Disable "insert keyframe" context menu when applicable

Fixes: QDS-2727
Change-Id: I0072e77e56f6bbb893e382fbeb39861d2d5e6a61
Reviewed-by: Henning Gründl <henning.gruendl@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/components/curveeditor/detail/curveitem.cpp

@@ -173,6 +173,11 @@ bool CurveItem::hasSelectedKeyframe() const
     return false;
 }
 
+bool CurveItem::hasEditableSegment(double time) const
+{
+    return curve().segment(time).interpolation() != Keyframe::Interpolation::Easing;
+}
+
 unsigned int CurveItem::id() const
 {
     return m_id;

src/plugins/qmldesigner/components/curveeditor/detail/curveitem.h

@@ -79,6 +79,8 @@ public:
 
     bool hasSelectedKeyframe() const;
 
+    bool hasEditableSegment(double time) const;
+
     unsigned int id() const;
 
     ValueType valueType() const;

src/plugins/qmldesigner/components/curveeditor/detail/graphicsscene.cpp

@@ -85,6 +85,15 @@ bool GraphicsScene::hasSelectedKeyframe() const
     return false;
 }
 
+bool GraphicsScene::hasEditableSegment(double time) const
+{
+    for (auto *curve : m_curves) {
+        if (curve->hasEditableSegment(time))
+            return true;
+    }
+    return false;
+}
+
 double GraphicsScene::minimumTime() const
 {
     return limits().left();

src/plugins/qmldesigner/components/curveeditor/detail/graphicsscene.h

@@ -57,6 +57,8 @@ public:
 
     bool hasSelectedKeyframe() const;
 
+    bool hasEditableSegment(double time) const;
+
     double minimumTime() const;
 
     double maximumTime() const;

src/plugins/qmldesigner/components/curveeditor/detail/graphicsview.cpp

@@ -350,13 +350,16 @@ void GraphicsView::contextMenuEvent(QContextMenuEvent *event)
         connect(openEditorAction, &QAction::triggered, openStyleEditor);
     }
 
+    QPointF rasterPos = globalToRaster(event->globalPos());
+
     menu.addSeparator();
-    auto insertKeyframes = [this, event]() {
-        m_scene->insertKeyframe(globalToRaster(event->globalPos()).x(), true);
-    };
+    auto insertKeyframes = [this, rasterPos]() { m_scene->insertKeyframe(rasterPos.x(), true); };
     QAction *insertKeyframeAction = menu.addAction(tr("Insert Keyframe"));
     connect(insertKeyframeAction, &QAction::triggered, insertKeyframes);
 
+    if (!m_scene->hasEditableSegment(rasterPos.x()))
+        insertKeyframeAction->setEnabled(false);
+
     auto deleteKeyframes = [this] { m_scene->deleteSelectedKeyframes(); };
     QAction *deleteKeyframeAction = menu.addAction(tr("Delete Selected Keyframes"));
     connect(deleteKeyframeAction, &QAction::triggered, deleteKeyframes);