summaryrefslogtreecommitdiffstats
path: root/siplib/qtlib.c
blob: 88432b7b821d5bd11a25085042c3612f929adbb5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
/*
 * The SIP library code that implements the interface to the optional module
 * supplied TQt support.
 *
 * Copyright (c) 2010 Riverbank Computing Limited <info@riverbankcomputing.com>
 *
 * This file is part of SIP.
 *
 * This copy of SIP is licensed for use under the terms of the SIP License
 * Agreement.  See the file LICENSE for more details.
 *
 * This copy of SIP may also used under the terms of the GNU General Public
 * License v2 or v3 as published by the Free Software Foundation which can be
 * found in the files LICENSE-GPL2 and LICENSE-GPL3 included in this package.
 *
 * SIP is supplied WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 */


#include <Python.h>
#include <assert.h>
#include <string.h>

#include "sip.h"
#include "sipint.h"


/* This is how TQt "types" signals and slots. */
#define isTQtSlot(s)     (*(s) == '1')
#define isTQtSignal(s)   (*(s) == '2')


static PyObject *getWeakRef(PyObject *obj);
static char *sipStrdup(const char *);
static void *createUniversalSlot(sipWrapper *txSelf, const char *sig,
        PyObject *rxObj, const char *slot, const char **member, int flags);
static void *findSignal(void *txrx, const char **sig);
static void *newSignal(void *txrx, const char **sig);


/*
 * Find an existing signal.
 */
static void *findSignal(void *txrx, const char **sig)
{
    if (sipTQtSupport->qt_find_universal_signal != NULL)
        txrx = sipTQtSupport->qt_find_universal_signal(txrx, sig);

    return txrx;
}


/*
 * Return a usable signal, creating a new universal signal if needed.
 */
static void *newSignal(void *txrx, const char **sig)
{
    void *new_txrx = findSignal(txrx, sig);

    if (new_txrx == NULL && sipTQtSupport->qt_create_universal_signal != NULL)
        new_txrx = sipTQtSupport->qt_create_universal_signal(txrx, sig);

    return new_txrx;
}


/*
 * Create a universal slot.  Returns a pointer to it or 0 if there was an
 * error.
 */
static void *createUniversalSlot(sipWrapper *txSelf, const char *sig,
        PyObject *rxObj, const char *slot, const char **member, int flags)
{
    void *us = sipTQtSupport->qt_create_universal_slot(txSelf, sig, rxObj, slot,
            member, flags);

    if (us && txSelf)
        sipSetPossibleProxy((sipSimpleWrapper *)txSelf);

    return us;
}


/*
 * Invoke a single slot (TQt or Python) and return the result.
 */
PyObject *sip_api_invoke_slot(const sipSlot *slot, PyObject *sigargs)
{
    PyObject *sa, *oxtype, *oxvalue, *oxtb, *sfunc, *sref;

    /* Keep some compilers quiet. */
    oxtype = oxvalue = oxtb = NULL;

    /* Fan out TQt signals.  (Only PyTQt3 will do this.) */
    if (slot->name != NULL && slot->name[0] != '\0')
    {
        assert(sipTQtSupport->qt_emit_signal);

        if (sipTQtSupport->qt_emit_signal(slot->pyobj, slot->name, sigargs) < 0)
            return NULL;

        Py_INCREF(Py_None);
        return Py_None;
    }

    /* Get the object to call, resolving any weak references. */
    if (slot->weakSlot == Py_True)
    {
        /*
         * The slot is guaranteed to be Ok because it has an extra reference or
         * is None.
         */
        sref = slot->pyobj;
        Py_INCREF(sref);
    }
    else if (slot -> weakSlot == NULL)
        sref = NULL;
    else if ((sref = PyWeakref_GetObject(slot -> weakSlot)) == NULL)
        return NULL;
    else
        Py_INCREF(sref);

    if (sref == Py_None)
    {
        /*
         * If the real object has gone then we pretend everything is Ok.  This
         * mimics the TQt behaviour of not caring if a receiving object has been
         * deleted.
         */
        Py_DECREF(sref);

        Py_INCREF(Py_None);
        return Py_None;
    }

    if (slot -> pyobj == NULL)
    {
        PyObject *self = (sref != NULL ? sref : slot->meth.mself);

        /*
         * If the receiver wraps a C++ object then ignore the call if it no
         * longer exists.
         */
        if (PyObject_TypeCheck(self, (PyTypeObject *)&sipSimpleWrapper_Type) &&
            sipGetAddress(self) == NULL)
        {
            Py_XDECREF(sref);

            Py_INCREF(Py_None);
            return Py_None;
        }

#if PY_MAJOR_VERSION >= 3
        sfunc = PyMethod_New(slot->meth.mfunc, self);
#else
        sfunc = PyMethod_New(slot->meth.mfunc, self, slot->meth.mclass);
#endif

        if (sfunc == NULL)
        {
            Py_XDECREF(sref);
            return NULL;
        }
    }
    else if (slot -> name != NULL)
    {
        char *mname = slot -> name + 1;
        PyObject *self = (sref != NULL ? sref : slot->pyobj);

        if ((sfunc = PyObject_GetAttrString(self, mname)) == NULL || !PyCFunction_Check(sfunc))
        {
            /*
             * Note that in earlier versions of SIP this error would be
             * detected when the slot was connected.
             */
            PyErr_Format(PyExc_NameError,"Invalid slot %s",mname);

            Py_XDECREF(sfunc);
            Py_XDECREF(sref);
            return NULL;
        }
    }
    else
    {
        sfunc = slot->pyobj;
        Py_INCREF(sfunc);
    }

    /*
     * We make repeated attempts to call a slot.  If we work out that it failed
     * because of an immediate type error we try again with one less argument.
     * We keep going until we run out of arguments to drop.  This emulates the
     * TQt ability of the slot to accept fewer arguments than a signal provides.
     */
    sa = sigargs;
    Py_INCREF(sa);

    for (;;)
    {
        PyObject *nsa, *xtype, *xvalue, *xtb, *resobj;

        if ((resobj = PyEval_CallObject(sfunc, sa)) != NULL)
        {
            Py_DECREF(sfunc);
            Py_XDECREF(sref);

            /* Remove any previous exception. */

            if (sa != sigargs)
            {
                Py_XDECREF(oxtype);
                Py_XDECREF(oxvalue);
                Py_XDECREF(oxtb);
                PyErr_Clear();
            }

            Py_DECREF(sa);

            return resobj;
        }

        /* Get the exception. */
        PyErr_Fetch(&xtype,&xvalue,&xtb);

        /*
         * See if it is unacceptable.  An acceptable failure is a type error
         * with no traceback - so long as we can still reduce the number of
         * arguments and try again.
         */
        if (!PyErr_GivenExceptionMatches(xtype,PyExc_TypeError) ||
            xtb != NULL ||
            PyTuple_GET_SIZE(sa) == 0)
        {
            /*
             * If there is a traceback then we must have called the slot and
             * the exception was later on - so report the exception as is.
             */
            if (xtb != NULL)
            {
                if (sa != sigargs)
                {
                    Py_XDECREF(oxtype);
                    Py_XDECREF(oxvalue);
                    Py_XDECREF(oxtb);
                }

                PyErr_Restore(xtype,xvalue,xtb);
            }
            else if (sa == sigargs)
                PyErr_Restore(xtype,xvalue,xtb);
            else
            {
                /*
                 * Discard the latest exception and restore the original one.
                 */
                Py_XDECREF(xtype);
                Py_XDECREF(xvalue);
                Py_XDECREF(xtb);

                PyErr_Restore(oxtype,oxvalue,oxtb);
            }

            break;
        }

        /* If this is the first attempt, save the exception. */
        if (sa == sigargs)
        {
            oxtype = xtype;
            oxvalue = xvalue;
            oxtb = xtb;
        }
        else
        {
            Py_XDECREF(xtype);
            Py_XDECREF(xvalue);
            Py_XDECREF(xtb);
        }

        /* Create the new argument tuple. */
        if ((nsa = PyTuple_GetSlice(sa,0,PyTuple_GET_SIZE(sa) - 1)) == NULL)
        {
            /* Tidy up. */
            Py_XDECREF(oxtype);
            Py_XDECREF(oxvalue);
            Py_XDECREF(oxtb);

            break;
        }

        Py_DECREF(sa);
        sa = nsa;
    }

    Py_DECREF(sfunc);
    Py_XDECREF(sref);

    Py_DECREF(sa);

    return NULL;
}


/*
 * Compare two slots to see if they are the same.
 */
int sip_api_same_slot(const sipSlot *sp, PyObject *rxObj, const char *slot)
{
    /* See if they are signals or TQt slots, ie. they have a name. */
    if (slot != NULL)
    {
        if (sp->name == NULL || sp->name[0] == '\0')
            return 0;

        return (sipTQtSupport->qt_same_name(sp->name, slot) && sp->pyobj == rxObj);
    }

    /* See if they are pure Python methods. */
    if (PyMethod_Check(rxObj))
    {
        if (sp->pyobj != NULL)
            return 0;

        return (sp->meth.mfunc == PyMethod_GET_FUNCTION(rxObj)
                && sp->meth.mself == PyMethod_GET_SELF(rxObj)
#if PY_MAJOR_VERSION < 3
                && sp->meth.mclass == PyMethod_GET_CLASS(rxObj)
#endif
                );
    }

    /* See if they are wrapped C++ methods. */
    if (PyCFunction_Check(rxObj))
    {
        if (sp->name == NULL || sp->name[0] != '\0')
            return 0;

        return (sp->pyobj == PyCFunction_GET_SELF(rxObj) &&
                strcmp(&sp->name[1], ((PyCFunctionObject *)rxObj)->m_ml->ml_name) == 0);
    }

    /* The objects must be the same. */
    return (sp->pyobj == rxObj);
}


/*
 * Convert a valid Python signal or slot to an existing universal slot.
 */
void *sipGetRx(sipSimpleWrapper *txSelf, const char *sigargs, PyObject *rxObj,
           const char *slot, const char **memberp)
{
    if (slot != NULL)
        if (isTQtSlot(slot) || isTQtSignal(slot))
        {
            void *rx;

            *memberp = slot;

            if ((rx = sip_api_get_cpp_ptr((sipSimpleWrapper *)rxObj, sipTQObjectType)) == NULL)
                return NULL;

            if (isTQtSignal(slot))
                rx = findSignal(rx, memberp);

            return rx;
        }

    /*
     * The slot was either a Python callable or PyTQt3 Python signal so there
     * should be a universal slot.
     */
    return sipTQtSupport->qt_find_slot(sipGetAddress(txSelf), sigargs, rxObj, slot, memberp);
}


/*
 * Convert a Python receiver (either a Python signal or slot or a TQt signal or
 * slot) to a TQt receiver.  It is only ever called when the signal is a TQt
 * signal.  Return NULL is there was an error.
 */
void *sip_api_convert_rx(sipWrapper *txSelf, const char *sigargs,
        PyObject *rxObj, const char *slot, const char **memberp, int flags)
{
    if (slot == NULL)
        return createUniversalSlot(txSelf, sigargs, rxObj, NULL, memberp, flags);

    if (isTQtSlot(slot) || isTQtSignal(slot))
    {
        void *rx;

        *memberp = slot;

        if ((rx = sip_api_get_cpp_ptr((sipSimpleWrapper *)rxObj, sipTQObjectType)) == NULL)
            return NULL;

        if (isTQtSignal(slot))
            rx = newSignal(rx, memberp);

        return rx;
    }

    /* The slot is a Python signal so we need a universal slot to catch it. */
    return createUniversalSlot(txSelf, sigargs, rxObj, slot, memberp, 0);
}


/*
 * Connect a TQt signal or a Python signal to a TQt slot, a TQt signal, a Python
 * slot or a Python signal.  This is all possible combinations.
 */
PyObject *sip_api_connect_rx(PyObject *txObj, const char *sig, PyObject *rxObj,
        const char *slot, int type)
{
    /* Handle TQt signals. */
    if (isTQtSignal(sig))
    {
        void *tx, *rx;
        const char *member, *real_sig;
        int res;

        if ((tx = sip_api_get_cpp_ptr((sipSimpleWrapper *)txObj, sipTQObjectType)) == NULL)
            return NULL;

        real_sig = sig;

        if ((tx = newSignal(tx, &real_sig)) == NULL)
            return NULL;

        if ((rx = sip_api_convert_rx((sipWrapper *)txObj, sig, rxObj, slot, &member, 0)) == NULL)
            return NULL;

        res = sipTQtSupport->qt_connect(tx, real_sig, rx, member, type);

        return PyBool_FromLong(res);
    }

    /* Handle Python signals.  Only PyTQt3 will get this far. */
    assert(sipTQtSupport->qt_connect_py_signal);

    if (sipTQtSupport->qt_connect_py_signal(txObj, sig, rxObj, slot) < 0)
        return NULL;

    Py_INCREF(Py_True);
    return Py_True;
}


/*
 * Disconnect a signal to a signal or a TQt slot.
 */
PyObject *sip_api_disconnect_rx(PyObject *txObj,const char *sig,
                PyObject *rxObj,const char *slot)
{
    /* Handle TQt signals. */
    if (isTQtSignal(sig))
    {
        sipSimpleWrapper *txSelf = (sipSimpleWrapper *)txObj;
        void *tx, *rx;
        const char *member;
        int res;

        if ((tx = sip_api_get_cpp_ptr(txSelf, sipTQObjectType)) == NULL)
            return NULL;

        if ((rx = sipGetRx(txSelf, sig, rxObj, slot, &member)) == NULL)
        {
            Py_INCREF(Py_False);
            return Py_False;
        }

        /* Handle Python signals. */
        tx = findSignal(tx, &sig);

        res = sipTQtSupport->qt_disconnect(tx, sig, rx, member);

        /*
         * Delete it if it is a universal slot as this will be it's only
         * connection.  If the slot is actually a universal signal then it
         * should leave it in place.
         */
        sipTQtSupport->qt_destroy_universal_slot(rx);

        return PyBool_FromLong(res);
    }

    /* Handle Python signals.  Only PyTQt3 will get this far. */
    assert(sipTQtSupport->qt_disconnect_py_signal);

    sipTQtSupport->qt_disconnect_py_signal(txObj, sig, rxObj, slot);

    Py_INCREF(Py_True);
    return Py_True;
}


/*
 * Free the resources of a slot.
 */
void sip_api_free_sipslot(sipSlot *slot)
{
    if (slot->name != NULL)
    {
        sip_api_free(slot->name);
    }
    else if (slot->weakSlot == Py_True)
    {
        Py_DECREF(slot->pyobj);
    }

    /* Remove any weak reference. */
    Py_XDECREF(slot->weakSlot);
}


/*
 * Implement strdup() using sip_api_malloc().
 */
static char *sipStrdup(const char *s)
{
    char *d;

    if ((d = (char *)sip_api_malloc(strlen(s) + 1)) != NULL)
        strcpy(d,s);

    return d;
}


/*
 * Initialise a slot, returning 0 if there was no error.  If the signal was a
 * TQt signal, then the slot may be a Python signal or a Python slot.  If the
 * signal was a Python signal, then the slot may be anything.
 */
int sip_api_save_slot(sipSlot *sp, PyObject *rxObj, const char *slot)
{
    sp -> weakSlot = NULL;

    if (slot == NULL)
    {
        sp -> name = NULL;

        if (PyMethod_Check(rxObj))
        {
            /*
             * Python creates methods on the fly.  We could increment the
             * reference count to keep it alive, but that would keep "self"
             * alive as well and would probably be a circular reference.
             * Instead we remember the component parts and hope they are still
             * valid when we re-create the method when we need it.
             */
            sipSaveMethod(&sp -> meth,rxObj);

            /* Notice if the class instance disappears. */
            sp -> weakSlot = getWeakRef(sp -> meth.mself);

            /* This acts a flag to say that the slot is a method. */
            sp -> pyobj = NULL;
        }
        else
        {
            PyObject *self;

            /*
             * We know that it is another type of callable, ie. a
             * function/builtin.
             */

            if (PyCFunction_Check(rxObj) &&
                (self = PyCFunction_GET_SELF(rxObj)) != NULL &&
                PyObject_TypeCheck(self, (PyTypeObject *)&sipSimpleWrapper_Type))
            {
                /*
                 * It is a wrapped C++ class method.  We can't keep a copy
                 * because they are generated on the fly and we can't take a
                 * reference as that may keep the instance (ie. self) alive.
                 * We therefore treat it as if the user had specified the slot
                 * at "obj, TQT_SLOT('meth()')" rather than "obj.meth" (see below).
                 */

                const char *meth;

                /* Get the method name. */
                meth = ((PyCFunctionObject *)rxObj) -> m_ml -> ml_name;

                if ((sp -> name = (char *)sip_api_malloc(strlen(meth) + 2)) == NULL)
                    return -1;

                /*
                 * Copy the name and set the marker that it needs converting to
                 * a built-in method.
                 */
                sp -> name[0] = '\0';
                strcpy(&sp -> name[1],meth);

                sp -> pyobj = self;
                sp -> weakSlot = getWeakRef(self);
            }
            else
            {
                /*
                 * Give the slot an extra reference to keep it alive and
                 * remember we have done so by treating weakSlot specially.
                 */
                Py_INCREF(rxObj);
                sp->pyobj = rxObj;

                Py_INCREF(Py_True);
                sp->weakSlot = Py_True;
            }
        }
    }
    else if ((sp -> name = sipStrdup(slot)) == NULL)
        return -1;
    else if (isTQtSlot(slot))
    {
        /*
         * The user has decided to connect a Python signal to a TQt slot and
         * specified the slot as "obj, TQT_SLOT('meth()')" rather than "obj.meth".
         */

        char *tail;

        /* Remove any arguments. */
        if ((tail = strchr(sp -> name,'(')) != NULL)
            *tail = '\0';

        /*
         * A bit of a hack to indicate that this needs converting to a built-in
         * method.
         */
        sp -> name[0] = '\0';

        /* Notice if the class instance disappears. */
        sp -> weakSlot = getWeakRef(rxObj);

        sp -> pyobj = rxObj;
    }
    else
        /* It's a TQt signal. */
        sp -> pyobj = rxObj;

    return 0;
}


/*
 * Return a weak reference to the given object.
 */
static PyObject *getWeakRef(PyObject *obj)
{
    PyObject *wr;

    if ((wr = PyWeakref_NewRef(obj,NULL)) == NULL)
        PyErr_Clear();

    return wr;
}