QAbstractScrollArea: add a getter for the margins

Strange API asymmetry that needed to be fixed.

Task-number: QTBUG-8315

[ChangeLog][QtWidgets][QAbstractScrollArea] A getter for the viewport
margins has been added.

Change-Id: Ie1460b572206922031fc4effc2aa8261e25088b5
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

3 files changed, 35 insertions, 2 deletions

diff --git a/src/widgets/widgets/qabstractscrollarea.cpp b/src/widgets/widgets/qabstractscrollarea.cpp
index 4cafeafcec..bcf0bbe1fc 100644
--- a/src/widgets/widgets/qabstractscrollarea.cpp
+++ b/src/widgets/widgets/qabstractscrollarea.cpp
@@ -923,7 +923,7 @@ QWidgetList QAbstractScrollArea::scrollBarWidgets(Qt::Alignment alignment)
     they should not call this function.
 
     By default all margins are zero.
-
+    \sa viewportMargins()
 */
 void QAbstractScrollArea::setViewportMargins(int left, int top, int right, int bottom)
 {
@@ -943,7 +943,7 @@ void QAbstractScrollArea::setViewportMargins(int left, int top, int right, int b
     area.
 
     By default all margins are zero.
-
+    \sa viewportMargins()
 */
 void QAbstractScrollArea::setViewportMargins(const QMargins &margins)
 {
@@ -951,6 +951,19 @@ void QAbstractScrollArea::setViewportMargins(const QMargins &margins)
                        margins.right(), margins.bottom());
 }
 
+/*!
+    \since 5.5
+    Returns the margins around the scrolling area.
+    By default all the margins are zero.
+
+    \sa setViewportMargins()
+*/
+QMargins QAbstractScrollArea::viewportMargins() const
+{
+    Q_D(const QAbstractScrollArea);
+    return QMargins(d->left, d->top, d->right, d->bottom);
+}
+
 /*! \internal */
 bool QAbstractScrollArea::eventFilter(QObject *o, QEvent *e)
 {
diff --git a/src/widgets/widgets/qabstractscrollarea.h b/src/widgets/widgets/qabstractscrollarea.h
index bd15ba8a52..6a9a86b07f 100644
--- a/src/widgets/widgets/qabstractscrollarea.h
+++ b/src/widgets/widgets/qabstractscrollarea.h
@@ -97,6 +97,7 @@ protected:
     QAbstractScrollArea(QAbstractScrollAreaPrivate &dd, QWidget *parent = 0);
     void setViewportMargins(int left, int top, int right, int bottom);
     void setViewportMargins(const QMargins &margins);
+    QMargins viewportMargins() const;
 
     bool eventFilter(QObject *, QEvent *) Q_DECL_OVERRIDE;
     bool event(QEvent *) Q_DECL_OVERRIDE;
diff --git a/tests/auto/widgets/widgets/qabstractscrollarea/tst_qabstractscrollarea.cpp b/tests/auto/widgets/widgets/qabstractscrollarea/tst_qabstractscrollarea.cpp
index b18801220c..83e6b94db9 100644
--- a/tests/auto/widgets/widgets/qabstractscrollarea/tst_qabstractscrollarea.cpp
+++ b/tests/auto/widgets/widgets/qabstractscrollarea/tst_qabstractscrollarea.cpp
@@ -60,6 +60,8 @@ private slots:
     void viewportCrash();
     void task214488_layoutDirection_data();
     void task214488_layoutDirection();
+
+    void margins();
 };
 
 tst_QAbstractScrollArea::tst_QAbstractScrollArea()
@@ -375,5 +377,22 @@ void tst_QAbstractScrollArea::patternBackground()
     QCOMPARE(image.pixel(QPoint(20,20)) , QColor(Qt::red).rgb());
 }
 
+class ScrollArea : public QAbstractScrollArea
+{
+public:
+    using QAbstractScrollArea::setViewportMargins;
+    using QAbstractScrollArea::viewportMargins;
+};
+
+void tst_QAbstractScrollArea::margins()
+{
+    ScrollArea area;
+    QCOMPARE(area.viewportMargins(), QMargins());
+
+    QMargins margins(10, 20, 30, 40);
+    area.setViewportMargins(margins);
+    QCOMPARE(area.viewportMargins(), margins);
+}
+
 QTEST_MAIN(tst_QAbstractScrollArea)
 #include "tst_qabstractscrollarea.moc"