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>

2 files changed, 3 insertions, 3 deletions

diff --git a/examples/corelib/threads/doc/src/mandelbrot.qdoc b/examples/corelib/threads/doc/src/mandelbrot.qdoc
index 274874632e..9e3fdc1dfe 100644
--- a/examples/corelib/threads/doc/src/mandelbrot.qdoc
+++ b/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
diff --git a/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp b/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp
index 71d0abb09f..822791533b 100644
--- a/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp
+++ b/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));
 }