1// Copyright (C) 2022 The Qt Company Ltd.
2// Copyright (C) 2016 Intel Corporation.
3// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
4
5#include "qcoreevent.h"
6#include "qcoreevent_p.h"
7#include "qcoreapplication.h"
8#include "qcoreapplication_p.h"
9
10#include "qbasicatomic.h"
11
12#include <qtcore_tracepoints_p.h>
13
14#include <limits>
15
16QT_BEGIN_NAMESPACE
17
18Q_TRACE_POINT(qtcore, QEvent_ctor, QEvent *event, QEvent::Type type);
19Q_TRACE_POINT(qtcore, QEvent_dtor, QEvent *event, QEvent::Type type);
20
21/*!
22 \class QEvent
23 \inmodule QtCore
24 \brief The QEvent class is the base class of all
25 event classes. Event objects contain event parameters.
26
27 \ingroup events
28
29 Qt's main event loop (QCoreApplication::exec()) fetches native
30 window system events from the event queue, translates them into
31 QEvents, and sends the translated events to \l{QObject}s.
32
33 In general, events come from the underlying window system
34 (spontaneous() returns \c true), but it is also possible to manually
35 send events using QCoreApplication::sendEvent() and
36 QCoreApplication::postEvent() (spontaneous() returns \c false).
37
38 \l {QObject}{QObjects} receive events by having their QObject::event() function
39 called. The function can be reimplemented in subclasses to
40 customize event handling and add additional event types;
41 QWidget::event() is a notable example. By default, events are
42 dispatched to event handlers like QObject::timerEvent() and
43 QWidget::mouseMoveEvent(). QObject::installEventFilter() allows an
44 object to intercept events destined for another object.
45
46 The basic QEvent contains only an event type parameter and an
47 "accept" flag. The accept flag set with accept(), and cleared
48 with ignore(). It is set by default, but don't rely on this as
49 subclasses may choose to clear it in their constructor.
50
51 Subclasses of QEvent contain additional parameters that describe
52 the particular event.
53
54 \sa QObject::event(), QObject::installEventFilter(),
55 QCoreApplication::sendEvent(),
56 QCoreApplication::postEvent(), QCoreApplication::processEvents()
57*/
58
59
60/*!
61 \enum QEvent::Type
62
63 This enum type defines the valid event types in Qt. The event
64 types and the specialized classes for each type are as follows:
65
66 \value None Not an event.
67 \value ActionAdded A new action has been added (QActionEvent).
68 \value ActionChanged An action has been changed (QActionEvent).
69 \value ActionRemoved An action has been removed (QActionEvent).
70 \value ActivationChange A widget's top-level window activation state has changed.
71 \value ApplicationActivate This enum has been deprecated. Use ApplicationStateChange instead.
72 \value ApplicationActivated This enum has been deprecated. Use ApplicationStateChange instead.
73 \value ApplicationDeactivate This enum has been deprecated. Use ApplicationStateChange instead.
74 \value ApplicationFontChange The default application font has changed.
75 \value ApplicationLayoutDirectionChange The default application layout direction has changed.
76 \value ApplicationPaletteChange The default application palette has changed.
77 \value ApplicationStateChange The state of the application has changed.
78 \value ApplicationWindowIconChange The application's icon has changed.
79 \value ChildAdded An object gets a child (QChildEvent).
80 \value ChildPolished A widget child gets polished (QChildEvent).
81 \value ChildRemoved An object loses a child (QChildEvent).
82 \value [since 6.7] ChildWindowAdded A child window was added to the window.
83 \value [since 6.7] ChildWindowRemoved A child window was removed from the window.
84 \value Clipboard The clipboard contents have changed.
85 \value Close Widget was closed (QCloseEvent).
86 \value CloseSoftwareInputPanel A widget wants to close the software input panel (SIP).
87 \value ContentsRectChange The margins of the widget's content rect changed.
88 \value ContextMenu Context popup menu (QContextMenuEvent).
89 \value CursorChange The widget's cursor has changed.
90 \value DeferredDelete The object will be deleted after it has cleaned up (QDeferredDeleteEvent)
91 \value [since 6.6] DevicePixelRatioChange
92 The devicePixelRatio has changed for this widget's or window's underlying backing store.
93 \value DragEnter The cursor enters a widget during a drag and drop operation (QDragEnterEvent).
94 \value DragLeave The cursor leaves a widget during a drag and drop operation (QDragLeaveEvent).
95 \value DragMove A drag and drop operation is in progress (QDragMoveEvent).
96 \value Drop A drag and drop operation is completed (QDropEvent).
97 \value DynamicPropertyChange A dynamic property was added, changed, or removed from the object.
98 \value EnabledChange Widget's enabled state has changed.
99 \value Enter Mouse enters widget's boundaries (QEnterEvent).
100 \value EnterEditFocus An editor widget gains focus for editing. \c QT_KEYPAD_NAVIGATION must be defined.
101 \value EnterWhatsThisMode Send to toplevel widgets when the application enters "What's This?" mode.
102 \value Expose Sent to a window when its on-screen contents are invalidated and need to be flushed from the backing store.
103 \value FileOpen File open request (QFileOpenEvent).
104 \value FocusIn Widget or Window gains keyboard focus (QFocusEvent).
105 \value FocusOut Widget or Window loses keyboard focus (QFocusEvent).
106 \value FocusAboutToChange Widget or Window focus is about to change (QFocusEvent)
107 \value FontChange Widget's font has changed.
108 \value Gesture A gesture was triggered (QGestureEvent).
109 \value GestureOverride A gesture override was triggered (QGestureEvent).
110 \value GrabKeyboard Item gains keyboard grab (QGraphicsItem only).
111 \value GrabMouse Item gains mouse grab (QGraphicsItem only).
112 \value GraphicsSceneContextMenu Context popup menu over a graphics scene (QGraphicsSceneContextMenuEvent).
113 \value GraphicsSceneDragEnter The cursor enters a graphics scene during a drag and drop operation (QGraphicsSceneDragDropEvent).
114 \value GraphicsSceneDragLeave The cursor leaves a graphics scene during a drag and drop operation (QGraphicsSceneDragDropEvent).
115 \value GraphicsSceneDragMove A drag and drop operation is in progress over a scene (QGraphicsSceneDragDropEvent).
116 \value GraphicsSceneDrop A drag and drop operation is completed over a scene (QGraphicsSceneDragDropEvent).
117 \value GraphicsSceneHelp The user requests help for a graphics scene (QHelpEvent).
118 \value GraphicsSceneHoverEnter The mouse cursor enters a hover item in a graphics scene (QGraphicsSceneHoverEvent).
119 \value GraphicsSceneHoverLeave The mouse cursor leaves a hover item in a graphics scene (QGraphicsSceneHoverEvent).
120 \value GraphicsSceneHoverMove The mouse cursor moves inside a hover item in a graphics scene (QGraphicsSceneHoverEvent).
121 \value GraphicsSceneMouseDoubleClick Mouse press again (double click) in a graphics scene (QGraphicsSceneMouseEvent).
122 \value GraphicsSceneMouseMove Move mouse in a graphics scene (QGraphicsSceneMouseEvent).
123 \value GraphicsSceneMousePress Mouse press in a graphics scene (QGraphicsSceneMouseEvent).
124 \value GraphicsSceneMouseRelease Mouse release in a graphics scene (QGraphicsSceneMouseEvent).
125 \value GraphicsSceneMove Widget was moved (QGraphicsSceneMoveEvent).
126 \value GraphicsSceneResize Widget was resized (QGraphicsSceneResizeEvent).
127 \value GraphicsSceneWheel Mouse wheel rolled in a graphics scene (QGraphicsSceneWheelEvent).
128 \value GraphicsSceneLeave The cursor leaves a graphics scene (QGraphicsSceneWheelEvent).
129 \value Hide Widget was hidden (QHideEvent).
130 \value HideToParent A child widget has been hidden.
131 \value HoverEnter The mouse cursor enters a hover widget (QHoverEvent).
132 \value HoverLeave The mouse cursor leaves a hover widget (QHoverEvent).
133 \value HoverMove The mouse cursor moves inside a hover widget (QHoverEvent).
134 \value IconDrag The main icon of a window has been dragged away (QIconDragEvent).
135 \value IconTextChange Widget's icon text has been changed. (Deprecated)
136 \value InputMethod An input method is being used (QInputMethodEvent).
137 \value InputMethodQuery A input method query event (QInputMethodQueryEvent)
138 \value KeyboardLayoutChange The keyboard layout has changed.
139 \value KeyPress Key press (QKeyEvent).
140 \value KeyRelease Key release (QKeyEvent).
141 \value LanguageChange The application translation changed.
142 \value LayoutDirectionChange The direction of layouts changed.
143 \value LayoutRequest Widget layout needs to be redone.
144 \value Leave Mouse leaves widget's boundaries.
145 \value LeaveEditFocus An editor widget loses focus for editing. QT_KEYPAD_NAVIGATION must be defined.
146 \value LeaveWhatsThisMode Send to toplevel widgets when the application leaves "What's This?" mode.
147 \value LocaleChange The system locale has changed.
148 \value NonClientAreaMouseButtonDblClick A mouse double click occurred outside the client area (QMouseEvent).
149 \value NonClientAreaMouseButtonPress A mouse button press occurred outside the client area (QMouseEvent).
150 \value NonClientAreaMouseButtonRelease A mouse button release occurred outside the client area (QMouseEvent).
151 \value NonClientAreaMouseMove A mouse move occurred outside the client area (QMouseEvent).
152 \value MacSizeChange The user changed his widget sizes (\macos only).
153 \value MetaCall An asynchronous method invocation via QMetaObject::invokeMethod().
154 \value ModifiedChange Widgets modification state has been changed.
155 \value MouseButtonDblClick Mouse press again (QMouseEvent).
156 \value MouseButtonPress Mouse press (QMouseEvent).
157 \value MouseButtonRelease Mouse release (QMouseEvent).
158 \value MouseMove Mouse move (QMouseEvent).
159 \value MouseTrackingChange The mouse tracking state has changed.
160 \value Move Widget's position changed (QMoveEvent).
161 \value NativeGesture The system has detected a gesture (QNativeGestureEvent).
162 \value OrientationChange The screens orientation has changes (QScreenOrientationChangeEvent).
163 \value Paint Screen update necessary (QPaintEvent).
164 \value PaletteChange Palette of the widget changed.
165 \value ParentAboutToChange The object parent is about to change.
166 Only sent to some object types, such as QWidget.
167 \value ParentChange The object parent has changed.
168 Only sent to some object types, such as QWidget.
169 \value [since 6.7] ParentWindowAboutToChange The parent window is about to change.
170 \value [since 6.7] ParentWindowChange The parent window has changed.
171 \value PlatformPanel A platform specific panel has been requested.
172 \value PlatformSurface A native platform surface has been created or is about to be destroyed (QPlatformSurfaceEvent).
173 \omitvalue Pointer
174 \value Polish The widget is polished.
175 \value PolishRequest The widget should be polished.
176 \value QueryWhatsThis The widget should accept the event if it has "What's This?" help (QHelpEvent).
177 \value Quit The application has exited.
178 \value [since 5.4] ReadOnlyChange Widget's read-only state has changed.
179 \value RequestSoftwareInputPanel A widget wants to open a software input panel (SIP).
180 \value Resize Widget's size changed (QResizeEvent).
181 \value ScrollPrepare The object needs to fill in its geometry information (QScrollPrepareEvent).
182 \value Scroll The object needs to scroll to the supplied position (QScrollEvent).
183 \value Shortcut Key press in child for shortcut key handling (QShortcutEvent).
184 \value ShortcutOverride Key press in child, for overriding shortcut key handling (QKeyEvent).
185 When a shortcut is about to trigger, \c ShortcutOverride
186 is sent to the active window. This allows clients (e.g. widgets)
187 to signal that they will handle the shortcut themselves, by
188 accepting the event. If the shortcut override is accepted, the
189 event is delivered as a normal key press to the focus widget.
190 Otherwise, it triggers the shortcut action, if one exists.
191 \value Show Widget was shown on screen (QShowEvent).
192 \value ShowToParent A child widget has been shown.
193 \value SockAct Socket activated, used to implement QSocketNotifier.
194 \omitvalue SockClose
195 \value StateMachineSignal A signal delivered to a state machine (QStateMachine::SignalEvent).
196 \value StateMachineWrapped The event is a wrapper for, i.e., contains, another event (QStateMachine::WrappedEvent).
197 \value StatusTip A status tip is requested (QStatusTipEvent).
198 \value StyleChange Widget's style has been changed.
199 \value TabletMove Wacom tablet move (QTabletEvent).
200 \value TabletPress Wacom tablet press (QTabletEvent).
201 \value TabletRelease Wacom tablet release (QTabletEvent).
202 \omitvalue OkRequest
203 \value TabletEnterProximity Wacom tablet enter proximity event (QTabletEvent), sent to QApplication.
204 \value TabletLeaveProximity Wacom tablet leave proximity event (QTabletEvent), sent to QApplication.
205 \value [since 5.9] TabletTrackingChange The Wacom tablet tracking state has changed.
206 \omitvalue ThemeChange
207 \value ThreadChange The object is moved to another thread. This is the last event sent to this object in the previous thread. See QObject::moveToThread().
208 \value Timer Regular timer events (QTimerEvent).
209 \value ToolBarChange The toolbar button is toggled on \macos.
210 \value ToolTip A tooltip was requested (QHelpEvent).
211 \value ToolTipChange The widget's tooltip has changed.
212 \value TouchBegin Beginning of a sequence of touch-screen or track-pad events (QTouchEvent).
213 \value TouchCancel Cancellation of touch-event sequence (QTouchEvent).
214 \value TouchEnd End of touch-event sequence (QTouchEvent).
215 \value TouchUpdate Touch-screen event (QTouchEvent).
216 \value UngrabKeyboard Item loses keyboard grab (QGraphicsItem only).
217 \value UngrabMouse Item loses mouse grab (QGraphicsItem, QQuickItem).
218 \value UpdateLater The widget should be queued to be repainted at a later time.
219 \value UpdateRequest The widget should be repainted.
220 \value WhatsThis The widget should reveal "What's This?" help (QHelpEvent).
221 \value WhatsThisClicked A link in a widget's "What's This?" help was clicked.
222 \value Wheel Mouse wheel rolled (QWheelEvent).
223 \value WinEventAct A Windows-specific activation event has occurred.
224 \value WindowActivate Window was activated.
225 \value WindowBlocked The window is blocked by a modal dialog.
226 \value WindowDeactivate Window was deactivated.
227 \value WindowIconChange The window's icon has changed.
228 \value WindowStateChange The \l{QWindow::windowState()}{window's state} (minimized, maximized or full-screen) has changed (QWindowStateChangeEvent).
229 \value WindowTitleChange The window title has changed.
230 \value WindowUnblocked The window is unblocked after a modal dialog exited.
231 \value WinIdChange The window system identifier for this native widget has changed.
232 \value ZOrderChange The widget's z-order has changed. This event is never sent to top level windows.
233
234 User events should have values between \c User and \c{MaxUser}:
235
236 \value User User-defined event.
237 \value MaxUser Last user event ID.
238
239 For convenience, you can use the registerEventType() function to
240 register and reserve a custom event type for your
241 application. Doing so will allow you to avoid accidentally
242 re-using a custom event type already in use elsewhere in your
243 application.
244
245 \omitvalue AcceptDropsChange
246 \omitvalue ActivateControl
247 \omitvalue Create
248 \omitvalue DeactivateControl
249 \omitvalue Destroy
250 \omitvalue DragResponse
251 \omitvalue EmbeddingControl
252 \omitvalue HelpRequest
253 \omitvalue Quit
254 \omitvalue ShowWindowRequest
255 \omitvalue Speech
256 \omitvalue Style
257 \omitvalue StyleAnimationUpdate
258 \omitvalue ZeroTimerEvent
259 \omitvalue ApplicationActivate
260 \omitvalue ApplicationActivated
261 \omitvalue ApplicationDeactivate
262 \omitvalue ApplicationDeactivated
263 \omitvalue MacGLWindowChange
264 \omitvalue NetworkReplyUpdated
265 \omitvalue FutureCallOut
266 \omitvalue NativeGesture
267 \omitvalue WindowChangeInternal
268 \omitvalue ScreenChangeInternal
269 \omitvalue WindowAboutToChangeInternal
270*/
271
272/*!
273 Constructs an event object of type \a type.
274*/
275QEvent::QEvent(Type type)
276 : t(type), m_reserved(0),
277 m_inputEvent(false), m_pointerEvent(false), m_singlePointEvent(false)
278{
279 Q_TRACE(QEvent_ctor, this, type);
280}
281
282/*!
283 \fn QEvent::QEvent(const QEvent &other)
284 \internal
285 Copies the \a other event.
286*/
287
288/*!
289 \internal
290 \since 6.0
291 \fn QEvent::QEvent(Type type, QEvent::InputEventTag)
292
293 Constructs an event object of type \a type, setting the inputEvent flag to \c true.
294*/
295
296/*!
297 \internal
298 \since 6.0
299 \fn QEvent::QEvent(Type type, QEvent::PointerEventTag)
300
301 Constructs an event object of type \a type, setting the pointerEvent and
302 inputEvent flags to \c true.
303*/
304
305/*!
306 \internal
307 \since 6.0
308 \fn QEvent::QEvent(Type type, QEvent::SinglePointEventTag)
309
310 Constructs an event object of type \a type, setting the singlePointEvent,
311 pointerEvent and inputEvent flags to \c true.
312*/
313
314/*!
315 \fn QEvent &QEvent::operator=(const QEvent &other)
316 \internal
317 Attempts to copy the \a other event.
318
319 Copying events is a bad idea, yet some Qt 4 code does it (notably,
320 QApplication and the state machine).
321 */
322
323/*!
324 Destroys the event. If it was \l{QCoreApplication::postEvent()}{posted},
325 it will be removed from the list of events to be posted.
326*/
327
328QEvent::~QEvent()
329{
330 if (m_posted && QCoreApplication::instance())
331 QCoreApplicationPrivate::removePostedEvent(this);
332}
333
334/*!
335 Creates and returns an identical copy of this event.
336 \since 6.0
337*/
338QEvent *QEvent::clone() const
339{ return new QEvent(*this); }
340
341/*!
342 \property QEvent::accepted
343 \brief the accept flag of the event object.
344
345 Setting the accept parameter indicates that the event receiver
346 wants the event. Unwanted events might be propagated to the parent
347 widget. By default, isAccepted() is set to true, but don't rely on
348 this as subclasses may choose to clear it in their constructor.
349
350 For convenience, the accept flag can also be set with accept(),
351 and cleared with ignore().
352
353 \note Accepting a QPointerEvent implicitly
354 \l {QEventPoint::setAccepted()}{accepts} all the
355 \l {QPointerEvent::points()}{points} that the event carries.
356*/
357
358/*!
359 \fn void QEvent::accept()
360
361 Sets the accept flag of the event object, the equivalent of
362 calling setAccepted(true).
363
364 Setting the accept parameter indicates that the event receiver
365 wants the event. Unwanted events might be propagated to the parent
366 widget.
367
368 \sa ignore()
369*/
370
371
372/*!
373 \fn void QEvent::ignore()
374
375 Clears the accept flag parameter of the event object, the
376 equivalent of calling setAccepted(false).
377
378 Clearing the accept parameter indicates that the event receiver
379 does not want the event. Unwanted events might be propagated to the
380 parent widget.
381
382 \sa accept()
383*/
384
385
386/*!
387 \fn QEvent::Type QEvent::type() const
388
389 Returns the event type.
390*/
391
392/*!
393 \fn bool QEvent::spontaneous() const
394
395 Returns \c true if the event originated outside the application (a
396 system event); otherwise returns \c false.
397*/
398
399/*!
400 \fn bool QEvent::isInputEvent() const
401 \since 6.0
402
403 Returns \c true if the event object is a QInputEvent or one of its
404 subclasses.
405*/
406
407/*!
408 \fn bool QEvent::isPointerEvent() const
409 \since 6.0
410
411 Returns \c true if the event object is a QPointerEvent or one of its
412 subclasses.
413*/
414
415/*!
416 \fn bool QEvent::isSinglePointEvent() const
417 \since 6.0
418
419 Returns \c true if the event object is a subclass of QSinglePointEvent.
420*/
421
422namespace {
423template <size_t N>
424struct QBasicAtomicBitField {
425 enum {
426 BitsPerInt = std::numeric_limits<uint>::digits,
427 NumInts = (N + BitsPerInt - 1) / BitsPerInt,
428 NumBits = N
429 };
430
431 // This atomic int points to the next (possibly) free ID saving
432 // the otherwise necessary scan through 'data':
433 QBasicAtomicInteger<uint> next;
434 QBasicAtomicInteger<uint> data[NumInts];
435
436 constexpr QBasicAtomicBitField() = default;
437
438 bool allocateSpecific(int which) noexcept
439 {
440 QBasicAtomicInteger<uint> &entry = data[which / BitsPerInt];
441 const uint old = entry.loadRelaxed();
442 const uint bit = 1U << (which % BitsPerInt);
443 if (old & bit)
444 return false; // already taken
445 return (entry.fetchAndOrRelaxed(valueToAdd: bit) & bit) == 0;
446
447 // don't update 'next' here - it's unlikely that it will need
448 // to be updated, in the general case, and having 'next'
449 // trailing a bit is not a problem, as it is just a starting
450 // hint for allocateNext(), which, when wrong, will just
451 // result in a few more rounds through the allocateNext()
452 // loop.
453 }
454
455 int allocateNext() noexcept
456 {
457 // Unroll loop to iterate over ints, then bits? Would save
458 // potentially a lot of cmpxchgs, because we can scan the
459 // whole int before having to load it again.
460
461 // Then again, this should never execute many iterations, so
462 // leave like this for now:
463 for (uint i = next.loadRelaxed(); i < NumBits; ++i) {
464 if (allocateSpecific(which: i)) {
465 // remember next (possibly) free id:
466 const uint oldNext = next.loadRelaxed();
467 next.testAndSetRelaxed(expectedValue: oldNext, newValue: qMax(a: i + 1, b: oldNext));
468 return i;
469 }
470 }
471 return -1;
472 }
473};
474
475} // unnamed namespace
476
477typedef QBasicAtomicBitField<QEvent::MaxUser - QEvent::User + 1> UserEventTypeRegistry;
478
479Q_CONSTINIT static UserEventTypeRegistry userEventTypeRegistry {};
480
481static inline int registerEventTypeZeroBased(int id) noexcept
482{
483 // if the type hint hasn't been registered yet, take it:
484 if (id < UserEventTypeRegistry::NumBits && id >= 0 && userEventTypeRegistry.allocateSpecific(which: id))
485 return id;
486
487 // otherwise, ignore hint:
488 return userEventTypeRegistry.allocateNext();
489}
490
491/*!
492 \since 4.4
493 \threadsafe
494
495 Registers and returns a custom event type. The \a hint provided
496 will be used if it is available, otherwise it will return a value
497 between QEvent::User and QEvent::MaxUser that has not yet been
498 registered. The \a hint is ignored if its value is not between
499 QEvent::User and QEvent::MaxUser.
500
501 Returns -1 if all available values are already taken or the
502 program is shutting down.
503*/
504int QEvent::registerEventType(int hint) noexcept
505{
506 const int result = registerEventTypeZeroBased(id: QEvent::MaxUser - hint);
507 return result < 0 ? -1 : QEvent::MaxUser - result ;
508}
509
510/*!
511 \class QTimerEvent
512 \inmodule QtCore
513 \brief The QTimerEvent class contains parameters that describe a
514 timer event.
515
516 \ingroup events
517
518 Timer events are sent at regular intervals to objects that have
519 started one or more timers. Each timer has a unique identifier. A
520 timer is started with QObject::startTimer().
521
522 The QChronoTimer class provides a high-level programming interface that
523 uses signals instead of events.
524
525 The event handler QObject::timerEvent() receives timer events.
526
527 \sa QChronoTimer, QObject::timerEvent(), QObject::startTimer(),
528 QObject::killTimer()
529*/
530
531/*!
532 Constructs a timer event object with the timer identifier set to
533 \a timerId.
534*/
535QTimerEvent::QTimerEvent(int timerId)
536 : QTimerEvent(Qt::TimerId{timerId})
537{}
538
539/*!
540 \since 6.8
541
542 Constructs a timer event object with the timer identifier set to
543 \a timerId.
544*/
545QTimerEvent::QTimerEvent(Qt::TimerId timerId)
546 : QEvent(Timer), m_id(timerId)
547{
548 static_assert(sizeof(Qt::TimerId) == sizeof(int));
549}
550
551Q_IMPL_EVENT_COMMON(QTimerEvent)
552
553/*!
554 \fn int QTimerEvent::timerId() const
555
556 Returns the unique timer identifier, which is the same identifier
557 as returned from QObject::startTimer().
558*/
559
560/*!
561 \fn Qt::TimerId QTimerEvent::id() const
562 \since 6.8
563
564 Returns the Qt::TimerId of the timer associated with this event, which
565 is the same identifier returned by QObject::startTimer() cast to
566 Qt::TimerId.
567*/
568
569/*!
570 \class QChildEvent
571 \inmodule QtCore
572 \brief The QChildEvent class contains event parameters for child object
573 events.
574
575 \ingroup events
576
577 Child events are sent immediately to objects when children are
578 added or removed.
579
580 In both cases you can only rely on the child being a QObject (or,
581 if QObject::isWidgetType() returns \c true, a QWidget). This is
582 because in the QEvent::ChildAdded case the child is not yet fully
583 constructed; in the QEvent::ChildRemoved case it might have
584 already been destructed.
585
586 The handler for these events is QObject::childEvent().
587*/
588
589/*!
590 Constructs a child event object of a particular \a type for the
591 \a child.
592
593 \a type can be QEvent::ChildAdded, QEvent::ChildRemoved,
594 or QEvent::ChildPolished.
595
596 \sa child()
597*/
598QChildEvent::QChildEvent(Type type, QObject *child)
599 : QEvent(type), c(child)
600{}
601
602Q_IMPL_EVENT_COMMON(QChildEvent)
603
604/*!
605 \fn QObject *QChildEvent::child() const
606
607 Returns the child object that was added or removed.
608*/
609
610/*!
611 \fn bool QChildEvent::added() const
612
613 Returns \c true if type() is QEvent::ChildAdded; otherwise returns
614 false.
615*/
616
617/*!
618 \fn bool QChildEvent::removed() const
619
620 Returns \c true if type() is QEvent::ChildRemoved; otherwise returns
621 false.
622*/
623
624/*!
625 \fn bool QChildEvent::polished() const
626
627 Returns \c true if type() is QEvent::ChildPolished; otherwise returns
628 false.
629*/
630
631
632/*!
633 \class QDynamicPropertyChangeEvent
634 \inmodule QtCore
635 \since 4.2
636 \brief The QDynamicPropertyChangeEvent class contains event parameters for dynamic
637 property change events.
638
639 \ingroup events
640
641 Dynamic property change events are sent to objects when properties are
642 dynamically added, changed or removed using QObject::setProperty().
643*/
644
645/*!
646 Constructs a dynamic property change event object with the property name set to
647 \a name.
648*/
649QDynamicPropertyChangeEvent::QDynamicPropertyChangeEvent(const QByteArray &name)
650 : QEvent(QEvent::DynamicPropertyChange), n(name)
651{
652}
653
654Q_IMPL_EVENT_COMMON(QDynamicPropertyChangeEvent)
655
656/*!
657 \fn QByteArray QDynamicPropertyChangeEvent::propertyName() const
658
659 Returns the name of the dynamic property that was added, changed or
660 removed.
661
662 \sa QObject::setProperty(), QObject::dynamicPropertyNames()
663*/
664
665/*!
666 Constructs a deferred delete event with the given loop and scope level.
667*/
668QDeferredDeleteEvent::QDeferredDeleteEvent(int loopLevel, int scopeLevel)
669 : QEvent(QEvent::DeferredDelete), m_loopLevel(loopLevel), m_scopeLevel(scopeLevel)
670{ }
671
672Q_IMPL_EVENT_COMMON(QDeferredDeleteEvent)
673
674QT_END_NAMESPACE
675
676#include "moc_qcoreevent.cpp"
677

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source code of qtbase/src/corelib/kernel/qcoreevent.cpp