Snap duration bar handles movement

When dragging a timeline's duration bar start, end, or center handle
while shift is down, snap the movement.

Task-number: QDS-1068
Change-Id: I713e27167ce358ba3e1e468b779363dd9f17b2ae
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

1 files changed, 18 insertions, 3 deletions

diff --git a/src/plugins/qmldesigner/components/timelineeditor/timelinesectionitem.cpp b/src/plugins/qmldesigner/components/timelineeditor/timelinesectionitem.cpp
index 450ca6cbb7..733834858e 100644
--- a/src/plugins/qmldesigner/components/timelineeditor/timelinesectionitem.cpp
+++ b/src/plugins/qmldesigner/components/timelineeditor/timelinesectionitem.cpp
@@ -987,7 +987,12 @@ void TimelineBarItem::dragInit(const QRectF &rect, const QPointF &pos)
 void TimelineBarItem::dragCenter(QRectF rect, const QPointF &pos, qreal min, qreal max)
 {
     if (validateBounds(pos.x() - rect.topLeft().x())) {
-        rect.moveLeft(pos.x() - m_pivot);
+        qreal targetX = pos.x() - m_pivot;
+        if (QApplication::keyboardModifiers() & Qt::ShiftModifier) { // snapping
+            qreal snappedTargetFrame = timelineScene()->snap(mapFromSceneToFrame(targetX));
+            targetX = mapFromFrameToScene(snappedTargetFrame);
+        }
+        rect.moveLeft(targetX);
         if (rect.topLeft().x() < min) {
             rect.moveLeft(min);
             setOutOfBounds(Location::Left);
@@ -1006,7 +1011,12 @@ void TimelineBarItem::dragHandle(QRectF rect, const QPointF &pos, qreal min, qre
 
     if (isActiveHandle(Location::Left)) {
         if (validateBounds(pos.x() - left.topLeft().x())) {
-            rect.setLeft(pos.x() - m_pivot);
+            qreal targetX = pos.x() - m_pivot;
+            if (QApplication::keyboardModifiers() & Qt::ShiftModifier) { // snapping
+                qreal snappedTargetFrame = timelineScene()->snap(mapFromSceneToFrame(targetX));
+                targetX = mapFromFrameToScene(snappedTargetFrame);
+            }
+            rect.setLeft(targetX);
             if (rect.left() < min) {
                 rect.setLeft(min);
                 setOutOfBounds(Location::Left);
@@ -1017,7 +1027,12 @@ void TimelineBarItem::dragHandle(QRectF rect, const QPointF &pos, qreal min, qre
         }
     } else if (isActiveHandle(Location::Right)) {
         if (validateBounds(pos.x() - right.topRight().x())) {
-            rect.setRight(pos.x() - m_pivot);
+            qreal targetX = pos.x() - m_pivot;
+            if (QApplication::keyboardModifiers() & Qt::ShiftModifier) { // snapping
+                qreal snappedTargetFrame = timelineScene()->snap(mapFromSceneToFrame(targetX));
+                targetX = mapFromFrameToScene(snappedTargetFrame);
+            }
+            rect.setRight(targetX);
             if (rect.right() > max) {
                 rect.setRight(max);
                 setOutOfBounds(Location::Right);