Fix flick() with ListView.SnapToItem at bounds.

Previously flick() would not always allow flicking to the very end of
a ListView if ListView.SnapToItem were set. Stop ListView from adding
overshoot, and then incorrectly correcting, if we are flicking exactly
to the end of a list.

Change-Id: Iad56e433bc1ba7d62f0553c4355469c9861df919
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>

3 files changed, 43 insertions, 4 deletions

diff --git a/src/quick/items/qquicklistview.cpp b/src/quick/items/qquicklistview.cpp
index 851204ccde..8afd5793fc 100644
--- a/src/quick/items/qquicklistview.cpp
+++ b/src/quick/items/qquicklistview.cpp
@@ -1603,10 +1603,10 @@ bool QQuickListViewPrivate::flick(AxisData &data, qreal minExtent, qreal maxExte
                 }
                 data.flickTarget = isContentFlowReversed() ? -data.flickTarget+size() : data.flickTarget;
                 if (overShoot) {
-                    if (data.flickTarget >= minExtent) {
+                    if (data.flickTarget > minExtent) {
                         overshootDist = overShootDistance(vSize);
                         data.flickTarget += overshootDist;
-                    } else if (data.flickTarget <= maxExtent) {
+                    } else if (data.flickTarget < maxExtent) {
                         overshootDist = overShootDistance(vSize);
                         data.flickTarget -= overshootDist;
                     }
@@ -1626,10 +1626,10 @@ bool QQuickListViewPrivate::flick(AxisData &data, qreal minExtent, qreal maxExte
                 accel = v2 / (2.0f * qAbs(dist));
             } else if (overShoot) {
                 data.flickTarget = data.move.value() - dist;
-                if (data.flickTarget >= minExtent) {
+                if (data.flickTarget > minExtent) {
                     overshootDist = overShootDistance(vSize);
                     data.flickTarget += overshootDist;
-                } else if (data.flickTarget <= maxExtent) {
+                } else if (data.flickTarget < maxExtent) {
                     overshootDist = overShootDistance(vSize);
                     data.flickTarget -= overshootDist;
                 }
diff --git a/tests/auto/quick/qquicklistview/data/programmaticFlickAtBounds2.qml b/tests/auto/quick/qquicklistview/data/programmaticFlickAtBounds2.qml
new file mode 100644
index 0000000000..08870a46b9
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/programmaticFlickAtBounds2.qml
@@ -0,0 +1,14 @@
+import QtQuick 2.0
+
+ListView {
+    id: view
+    width: 200; height: 400
+
+    snapMode: ListView.SnapToItem
+
+    model: 10
+    delegate: Rectangle {
+        width: 200; height: 50
+        color: index % 2 ? "red" : "green"
+    }
+}
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index 9e8a813d54..b29b2cf3a1 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -233,6 +233,7 @@ private slots:
 
     void QTBUG_38209();
     void programmaticFlickAtBounds();
+    void programmaticFlickAtBounds2();
 
     void layoutChange();
 
@@ -7833,6 +7834,30 @@ void tst_QQuickListView::programmaticFlickAtBounds()
     QVERIFY(!spy.wait(100));
 }
 
+void tst_QQuickListView::programmaticFlickAtBounds2()
+{
+    QScopedPointer<QQuickView> window(createView());
+    window->setSource(testFileUrl("programmaticFlickAtBounds2.qml"));
+    window->show();
+    QVERIFY(QTest::qWaitForWindowExposed(window.data()));
+
+    QQuickListView *listview = qobject_cast<QQuickListView *>(window->rootObject());
+    QVERIFY(listview);
+
+    // move exactly one item
+    qreal velocity = -qSqrt(2 * 50 * listview->flickDeceleration());
+
+    // flick down
+    listview->flick(0, velocity);
+
+    QTRY_COMPARE(listview->contentY(), qreal(50.0));
+
+    // flick down
+    listview->flick(0, velocity);
+
+    QTRY_COMPARE(listview->contentY(), qreal(100.0));
+}
+
 void tst_QQuickListView::layoutChange()
 {
     RandomSortModel *model = new RandomSortModel;