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| 40 | |
| 41 | #include "qtimer.h" |
| 42 | #include "qabstracteventdispatcher.h" |
| 43 | #include "qcoreapplication.h" |
| 44 | #include "qobject_p.h" |
| 45 | #include "qthread.h" |
| 46 | #include "qcoreapplication_p.h" |
| 47 | |
| 48 | QT_BEGIN_NAMESPACE |
| 49 | |
| 50 | static constexpr int INV_TIMER = -1; // invalid timer id |
| 51 | |
| 52 | class QTimerPrivate : public QObjectPrivate |
| 53 | { |
| 54 | public: |
| 55 | int id = INV_TIMER; |
| 56 | int inter = 0; |
| 57 | bool single = false; |
| 58 | bool nulltimer = false; |
| 59 | Qt::TimerType type = Qt::CoarseTimer; |
| 60 | }; |
| 61 | |
| 62 | /*! |
| 63 | \class QTimer |
| 64 | \inmodule QtCore |
| 65 | \brief The QTimer class provides repetitive and single-shot timers. |
| 66 | |
| 67 | \ingroup events |
| 68 | |
| 69 | |
| 70 | The QTimer class provides a high-level programming interface for |
| 71 | timers. To use it, create a QTimer, connect its timeout() signal |
| 72 | to the appropriate slots, and call start(). From then on, it will |
| 73 | emit the timeout() signal at constant intervals. |
| 74 | |
| 75 | Example for a one second (1000 millisecond) timer (from the |
| 76 | \l{widgets/analogclock}{Analog Clock} example): |
| 77 | |
| 78 | \snippet ../widgets/widgets/analogclock/analogclock.cpp 4 |
| 79 | \snippet ../widgets/widgets/analogclock/analogclock.cpp 5 |
| 80 | \snippet ../widgets/widgets/analogclock/analogclock.cpp 6 |
| 81 | |
| 82 | From then on, the \c update() slot is called every second. |
| 83 | |
| 84 | You can set a timer to time out only once by calling |
| 85 | setSingleShot(true). You can also use the static |
| 86 | QTimer::singleShot() function to call a slot after a specified |
| 87 | interval: |
| 88 | |
| 89 | \snippet timers/timers.cpp 3 |
| 90 | |
| 91 | In multithreaded applications, you can use QTimer in any thread |
| 92 | that has an event loop. To start an event loop from a non-GUI |
| 93 | thread, use QThread::exec(). Qt uses the timer's |
| 94 | \l{QObject::thread()}{thread affinity} to determine which thread |
| 95 | will emit the \l{QTimer::}{timeout()} signal. Because of this, you |
| 96 | must start and stop the timer in its thread; it is not possible to |
| 97 | start a timer from another thread. |
| 98 | |
| 99 | As a special case, a QTimer with a timeout of 0 will time out as soon as |
| 100 | possible, though the ordering between zero timers and other sources of |
| 101 | events is unspecified. Zero timers can be used to do some work while still |
| 102 | providing a snappy user interface: |
| 103 | |
| 104 | \snippet timers/timers.cpp 4 |
| 105 | \snippet timers/timers.cpp 5 |
| 106 | \snippet timers/timers.cpp 6 |
| 107 | |
| 108 | From then on, \c processOneThing() will be called repeatedly. It |
| 109 | should be written in such a way that it always returns quickly |
| 110 | (typically after processing one data item) so that Qt can deliver |
| 111 | events to the user interface and stop the timer as soon as it has done all |
| 112 | its work. This is the traditional way of implementing heavy work |
| 113 | in GUI applications, but as multithreading is nowadays becoming available on |
| 114 | more and more platforms, we expect that zero-millisecond |
| 115 | QTimer objects will gradually be replaced by \l{QThread}s. |
| 116 | |
| 117 | \section1 Accuracy and Timer Resolution |
| 118 | |
| 119 | The accuracy of timers depends on the underlying operating system |
| 120 | and hardware. Most platforms support a resolution of 1 millisecond, |
| 121 | though the accuracy of the timer will not equal this resolution |
| 122 | in many real-world situations. |
| 123 | |
| 124 | The accuracy also depends on the \l{Qt::TimerType}{timer type}. For |
| 125 | Qt::PreciseTimer, QTimer will try to keep the accuracy at 1 millisecond. |
| 126 | Precise timers will also never time out earlier than expected. |
| 127 | |
| 128 | For Qt::CoarseTimer and Qt::VeryCoarseTimer types, QTimer may wake up |
| 129 | earlier than expected, within the margins for those types: 5% of the |
| 130 | interval for Qt::CoarseTimer and 500 ms for Qt::VeryCoarseTimer. |
| 131 | |
| 132 | All timer types may time out later than expected if the system is busy or |
| 133 | unable to provide the requested accuracy. In such a case of timeout |
| 134 | overrun, Qt will emit timeout() only once, even if multiple timeouts have |
| 135 | expired, and then will resume the original interval. |
| 136 | |
| 137 | \section1 Alternatives to QTimer |
| 138 | |
| 139 | An alternative to using QTimer is to call QObject::startTimer() |
| 140 | for your object and reimplement the QObject::timerEvent() event |
| 141 | handler in your class (which must inherit QObject). The |
| 142 | disadvantage is that timerEvent() does not support such |
| 143 | high-level features as single-shot timers or signals. |
| 144 | |
| 145 | Another alternative is QBasicTimer. It is typically less |
| 146 | cumbersome than using QObject::startTimer() |
| 147 | directly. See \l{Timers} for an overview of all three approaches. |
| 148 | |
| 149 | Some operating systems limit the number of timers that may be |
| 150 | used; Qt tries to work around these limitations. |
| 151 | |
| 152 | \sa QBasicTimer, QTimerEvent, QObject::timerEvent(), Timers, |
| 153 | {Analog Clock Example}, {Wiggly Example} |
| 154 | */ |
| 155 | |
| 156 | /*! |
| 157 | Constructs a timer with the given \a parent. |
| 158 | */ |
| 159 | |
| 160 | QTimer::QTimer(QObject *parent) |
| 161 | : QObject(*new QTimerPrivate, parent) |
| 162 | { |
| 163 | } |
| 164 | |
| 165 | |
| 166 | /*! |
| 167 | Destroys the timer. |
| 168 | */ |
| 169 | |
| 170 | QTimer::~QTimer() |
| 171 | { |
| 172 | if (d_func()->id != INV_TIMER) // stop running timer |
| 173 | stop(); |
| 174 | } |
| 175 | |
| 176 | |
| 177 | /*! |
| 178 | \fn void QTimer::timeout() |
| 179 | |
| 180 | This signal is emitted when the timer times out. |
| 181 | |
| 182 | \sa interval, start(), stop() |
| 183 | */ |
| 184 | |
| 185 | /*! |
| 186 | \property QTimer::active |
| 187 | \since 4.3 |
| 188 | |
| 189 | This boolean property is \c true if the timer is running; otherwise |
| 190 | false. |
| 191 | */ |
| 192 | |
| 193 | /*! |
| 194 | \fn bool QTimer::isActive() const |
| 195 | |
| 196 | Returns \c true if the timer is running (pending); otherwise returns |
| 197 | false. |
| 198 | */ |
| 199 | bool QTimer::isActive() const |
| 200 | { |
| 201 | return d_func()->id >= 0; |
| 202 | } |
| 203 | |
| 204 | /*! |
| 205 | \fn int QTimer::timerId() const |
| 206 | |
| 207 | Returns the ID of the timer if the timer is running; otherwise returns |
| 208 | -1. |
| 209 | */ |
| 210 | int QTimer::timerId() const |
| 211 | { |
| 212 | return d_func()->id; |
| 213 | } |
| 214 | |
| 215 | |
| 216 | /*! \overload start() |
| 217 | |
| 218 | Starts or restarts the timer with the timeout specified in \l interval. |
| 219 | |
| 220 | If the timer is already running, it will be |
| 221 | \l{QTimer::stop()}{stopped} and restarted. |
| 222 | |
| 223 | If \l singleShot is true, the timer will be activated only once. |
| 224 | */ |
| 225 | void QTimer::start() |
| 226 | { |
| 227 | Q_D(QTimer); |
| 228 | if (d->id != INV_TIMER) // stop running timer |
| 229 | stop(); |
| 230 | d->nulltimer = (!d->inter && d->single); |
| 231 | d->id = QObject::startTimer(d->inter, d->type); |
| 232 | } |
| 233 | |
| 234 | /*! |
| 235 | Starts or restarts the timer with a timeout interval of \a msec |
| 236 | milliseconds. |
| 237 | |
| 238 | If the timer is already running, it will be |
| 239 | \l{QTimer::stop()}{stopped} and restarted. |
| 240 | |
| 241 | If \l singleShot is true, the timer will be activated only once. |
| 242 | |
| 243 | */ |
| 244 | void QTimer::start(int msec) |
| 245 | { |
| 246 | Q_D(QTimer); |
| 247 | d->inter = msec; |
| 248 | start(); |
| 249 | } |
| 250 | |
| 251 | |
| 252 | |
| 253 | /*! |
| 254 | Stops the timer. |
| 255 | |
| 256 | \sa start() |
| 257 | */ |
| 258 | |
| 259 | void QTimer::stop() |
| 260 | { |
| 261 | Q_D(QTimer); |
| 262 | if (d->id != INV_TIMER) { |
| 263 | QObject::killTimer(d->id); |
| 264 | d->id = INV_TIMER; |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | |
| 269 | /*! |
| 270 | \reimp |
| 271 | */ |
| 272 | void QTimer::timerEvent(QTimerEvent *e) |
| 273 | { |
| 274 | Q_D(QTimer); |
| 275 | if (e->timerId() == d->id) { |
| 276 | if (d->single) |
| 277 | stop(); |
| 278 | emit timeout(QPrivateSignal()); |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | class QSingleShotTimer : public QObject |
| 283 | { |
| 284 | Q_OBJECT |
| 285 | int timerId; |
| 286 | bool hasValidReceiver; |
| 287 | QPointer<const QObject> receiver; |
| 288 | QtPrivate::QSlotObjectBase *slotObj; |
| 289 | public: |
| 290 | ~QSingleShotTimer(); |
| 291 | QSingleShotTimer(int msec, Qt::TimerType timerType, const QObject *r, const char * m); |
| 292 | QSingleShotTimer(int msec, Qt::TimerType timerType, const QObject *r, QtPrivate::QSlotObjectBase *slotObj); |
| 293 | |
| 294 | Q_SIGNALS: |
| 295 | void timeout(); |
| 296 | protected: |
| 297 | void timerEvent(QTimerEvent *) override; |
| 298 | }; |
| 299 | |
| 300 | QSingleShotTimer::QSingleShotTimer(int msec, Qt::TimerType timerType, const QObject *r, const char *member) |
| 301 | : QObject(QAbstractEventDispatcher::instance()), hasValidReceiver(true), slotObj(nullptr) |
| 302 | { |
| 303 | timerId = startTimer(msec, timerType); |
| 304 | connect(this, SIGNAL(timeout()), r, member); |
| 305 | } |
| 306 | |
| 307 | QSingleShotTimer::QSingleShotTimer(int msec, Qt::TimerType timerType, const QObject *r, QtPrivate::QSlotObjectBase *slotObj) |
| 308 | : QObject(QAbstractEventDispatcher::instance()), hasValidReceiver(r), receiver(r), slotObj(slotObj) |
| 309 | { |
| 310 | timerId = startTimer(msec, timerType); |
| 311 | if (r && thread() != r->thread()) { |
| 312 | // Avoid leaking the QSingleShotTimer instance in case the application exits before the timer fires |
| 313 | connect(QCoreApplication::instance(), &QCoreApplication::aboutToQuit, this, &QObject::deleteLater); |
| 314 | setParent(nullptr); |
| 315 | moveToThread(r->thread()); |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | QSingleShotTimer::~QSingleShotTimer() |
| 320 | { |
| 321 | if (timerId > 0) |
| 322 | killTimer(timerId); |
| 323 | if (slotObj) |
| 324 | slotObj->destroyIfLastRef(); |
| 325 | } |
| 326 | |
| 327 | void QSingleShotTimer::timerEvent(QTimerEvent *) |
| 328 | { |
| 329 | // need to kill the timer _before_ we emit timeout() in case the |
| 330 | // slot connected to timeout calls processEvents() |
| 331 | if (timerId > 0) |
| 332 | killTimer(timerId); |
| 333 | timerId = -1; |
| 334 | |
| 335 | if (slotObj) { |
| 336 | // If the receiver was destroyed, skip this part |
| 337 | if (Q_LIKELY(!receiver.isNull() || !hasValidReceiver)) { |
| 338 | // We allocate only the return type - we previously checked the function had |
| 339 | // no arguments. |
| 340 | void *args[1] = { nullptr }; |
| 341 | slotObj->call(const_cast<QObject*>(receiver.data()), args); |
| 342 | } |
| 343 | } else { |
| 344 | emit timeout(); |
| 345 | } |
| 346 | |
| 347 | // we would like to use delete later here, but it feels like a |
| 348 | // waste to post a new event to handle this event, so we just unset the flag |
| 349 | // and explicitly delete... |
| 350 | qDeleteInEventHandler(this); |
| 351 | } |
| 352 | |
| 353 | /*! |
| 354 | \internal |
| 355 | |
| 356 | Implementation of the template version of singleShot |
| 357 | |
| 358 | \a msec is the timer interval |
| 359 | \a timerType is the timer type |
| 360 | \a receiver is the receiver object, can be null. In such a case, it will be the same |
| 361 | as the final sender class. |
| 362 | \a slot a pointer only used when using Qt::UniqueConnection |
| 363 | \a slotObj the slot object |
| 364 | */ |
| 365 | void QTimer::singleShotImpl(int msec, Qt::TimerType timerType, |
| 366 | const QObject *receiver, |
| 367 | QtPrivate::QSlotObjectBase *slotObj) |
| 368 | { |
| 369 | if (msec == 0) { |
| 370 | bool deleteReceiver = false; |
| 371 | // Optimize: set a receiver context when none is given, such that we can use |
| 372 | // QMetaObject::invokeMethod which is more efficient than going through a timer. |
| 373 | // We need a QObject living in the current thread. But the QThread itself lives |
| 374 | // in a different thread - with the exception of the main QThread which lives in |
| 375 | // itself. And QThread::currentThread() is among the few QObjects we know that will |
| 376 | // most certainly be there. Note that one can actually call singleShot before the |
| 377 | // QApplication is created! |
| 378 | if (!receiver && QThread::currentThread() == QCoreApplicationPrivate::mainThread()) { |
| 379 | // reuse main thread as context object |
| 380 | receiver = QThread::currentThread(); |
| 381 | } else if (!receiver) { |
| 382 | // Create a receiver context object on-demand. According to the benchmarks, |
| 383 | // this is still more efficient than going through a timer. |
| 384 | receiver = new QObject; |
| 385 | deleteReceiver = true; |
| 386 | } |
| 387 | |
| 388 | QMetaObject::invokeMethodImpl(const_cast<QObject *>(receiver), slotObj, |
| 389 | Qt::QueuedConnection, nullptr); |
| 390 | |
| 391 | if (deleteReceiver) |
| 392 | const_cast<QObject *>(receiver)->deleteLater(); |
| 393 | return; |
| 394 | } |
| 395 | |
| 396 | new QSingleShotTimer(msec, timerType, receiver, slotObj); |
| 397 | } |
| 398 | |
| 399 | /*! |
| 400 | \reentrant |
| 401 | This static function calls a slot after a given time interval. |
| 402 | |
| 403 | It is very convenient to use this function because you do not need |
| 404 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 405 | create a local QTimer object. |
| 406 | |
| 407 | Example: |
| 408 | \snippet code/src_corelib_kernel_qtimer.cpp 0 |
| 409 | |
| 410 | This sample program automatically terminates after 10 minutes |
| 411 | (600,000 milliseconds). |
| 412 | |
| 413 | The \a receiver is the receiving object and the \a member is the |
| 414 | slot. The time interval is \a msec milliseconds. |
| 415 | |
| 416 | \sa start() |
| 417 | */ |
| 418 | |
| 419 | void QTimer::singleShot(int msec, const QObject *receiver, const char *member) |
| 420 | { |
| 421 | // coarse timers are worst in their first firing |
| 422 | // so we prefer a high precision timer for something that happens only once |
| 423 | // unless the timeout is too big, in which case we go for coarse anyway |
| 424 | singleShot(msec, msec >= 2000 ? Qt::CoarseTimer : Qt::PreciseTimer, receiver, member); |
| 425 | } |
| 426 | |
| 427 | /*! \overload |
| 428 | \reentrant |
| 429 | This static function calls a slot after a given time interval. |
| 430 | |
| 431 | It is very convenient to use this function because you do not need |
| 432 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 433 | create a local QTimer object. |
| 434 | |
| 435 | The \a receiver is the receiving object and the \a member is the slot. The |
| 436 | time interval is \a msec milliseconds. The \a timerType affects the |
| 437 | accuracy of the timer. |
| 438 | |
| 439 | \sa start() |
| 440 | */ |
| 441 | void QTimer::singleShot(int msec, Qt::TimerType timerType, const QObject *receiver, const char *member) |
| 442 | { |
| 443 | if (Q_UNLIKELY(msec < 0)) { |
| 444 | qWarning("QTimer::singleShot: Timers cannot have negative timeouts" ); |
| 445 | return; |
| 446 | } |
| 447 | if (receiver && member) { |
| 448 | if (msec == 0) { |
| 449 | // special code shortpath for 0-timers |
| 450 | const char* bracketPosition = strchr(member, '('); |
| 451 | if (!bracketPosition || !(member[0] >= '0' && member[0] <= '2')) { |
| 452 | qWarning("QTimer::singleShot: Invalid slot specification" ); |
| 453 | return; |
| 454 | } |
| 455 | QByteArray methodName(member+1, bracketPosition - 1 - member); // extract method name |
| 456 | QMetaObject::invokeMethod(const_cast<QObject *>(receiver), methodName.constData(), Qt::QueuedConnection); |
| 457 | return; |
| 458 | } |
| 459 | (void) new QSingleShotTimer(msec, timerType, receiver, member); |
| 460 | } |
| 461 | } |
| 462 | |
| 463 | /*! \fn template<typename PointerToMemberFunction> void QTimer::singleShot(int msec, const QObject *receiver, PointerToMemberFunction method) |
| 464 | |
| 465 | \since 5.4 |
| 466 | |
| 467 | \overload |
| 468 | \reentrant |
| 469 | This static function calls a member function of a QObject after a given time interval. |
| 470 | |
| 471 | It is very convenient to use this function because you do not need |
| 472 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 473 | create a local QTimer object. |
| 474 | |
| 475 | The \a receiver is the receiving object and the \a method is the member function. The |
| 476 | time interval is \a msec milliseconds. |
| 477 | |
| 478 | If \a receiver is destroyed before the interval occurs, the method will not be called. |
| 479 | The function will be run in the thread of \a receiver. The receiver's thread must have |
| 480 | a running Qt event loop. |
| 481 | |
| 482 | \sa start() |
| 483 | */ |
| 484 | |
| 485 | /*! \fn template<typename PointerToMemberFunction> void QTimer::singleShot(int msec, Qt::TimerType timerType, const QObject *receiver, PointerToMemberFunction method) |
| 486 | |
| 487 | \since 5.4 |
| 488 | |
| 489 | \overload |
| 490 | \reentrant |
| 491 | This static function calls a member function of a QObject after a given time interval. |
| 492 | |
| 493 | It is very convenient to use this function because you do not need |
| 494 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 495 | create a local QTimer object. |
| 496 | |
| 497 | The \a receiver is the receiving object and the \a method is the member function. The |
| 498 | time interval is \a msec milliseconds. The \a timerType affects the |
| 499 | accuracy of the timer. |
| 500 | |
| 501 | If \a receiver is destroyed before the interval occurs, the method will not be called. |
| 502 | The function will be run in the thread of \a receiver. The receiver's thread must have |
| 503 | a running Qt event loop. |
| 504 | |
| 505 | \sa start() |
| 506 | */ |
| 507 | |
| 508 | /*! \fn template<typename Functor> void QTimer::singleShot(int msec, Functor functor) |
| 509 | |
| 510 | \since 5.4 |
| 511 | |
| 512 | \overload |
| 513 | \reentrant |
| 514 | This static function calls \a functor after a given time interval. |
| 515 | |
| 516 | It is very convenient to use this function because you do not need |
| 517 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 518 | create a local QTimer object. |
| 519 | |
| 520 | The time interval is \a msec milliseconds. |
| 521 | |
| 522 | \sa start() |
| 523 | */ |
| 524 | |
| 525 | /*! \fn template<typename Functor> void QTimer::singleShot(int msec, Qt::TimerType timerType, Functor functor) |
| 526 | |
| 527 | \since 5.4 |
| 528 | |
| 529 | \overload |
| 530 | \reentrant |
| 531 | This static function calls \a functor after a given time interval. |
| 532 | |
| 533 | It is very convenient to use this function because you do not need |
| 534 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 535 | create a local QTimer object. |
| 536 | |
| 537 | The time interval is \a msec milliseconds. The \a timerType affects the |
| 538 | accuracy of the timer. |
| 539 | |
| 540 | \sa start() |
| 541 | */ |
| 542 | |
| 543 | /*! \fn template<typename Functor> void QTimer::singleShot(int msec, const QObject *context, Functor functor) |
| 544 | |
| 545 | \since 5.4 |
| 546 | |
| 547 | \overload |
| 548 | \reentrant |
| 549 | This static function calls \a functor after a given time interval. |
| 550 | |
| 551 | It is very convenient to use this function because you do not need |
| 552 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 553 | create a local QTimer object. |
| 554 | |
| 555 | The time interval is \a msec milliseconds. |
| 556 | |
| 557 | If \a context is destroyed before the interval occurs, the method will not be called. |
| 558 | The function will be run in the thread of \a context. The context's thread must have |
| 559 | a running Qt event loop. |
| 560 | |
| 561 | \sa start() |
| 562 | */ |
| 563 | |
| 564 | /*! \fn template<typename Functor> void QTimer::singleShot(int msec, Qt::TimerType timerType, const QObject *context, Functor functor) |
| 565 | |
| 566 | \since 5.4 |
| 567 | |
| 568 | \overload |
| 569 | \reentrant |
| 570 | This static function calls \a functor after a given time interval. |
| 571 | |
| 572 | It is very convenient to use this function because you do not need |
| 573 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 574 | create a local QTimer object. |
| 575 | |
| 576 | The time interval is \a msec milliseconds. The \a timerType affects the |
| 577 | accuracy of the timer. |
| 578 | |
| 579 | If \a context is destroyed before the interval occurs, the method will not be called. |
| 580 | The function will be run in the thread of \a context. The context's thread must have |
| 581 | a running Qt event loop. |
| 582 | |
| 583 | \sa start() |
| 584 | */ |
| 585 | |
| 586 | /*! |
| 587 | \fn void QTimer::singleShot(std::chrono::milliseconds msec, const QObject *receiver, const char *member) |
| 588 | \since 5.8 |
| 589 | \overload |
| 590 | \reentrant |
| 591 | |
| 592 | This static function calls a slot after a given time interval. |
| 593 | |
| 594 | It is very convenient to use this function because you do not need |
| 595 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 596 | create a local QTimer object. |
| 597 | |
| 598 | The \a receiver is the receiving object and the \a member is the slot. The |
| 599 | time interval is given in the duration object \a msec. |
| 600 | |
| 601 | \sa start() |
| 602 | */ |
| 603 | |
| 604 | /*! |
| 605 | \fn void QTimer::singleShot(std::chrono::milliseconds msec, Qt::TimerType timerType, const QObject *receiver, const char *member) |
| 606 | \since 5.8 |
| 607 | \overload |
| 608 | \reentrant |
| 609 | |
| 610 | This static function calls a slot after a given time interval. |
| 611 | |
| 612 | It is very convenient to use this function because you do not need |
| 613 | to bother with a \l{QObject::timerEvent()}{timerEvent} or |
| 614 | create a local QTimer object. |
| 615 | |
| 616 | The \a receiver is the receiving object and the \a member is the slot. The |
| 617 | time interval is given in the duration object \a msec. The \a timerType affects the |
| 618 | accuracy of the timer. |
| 619 | |
| 620 | \sa start() |
| 621 | */ |
| 622 | |
| 623 | /*! |
| 624 | \fn template <typename Functor> QMetaObject::Connection QTimer::callOnTimeout(Functor slot, Qt::ConnectionType connectionType = Qt::AutoConnection) |
| 625 | \since 5.12 |
| 626 | \overload |
| 627 | |
| 628 | Creates a connection of type \a connectionType from the timeout() signal |
| 629 | to \a slot, and returns a handle to the connection. |
| 630 | |
| 631 | This method is provided for convenience. |
| 632 | It's equivalent to calling \c {QObject::connect(timer, &QTimer::timeout, timer, slot, connectionType)}. |
| 633 | |
| 634 | \sa QObject::connect(), timeout() |
| 635 | */ |
| 636 | |
| 637 | /*! |
| 638 | \fn template <typename Functor> QMetaObject::Connection QTimer::callOnTimeout(const QObject *context, Functor slot, Qt::ConnectionType connectionType = Qt::AutoConnection) |
| 639 | \since 5.12 |
| 640 | \overload callOnTimeout() |
| 641 | |
| 642 | Creates a connection from the timeout() signal to \a slot to be placed in a specific |
| 643 | event loop of \a context, and returns a handle to the connection. |
| 644 | |
| 645 | This method is provided for convenience. It's equivalent to calling |
| 646 | \c {QObject::connect(timer, &QTimer::timeout, context, slot, connectionType)}. |
| 647 | |
| 648 | \sa QObject::connect(), timeout() |
| 649 | */ |
| 650 | |
| 651 | /*! |
| 652 | \fn template <typename MemberFunction> QMetaObject::Connection QTimer::callOnTimeout(const QObject *receiver, MemberFunction *slot, Qt::ConnectionType connectionType = Qt::AutoConnection) |
| 653 | \since 5.12 |
| 654 | \overload callOnTimeout() |
| 655 | |
| 656 | Creates a connection from the timeout() signal to the \a slot in the \a receiver object. Returns |
| 657 | a handle to the connection. |
| 658 | |
| 659 | This method is provided for convenience. It's equivalent to calling |
| 660 | \c {QObject::connect(timer, &QTimer::timeout, receiver, slot, connectionType)}. |
| 661 | |
| 662 | \sa QObject::connect(), timeout() |
| 663 | */ |
| 664 | |
| 665 | /*! |
| 666 | \fn void QTimer::start(std::chrono::milliseconds msec) |
| 667 | \since 5.8 |
| 668 | \overload |
| 669 | |
| 670 | Starts or restarts the timer with a timeout of duration \a msec milliseconds. |
| 671 | |
| 672 | If the timer is already running, it will be |
| 673 | \l{QTimer::stop()}{stopped} and restarted. |
| 674 | |
| 675 | If \l singleShot is true, the timer will be activated only once. |
| 676 | */ |
| 677 | |
| 678 | /*! |
| 679 | \fn std::chrono::milliseconds QTimer::intervalAsDuration() const |
| 680 | \since 5.8 |
| 681 | |
| 682 | Returns the interval of this timer as a \c std::chrono::milliseconds object. |
| 683 | |
| 684 | \sa interval |
| 685 | */ |
| 686 | |
| 687 | /*! |
| 688 | \fn std::chrono::milliseconds QTimer::remainingTimeAsDuration() const |
| 689 | \since 5.8 |
| 690 | |
| 691 | Returns the time remaining in this timer object as a \c |
| 692 | std::chrono::milliseconds object. If this timer is due or overdue, the |
| 693 | returned value is \c std::chrono::milliseconds::zero(). If the remaining |
| 694 | time could not be found or the timer is not active, this function returns a |
| 695 | negative duration. |
| 696 | |
| 697 | \sa remainingTime() |
| 698 | */ |
| 699 | |
| 700 | /*! |
| 701 | \property QTimer::singleShot |
| 702 | \brief whether the timer is a single-shot timer |
| 703 | |
| 704 | A single-shot timer fires only once, non-single-shot timers fire |
| 705 | every \l interval milliseconds. |
| 706 | |
| 707 | The default value for this property is \c false. |
| 708 | |
| 709 | \sa interval, singleShot() |
| 710 | */ |
| 711 | void QTimer::setSingleShot(bool singleShot) |
| 712 | { |
| 713 | d_func()->single = singleShot; |
| 714 | } |
| 715 | |
| 716 | bool QTimer::isSingleShot() const |
| 717 | { |
| 718 | return d_func()->single; |
| 719 | } |
| 720 | |
| 721 | /*! |
| 722 | \property QTimer::interval |
| 723 | \brief the timeout interval in milliseconds |
| 724 | |
| 725 | The default value for this property is 0. A QTimer with a timeout |
| 726 | interval of 0 will time out as soon as all the events in the window |
| 727 | system's event queue have been processed. |
| 728 | |
| 729 | Setting the interval of an active timer changes its timerId(). |
| 730 | |
| 731 | \sa singleShot |
| 732 | */ |
| 733 | void QTimer::setInterval(int msec) |
| 734 | { |
| 735 | Q_D(QTimer); |
| 736 | d->inter = msec; |
| 737 | if (d->id != INV_TIMER) { // create new timer |
| 738 | QObject::killTimer(d->id); // restart timer |
| 739 | d->id = QObject::startTimer(msec, d->type); |
| 740 | } |
| 741 | } |
| 742 | |
| 743 | int QTimer::interval() const |
| 744 | { |
| 745 | return d_func()->inter; |
| 746 | } |
| 747 | |
| 748 | /*! |
| 749 | \property QTimer::remainingTime |
| 750 | \since 5.0 |
| 751 | \brief the remaining time in milliseconds |
| 752 | |
| 753 | Returns the timer's remaining value in milliseconds left until the timeout. |
| 754 | If the timer is inactive, the returned value will be -1. If the timer is |
| 755 | overdue, the returned value will be 0. |
| 756 | |
| 757 | \sa interval |
| 758 | */ |
| 759 | int QTimer::remainingTime() const |
| 760 | { |
| 761 | Q_D(const QTimer); |
| 762 | if (d->id != INV_TIMER) { |
| 763 | return QAbstractEventDispatcher::instance()->remainingTime(d->id); |
| 764 | } |
| 765 | |
| 766 | return -1; |
| 767 | } |
| 768 | |
| 769 | /*! |
| 770 | \property QTimer::timerType |
| 771 | \brief controls the accuracy of the timer |
| 772 | |
| 773 | The default value for this property is \c Qt::CoarseTimer. |
| 774 | |
| 775 | \sa Qt::TimerType |
| 776 | */ |
| 777 | void QTimer::setTimerType(Qt::TimerType atype) |
| 778 | { |
| 779 | d_func()->type = atype; |
| 780 | } |
| 781 | |
| 782 | Qt::TimerType QTimer::timerType() const |
| 783 | { |
| 784 | return d_func()->type; |
| 785 | } |
| 786 | |
| 787 | QT_END_NAMESPACE |
| 788 | |
| 789 | #include "qtimer.moc" |
| 790 | #include "moc_qtimer.cpp" |
| 791 | |