Clean up documentation of deprecated APIs from QApplication

Build docs for deprecated APIs conditionally, based on deprecation
version. Remove the docs of methods deprecated since 5.0.0, these
methods are not compiled anymore.

Change-Id: If9302eecc8b3fff4a27c2e4a66ac102add7d66c5
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/widgets/kernel/qapplication.cpp

@@ -236,9 +236,6 @@ void QApplicationPrivate::createEventDispatcher()
                 encapsulated in a QStyle object. This can be changed at runtime
                 with setStyle().
 
-            \li  It specifies how the application is to allocate colors. See
-                setColorSpec() for details.
-
             \li  It provides localization of strings that are visible to the
                 user via translate().
 
@@ -298,11 +295,6 @@ void QApplicationPrivate::createEventDispatcher()
         \li  style(),
             setStyle().
 
-        \row
-        \li  Color usage
-        \li  colorSpec(),
-            setColorSpec().
-
         \row
         \li  Text handling
         \li  installTranslator(),
@@ -337,6 +329,7 @@ void QApplicationPrivate::createEventDispatcher()
     \sa QCoreApplication, QAbstractEventDispatcher, QEventLoop, QSettings
 */
 
+#if QT_DEPRECATED_SINCE(5, 8)
 // ### fixme: Qt 6: Remove ColorSpec and accessors.
 /*!
     \enum QApplication::ColorSpec
@@ -350,15 +343,7 @@ void QApplicationPrivate::createEventDispatcher()
 
     See setColorSpec() for full details.
 */
-
-/*!
-    \fn QApplication::setGraphicsSystem(const QString &)
-    \obsolete
-
-    This call has no effect.
-
-    Use the QPA framework instead.
-*/
+#endif
 
 /*!
     \fn QWidget *QApplication::topLevelAt(const QPoint &point)
@@ -1956,13 +1941,6 @@ bool QApplication::event(QEvent *e)
     return QGuiApplication::event(e);
 }
 
-/*!
-   \fn void QApplication::syncX()
-    Was used to synchronize with the X server in 4.x, here for source compatibility.
-    \internal
-    \obsolete
-*/
-
 // ### FIXME: topLevelWindows does not contain QWidgets without a parent
 // until QWidgetPrivate::create is called. So we have to override the
 // QGuiApplication::notifyLayoutDirectionChange
@@ -3989,15 +3967,6 @@ int QApplication::doubleClickInterval()
     return QGuiApplication::styleHints()->mouseDoubleClickInterval();
 }
 
-/*!
-    \fn QApplication::keyboardInputDirection()
-    \since 4.2
-    \deprecated
-
-    Returns the current keyboard input direction. Replaced with QInputMethod::inputDirection()
-    \sa QInputMethod::inputDirection()
-*/
-
 /*!
     \property QApplication::keyboardInputInterval
     \brief the time limit in milliseconds that distinguishes a key press
@@ -4135,14 +4104,6 @@ void QApplication::beep()
     \sa QCoreApplication::instance(), qGuiApp
 */
 
-/*!
-    \fn QLocale QApplication::keyboardInputLocale()
-    \since 4.2
-    \obsolete
-
-    Returns the current keyboard input locale. Replaced with QInputMethod::locale()
-*/
-
 bool qt_sendSpontaneousEvent(QObject *receiver, QEvent *event)
 {
     return QGuiApplication::sendSpontaneousEvent(receiver, event);