Change QWidget::enterEvent signature to take a QEnterEvent

This is a source incompatible change for widget implementors.
Leaving the old enterEvent as a virtual overload is problematic due to
shadowing. Best to make a clean cut, widget reimplementors will get a compile
time warning if they mark their override as such, or if they try to call the
parent class implementation.

Addresses ### Qt 6 comment.

[ChangeLog][QtWidgets][QWidget] The virtual enterEvent handler now receives
a QEnterEvent, which contains information about mouse position and button
states, rather than a plain QEvent.

Change-Id: I233f594fd79c0c090983b3db8532913d00132fde
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

src/widgets/dialogs/qwizard_win.cpp

@@ -94,7 +94,7 @@ QSize QVistaBackButton::sizeHint() const
     return QSize(width, height);
 }
 
-void QVistaBackButton::enterEvent(QEvent *event)
+void QVistaBackButton::enterEvent(QEnterEvent *event)
 {
     if (isEnabled())
         update();

src/widgets/dialogs/qwizard_win_p.h

@@ -75,7 +75,7 @@ public:
     inline QSize minimumSizeHint() const override
     { return sizeHint(); }
 
-    void enterEvent(QEvent *event) override;
+    void enterEvent(QEnterEvent *event) override;
     void leaveEvent(QEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
 };

src/widgets/kernel/qwidget.cpp

@@ -8756,7 +8756,7 @@ bool QWidget::event(QEvent *event)
             QCoreApplication::sendEvent(const_cast<QWidget *>(this), &tip);
         }
 #endif
-        enterEvent(event);
+        enterEvent(static_cast<QEnterEvent*>(event));
         break;
 
     case QEvent::Leave:
@@ -9402,7 +9402,7 @@ void QWidget::focusOutEvent(QFocusEvent *)
 }
 
 /*!
-    \fn void QWidget::enterEvent(QEvent *event)
+    \fn void QWidget::enterEvent(QEnterEvent *event)
 
     This event handler can be reimplemented in a subclass to receive
     widget enter events which are passed in the \a event parameter.
@@ -9413,12 +9413,10 @@ void QWidget::focusOutEvent(QFocusEvent *)
     \sa leaveEvent(), mouseMoveEvent(), event()
 */
 
-void QWidget::enterEvent(QEvent *)
+void QWidget::enterEvent(QEnterEvent *)
 {
 }
 
-// ### Qt 6: void QWidget::enterEvent(QEnterEvent *).
-
 /*!
     \fn void QWidget::leaveEvent(QEvent *event)
 

src/widgets/kernel/qwidget.h

@@ -75,6 +75,7 @@ class QMouseEvent;
 class QWheelEvent;
 class QHoverEvent;
 class QKeyEvent;
+class QEnterEvent;
 class QFocusEvent;
 class QPaintEvent;
 class QMoveEvent;
@@ -622,7 +623,7 @@ protected:
     virtual void keyReleaseEvent(QKeyEvent *event);
     virtual void focusInEvent(QFocusEvent *event);
     virtual void focusOutEvent(QFocusEvent *event);
-    virtual void enterEvent(QEvent *event);
+    virtual void enterEvent(QEnterEvent *event);
     virtual void leaveEvent(QEvent *event);
     virtual void paintEvent(QPaintEvent *event);
     virtual void moveEvent(QMoveEvent *event);

src/widgets/widgets/qcombobox_p.h

@@ -154,7 +154,7 @@ protected:
         fast = false;
     }
 
-    void enterEvent(QEvent *) override {
+    void enterEvent(QEnterEvent *) override {
         startTimer();
     }
 

src/widgets/widgets/qdockwidget.cpp

@@ -129,7 +129,7 @@ public:
     QSize minimumSizeHint() const override
     { return sizeHint(); }
 
-    void enterEvent(QEvent *event) override;
+    void enterEvent(QEnterEvent *event) override;
     void leaveEvent(QEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
 
@@ -205,7 +205,7 @@ QSize QDockWidgetTitleButton::sizeHint() const
     return QSize(size, size);
 }
 
-void QDockWidgetTitleButton::enterEvent(QEvent *event)
+void QDockWidgetTitleButton::enterEvent(QEnterEvent *event)
 {
     if (isEnabled()) update();
     QAbstractButton::enterEvent(event);

src/widgets/widgets/qmenu.cpp

@@ -3502,7 +3502,7 @@ void QMenu::mouseMoveEvent(QMouseEvent *e)
 /*!
   \reimp
 */
-void QMenu::enterEvent(QEvent *)
+void QMenu::enterEvent(QEnterEvent *)
 {
     Q_D(QMenu);
     d->hasReceievedEnter = true;

src/widgets/widgets/qmenu.h

@@ -249,7 +249,7 @@ protected:
 #if QT_CONFIG(wheelevent)
     void wheelEvent(QWheelEvent *) override;
 #endif
-    void enterEvent(QEvent *) override;
+    void enterEvent(QEnterEvent *) override;
     void leaveEvent(QEvent *) override;
     void hideEvent(QHideEvent *) override;
     void paintEvent(QPaintEvent *) override;

src/widgets/widgets/qtabbar.cpp

@@ -83,7 +83,7 @@ public:
     QSize sizeHint() const override;
     QSize minimumSizeHint() const override
         { return sizeHint(); }
-    void enterEvent(QEvent *event) override;
+    void enterEvent(QEnterEvent *event) override;
     void leaveEvent(QEvent *event) override;
     void paintEvent(QPaintEvent *event) override;
 };
@@ -2814,7 +2814,7 @@ QSize CloseButton::sizeHint() const
     return QSize(width, height);
 }
 
-void CloseButton::enterEvent(QEvent *event)
+void CloseButton::enterEvent(QEnterEvent *event)
 {
     if (isEnabled())
         update();

src/widgets/widgets/qtoolbutton.cpp

@@ -527,7 +527,7 @@ void QToolButtonPrivate::_q_actionTriggered()
 /*!
     \reimp
  */
-void QToolButton::enterEvent(QEvent * e)
+void QToolButton::enterEvent(QEnterEvent * e)
 {
     Q_D(QToolButton);
     if (d->autoRaise)

src/widgets/widgets/qtoolbutton.h

@@ -112,7 +112,7 @@ protected:
     void paintEvent(QPaintEvent *) override;
     void actionEvent(QActionEvent *) override;
 
-    void enterEvent(QEvent *) override;
+    void enterEvent(QEnterEvent *) override;
     void leaveEvent(QEvent *) override;
     void timerEvent(QTimerEvent *) override;
     void changeEvent(QEvent *) override;

tests/auto/widgets/graphicsview/qgraphicsproxywidget/tst_qgraphicsproxywidget.cpp

@@ -943,7 +943,7 @@ public:
         installEventFilter(this);
     }
 
-    void enterEvent(QEvent *event)
+    void enterEvent(QEnterEvent *event)
     {
         enterCount++;
         QWidget::enterEvent(event);

tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp

@@ -5596,7 +5596,7 @@ public:
         r = QRegion();
     }
 
-    void enterEvent(QEvent *) override { ++enters; }
+    void enterEvent(QEnterEvent *) override { ++enters; }
     void leaveEvent(QEvent *) override { ++leaves; }
 
     void resetCounts()
@@ -9627,7 +9627,7 @@ void tst_QWidget::syntheticEnterLeave()
     {
     public:
         using QWidget::QWidget;
-        void enterEvent(QEvent *) override { ++numEnterEvents; }
+        void enterEvent(QEnterEvent *) override { ++numEnterEvents; }
         void leaveEvent(QEvent *) override { ++numLeaveEvents; }
         int numEnterEvents = 0;
         int numLeaveEvents = 0;
@@ -9742,7 +9742,7 @@ void tst_QWidget::taskQTBUG_4055_sendSyntheticEnterLeave()
     {
     public:
         using QWidget::QWidget;
-        void enterEvent(QEvent *) override { ++numEnterEvents; }
+        void enterEvent(QEnterEvent *) override { ++numEnterEvents; }
         void mouseMoveEvent(QMouseEvent *event) override
         {
             QCOMPARE(event->button(), Qt::NoButton);

tests/manual/cocoa/nativewidgets/main.cpp

@@ -61,7 +61,7 @@ public:
         update();
     }
 
-    void enterEvent(QEvent *)
+    void enterEvent(QEnterEvent *)
     {
         s = 200;
         v = 200;