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These rights are described in the Digia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "qcoreevent.h" #include "qcoreapplication.h" #include "qcoreapplication_p.h" #include "qbasicatomic.h" #include QT_BEGIN_NAMESPACE /*! \class QEvent \inmodule QtCore \brief The QEvent class is the base class of all event classes. Event objects contain event parameters. \ingroup events Qt's main event loop (QCoreApplication::exec()) fetches native window system events from the event queue, translates them into QEvents, and sends the translated events to \l{QObject}s. In general, events come from the underlying window system (spontaneous() returns \c true), but it is also possible to manually send events using QCoreApplication::sendEvent() and QCoreApplication::postEvent() (spontaneous() returns \c false). QObjects receive events by having their QObject::event() function called. The function can be reimplemented in subclasses to customize event handling and add additional event types; QWidget::event() is a notable example. By default, events are dispatched to event handlers like QObject::timerEvent() and QWidget::mouseMoveEvent(). QObject::installEventFilter() allows an object to intercept events destined for another object. The basic QEvent contains only an event type parameter and an "accept" flag. The accept flag set with accept(), and cleared with ignore(). It is set by default, but don't rely on this as subclasses may choose to clear it in their constructor. Subclasses of QEvent contain additional parameters that describe the particular event. \sa QObject::event(), QObject::installEventFilter(), QCoreApplication::sendEvent(), QCoreApplication::postEvent(), QCoreApplication::processEvents() */ /*! \enum QEvent::Type This enum type defines the valid event types in Qt. The event types and the specialized classes for each type are as follows: \value None Not an event. \value ActionAdded A new action has been added (QActionEvent). \value ActionChanged An action has been changed (QActionEvent). \value ActionRemoved An action has been removed (QActionEvent). \value ActivationChange A widget's top-level window activation state has changed. \value ApplicationActivate This enum has been deprecated. Use ApplicationStateChange instead. \value ApplicationActivated This enum has been deprecated. Use ApplicationStateChange instead. \value ApplicationDeactivate This enum has been deprecated. Use ApplicationStateChange instead. \value ApplicationFontChange The default application font has changed. \value ApplicationLayoutDirectionChange The default application layout direction has changed. \value ApplicationPaletteChange The default application palette has changed. \value ApplicationStateChange The state of the application has changed. \value ApplicationWindowIconChange The application's icon has changed. \value ChildAdded An object gets a child (QChildEvent). \value ChildPolished A widget child gets polished (QChildEvent). \value ChildRemoved An object loses a child (QChildEvent). \value Clipboard The clipboard contents have changed (QClipboardEvent). \value Close Widget was closed (QCloseEvent). \value CloseSoftwareInputPanel A widget wants to close the software input panel (SIP). \value ContentsRectChange The margins of the widget's content rect changed. \value ContextMenu Context popup menu (QContextMenuEvent). \value CursorChange The widget's cursor has changed. \value DeferredDelete The object will be deleted after it has cleaned up (QDeferredDeleteEvent). \value DragEnter The cursor enters a widget during a drag and drop operation (QDragEnterEvent). \value DragLeave The cursor leaves a widget during a drag and drop operation (QDragLeaveEvent). \value DragMove A drag and drop operation is in progress (QDragMoveEvent). \value Drop A drag and drop operation is completed (QDropEvent). \value DynamicPropertyChange A dynamic property was added, changed, or removed from the object. \value EnabledChange Widget's enabled state has changed. \value Enter Mouse enters widget's boundaries (QEnterEvent). \value EnterEditFocus An editor widget gains focus for editing. QT_KEYPAD_NAVIGATION must be defined. \value EnterWhatsThisMode Send to toplevel widgets when the application enters "What's This?" mode. \value Expose Sent to a window when its on-screen contents are invalidated and need to be flushed from the backing store. \value FileOpen File open request (QFileOpenEvent). \value FocusIn Widget or Window gains keyboard focus (QFocusEvent). \value FocusOut Widget or Window loses keyboard focus (QFocusEvent). \value FocusAboutToChange Widget or Window focus is about to change (QFocusEvent) \value FontChange Widget's font has changed. \value Gesture A gesture was triggered (QGestureEvent). \value GestureOverride A gesture override was triggered (QGestureEvent). \value GrabKeyboard Item gains keyboard grab (QGraphicsItem only). \value GrabMouse Item gains mouse grab (QGraphicsItem only). \value GraphicsSceneContextMenu Context popup menu over a graphics scene (QGraphicsSceneContextMenuEvent). \value GraphicsSceneDragEnter The cursor enters a graphics scene during a drag and drop operation (QGraphicsSceneDragDropEvent). \value GraphicsSceneDragLeave The cursor leaves a graphics scene during a drag and drop operation (QGraphicsSceneDragDropEvent). \value GraphicsSceneDragMove A drag and drop operation is in progress over a scene (QGraphicsSceneDragDropEvent). \value GraphicsSceneDrop A drag and drop operation is completed over a scene (QGraphicsSceneDragDropEvent). \value GraphicsSceneHelp The user requests help for a graphics scene (QHelpEvent). \value GraphicsSceneHoverEnter The mouse cursor enters a hover item in a graphics scene (QGraphicsSceneHoverEvent). \value GraphicsSceneHoverLeave The mouse cursor leaves a hover item in a graphics scene (QGraphicsSceneHoverEvent). \value GraphicsSceneHoverMove The mouse cursor moves inside a hover item in a graphics scene (QGraphicsSceneHoverEvent). \value GraphicsSceneMouseDoubleClick Mouse press again (double click) in a graphics scene (QGraphicsSceneMouseEvent). \value GraphicsSceneMouseMove Move mouse in a graphics scene (QGraphicsSceneMouseEvent). \value GraphicsSceneMousePress Mouse press in a graphics scene (QGraphicsSceneMouseEvent). \value GraphicsSceneMouseRelease Mouse release in a graphics scene (QGraphicsSceneMouseEvent). \value GraphicsSceneMove Widget was moved (QGraphicsSceneMoveEvent). \value GraphicsSceneResize Widget was resized (QGraphicsSceneResizeEvent). \value GraphicsSceneWheel Mouse wheel rolled in a graphics scene (QGraphicsSceneWheelEvent). \value Hide Widget was hidden (QHideEvent). \value HideToParent A child widget has been hidden. \value HoverEnter The mouse cursor enters a hover widget (QHoverEvent). \value HoverLeave The mouse cursor leaves a hover widget (QHoverEvent). \value HoverMove The mouse cursor moves inside a hover widget (QHoverEvent). \value IconDrag The main icon of a window has been dragged away (QIconDragEvent). \value IconTextChange Widget's icon text has been changed. \value InputMethod An input method is being used (QInputMethodEvent). \value InputMethodQuery A input method query event (QInputMethodQueryEvent) \value KeyboardLayoutChange The keyboard layout has changed. \value KeyPress Key press (QKeyEvent). \value KeyRelease Key release (QKeyEvent). \value LanguageChange The application translation changed. \value LayoutDirectionChange The direction of layouts changed. \value LayoutRequest Widget layout needs to be redone. \value Leave Mouse leaves widget's boundaries. \value LeaveEditFocus An editor widget loses focus for editing. QT_KEYPAD_NAVIGATION must be defined. \value LeaveWhatsThisMode Send to toplevel widgets when the application leaves "What's This?" mode. \value LocaleChange The system locale has changed. \value NonClientAreaMouseButtonDblClick A mouse double click occurred outside the client area. \value NonClientAreaMouseButtonPress A mouse button press occurred outside the client area. \value NonClientAreaMouseButtonRelease A mouse button release occurred outside the client area. \value NonClientAreaMouseMove A mouse move occurred outside the client area. \value MacSizeChange The user changed his widget sizes (Mac OS X only). \value MetaCall An asynchronous method invocation via QMetaObject::invokeMethod(). \value ModifiedChange Widgets modification state has been changed. \value MouseButtonDblClick Mouse press again (QMouseEvent). \value MouseButtonPress Mouse press (QMouseEvent). \value MouseButtonRelease Mouse release (QMouseEvent). \value MouseMove Mouse move (QMouseEvent). \value MouseTrackingChange The mouse tracking state has changed. \value Move Widget's position changed (QMoveEvent). \value OrientationChange The screens orientation has changes (QScreenOrientationChangeEvent) \value Paint Screen update necessary (QPaintEvent). \value PaletteChange Palette of the widget changed. \value ParentAboutToChange The widget parent is about to change. \value ParentChange The widget parent has changed. \value PlatformPanel A platform specific panel has been requested. \value Polish The widget is polished. \value PolishRequest The widget should be polished. \value QueryWhatsThis The widget should accept the event if it has "What's This?" help. \value ReadOnlyChange Widget's read-only state has changed (since Qt 5.4). \value RequestSoftwareInputPanel A widget wants to open a software input panel (SIP). \value Resize Widget's size changed (QResizeEvent). \value ScrollPrepare The object needs to fill in its geometry information (QScrollPrepareEvent). \value Scroll The object needs to scroll to the supplied position (QScrollEvent). \value Shortcut Key press in child for shortcut key handling (QShortcutEvent). \value ShortcutOverride Key press in child, for overriding shortcut key handling (QKeyEvent). \value Show Widget was shown on screen (QShowEvent). \value ShowToParent A child widget has been shown. \value SockAct Socket activated, used to implement QSocketNotifier. \omitvalue SockClose \value StateMachineSignal A signal delivered to a state machine (QStateMachine::SignalEvent). \value StateMachineWrapped The event is a wrapper for, i.e., contains, another event (QStateMachine::WrappedEvent). \value StatusTip A status tip is requested (QStatusTipEvent). \value StyleChange Widget's style has been changed. \value TabletMove Wacom tablet move (QTabletEvent). \value TabletPress Wacom tablet press (QTabletEvent). \value TabletRelease Wacom tablet release (QTabletEvent). \value OkRequest Ok button in decoration pressed. Supported only for Windows CE. \value TabletEnterProximity Wacom tablet enter proximity event (QTabletEvent), sent to QApplication. \value TabletLeaveProximity Wacom tablet leave proximity event (QTabletEvent), sent to QApplication. \omitvalue ThemeChange \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(). \value Timer Regular timer events (QTimerEvent). \value ToolBarChange The toolbar button is toggled on Mac OS X. \value ToolTip A tooltip was requested (QHelpEvent). \value ToolTipChange The widget's tooltip has changed. \value TouchBegin Beginning of a sequence of touch-screen or track-pad events (QTouchEvent). \value TouchCancel Cancellation of touch-event sequence (QTouchEvent). \value TouchEnd End of touch-event sequence (QTouchEvent). \value TouchUpdate Touch-screen event (QTouchEvent). \value UngrabKeyboard Item loses keyboard grab (QGraphicsItem only). \value UngrabMouse Item loses mouse grab (QGraphicsItem only). \value UpdateLater The widget should be queued to be repainted at a later time. \value UpdateRequest The widget should be repainted. \value WhatsThis The widget should reveal "What's This?" help (QHelpEvent). \value WhatsThisClicked A link in a widget's "What's This?" help was clicked. \value Wheel Mouse wheel rolled (QWheelEvent). \value WinEventAct A Windows-specific activation event has occurred. \value WindowActivate Window was activated. \value WindowBlocked The window is blocked by a modal dialog. \value WindowDeactivate Window was deactivated. \value WindowIconChange The window's icon has changed. \value WindowStateChange The \l{QWindow::windowState()}{window's state} (minimized, maximized or full-screen) has changed (QWindowStateChangeEvent). \value WindowTitleChange The window title has changed. \value WindowUnblocked The window is unblocked after a modal dialog exited. \value WinIdChange The window system identifer for this native widget has changed. \value ZOrderChange The widget's z-order has changed. This event is never sent to top level windows. User events should have values between \c User and \c{MaxUser}: \value User User-defined event. \value MaxUser Last user event ID. For convenience, you can use the registerEventType() function to register and reserve a custom event type for your application. Doing so will allow you to avoid accidentally re-using a custom event type already in use elsewhere in your application. \omitvalue AcceptDropsChange \omitvalue ActivateControl \omitvalue Create \omitvalue DeactivateControl \omitvalue Destroy \omitvalue DragResponse \omitvalue EmbeddingControl \omitvalue HelpRequest \omitvalue Quit \omitvalue ShowWindowRequest \omitvalue Speech \omitvalue Style \omitvalue StyleAnimationUpdate \omitvalue ZeroTimerEvent \omitvalue ApplicationActivate \omitvalue ApplicationActivated \omitvalue ApplicationDeactivate \omitvalue ApplicationDeactivated \omitvalue MacGLWindowChange \omitvalue MacGLClearDrawable \omitvalue NetworkReplyUpdated \omitvalue FutureCallOut \omitvalue NativeGesture \omitvalue WindowChangeInternal */ /*! Contructs an event object of type \a type. */ QEvent::QEvent(Type type) : d(0), t(type), posted(false), spont(false), m_accept(true) {} /*! \internal Attempts to copy the \a other event. Copying events is a bad idea, yet some Qt 4 code does it (notably, QApplication and the state machine). */ QEvent::QEvent(const QEvent &other) : d(other.d), t(other.t), posted(other.posted), spont(other.spont), m_accept(other.m_accept) { // if QEventPrivate becomes available, make sure to implement a // virtual QEventPrivate *clone() const; function so we can copy here Q_ASSERT_X(!d, "QEvent", "Impossible, this can't happen: QEventPrivate isn't defined anywhere"); } /*! \internal Attempts to copy the \a other event. Copying events is a bad idea, yet some Qt 4 code does it (notably, QApplication and the state machine). */ QEvent &QEvent::operator=(const QEvent &other) { // if QEventPrivate becomes available, make sure to implement a // virtual QEventPrivate *clone() const; function so we can copy here Q_ASSERT_X(!other.d, "QEvent", "Impossible, this can't happen: QEventPrivate isn't defined anywhere"); t = other.t; posted = other.posted; spont = other.spont; m_accept = other.m_accept; return *this; } /*! Destroys the event. If it was \l{QCoreApplication::postEvent()}{posted}, it will be removed from the list of events to be posted. */ QEvent::~QEvent() { if (posted && QCoreApplication::instance()) QCoreApplicationPrivate::removePostedEvent(this); Q_ASSERT_X(!d, "QEvent", "Impossible, this can't happen: QEventPrivate isn't defined anywhere"); } /*! \property QEvent::accepted the accept flag of the event object Setting the accept parameter indicates that the event receiver wants the event. Unwanted events might be propagated to the parent widget. By default, isAccepted() is set to true, but don't rely on this as subclasses may choose to clear it in their constructor. For convenience, the accept flag can also be set with accept(), and cleared with ignore(). */ /*! \fn void QEvent::accept() Sets the accept flag of the event object, the equivalent of calling setAccepted(true). Setting the accept parameter indicates that the event receiver wants the event. Unwanted events might be propagated to the parent widget. \sa ignore() */ /*! \fn void QEvent::ignore() Clears the accept flag parameter of the event object, the equivalent of calling setAccepted(false). Clearing the accept parameter indicates that the event receiver does not want the event. Unwanted events might be propagated to the parent widget. \sa accept() */ /*! \fn QEvent::Type QEvent::type() const Returns the event type. */ /*! \fn bool QEvent::spontaneous() const Returns \c true if the event originated outside the application (a system event); otherwise returns \c false. The return value of this function is not defined for paint events. */ namespace { template struct QBasicAtomicBitField { enum { BitsPerInt = std::numeric_limits::digits, NumInts = (N + BitsPerInt - 1) / BitsPerInt, NumBits = N }; // This atomic int points to the next (possibly) free ID saving // the otherwise necessary scan through 'data': QBasicAtomicInteger next; QBasicAtomicInteger data[NumInts]; bool allocateSpecific(int which) Q_DECL_NOTHROW { QBasicAtomicInteger &entry = data[which / BitsPerInt]; const uint old = entry.load(); const uint bit = 1U << (which % BitsPerInt); return !(old & bit) // wasn't taken && entry.testAndSetRelaxed(old, old | bit); // still wasn't taken // don't update 'next' here - it's unlikely that it will need // to be updated, in the general case, and having 'next' // trailing a bit is not a problem, as it is just a starting // hint for allocateNext(), which, when wrong, will just // result in a few more rounds through the allocateNext() // loop. } int allocateNext() Q_DECL_NOTHROW { // Unroll loop to iterate over ints, then bits? Would save // potentially a lot of cmpxchgs, because we can scan the // whole int before having to load it again. // Then again, this should never execute many iterations, so // leave like this for now: for (uint i = next.load(); i < NumBits; ++i) { if (allocateSpecific(i)) { // remember next (possibly) free id: const uint oldNext = next.load(); next.testAndSetRelaxed(oldNext, qMax(i + 1, oldNext)); return i; } } return -1; } }; } // unnamed namespace static const int UserEventRegistrationBitFieldSize = QEvent::MaxUser - QEvent::User + 1; typedef QBasicAtomicBitField UserEventTypeRegistry; static UserEventTypeRegistry userEventTypeRegistry; static inline int registerEventTypeZeroBased(int id) Q_DECL_NOTHROW { // if the type hint hasn't been registered yet, take it: if (id < UserEventTypeRegistry::NumBits && id >= 0 && userEventTypeRegistry.allocateSpecific(id)) return id; // otherwise, ignore hint: return userEventTypeRegistry.allocateNext(); } /*! \since 4.4 \threadsafe Registers and returns a custom event type. The \a hint provided will be used if it is available, otherwise it will return a value between QEvent::User and QEvent::MaxUser that has not yet been registered. The \a hint is ignored if its value is not between QEvent::User and QEvent::MaxUser. Returns -1 if all available values are already taken or the program is shutting down. */ int QEvent::registerEventType(int hint) Q_DECL_NOTHROW { const int result = registerEventTypeZeroBased(QEvent::MaxUser - hint); return result < 0 ? -1 : QEvent::MaxUser - result ; } /*! \class QTimerEvent \inmodule QtCore \brief The QTimerEvent class contains parameters that describe a timer event. \ingroup events Timer events are sent at regular intervals to objects that have started one or more timers. Each timer has a unique identifier. A timer is started with QObject::startTimer(). The QTimer class provides a high-level programming interface that uses signals instead of events. It also provides single-shot timers. The event handler QObject::timerEvent() receives timer events. \sa QTimer, QObject::timerEvent(), QObject::startTimer(), QObject::killTimer() */ /*! Constructs a timer event object with the timer identifier set to \a timerId. */ QTimerEvent::QTimerEvent(int timerId) : QEvent(Timer), id(timerId) {} /*! \internal */ QTimerEvent::~QTimerEvent() { } /*! \fn int QTimerEvent::timerId() const Returns the unique timer identifier, which is the same identifier as returned from QObject::startTimer(). */ /*! \class QChildEvent \inmodule QtCore \brief The QChildEvent class contains event parameters for child object events. \ingroup events Child events are sent immediately to objects when children are added or removed. In both cases you can only rely on the child being a QObject (or, if QObject::isWidgetType() returns \c true, a QWidget). This is because in the QEvent::ChildAdded case the child is not yet fully constructed; in the QEvent::ChildRemoved case it might have already been destructed. The handler for these events is QObject::childEvent(). */ /*! Constructs a child event object of a particular \a type for the \a child. \a type can be QEvent::ChildAdded, QEvent::ChildRemoved, QEvent::ChildPolished, or QEvent::ChildRemoved. \sa child() */ QChildEvent::QChildEvent(Type type, QObject *child) : QEvent(type), c(child) {} /*! \internal */ QChildEvent::~QChildEvent() { } /*! \fn QObject *QChildEvent::child() const Returns the child object that was added or removed. */ /*! \fn bool QChildEvent::added() const Returns \c true if type() is QEvent::ChildAdded; otherwise returns false. */ /*! \fn bool QChildEvent::removed() const Returns \c true if type() is QEvent::ChildRemoved; otherwise returns false. */ /*! \fn bool QChildEvent::polished() const Returns \c true if type() is QEvent::ChildPolished; otherwise returns false. */ /*! \class QDynamicPropertyChangeEvent \inmodule QtCore \since 4.2 \brief The QDynamicPropertyChangeEvent class contains event parameters for dynamic property change events. \ingroup events Dynamic property change events are sent to objects when properties are dynamically added, changed or removed using QObject::setProperty(). */ /*! Constructs a dynamic property change event object with the property name set to \a name. */ QDynamicPropertyChangeEvent::QDynamicPropertyChangeEvent(const QByteArray &name) : QEvent(QEvent::DynamicPropertyChange), n(name) { } /*! \internal */ QDynamicPropertyChangeEvent::~QDynamicPropertyChangeEvent() { } /*! \fn QByteArray QDynamicPropertyChangeEvent::propertyName() const Returns the name of the dynamic property that was added, changed or removed. \sa QObject::setProperty(), QObject::dynamicPropertyNames() */ /*! Constructs a deferred delete event with an initial loopLevel() of zero. */ QDeferredDeleteEvent::QDeferredDeleteEvent() : QEvent(QEvent::DeferredDelete) , level(0) { } /*! \internal */ QDeferredDeleteEvent::~QDeferredDeleteEvent() { } /*! \fn int QDeferredDeleteEvent::loopLevel() const Returns the loop-level in which the event was posted. The loop-level is set by QCoreApplication::postEvent(). \sa QObject::deleteLater() */ QT_END_NAMESPACE