Cannot flick to the end of a horizontal ListView with LayoutMirroring

Forward port of fix for QTBUG-21756.
minXExtent calculated the offset due to highlight range incorrectly
(reversed) when mirroring enabled.  Also us same algorithm for fixup()
in GridView and ListView uses.

For QtQuick 2, this change also reverses the beginning and end highlight
range, as it should be, i.e. the preferredHighlightBegin is from the
right side in RightToLeft mode.  Also added snapping tests.

Task-number: QTBUG-21756
Change-Id: Ica0ba4ab5db0ce9c77f2da75e9f8293550bd37d1
Reviewed-by: Martin Jones <martin.jones@nokia.com>

2 files changed, 166 insertions, 0 deletions

diff --git a/tests/auto/declarative/qsglistview/data/snapToItem.qml b/tests/auto/declarative/qsglistview/data/snapToItem.qml
new file mode 100644
index 0000000000..6f201072f0
--- /dev/null
+++ b/tests/auto/declarative/qsglistview/data/snapToItem.qml
@@ -0,0 +1,49 @@
+import QtQuick 2.0
+
+Rectangle {
+    id: root
+    width: 240
+    height: 240
+    color: "#ffffff"
+
+    Component {
+        id: myDelegate
+        Rectangle {
+            id: wrapper
+            objectName: "wrapper"
+            height: 80
+            width: 80
+            Column {
+                Text {
+                    text: index
+                }
+                Text {
+                    text: wrapper.x + ", " + wrapper.y
+                }
+            }
+            color: ListView.isCurrentItem ? "lightsteelblue" : "transparent"
+        }
+    }
+    ListView {
+        id: list
+        objectName: "list"
+        anchors.fill: parent
+//        preferredHighlightBegin: 20
+//        preferredHighlightEnd: 100
+        preferredHighlightBegin: 20
+        preferredHighlightEnd: 100
+        snapMode: ListView.SnapToItem
+        orientation: ListView.Horizontal
+        layoutDirection: Qt.RightToLeft
+        highlightRangeMode: ListView.StrictlyEnforceRange
+        highlight: Rectangle { width: 80; height: 80; color: "yellow" }
+        model: 18
+        delegate: myDelegate
+    }
+
+    Text {
+        anchors.right: parent.right
+        anchors.bottom: parent.bottom
+        text: list.contentX + ", " + list.contentY
+    }
+}
diff --git a/tests/auto/declarative/qsglistview/tst_qsglistview.cpp b/tests/auto/declarative/qsglistview/tst_qsglistview.cpp
index 386a03b81a..be297122ba 100644
--- a/tests/auto/declarative/qsglistview/tst_qsglistview.cpp
+++ b/tests/auto/declarative/qsglistview/tst_qsglistview.cpp
@@ -55,6 +55,7 @@
 #include "../shared/util.h"
 #include "../../../shared/util.h"
 #include "incrementalmodel.h"
+#include <math.h>
 
 Q_DECLARE_METATYPE(Qt::LayoutDirection)
 Q_DECLARE_METATYPE(QSGListView::Orientation)
@@ -139,6 +140,8 @@ private slots:
     void test_mirroring();
     void margins();
     void creationContext();
+    void snapToItem_data();
+    void snapToItem();
 
 private:
     template <class T> void items();
@@ -149,6 +152,7 @@ private:
     template <class T> void moved();
     template <class T> void clear();
     QSGView *createView();
+    void flick(QSGView *canvas, const QPoint &from, const QPoint &to, int duration);
     QSGItem *findVisibleChild(QSGItem *parent, const QString &objectName);
     template<typename T>
     T *findItem(QSGItem *parent, const QString &id, int index=-1);
@@ -3800,6 +3804,100 @@ void tst_QSGListView::margins()
     delete canvas;
 }
 
+void tst_QSGListView::snapToItem_data()
+{
+    QTest::addColumn<QSGListView::Orientation>("orientation");
+    QTest::addColumn<Qt::LayoutDirection>("layoutDirection");
+    QTest::addColumn<int>("highlightRangeMode");
+    QTest::addColumn<QPoint>("flickStart");
+    QTest::addColumn<QPoint>("flickEnd");
+    QTest::addColumn<qreal>("snapAlignment");
+    QTest::addColumn<qreal>("endExtent");
+    QTest::addColumn<qreal>("startExtent");
+
+    QTest::newRow("vertical, left to right") << QSGListView::Vertical << Qt::LeftToRight << int(QSGItemView::NoHighlightRange)
+        << QPoint(20, 200) << QPoint(20, 20) << 60.0 << 1200.0 << 0.0;
+
+    QTest::newRow("horizontal, left to right") << QSGListView::Horizontal << Qt::LeftToRight << int(QSGItemView::NoHighlightRange)
+        << QPoint(200, 20) << QPoint(20, 20) << 60.0 << 1200.0 << 0.0;
+
+    QTest::newRow("horizontal, right to left") << QSGListView::Horizontal << Qt::RightToLeft << int(QSGItemView::NoHighlightRange)
+        << QPoint(20, 20) << QPoint(200, 20) << -60.0 << -1200.0 - 240.0 << -240.0;
+
+    QTest::newRow("vertical, left to right, enforce range") << QSGListView::Vertical << Qt::LeftToRight << int(QSGItemView::StrictlyEnforceRange)
+        << QPoint(20, 200) << QPoint(20, 20) << 60.0 << 1340.0 << -20.0;
+
+    QTest::newRow("horizontal, left to right, enforce range") << QSGListView::Horizontal << Qt::LeftToRight << int(QSGItemView::StrictlyEnforceRange)
+        << QPoint(200, 20) << QPoint(20, 20) << 60.0 << 1340.0 << -20.0;
+
+    QTest::newRow("horizontal, right to left, enforce range") << QSGListView::Horizontal << Qt::RightToLeft << int(QSGItemView::StrictlyEnforceRange)
+        << QPoint(20, 20) << QPoint(200, 20) << -60.0 << -1200.0 - 240.0 - 140.0 << -220.0;
+}
+
+void tst_QSGListView::snapToItem()
+{
+    QFETCH(QSGListView::Orientation, orientation);
+    QFETCH(Qt::LayoutDirection, layoutDirection);
+    QFETCH(int, highlightRangeMode);
+    QFETCH(QPoint, flickStart);
+    QFETCH(QPoint, flickEnd);
+    QFETCH(qreal, snapAlignment);
+    QFETCH(qreal, endExtent);
+    QFETCH(qreal, startExtent);
+
+    QSGView *canvas = createView();
+
+    canvas->setSource(QUrl::fromLocalFile(TESTDATA("snapToItem.qml")));
+    canvas->show();
+    qApp->processEvents();
+
+    QSGListView *listview = findItem<QSGListView>(canvas->rootObject(), "list");
+    QTRY_VERIFY(listview != 0);
+
+    listview->setOrientation(orientation);
+    listview->setLayoutDirection(layoutDirection);
+    listview->setHighlightRangeMode(QSGItemView::HighlightRangeMode(highlightRangeMode));
+
+    QSGItem *contentItem = listview->contentItem();
+    QTRY_VERIFY(contentItem != 0);
+
+    // confirm that a flick hits an item boundary
+    flick(canvas, flickStart, flickEnd, 180);
+    QTRY_VERIFY(listview->isMoving() == false); // wait until it stops
+    if (orientation == QSGListView::Vertical)
+        QCOMPARE(qreal(fmod(listview->contentY(),80.0)), snapAlignment);
+    else
+        QCOMPARE(qreal(fmod(listview->contentX(),80.0)), snapAlignment);
+
+    // flick to end
+    do {
+        flick(canvas, flickStart, flickEnd, 180);
+        QTRY_VERIFY(listview->isMoving() == false); // wait until it stops
+    } while (orientation == QSGListView::Vertical
+           ? !listview->isAtYEnd()
+           : layoutDirection == Qt::LeftToRight ? !listview->isAtXEnd() : !listview->isAtXBeginning());
+
+    if (orientation == QSGListView::Vertical)
+        QCOMPARE(listview->contentY(), endExtent);
+    else
+        QCOMPARE(listview->contentX(), endExtent);
+
+    // flick to start
+    do {
+        flick(canvas, flickEnd, flickStart, 180);
+        QTRY_VERIFY(listview->isMoving() == false); // wait until it stops
+    } while (orientation == QSGListView::Vertical
+           ? !listview->isAtYBeginning()
+           : layoutDirection == Qt::LeftToRight ? !listview->isAtXBeginning() : !listview->isAtXEnd());
+
+    if (orientation == QSGListView::Vertical)
+        QCOMPARE(listview->contentY(), startExtent);
+    else
+        QCOMPARE(listview->contentX(), startExtent);
+
+    delete canvas;
+}
+
 void tst_QSGListView::qListModelInterface_items()
 {
     items<TestModel>();
@@ -3922,6 +4020,25 @@ QSGView *tst_QSGListView::createView()
     return canvas;
 }
 
+void tst_QSGListView::flick(QSGView *canvas, const QPoint &from, const QPoint &to, int duration)
+{
+    const int pointCount = 5;
+    QPoint diff = to - from;
+
+    // send press, five equally spaced moves, and release.
+    QTest::mousePress(canvas, Qt::LeftButton, 0, from);
+
+    for (int i = 0; i < pointCount; ++i) {
+        QMouseEvent mv(QEvent::MouseMove, from + (i+1)*diff/pointCount, Qt::LeftButton, Qt::LeftButton,Qt::NoModifier);
+        QApplication::sendEvent(canvas, &mv);
+        QTest::qWait(duration/pointCount);
+        QCoreApplication::processEvents();
+    }
+
+    QTest::mouseRelease(canvas, Qt::LeftButton, 0, to);
+}
+
+
 QSGItem *tst_QSGListView::findVisibleChild(QSGItem *parent, const QString &objectName)
 {
     QSGItem *item = 0;