 }
 105
 106 static PyObject *hook_remove(HookObject *self, PyObject *args)
 107 {
 108     PyObject *func;
 109     GSList *it;
 110
 111     if (!IS_HOOK(self)) {
 112         PyErr_SetString(PyExc_TypeError,
 113                         "descriptor 'remove' requires a 'Hook' object");
 114         return NULL;
 115     }
 116     if (!PyArg_ParseTuple(args, "O:remove", &func))
 117         return NULL;
 118     if (!PyCallable_Check(func)) {
 119         PyErr_SetString(PyExc_TypeError,
 120                         "descriptor 'remove' requires a callable argument");
 121         return NULL;
 122     }
 123     it = g_slist_find(self->funcs, func);
 124     if (it != NULL) {
 125         self->funcs = g_slist_delete_link(self->funcs, it);
 126         Py_DECREF(func);
 127
 128         Py_INCREF(Py_None);
 129         return Py_None;
 130     }
 131     PyErr_SetString(PyExc_TypeError,
 132                     "given callable object was not found in Hook");
 133     return NULL;
 134 }
 135
 136 static PyObject *hook_count(HookObject *self, PyObject *args)
 137 {
 138     if (!IS_HOOK(self)) {
 139         PyErr_SetString(PyExc_TypeError,
 140                         "descriptor 'fire' requires a 'Hook' object");
 141         return NULL;
 142     }
 143     if (!PyArg_ParseTuple(args, ":count"))
 144         return NULL;
 145
 146     return PyInt_FromLong(g_slist_length(self->funcs));
 147 }
 148
 149 static PyTypeObject HookType = {
 150     PyObject_HEAD_INIT(NULL)
 151     0,
 152     "Hook",
 153     sizeof(HookObject),
 154     0,
 155     (destructor) hook_dealloc, /*tp_dealloc*/
 156     0,                         /*tp_print*/
 157     0,                         /*tp_getattr*/
 158     0,                         /*tp_setattr*/
 159     0,                         /*tp_compare*/
 160     0,                         /*tp_repr*/
 161     0,                         /*tp_as_number*/
 162     0,                         /*tp_as_sequence*/
 163     0,                         /*tp_as_mapping*/
 164     0,                         /*tp_hash */
 165 };
 166
 167 static PyMethodDef HookMethods[] = {
 168     {"fire", (PyCFunction)hook_fire, METH_VARARGS,
 169      "hook.fire() -- Fire the added hook functions for the Hook."},
 170     {"add", (PyCFunction)hook_add, METH_VARARGS,
 171      "hook.add(func) -- Add a function to the hook." },
 172     {"remove", (PyCFunction)hook_remove, METH_VARARGS,
 173      "hook.remove(func) -- Remove a function from the hook." },
 174     {"count", (PyCFunction)hook_count, METH_VARARGS,
 175      "hook.count() -- Return the number of functions in the hook." },
 176
 177     { NULL, NULL, 0, NULL }
 178 };
 179
 180
 181 /*
 182  *
 183  * Module initialization/finalization
 184  *
 185  */
 186
 187 /* the "events" hook */
 188 static HookObject *events_hook = NULL, *keyboard_hook = NULL,
 189     *pointer_hook = NULL;
 190
 191 static PyMethodDef HooksMethods[] = {
 192     {"create", create_Hook, METH_VARARGS,
 193      "hooks.create('name') -- Add a hook called 'name' to the hooks module."},
 194
 195     { NULL, NULL, 0, NULL }
 196 };
 197
 198 void hooks_startup()
 199 {
 200     int ret;
 201
 202     HookType.ob_type = &PyType_Type;
 203     HookType.tp_methods = HookMethods;
 204     PyType_Ready(&HookType);
 205
 206     Py_InitModule("hooks", HooksMethods);
 207
 208     /* get the hooks module/dict */
 209     hooks = PyImport_ImportModule("hooks"); /* new */
 210     g_assert(hooks != NULL);
 211     hooksdict = PyModule_GetDict(hooks); /* borrowed */
 212     g_assert(hooksdict != NULL);
 213
 214     /* create the "events" hook */
 215     events_hook = PyObject_New(HookObject, &HookType);
 216     events_hook->funcs = NULL;
 217
 218     /* add it to the hooks module */
 219     ret = PyDict_SetItemString(hooksdict, "events", (PyObject*) events_hook);
 220     g_assert(ret == 0);
 221
 222     /* create the "keyboard" hook */
 223     keyboard_hook = PyObject_New(HookObject, &HookType);
 224     keyboard_hook->funcs = NULL;
 225
 226     /* add it to the hooks module */
 227     ret = PyDict_SetItemString(hooksdict, "keyboard",
 228                                (PyObject*) keyboard_hook);
 229     g_assert(ret == 0);
 230
 231     /* create the "pointer" hook */
 232     pointer_hook = PyObject_New(HookObject, &HookType);
 233     pointer_hook->funcs = NULL;
 234
 235     /* add it to the hooks module */
 236     ret = PyDict_SetItemString(hooksdict, "pointer", (PyObject*) pointer_hook);
 237     g_assert(ret == 0);
 238 }
 239
 240 void hooks_shutdown()
 241 {
 242     Py_DECREF(pointer_hook);
 243     Py_DECREF(keyboard_hook);
 244     Py_DECREF(events_hook);
 245     Py_DECREF(hooks);
 246 }
 247
 248 void hooks_fire(EventData *data)
 249 {
 250     PyObject *ret, *args;
 251
 252     g_assert(events_hook != NULL);
 253
 254     args = Py_BuildValue("(O)", data);
 255     ret = hook_fire(events_hook, args);
 256     Py_DECREF(args);
 257     if (ret == NULL)
 258         PyErr_Print();
 259 }
 260
 261 void hooks_fire_keyboard(EventData *data)
 262 {
 263     PyObject *ret, *args;
 264
 265     g_assert(events_hook != NULL);
 266
 267     args = Py_BuildValue("(O)", data);
 268     ret = hook_fire(keyboard_hook, args);
 269     Py_DECREF(args);
 270     if (ret == NULL)
 271         PyErr_Print();
 272 }
 273
 274 void hooks_fire_pointer(EventData *data)
 275 {
 276     PyObject *ret, *args;
 277
 278     g_assert(events_hook != NULL);
 279
 280     args = Py_BuildValue("(O)", data);
 281     ret = hook_fire(pointer_hook, args);
 282     Py_DECREF(args);
 283     if (ret == NULL)
 284         PyErr_Print();
 285 }