QTimerEvent: port to Qt::TimerId

[ChangeLog][QtCore][QTimerEvent] Added constructor taking a Qt::TimerId.
Also added a getter for Qt::TimerId.

[ChangeLog][Potentially Source-Incompatible Changes] The protected
(and undocumented) QTimerEvent::id member variable has been renamed to
m_id to allow for the addition of an id() getter that returns a
Qt::TimerId.

Task-number: QTBUG-128144
Pick-to: 6.8
Change-Id: Ia156f11e9e9347b6bf61b36e40da3ad551d23407
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/corelib/kernel/qcoreevent.cpp

@@ -533,9 +533,21 @@ int QEvent::registerEventType(int hint) noexcept
     \a timerId.
 */
 QTimerEvent::QTimerEvent(int timerId)
-    : QEvent(Timer), id(timerId)
+    : QTimerEvent(Qt::TimerId{timerId})
 {}
 
+/*!
+    \since 6.8
+
+    Constructs a timer event object with the timer identifier set to
+    \a timerId.
+*/
+QTimerEvent::QTimerEvent(Qt::TimerId timerId)
+    : QEvent(Timer), m_id(timerId)
+{
+    static_assert(sizeof(Qt::TimerId) == sizeof(int));
+}
+
 Q_IMPL_EVENT_COMMON(QTimerEvent)
 
 /*!
@@ -545,6 +557,15 @@ Q_IMPL_EVENT_COMMON(QTimerEvent)
     as returned from QObject::startTimer().
 */
 
+/*!
+    \fn Qt::TimerId QTimerEvent::id() const
+    \since 6.8
+
+    Returns the Qt::TimerId of the timer associated with this event, which
+    is the same identifier returned by QObject::startTimer() cast to
+    Qt::TimerId.
+*/
+
 /*!
     \class QChildEvent
     \inmodule QtCore

src/corelib/kernel/qcoreevent.h

@@ -367,10 +367,13 @@ class Q_CORE_EXPORT QTimerEvent : public QEvent
     Q_DECL_EVENT_COMMON(QTimerEvent)
 public:
     explicit QTimerEvent(int timerId);
-    int timerId() const { return id; }
+    explicit QTimerEvent(Qt::TimerId timerId);
+
+    int timerId() const { return qToUnderlying(id()); }
+    Qt::TimerId id() const { return m_id; }
 
 protected:
-    int id;
+    Qt::TimerId m_id;
 };
 
 class QObject;