Disable three nodes branch by default

Three nodes branch wrapping is very easy to fail, so disable by default.

CONTRIBUTORS

@@ -28,3 +28,4 @@ bvanevery <https://www.reddit.com/user/bvanevery>
 Toshio Araki <https://github.com/Toshiwoz>
 Evan Gruda <evangruda@ufl.edu>
 KeepFenDou <https://github.com/KeepFenDou>
+Kubilay Yalçın <https://twitter.com/KhaynaraKioni>

src/document.cpp

@@ -61,6 +61,9 @@ Document::Document() :
 {
     connect(&Preferences::instance(), &Preferences::partColorChanged, this, &Document::applyPreferencePartColorChange);
     connect(&Preferences::instance(), &Preferences::flatShadingChanged, this, &Document::applyPreferenceFlatShadingChange);
+    connect(&Preferences::instance(), &Preferences::threeNodesBranchEnableStateChanged, this, [&]() {
+        threeNodesBranchEnabled = Preferences::instance().threeNodesBranchEnabled();
+    });
 }
 
 void Document::applyPreferencePartColorChange()

src/preferences.cpp

@@ -15,6 +15,7 @@ void Preferences::loadDefault()
     m_componentCombineMode = CombineMode::Normal;
     m_partColor = Qt::white;
     m_flatShading = false;
+    m_threeNodesBranchEnabled = false;
 }
 
 Preferences::Preferences()
@@ -32,9 +33,16 @@ Preferences::Preferences()
     }
     {
         QString value = m_settings.value("flatShading").toString();
-        if (!value.isEmpty())
+        if (value.isEmpty())
+            m_flatShading = true;
+        else
             m_flatShading = isTrueValueString(value);
     }
+    {
+        QString value = m_settings.value("threeNodesBranchEnabled").toString();
+        if (!value.isEmpty())
+            m_threeNodesBranchEnabled = isTrueValueString(value);
+    }
 }
 
 CombineMode Preferences::componentCombineMode() const
@@ -52,6 +60,11 @@ bool Preferences::flatShading() const
     return m_flatShading;
 }
 
+bool Preferences::threeNodesBranchEnabled() const
+{
+    return m_threeNodesBranchEnabled;
+}
+
 void Preferences::setComponentCombineMode(CombineMode mode)
 {
     if (m_componentCombineMode == mode)
@@ -79,6 +92,15 @@ void Preferences::setFlatShading(bool flatShading)
     emit flatShadingChanged();
 }
 
+void Preferences::setThreeNodesBranchEnableState(bool enabled)
+{
+    if (m_threeNodesBranchEnabled == enabled)
+        return;
+    m_threeNodesBranchEnabled = enabled;
+    m_settings.setValue("threeNodesBranchEnabled", enabled ? "true" : "false");
+    emit threeNodesBranchEnableStateChanged();
+}
+
 void Preferences::reset()
 {
     m_settings.clear();
@@ -86,4 +108,5 @@ void Preferences::reset()
     emit componentCombineModeChanged();
     emit partColorChanged();
     emit flatShadingChanged();
+    emit threeNodesBranchEnableStateChanged();
 }

src/preferences.h

@@ -13,20 +13,24 @@ public:
     CombineMode componentCombineMode() const;
     const QColor &partColor() const;
     bool flatShading() const;
+    bool threeNodesBranchEnabled() const;
 signals:
     void componentCombineModeChanged();
     void partColorChanged();
     void flatShadingChanged();
+    void threeNodesBranchEnableStateChanged();
 public slots:
     void setComponentCombineMode(CombineMode mode);
     void setPartColor(const QColor &color);
     void setFlatShading(bool flatShading);
+    void setThreeNodesBranchEnableState(bool enabled);
     void reset();
 private:
     CombineMode m_componentCombineMode = CombineMode::Normal;
     QColor m_partColor;
     bool m_flatShading;
     QSettings m_settings;
+    bool m_threeNodesBranchEnabled;
 private:
     void loadDefault();
 };

src/preferenceswidget.cpp

@@ -60,15 +60,22 @@ PreferencesWidget::PreferencesWidget(const Document *document, QWidget *parent)
         Preferences::instance().setFlatShading(flatShadingBox->isChecked());
     });
     
+    QCheckBox *threeNodesBranchEnabledBox = new QCheckBox();
+    connect(threeNodesBranchEnabledBox, &QCheckBox::stateChanged, this, [=]() {
+        Preferences::instance().setThreeNodesBranchEnableState(threeNodesBranchEnabledBox->isChecked());
+    });
+    
     QFormLayout *formLayout = new QFormLayout;
     formLayout->addRow(tr("Part color:"), colorLayout);
     formLayout->addRow(tr("Combine mode:"), combineModeSelectBox);
     formLayout->addRow(tr("Flat shading:"), flatShadingBox);
+    formLayout->addRow(tr("Three nodes branch:"), threeNodesBranchEnabledBox);
     
     auto loadFromPreferences = [=]() {
         updatePickButtonColor();
         combineModeSelectBox->setCurrentIndex((int)Preferences::instance().componentCombineMode());
         flatShadingBox->setChecked(Preferences::instance().flatShading());
+        threeNodesBranchEnabledBox->setChecked(Preferences::instance().threeNodesBranchEnabled());
     };
     
     loadFromPreferences();

src/skeletondocument.cpp

@@ -71,3 +71,12 @@ void SkeletonDocument::findAllNeighbors(QUuid nodeId, std::set<QUuid> &neighbors
     }
 }
 
+bool SkeletonDocument::isNodeConnectable(QUuid nodeId) const
+{
+    if (threeNodesBranchEnabled)
+        return true;
+    const SkeletonNode *node = findNode(nodeId);
+    if (nullptr == node)
+        return false;
+    return node->edgeIds.size() < 2;
+}

src/skeletondocument.h

@@ -259,6 +259,7 @@ public:
     bool ylocked = false;
     bool zlocked = false;
     bool radiusLocked = false;
+    bool threeNodesBranchEnabled = Preferences::instance().threeNodesBranchEnabled();
     QImage turnaround;
     QByteArray turnaroundPngByteArray;
     std::map<QUuid, SkeletonPart> partMap;
@@ -270,6 +271,7 @@ public:
     const SkeletonPart *findPart(QUuid partId) const;
     const SkeletonEdge *findEdgeByNodes(QUuid firstNodeId, QUuid secondNodeId) const;
     void findAllNeighbors(QUuid nodeId, std::set<QUuid> &neighbors) const;
+    bool isNodeConnectable(QUuid nodeId) const;
     
     virtual bool undoable() const = 0;
     virtual bool redoable() const = 0;

src/skeletongraphicswidget.cpp

@@ -346,6 +346,10 @@ bool SkeletonGraphicsWidget::hasTwoDisconnectedNodesSelection()
         return false;
     if (m_document->findEdgeByNodes(nodeIds[0], nodeIds[1]))
         return false;
+    if (!m_document->isNodeConnectable(nodeIds[0]))
+        return false;
+    if (!m_document->isNodeConnectable(nodeIds[1]))
+        return false;
     return true;
 }
 
@@ -378,6 +382,10 @@ void SkeletonGraphicsWidget::connectSelected()
         return;
     if (m_document->findEdgeByNodes(nodeIds[0], nodeIds[1]))
         return;
+    if (!m_document->isNodeConnectable(nodeIds[0]))
+        return;
+    if (!m_document->isNodeConnectable(nodeIds[1]))
+        return;
     emit addEdge(nodeIds[0], nodeIds[1]);
     emit groupOperationAdded();
 }
@@ -581,8 +589,11 @@ void SkeletonGraphicsWidget::editModeChanged()
         if (!m_rangeSelectionSet.empty()) {
             std::set<SkeletonGraphicsNodeItem *> nodeItems;
             readMergedSkeletonNodeSetFromRangeSelection(&nodeItems);
-            if (nodeItems.size() == 1)
+            if (nodeItems.size() == 1) {
                 choosenNodeItem = *nodeItems.begin();
+                if (!m_document->isNodeConnectable(choosenNodeItem->id()))
+                    choosenNodeItem = nullptr;
+            }
         }
         m_addFromNodeItem = choosenNodeItem;
     }
@@ -1267,9 +1278,11 @@ bool SkeletonGraphicsWidget::mousePress(QMouseEvent *event)
                             m_hoveredNodeItem->profile() == m_addFromNodeItem->profile() &&
                             !m_document->findEdgeByNodes(m_addFromNodeItem->id(), m_hoveredNodeItem->id()) &&
                             m_document->isNodeEditable(m_hoveredNodeItem->id())) {
-                        emit addEdge(m_addFromNodeItem->id(), m_hoveredNodeItem->id());
+                        if (m_document->isNodeConnectable(m_hoveredNodeItem->id())) {
-                        emit groupOperationAdded();
+                            emit addEdge(m_addFromNodeItem->id(), m_hoveredNodeItem->id());
-                        return true;
+                            emit groupOperationAdded();
+                            return true;
+                        }
                     }
                 }
                 QPointF mainProfile = m_cursorNodeItem->origin();