Fix ListView::positionViewAtIndex with ListView.Contain mode

Sticky headers and footers weren't accounted for when calculating new
view position causing the requested item to be left behind them.

Task-number: QTBUG-63974
Change-Id: Id69579643a942e8558960b2c8b0fee980fa86947
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

2 files changed, 75 insertions, 0 deletions

diff --git a/tests/auto/quick/qquicklistview/data/qtbug63974.qml b/tests/auto/quick/qquicklistview/data/qtbug63974.qml
new file mode 100644
index 0000000000..1e0afa54f8
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/qtbug63974.qml
@@ -0,0 +1,34 @@
+import QtQuick 2.6
+
+ListView {
+    id: table
+    height: 200
+    width: 100
+
+    headerPositioning: ListView.OverlayHeader
+    header: Rectangle {
+        width: table.width
+        height: 20
+        color: "red"
+        z: 100
+    }
+
+    footerPositioning: ListView.OverlayFooter
+    footer: Rectangle {
+        width: table.width
+        height: 20
+        color: "blue"
+        z: 200
+    }
+
+    model: 30
+    delegate: Rectangle {
+        height: 20
+        width: table.width
+        color: "lightgray"
+        Text {
+            text: "Item " + index
+            anchors.centerIn: parent
+        }
+    }
+}
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index a31cb37c16..c08d5d31b4 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -256,6 +256,7 @@ private slots:
     void keyNavigationEnabled();
     void QTBUG_61269_appendDuringScrollDown();
     void QTBUG_50097_stickyHeader_positionViewAtIndex();
+    void QTBUG_63974_stickyHeader_positionViewAtIndex_Contain();
     void itemFiltered();
     void releaseItems();
 
@@ -8561,6 +8562,46 @@ void tst_QQuickListView::QTBUG_50097_stickyHeader_positionViewAtIndex()
     QTRY_COMPARE(listview->contentY(), -100.0); // back to the same position: header visible, items not under the header.
 }
 
+void tst_QQuickListView::QTBUG_63974_stickyHeader_positionViewAtIndex_Contain()
+{
+    QScopedPointer<QQuickView> window(createView());
+    window->setSource(testFileUrl("qtbug63974.qml"));
+    window->show();
+    QVERIFY(QTest::qWaitForWindowExposed(window.data()));
+
+    QQuickListView *listview = qobject_cast<QQuickListView*>(window->rootObject());
+    QVERIFY(listview != 0);
+
+    const qreal headerSize = 20;
+    const qreal footerSize = 20;
+    const qreal itemSize = 20;
+    const int itemCount = 30;
+    const qreal contentHeight = itemCount * itemSize;
+
+    const qreal initialY = listview->contentY();
+    const qreal endPosition = contentHeight + footerSize - listview->height();
+
+    QVERIFY(qFuzzyCompare(initialY, -headerSize));
+
+    listview->positionViewAtIndex(itemCount - 1, QQuickListView::Contain);
+    QTRY_COMPARE(listview->contentY(), endPosition);
+
+    listview->positionViewAtIndex(0, QQuickListView::Contain);
+    QTRY_COMPARE(listview->contentY(), -headerSize);
+
+    listview->positionViewAtIndex(itemCount - 1, QQuickListView::Visible);
+    QTRY_COMPARE(listview->contentY(), endPosition);
+
+    listview->positionViewAtIndex(0, QQuickListView::Visible);
+    QTRY_COMPARE(listview->contentY(), -headerSize);
+
+    listview->positionViewAtIndex(itemCount - 1, QQuickListView::SnapPosition);
+    QTRY_COMPARE(listview->contentY(), endPosition);
+
+    listview->positionViewAtIndex(0, QQuickListView::SnapPosition);
+    QTRY_COMPARE(listview->contentY(), -headerSize);
+}
+
 void tst_QQuickListView::itemFiltered()
 {
     QStringListModel model(QStringList() << "one" << "two" << "three" << "four" << "five" << "six");