Doc: Fixes for several doc errors

Change-Id: I5be9c8e9ff9c17fae0fbbe468f34439411aca06b
Reviewed-by: Kim M. Kalland <kim.kalland@nokia.com>

src/gui/image/qpictureformatplugin.cpp

@@ -77,7 +77,7 @@ QT_BEGIN_NAMESPACE
     \fn bool QPictureFormatPlugin::installIOHandler(const QString &format)
 
     Installs a QPictureIO picture I/O handler for the picture format \a
-    format.
+    format. Returns \c true on success.
 
     \sa keys()
 */

src/gui/image/qpixmap.cpp

@@ -1631,4 +1631,16 @@ QDebug operator<<(QDebug dbg, const QPixmap &r)
 }
 #endif
 
+/*!
+    \fn QPixmap QPixmap::alphaChannel() const
+
+    Use QImage::alphaChannel() instead.
+*/
+
+/*!
+    \fn void QPixmap::setAlphaChannel(const QPixmap &p)
+
+    Use QImage::setAlphaChannel() for \a p instead.
+*/
+
 QT_END_NAMESPACE

src/gui/kernel/qguiapplication.cpp

@@ -342,6 +342,9 @@ QGuiApplication::QGuiApplication(int &argc, char **argv, int flags)
     QCoreApplicationPrivate::eventDispatcher->startingUp();
 }
 
+/*!
+    \internal
+*/
 QGuiApplication::QGuiApplication(QGuiApplicationPrivate &p)
     : QCoreApplication(p)
 {
@@ -557,6 +560,8 @@ QWindow *QGuiApplication::focusWindow()
     \fn QGuiApplication::focusObjectChanged(QObject *focusObject)
 
     This signal is emitted when final receiver of events tied to focus is changed.
+    \a focusObject is the new receiver.
+
     \sa focusObject()
 */
 
@@ -564,6 +569,8 @@ QWindow *QGuiApplication::focusWindow()
     \fn QGuiApplication::focusWindowChanged(QWindow *focusWindow)
 
     This signal is emitted when the focused window changes.
+    \a focusWindow is the new focused window.
+
     \sa focusWindow()
 */
 
@@ -637,7 +644,7 @@ QList<QScreen *> QGuiApplication::screens()
 }
 
 /*!
-    Returns the top level window at the given position, if any.
+    Returns the top level window at the given position \a pos, if any.
 */
 QWindow *QGuiApplication::topLevelAt(const QPoint &pos)
 {
@@ -2076,7 +2083,7 @@ QPalette QGuiApplication::palette()
 }
 
 /*!
-    Changes the default application palette to \a palette.
+    Changes the default application palette to \a pal.
 
     \sa palette()
 */

src/gui/kernel/qscreen.cpp

@@ -298,8 +298,7 @@ QSize QScreen::virtualSize() const
 }
 
 /*!
-  \property QScreen::virtualGeometry
-  \brief the pixel geometry of the virtual desktop corresponding to this screen
+  Returns the pixel geometry of the virtual desktop corresponding to this screen.
 
   This is the union of the virtual siblings' individual geometries.
 

src/gui/kernel/qsessionmanager.cpp

@@ -117,11 +117,6 @@ QT_BEGIN_NAMESPACE
     The default hint is \c RestartIfRunning.
 */
 
-/*!
-    \fn void* QSessionManager::handle() const
-
-    \internal
-*/
 
 class QSessionManagerPrivate : public QObjectPrivate
 {

src/gui/painting/qpaintengine_raster.cpp

@@ -3222,9 +3222,6 @@ void QRasterPaintEngine::drawEllipse(const QRectF &rect)
     QPaintEngineEx::drawEllipse(rect);
 }
 
-/*!
-    \internal
-*/
 
 #ifdef Q_OS_WIN
 /*!
@@ -4721,13 +4718,6 @@ static void drawEllipse_midpoint_i(const QRect &rect, const QRect &clip,
     to QPointFs and calls the floating point version of drawPoints.
 */
 
-/*!
-    \fn void QRasterPaintEngine::drawEllipse(const QRect &rect)
-    \overload
-
-    Reimplement this function to draw the largest ellipse that can be
-    contained within rectangle \a rect.
-*/
 
 #ifdef QT_DEBUG_DRAW
 void dumpClip(int width, int height, const QClipData *clip)

src/gui/painting/qpainter.cpp

@@ -5654,7 +5654,7 @@ void QPainterPrivate::drawGlyphs(const quint32 *glyphArray, QFixedPoint *positio
     Draws the given \a text with the currently defined text direction,
     beginning at the given \a position.
 
-    This function does not handle the newline character (\n), as it cannot
+    This function does not handle the newline character (\\n), as it cannot
     break text into multiple lines, and it cannot display the newline character.
     Use the QPainter::drawText() overload that takes a rectangle instead
     if you want to draw multiple lines of text with the newline character, or