Remove usages of deprecated APIs of QWheelEvent

- Replaced the usages of deprecated QWheelEvent::delta() and
  QWheelEvent::orientation() with QWheelEvent::angleDelta().
  In most of the examples it is acceptable to use only the vertical
  component of angle delta.

- Made the docs APIs to build conditionally, based on the
  deprecation version.

Task-number: QTBUG-76491
Task-number: QTBUG-76540
Change-Id: Id4230d483f724af49e4b6349b44881c3944de2a2
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

examples/corelib/threads/doc/src/mandelbrot.qdoc

@@ -304,8 +304,8 @@
     \snippet threads/mandelbrot/mandelbrotwidget.cpp 12
 
     The wheel event handler is reimplemented to make the mouse wheel
-    control the zoom level. QWheelEvent::delta() returns the angle of
-    the wheel mouse movement, in eights of a degree. For most mice,
+    control the zoom level. QWheelEvent::angleDelta() returns the angle
+    of the wheel mouse movement, in eighths of a degree. For most mice,
     one wheel step corresponds to 15 degrees. We find out how many
     mouse steps we have and determine the resulting zoom factor.
     For example, if we have two wheel steps in the positive direction

examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp

@@ -176,7 +176,7 @@ void MandelbrotWidget::keyPressEvent(QKeyEvent *event)
 //! [12]
 void MandelbrotWidget::wheelEvent(QWheelEvent *event)
 {
-    int numDegrees = event->delta() / 8;
+    int numDegrees = event->angleDelta().y() / 8;
     double numSteps = numDegrees / 15.0f;
     zoom(pow(ZoomInFactor, numSteps));
 }

examples/widgets/graphicsview/chip/view.cpp

@@ -68,7 +68,7 @@
 void GraphicsView::wheelEvent(QWheelEvent *e)
 {
     if (e->modifiers() & Qt::ControlModifier) {
-        if (e->delta() > 0)
+        if (e->angleDelta().y() > 0)
             view->zoomIn(6);
         else
             view->zoomOut(6);

examples/widgets/graphicsview/elasticnodes/graphwidget.cpp

@@ -190,7 +190,7 @@ void GraphWidget::timerEvent(QTimerEvent *event)
 //! [5]
 void GraphWidget::wheelEvent(QWheelEvent *event)
 {
-    scaleView(pow((double)2, -event->delta() / 240.0));
+    scaleView(pow((double)2, -event->angleDelta().y() / 240.0));
 }
 //! [5]
 #endif

examples/widgets/painting/affine/xform.cpp

@@ -260,7 +260,7 @@ void XFormView::timerEvent(QTimerEvent *e)
 #if QT_CONFIG(wheelevent)
 void XFormView::wheelEvent(QWheelEvent *e)
 {
-    m_scale += e->delta() / qreal(600);
+    m_scale += e->angleDelta().y() / qreal(600);
     m_scale = qMax(qreal(0.1), qMin(qreal(4), m_scale));
     emit scaleChanged(int(m_scale*1000));
 }

examples/widgets/widgets/mousebuttons/buttontester.cpp

@@ -93,15 +93,16 @@ void ButtonTester::mouseDoubleClickEvent(QMouseEvent *e)
 void ButtonTester::wheelEvent (QWheelEvent *e)
 {
     QString result;
-    if (e->delta() > 0) {
-
-        if (e->orientation() == Qt::Vertical) {
+    const bool vertical = qAbs(e->angleDelta().y()) >= qAbs(e->angleDelta().x());
+    const int delta = vertical ? e->angleDelta().y() : e->angleDelta().x();
+    if (delta > 0) {
+        if (vertical) {
             result = "Mouse Wheel Event: UP";
         } else {
             result = "Mouse Wheel Event: LEFT";
         }
-    } else if (e->delta() < 0) {
-        if (e->orientation() == Qt::Vertical) {
+    } else if (delta < 0) {
+        if (vertical) {
             result = "Mouse Wheel Event: DOWN";
         } else {
             result = "Mouse Wheel Event: RIGHT";

src/gui/kernel/qevent.cpp

@@ -743,12 +743,14 @@ QHoverEvent::~QHoverEvent()
     \l inverted always returns false.
 */
 
+#if QT_DEPRECATED_SINCE(5, 15)
 /*!
     \fn Qt::Orientation QWheelEvent::orientation() const
     \obsolete
 
     Use angleDelta() instead.
 */
+#endif
 
 #if QT_CONFIG(wheelevent)
 #if QT_DEPRECATED_SINCE(5, 15)
@@ -929,6 +931,7 @@ QWheelEvent::~QWheelEvent()
     \endlist
 */
 
+#if QT_DEPRECATED_SINCE(5, 15)
 /*!
     \fn int QWheelEvent::delta() const
     \obsolete
@@ -992,6 +995,7 @@ QWheelEvent::~QWheelEvent()
 
     This function has been deprecated, use globalPosition() instead.
 */
+#endif
 
 /*!
     \fn Qt::ScrollPhase QWheelEvent::phase() const