QQuickSelectionRectangle: ensure we start the selection where the drag started

We should start the selection in TableView at the position where the
user started the drag, and not where the centroid at the time when the
dragging gets active (which is an offset equal to the
mousePressAndHoldInterval property in QStyleHints).

Change-Id: Ibe330d31c1e2c8022006a56b7119b1dcb3e0e5b9
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
(cherry picked from commit 6d2d4914f884fc1a88382ba5cb6eeeeab272874e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 5 insertions, 4 deletions

diff --git a/src/quicktemplates2/qquickselectionrectangle.cpp b/src/quicktemplates2/qquickselectionrectangle.cpp
index 69eda47f9b..37e60e0c2c 100644
--- a/src/quicktemplates2/qquickselectionrectangle.cpp
+++ b/src/quicktemplates2/qquickselectionrectangle.cpp
@@ -210,11 +210,12 @@ QQuickSelectionRectanglePrivate::QQuickSelectionRectanglePrivate()
     });
 
     QObject::connect(m_dragHandler, &QQuickDragHandler::activeChanged, [this]() {
-        const QPointF pos = m_dragHandler->centroid().position();
+        const QPointF startPos = m_dragHandler->centroid().pressPosition();
+        const QPointF dragPos = m_dragHandler->centroid().position();
         if (m_dragHandler->active()) {
             m_selectable->clearSelection();
-            m_selectable->setSelectionStartPos(pos);
-            m_selectable->setSelectionEndPos(pos);
+            m_selectable->setSelectionStartPos(startPos);
+            m_selectable->setSelectionEndPos(dragPos);
             m_draggedHandle = nullptr;
             updateHandles();
             updateActiveState(true);
diff --git a/tests/auto/quickcontrols2/controls/data/tst_selectionrectangle.qml b/tests/auto/quickcontrols2/controls/data/tst_selectionrectangle.qml
index 437e8ec7f2..210c6594cd 100644
--- a/tests/auto/quickcontrols2/controls/data/tst_selectionrectangle.qml
+++ b/tests/auto/quickcontrols2/controls/data/tst_selectionrectangle.qml
@@ -337,7 +337,7 @@ TestCase {
         }
 
         // Drag on the bottom right handle, so that the selection shrinks to cell 1, 1
-        mouseDrag(tableView, cellWidth * 2, cellHeight * 2, -cellWidth / 2, -cellHeight / 2, Qt.LeftButton)
+        mouseDrag(tableView, (cellWidth * 3) - 1, (cellHeight * 3) - 1, -cellWidth, -cellHeight, Qt.LeftButton)
         compare(tableView.selectionModel.selectedIndexes.length, 1)
         verify(tableView.selectionModel.isSelected(tableView.model.index(1, 1)))
     }