Make sure to neither load nor store invalid qeasing-curves

Remove set-value-spinbox.
Do not convert single-segment-qeasing-curves to bezier if they would become invalid.
Do not store invalid qeasing-curves in the keyframe ModelNode.
Make sure that a conversion does not produce nans

Change-Id: I0688de55bf6b0ef6fe69d70d9192d852c8d6b895
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

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

@@ -106,13 +106,6 @@ QToolBar *CurveEditor::createToolBar(CurveEditorModel *model)
     Q_UNUSED(tangentStepAction);
     Q_UNUSED(tangentDefaultAction);
 
-    auto *valueBox = new QHBoxLayout;
-    valueBox->addWidget(new QLabel(tr("Value")));
-    valueBox->addWidget(new QDoubleSpinBox);
-    auto *valueWidget = new QWidget;
-    valueWidget->setLayout(valueBox);
-    bar->addWidget(valueWidget);
-
     auto *durationBox = new QHBoxLayout;
     auto *startSpin = new QSpinBox;
     auto *endSpin = new QSpinBox;

src/plugins/qmldesigner/components/curveeditor/curvesegment.cpp

@@ -150,7 +150,18 @@ CurveSegment::CurveSegment(const Keyframe &left, const Keyframe &right)
 
 bool CurveSegment::isValid() const
 {
-    return m_left.position() != m_right.position();
+    if (m_left.position() == m_right.position())
+        return false;
+
+    if (interpolation() == Keyframe::Interpolation::Undefined)
+        return false;
+
+    if (interpolation() == Keyframe::Interpolation::Easing
+        || interpolation() == Keyframe::Interpolation::Bezier) {
+        if (qFuzzyCompare(m_left.position().y(), m_right.position().y()))
+            return false;
+    }
+    return true;
 }
 
 bool CurveSegment::containsX(double x) const
@@ -263,6 +274,10 @@ QEasingCurve CurveSegment::easingCurve() const
     auto mapPosition = [this](const QPointF &position) {
         QPointF min = m_left.position();
         QPointF max = m_right.position();
+        if (qFuzzyCompare(min.y(), max.y()))
+            return QPointF((position.x() - min.x()) / (max.x() - min.x()),
+                           (position.y() - min.y()) / (max.y()));
+
         return QPointF((position.x() - min.x()) / (max.x() - min.x()),
                        (position.y() - min.y()) / (max.y() - min.y()));
     };
@@ -270,8 +285,7 @@ QEasingCurve CurveSegment::easingCurve() const
     QEasingCurve curve;
     curve.addCubicBezierSegment(mapPosition(m_left.rightHandle()),
                                 mapPosition(m_right.leftHandle()),
-                                mapPosition(m_right.position()));
-
+                                QPointF(1., 1.));
     return curve;
 }
 

src/plugins/qmldesigner/components/timelineeditor/animationcurveeditormodel.cpp

@@ -30,8 +30,8 @@
 #include "qmltimeline.h"
 
 #include <bindingproperty.h>
-#include <variantproperty.h>
 #include <theme.h>
+#include <variantproperty.h>
 
 namespace QmlDesigner {
 
@@ -204,6 +204,7 @@ std::vector<DesignTools::Keyframe> resolveSmallCurves(
     for (auto &&frame : frames) {
         if (frame.hasData() && !out.empty()) {
             QEasingCurve curve = frame.data().toEasingCurve();
+            // One-segment-curve: Since (0,0) is implicit => 3
             if (curve.toCubicSpline().count() == 3) {
                 DesignTools::Keyframe &previous = out.back();
 #if 0

src/plugins/qmldesigner/components/timelineeditor/timelinewidget.cpp

@@ -355,7 +355,8 @@ void TimelineWidget::updateAnimationCurve(DesignTools::PropertyTreeItem *item)
                 if (previous.isValid()) {
                     if (frame.interpolation() == DesignTools::Keyframe::Interpolation::Bezier) {
                         DesignTools::CurveSegment segment(previous, frame);
-                        attachEasingCurve(pos.x(), segment.easingCurve(), group);
+                        if (segment.isValid())
+                            attachEasingCurve(pos.x(), segment.easingCurve(), group);
                     } else if (frame.interpolation()
                                == DesignTools::Keyframe::Interpolation::Easing) {
                         QVariant data = frame.data();