From 2c80968d21ff15f574cbbfd93ce4409cda7eeebf Mon Sep 17 00:00:00 2001
From: Michael Brasser <michael.brasser@live.com>
Date: Wed, 23 Jul 2014 19:39:26 -0500
Subject: [PATCH] Improve programmatic flicking of ListView (and Flickable).

Fix bug when programmatically flicking ListView after a real flick in the
opposite direction. Also ensure a programmatic flick can flick past
bounds when situated at the bounds and DragAndOvershootBounds is set.

Task-number: QTBUG-38209
Change-Id: If4a2f65d0e7cb620b9af21f8a25a8a8797976125
Reviewed-by: Martin Jones <martin.jones@jollamobile.com>
---
 src/quick/items/qquickflickable.cpp                |  6 ++-
 .../quick/qquicklistview/data/simplelistview.qml   | 11 +++++
 .../quick/qquicklistview/tst_qquicklistview.cpp    | 55 ++++++++++++++++++++++
 3 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 tests/auto/quick/qquicklistview/data/simplelistview.qml

diff --git a/src/quick/items/qquickflickable.cpp b/src/quick/items/qquickflickable.cpp
index 45566f2..ee71ea8 100644
--- a/src/quick/items/qquickflickable.cpp
+++ b/src/quick/items/qquickflickable.cpp
@@ -327,7 +327,7 @@ bool QQuickFlickablePrivate::flick(AxisData &data, qreal minExtent, qreal maxExt
         maxDistance = qAbs(maxExtent - data.move.value());
         data.flickTarget = maxExtent;
     }
-    if (maxDistance > 0) {
+    if (maxDistance > 0 || boundsBehavior == QQuickFlickable::DragAndOvershootBounds) {
         qreal v = velocity;
         if (maxVelocity != -1 && maxVelocity < qAbs(v)) {
             if (v < 0)
@@ -1541,6 +1541,10 @@ void QQuickFlickable::geometryChanged(const QRectF &newGeometry,
 void QQuickFlickable::flick(qreal xVelocity, qreal yVelocity)
 {
     Q_D(QQuickFlickable);
+    d->hData.reset();
+    d->vData.reset();
+    d->hData.velocity = xVelocity;
+    d->vData.velocity = yVelocity;
     bool flickedX = d->flickX(xVelocity);
     bool flickedY = d->flickY(yVelocity);
     d->flickingStarted(flickedX, flickedY);
diff --git a/tests/auto/quick/qquicklistview/data/simplelistview.qml b/tests/auto/quick/qquicklistview/data/simplelistview.qml
new file mode 100644
index 0000000..56a9615
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/simplelistview.qml
@@ -0,0 +1,11 @@
+import QtQuick 2.0
+
+ListView {
+    width: 400
+    height: 400
+    model: 100
+    delegate: Rectangle {
+        height: 40; width: 400
+        color: index % 2 ? "lightsteelblue" : "lightgray"
+    }
+}
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index 2093265..14e26b7 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -228,6 +228,9 @@ private slots:
     void roundingErrors();
     void roundingErrors_data();
 
+    void QTBUG_38209();
+    void programmaticFlickAtBounds();
+
 private:
     template <class T> void items(const QUrl &source);
     template <class T> void changed(const QUrl &source);
@@ -7309,6 +7312,58 @@ void tst_QQuickListView::roundingErrors_data()
     QTest::newRow("pixelAligned=false") << false;
 }
 
+void tst_QQuickListView::QTBUG_38209()
+{
+    QScopedPointer<QQuickView> window(createView());
+    window->setSource(testFileUrl("simplelistview.qml"));
+    window->show();
+    QVERIFY(QTest::qWaitForWindowExposed(window.data()));
+
+    QQuickListView *listview = qobject_cast<QQuickListView *>(window->rootObject());
+    QVERIFY(listview);
+
+    // simulate mouse flick
+    flick(window.data(), QPoint(200, 200), QPoint(200, 50), 100);
+    QTRY_VERIFY(listview->isMoving() == false);
+    qreal contentY = listview->contentY();
+
+    // flick down
+    listview->flick(0, 1000);
+
+    // ensure we move more than just a couple pixels
+    QTRY_VERIFY(contentY - listview->contentY() > qreal(100.0));
+}
+
+void tst_QQuickListView::programmaticFlickAtBounds()
+{
+    QScopedPointer<QQuickView> window(createView());
+    window->setSource(testFileUrl("simplelistview.qml"));
+    window->show();
+    QVERIFY(QTest::qWaitForWindowExposed(window.data()));
+
+    QQuickListView *listview = qobject_cast<QQuickListView *>(window->rootObject());
+    QVERIFY(listview);
+    QSignalSpy spy(listview, SIGNAL(contentYChanged()));
+
+    // flick down
+    listview->flick(0, 1000);
+
+    // verify that there is movement beyond bounds
+    QVERIFY(spy.wait(100));
+
+    // reset, and test with StopAtBounds
+    listview->cancelFlick();
+    listview->returnToBounds();
+    QTRY_COMPARE(listview->contentY(), qreal(0.0));
+    listview->setBoundsBehavior(QQuickFlickable::StopAtBounds);
+
+    // flick down
+    listview->flick(0, 1000);
+
+    // verify that there is no movement beyond bounds
+    QVERIFY(!spy.wait(100));
+}
+
 QTEST_MAIN(tst_QQuickListView)
 
 #include "tst_qquicklistview.moc"
-- 
2.7.4