various node UI improvements

app/node/generator/solid/solid.cpp

@@ -1,11 +1,15 @@
 #include "solid.h"
 
-SolidGenerator::SolidGenerator(QObject *parent) :
-  Node(parent),
+SolidGenerator::SolidGenerator() :
   texture_(nullptr)
 {
-  texture_output_ = new NodeOutput(this);
+  color_input_ = new NodeInput();
+  color_input_->add_data_input(NodeParam::kColor);
+  AddParameter(color_input_);
+
+  texture_output_ = new NodeOutput();
   texture_output_->set_data_type(NodeOutput::kTexture);
+  AddParameter(texture_output_);
 }
 
 QString SolidGenerator::Name()

app/node/generator/solid/solid.h

@@ -9,7 +9,7 @@ class SolidGenerator : public Node
 {
   Q_OBJECT
 public:
-  SolidGenerator(QObject* parent = nullptr);
+  SolidGenerator();
 
   virtual QString Name() override;
   virtual QString Category() override;
@@ -21,6 +21,8 @@ public slots:
   virtual void Process(const rational &time) override;
 
 private:
+  NodeInput* color_input_;
+
   NodeOutput* texture_output_;
 
   QOpenGLTexture* texture_;

app/node/graph.cpp

@@ -27,6 +27,14 @@ NodeGraph::NodeGraph()
 
 }
 
+void NodeGraph::AddNode(Node *node)
+{
+  node->setParent(this);
+
+  connect(node, SIGNAL(EdgeAdded(NodeEdgePtr)), this, SIGNAL(EdgeAdded(NodeEdgePtr)));
+  connect(node, SIGNAL(EdgeRemoved(NodeEdgePtr)), this, SIGNAL(EdgeRemoved(NodeEdgePtr)));
+}
+
 const QString &NodeGraph::name()
 {
   return name_;

app/node/graph.h

@@ -27,14 +27,21 @@
 
 class NodeGraph : public QObject
 {
+  Q_OBJECT
 public:
   NodeGraph();
 
+  void AddNode(Node* node);
+
   const QString& name();
   void set_name(const QString& name);
 
   QList<Node*> nodes();
 
+signals:
+  void EdgeAdded(NodeEdgePtr edge);
+  void EdgeRemoved(NodeEdgePtr edge);
+
 private:
   QString name_;
 };

app/node/input.cpp

@@ -22,8 +22,7 @@
 
 #include "output.h"
 
-NodeInput::NodeInput(Node* parent) :
-  NodeParam(parent),
+NodeInput::NodeInput() :
   can_accept_multiple_inputs_(false)
 {
   // Have at least one keyframe/value active at any time
@@ -97,3 +96,8 @@ void NodeInput::set_keyframing(bool k)
 {
   keyframing_ = k;
 }
+
+const QList<NodeParam::DataType> &NodeInput::inputs()
+{
+  return inputs_;
+}

app/node/input.h

@@ -27,7 +27,7 @@
 class NodeInput : public NodeParam
 {
 public:
-  NodeInput(Node *parent);
+  NodeInput();
 
   virtual Type type() override;
 
@@ -43,6 +43,8 @@ public:
   bool keyframing();
   void set_keyframing(bool k);
 
+  const QList<DataType>& inputs();
+
 private:
   QList<DataType> inputs_;
 

app/node/node.cpp

@@ -22,8 +22,7 @@
 
 #include "common/qobjectlistcast.h"
 
-Node::Node(QObject *parent) :
-  QObject(parent)
+Node::Node()
 {
 }
 
@@ -39,6 +38,14 @@ QString Node::Description()
   return QString();
 }
 
+void Node::AddParameter(NodeParam *param)
+{
+  param->setParent(this);
+
+  connect(param, SIGNAL(EdgeAdded(NodeEdgePtr)), this, SIGNAL(EdgeAdded(NodeEdgePtr)));
+  connect(param, SIGNAL(EdgeRemoved(NodeEdgePtr)), this, SIGNAL(EdgeRemoved(NodeEdgePtr)));
+}
+
 void Node::InvalidateCache(const rational &start_range, const rational &end_range)
 {
   QList<NodeParam *> params = parameters();

app/node/node.h

@@ -31,12 +31,14 @@ class Node : public QObject
 {
   Q_OBJECT
 public:
-  Node(QObject* parent = nullptr);
+  Node();
 
   virtual QString Name() = 0;
   virtual QString Category();
   virtual QString Description();
 
+  void AddParameter(NodeParam* param);
+
   /**
    * @brief Signal all dependent Nodes that anything cached between start_range and end_range is now invalid and
    *        requires re-rendering
@@ -71,6 +73,10 @@ public:
 
 public slots:
   virtual void Process(const rational& time) = 0;
+
+signals:
+  void EdgeAdded(NodeEdgePtr edge);
+  void EdgeRemoved(NodeEdgePtr edge);
 };
 
 #endif // NODE_H

app/node/output.cpp

@@ -22,8 +22,7 @@
 
 #include "node/node.h"
 
-NodeOutput::NodeOutput(Node *parent) :
-  NodeParam(parent)
+NodeOutput::NodeOutput()
 {
 
 }

app/node/output.h

@@ -26,7 +26,7 @@
 class NodeOutput : public NodeParam
 {
 public:
-  NodeOutput(Node* parent);
+  NodeOutput();
 
   virtual Type type() override;
 

app/node/output/viewer/viewer.cpp

@@ -2,12 +2,12 @@
 
 #include "panel/panelfocusmanager.h"
 
-ViewerOutput::ViewerOutput(QObject* parent) :
-  Node(parent),
+ViewerOutput::ViewerOutput() :
   attached_viewer_(nullptr)
 {
-  texture_input_ = new NodeInput(this);
+  texture_input_ = new NodeInput();
   texture_input_->add_data_input(NodeInput::kTexture);
+  AddParameter(texture_input_);
 }
 
 QString ViewerOutput::Name()

app/node/output/viewer/viewer.h

@@ -8,7 +8,7 @@ class ViewerOutput : public Node
 {
   Q_OBJECT
 public:
-  ViewerOutput(QObject* parent = nullptr);
+  ViewerOutput();
 
   virtual QString Name() override;
   virtual QString Category() override;

app/node/param.cpp

@@ -20,12 +20,13 @@
 
 #include "param.h"
 
+#include <QDebug>
+
 #include "node/node.h"
 #include "node/input.h"
 #include "node/output.h"
 
-NodeParam::NodeParam(Node *parent) :
-  QObject(parent)
+NodeParam::NodeParam()
 {
 }
 
@@ -54,6 +55,28 @@ const QVector<NodeEdgePtr> &NodeParam::edges()
   return edges_;
 }
 
+bool NodeParam::AreDataTypesCompatible(NodeParam *a, NodeParam *b)
+{
+  // Make sure one is an input and one is an output
+  if (a->type() == b->type()) {
+    return false;
+  }
+
+  NodeInput* input;
+  NodeOutput* output;
+
+  // Work out which parameter is which
+  if (a->type() == NodeParam::kInput) {
+    input = static_cast<NodeInput*>(a);
+    output = static_cast<NodeOutput*>(b);
+  } else {
+    input = static_cast<NodeInput*>(b);
+    output = static_cast<NodeOutput*>(a);
+  }
+
+  return AreDataTypesCompatible(output->data_type(), input->inputs());
+}
+
 bool NodeParam::AreDataTypesCompatible(const NodeParam::DataType &output_type, const NodeParam::DataType &input_type)
 {
   if (input_type == output_type) {
@@ -94,11 +117,21 @@ NodeEdgePtr NodeParam::ConnectEdge(NodeOutput *output, NodeInput *input)
     DisconnectEdge(input->edges_.first());
   }
 
+  // Make sure it's not a duplicate of an edge that already exists
+  foreach (NodeEdgePtr existing, input->edges()) {
+    if (existing->output() == output) {
+      return nullptr;
+    }
+  }
+
   NodeEdgePtr edge = std::make_shared<NodeEdge>(output, input);
 
   output->edges_.append(edge);
   input->edges_.append(edge);
 
+  // Emit a signal than an edge was added (only one signal needs emitting)
+  emit output->EdgeAdded(edge);
+
   return edge;
 }
 
@@ -109,6 +142,8 @@ void NodeParam::DisconnectEdge(NodeEdgePtr edge)
 
   output->edges_.removeAll(edge);
   input->edges_.removeAll(edge);
+
+  emit output->EdgeRemoved(edge);
 }
 
 QString NodeParam::GetDefaultDataTypeName(const DataType& type)

app/node/param.h

@@ -31,6 +31,7 @@ class Node;
 
 class NodeParam : public QObject
 {
+  Q_OBJECT
 public:
   enum Type {
     kInput,
@@ -52,7 +53,7 @@ public:
     kAny
   };
 
-  NodeParam(Node* parent);
+  NodeParam();
 
   virtual Type type() = 0;
 
@@ -65,6 +66,7 @@ public:
 
   const QVector<NodeEdgePtr>& edges();
 
+  static bool AreDataTypesCompatible(NodeParam* a, NodeParam* b);
   static bool AreDataTypesCompatible(const DataType& output_type, const DataType& input_type);
   static bool AreDataTypesCompatible(const DataType& output_type, const QList<DataType>& input_types);
 
@@ -73,6 +75,10 @@ public:
 
   static QString GetDefaultDataTypeName(const DataType &type);
 
+signals:
+  void EdgeAdded(NodeEdgePtr edge);
+  void EdgeRemoved(NodeEdgePtr edge);
+
 protected:
   QVector<NodeEdgePtr> edges_;
 

app/node/processor/renderer/renderer.cpp

@@ -20,8 +20,7 @@
 
 #include "renderer.h"
 
-RendererProcessor::RendererProcessor(QObject *parent) :
-  Node(parent),
+RendererProcessor::RendererProcessor() :
   started_(false)
 {
 

app/node/processor/renderer/renderer.h

@@ -34,7 +34,7 @@ public:
    * Constructing a Renderer object will not start any threads/backend on its own. Use Start() to do this and Stop()
    * when the Renderer is about to be destroyed.
    */
-  RendererProcessor(QObject* parent = nullptr);
+  RendererProcessor();
 
   virtual QString Name() override;
   virtual QString Category() override;

app/widget/nodeview/CMakeLists.txt

@@ -18,9 +18,11 @@ set(OLIVE_SOURCES
   ${OLIVE_SOURCES}
   widget/nodeview/nodeview.h
   widget/nodeview/nodeview.cpp
-  widget/nodeview/nodeviewitem.h
-  widget/nodeview/nodeviewitem.cpp
   widget/nodeview/nodeviewedge.h
   widget/nodeview/nodeviewedge.cpp
+  widget/nodeview/nodeviewitem.h
+  widget/nodeview/nodeviewitem.cpp
+  widget/nodeview/nodeviewitemwidgetproxy.h
+  widget/nodeview/nodeviewitemwidgetproxy.cpp
   PARENT_SCOPE
 )

app/widget/nodeview/nodeview.cpp

@@ -33,6 +33,11 @@ NodeView::NodeView(QWidget *parent) :
 
 void NodeView::SetGraph(NodeGraph *graph)
 {
+  if (graph_ != nullptr) {
+    disconnect(graph_, SIGNAL(EdgeAdded(NodeEdgePtr)), this, SLOT(AddEdge(NodeEdgePtr)));
+    disconnect(graph_, SIGNAL(EdgeRemoved(NodeEdgePtr)), this, SLOT(RemoveEdge(NodeEdgePtr)));
+  }
+
   // Clear the scene of all UI objects
   scene_.clear();
 
@@ -41,6 +46,9 @@ void NodeView::SetGraph(NodeGraph *graph)
 
   // If the graph is valid, add UI objects for each of its Nodes
   if (graph_ != nullptr) {
+    connect(graph_, SIGNAL(EdgeAdded(NodeEdgePtr)), this, SLOT(AddEdge(NodeEdgePtr)));
+    connect(graph_, SIGNAL(EdgeRemoved(NodeEdgePtr)), this, SLOT(RemoveEdge(NodeEdgePtr)));
+
     QList<Node*> graph_nodes = graph_->nodes();
 
     foreach (Node* node, graph_nodes) {
@@ -61,11 +69,7 @@ void NodeView::SetGraph(NodeGraph *graph)
           const QVector<NodeEdgePtr>& edges = param->edges();
 
           foreach(NodeEdgePtr edge, edges) {
-            NodeViewEdge* edge_ui = new NodeViewEdge();
-
-            edge_ui->SetEdge(edge);
-
-            scene_.addItem(edge_ui);
+            AddEdge(edge);
           }
         }
       }
@@ -107,6 +111,22 @@ NodeViewEdge *NodeView::EdgeToUIObject(QGraphicsScene *scene, NodeEdgePtr n)
   return nullptr;
 }
 
+void NodeView::AddEdge(NodeEdgePtr edge)
+{
+  NodeViewEdge* edge_ui = new NodeViewEdge();
+
+  edge_ui->SetEdge(edge);
+
+  scene_.addItem(edge_ui);
+}
+
+void NodeView::RemoveEdge(NodeEdgePtr edge)
+{
+  NodeViewEdge* edge_ui = EdgeToUIObject(scene(), edge);
+
+  scene_.removeItem(edge_ui);
+}
+
 void NodeView::ItemsChanged()
 {
   QList<QGraphicsItem*> items = scene_.items();

app/widget/nodeview/nodeview.h

@@ -44,6 +44,10 @@ private:
   QGraphicsScene scene_;
 
 private slots:
+  void AddEdge(NodeEdgePtr edge);
+
+  void RemoveEdge(NodeEdgePtr edge);
+
   void ItemsChanged();
 
 };

app/widget/nodeview/nodeviewedge.cpp

@@ -27,23 +27,20 @@
 #include "common/lerp.h"
 #include "nodeview.h"
 
-const int kNodeEdgeWidth = 2;
-
 NodeViewEdge::NodeViewEdge(QGraphicsItem *parent) :
   QGraphicsLineItem(parent),
   edge_(nullptr),
-  moving_(false),
   connected_(false)
 {
   // Ensures this UI object is drawn behind other objects
   setZValue(-1);
 
-  setAcceptHoverEvents(true);
+  // Use font metrics to set edge width for basic high DPI support
+  edge_width_ = QFontMetrics(QFont()).height() / 12;
 }
 
 void NodeViewEdge::SetEdge(NodeEdgePtr edge)
 {
-  SetMoving(false);
   SetConnected(true);
 
   // Set the new edge pointer
@@ -78,7 +75,7 @@ qreal CalculateEdgeYPoint(NodeViewItem *item, int param_index, NodeViewItem *opp
 
 void NodeViewEdge::Adjust()
 {
-  if (edge_ == nullptr || scene() == nullptr || moving_) {
+  if (edge_ == nullptr || scene() == nullptr) {
     return;
   }
 
@@ -101,11 +98,6 @@ void NodeViewEdge::Adjust()
             ));
 }
 
-void NodeViewEdge::SetMoving(bool m)
-{
-  moving_ = m;
-}
-
 void NodeViewEdge::SetConnected(bool c)
 {
   connected_ = c;
@@ -121,7 +113,7 @@ void NodeViewEdge::paint(QPainter *painter, const QStyleOptionGraphicsItem *opti
     color_mode = QPalette::Disabled;
   }
 
-  setPen(QPen(widget->palette().color(color_mode, QPalette::Text), kNodeEdgeWidth));
+  setPen(QPen(widget->palette().color(color_mode, QPalette::Text), edge_width_));
 
   QGraphicsLineItem::paint(painter, option, widget);
 }

app/widget/nodeview/nodeviewedge.h

@@ -35,7 +35,6 @@ public:
 
   void Adjust();
 
-  void SetMoving(bool m);
   void SetConnected(bool c);
 
 protected:
@@ -44,7 +43,8 @@ protected:
 private:
   NodeEdgePtr edge_;
 
-  bool moving_;
+  int edge_width_;
+
   bool connected_;
 };
 

app/widget/nodeview/nodeviewitem.cpp

@@ -31,11 +31,6 @@
 #include "ui/icons/icons.h"
 #include "window/mainwindow/mainwindow.h"
 
-const int kNodeViewItemBorderWidth = 2;
-const int kNodeViewItemWidth = 200;
-const int kNodeViewItemTextPadding = 4;
-const int kNodeViewItemIconPadding = 12;
-
 NodeViewItem::NodeViewItem(QGraphicsItem *parent) :
   QGraphicsRectItem(parent),
   node_(nullptr),
@@ -48,13 +43,31 @@ NodeViewItem::NodeViewItem(QGraphicsItem *parent) :
   setFlag(QGraphicsItem::ItemIsMovable);
   setFlag(QGraphicsItem::ItemIsSelectable);
 
-  // Use the current default font height to size this widget
-  // Set default "collapsed" size
-  title_bar_rect_ = QRectF(0, 0, kNodeViewItemWidth, font_metrics.height() + kNodeViewItemTextPadding * 2);
-  setRect(title_bar_rect_);
+  //
+  // We use font metrics to set all the UI measurements for DPI-awareness
+  //
+
+  // Not particularly great way of using text scaling to set the width (DPI-awareness, etc.)
+#if QT_VERSION < QT_VERSION_CHECK(5, 11, 0)
+  int widget_width = font_metrics.width("HHHHHHHHHHHHHHHH");
+#else
+  int widget_width = font_metrics.horizontalAdvance("HHHHHHHHHHHHHHHH");
+#endif
+
+  // Set border width
+  node_border_width_ = font_metrics.height() / 12;
 
   // Set default node connector size
   node_connector_size_ = font_metrics.height() / 3;
+
+  // Set text and icon padding
+  node_text_padding_ = font_metrics.height() / 6;
+  node_icon_padding_ = node_text_padding_ * 3;
+
+  // Use the current default font height to size this widget
+  // Set default "collapsed" size
+  title_bar_rect_ = QRectF(0, 0, widget_width, font_metrics.height() + node_text_padding_ * 2);
+  setRect(title_bar_rect_);
 }
 
 void NodeViewItem::SetNode(Node *n)
@@ -85,7 +98,7 @@ void NodeViewItem::SetExpanded(bool e)
 
     // If a node is connected, use its parameter count to set the height
     if (node_ != nullptr) {
-      full_size_rect.adjust(0, 0, 0, kNodeViewItemTextPadding*2 + font_metrics.height() * node_->ParameterCount());
+      full_size_rect.adjust(0, 0, 0, node_text_padding_*2 + font_metrics.height() * node_->ParameterCount());
     }
 
     // Store content_rect (the rect without the titlebar)
@@ -110,10 +123,14 @@ QRectF NodeViewItem::GetParameterConnectorRect(int index)
   NodeParam* param = node_->ParamAt(index);
 
   QRectF connector_rect(rect().x(),
-                        content_rect_.y() + kNodeViewItemTextPadding + font_metrics.height() / 2 - node_connector_size_ / 2,
+                        content_rect_.y() + node_text_padding_ + font_metrics.height() / 2 - node_connector_size_ / 2,
                         node_connector_size_,
                         node_connector_size_);
 
+  if (index > 0) {
+    connector_rect.translate(0, font_metrics.height() * index);
+  }
+
   // FIXME: I don't know how this will work with NodeParam::kBidirectional
   if (param->type() == NodeParam::kOutput) {
     connector_rect.translate(rect().width() - node_connector_size_, 0);
@@ -132,11 +149,11 @@ QPointF NodeViewItem::GetParameterTextPoint(int index)
 
   // FIXME: I don't know how this will work with NodeParam::kBidirectional
   if (param->type() == NodeParam::kOutput) {
-    return content_rect_.topRight() + QPointF(-(node_connector_size_ + kNodeViewItemTextPadding),
-                                             kNodeViewItemTextPadding + font_metrics.ascent() + font_metrics.height()*index);
+    return content_rect_.topRight() + QPointF(-(node_connector_size_ + node_text_padding_),
+                                              node_text_padding_ + font_metrics.ascent() + font_metrics.height()*index);
   } else {
-    return content_rect_.topLeft() + QPointF(node_connector_size_ + kNodeViewItemTextPadding,
-                                             kNodeViewItemTextPadding + font_metrics.ascent() + font_metrics.height()*index);
+    return content_rect_.topLeft() + QPointF(node_connector_size_ + node_text_padding_,
+                                             node_text_padding_ + font_metrics.ascent() + font_metrics.height()*index);
   }
 }
 
@@ -147,7 +164,7 @@ void NodeViewItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *opti
   QPalette app_pal = olive::core.main_window()->palette();
 
   // Set up border, which will change color if selected
-  QPen border_pen(obj_proxy_.BorderColor(), kNodeViewItemBorderWidth);
+  QPen border_pen(css_proxy_.BorderColor(), node_border_width_);
 
   QPen text_pen(app_pal.color(QPalette::Text));
 
@@ -157,7 +174,7 @@ void NodeViewItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *opti
 
   if (expanded_ && node_ != nullptr) {
 
-
+    // Use main widget color for node contents
     painter->setBrush(app_pal.window());
 
     // Draw background rect
@@ -197,7 +214,7 @@ void NodeViewItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *opti
   }
 
   // Draw rect
-  painter->setBrush(obj_proxy_.TitleBarColor());
+  painter->setBrush(css_proxy_.TitleBarColor());
   painter->drawRect(title_bar_rect_);
 
   // If selected, draw selection outline
@@ -216,10 +233,10 @@ void NodeViewItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *opti
     painter->setPen(text_pen);
 
     // Draw the expand icon
-    expand_hitbox_ = title_bar_rect_.adjusted(kNodeViewItemIconPadding,
-                                              kNodeViewItemIconPadding,
-                                              -kNodeViewItemIconPadding,
-                                              -kNodeViewItemIconPadding);
+    expand_hitbox_ = title_bar_rect_.adjusted(node_icon_padding_,
+                                              node_icon_padding_,
+                                              -node_icon_padding_,
+                                              -node_icon_padding_);
 
     // Make the icon rect a square
     expand_hitbox_.setWidth(expand_hitbox_.height());
@@ -232,10 +249,10 @@ void NodeViewItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *opti
     }
 
     // Draw the text in a rect (the rect is sized around text already in the constructor)
-    QRectF text_rect = title_bar_rect_.adjusted(kNodeViewItemIconPadding + expand_hitbox_.width() + kNodeViewItemTextPadding,
-                                                kNodeViewItemTextPadding,
-                                                -kNodeViewItemTextPadding,
-                                                -kNodeViewItemTextPadding);
+    QRectF text_rect = title_bar_rect_.adjusted(node_icon_padding_ + expand_hitbox_.width() + node_text_padding_,
+                                                node_text_padding_,
+                                                -node_text_padding_,
+                                                -node_text_padding_);
     painter->drawText(text_rect, Qt::AlignVCenter | Qt::AlignLeft, node_->Name());
   }
 }
@@ -261,42 +278,43 @@ void NodeViewItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
 
         NodeParam* param = node_->ParamAt(i);
 
+        // Create draggable object
+        dragging_edge_ = new NodeViewEdge();
+
         if (param->type() == NodeParam::kOutput || param->edges().isEmpty()) {
           // For an output param (or an input param with no connections), we default to creating a new edge
-
-          // Create new NodeViewEdge object for the user to create an edge
-          dragging_edge_ = new NodeViewEdge();
-          dragging_edge_->SetMoving(true);
-
           drag_source_ = this;
           drag_src_param_ = param;
 
           // Set the starting position to the current param's connector
-          dragging_edge_start_ = pos() + GetParameterConnectorRect(i).center();
-          dragging_edge_->setLine(QLineF(dragging_edge_start_, dragging_edge_start_));
-
-          // Add it to the scene
-          scene()->addItem(dragging_edge_);
+          dragging_edge_start_ = mapToScene(GetParameterConnectorRect(i).center());
 
         } else if (param->type() == NodeParam::kInput) {
           // For an input param, we default to moving an existing edge
           // (here we use the last one, which will usually also be the first)
           NodeEdgePtr edge = param->edges().last();
 
-          dragging_edge_ = NodeView::EdgeToUIObject(scene(), edge);
-          dragging_edge_->SetMoving(true);
+          // Remove old edge
+          NodeParam::DisconnectEdge(edge);
 
-          // The starting position will be the OPPOSING param's rect
-          NodeOutput* opposing_param = edge->output();
-          Node* opposing_node = opposing_param->parent();
-          NodeViewItem* opposing_node_view_item = NodeView::NodeToUIObject(scene(), opposing_node);
-          dragging_edge_start_ = opposing_node_view_item->pos() + opposing_node_view_item->GetParameterConnectorRect(opposing_param->index()).center();
+          // The starting position will be the OPPOSING parameter's rectangle
 
-          drag_source_ = opposing_node_view_item;
-          drag_src_param_ = opposing_param;
+          // Get the opposing parameter
+          drag_src_param_ = edge->output();
 
+          // Get its Node UI object
+          drag_source_ = NodeView::NodeToUIObject(scene(), drag_src_param_->parent());
+
+          // Get the opposing parameter's rect center
+          dragging_edge_start_ = drag_source_->mapToScene(drag_source_->GetParameterConnectorRect(drag_src_param_->index()).center());
         }
 
+        // Add it to the scene
+        scene()->addItem(dragging_edge_);
+
+        // Trigger initial line setting
+        mouseMoveEvent(event);
+
         return;
       }
 
@@ -324,15 +342,18 @@ void NodeViewItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
 
       // See if the mouse is currently inside a connector rect
       for (int i=0;i<drop_item->node()->ParameterCount();i++) {
-        QRectF comp_rect = drop_item->GetParameterConnectorRect(i).adjusted(-node_connector_size_,
-                                                                            -node_connector_size_,
-                                                                            node_connector_size_,
-                                                                            node_connector_size_);
 
+        // Make a larger "hitbox" rect to make it easier to drag into
+        QRectF param_hitbox = drop_item->GetParameterConnectorRect(i).adjusted(-node_connector_size_,
+                                                                               -node_connector_size_,
+                                                                               node_connector_size_,
+                                                                               node_connector_size_);
+
+        // Get the parameter we're dragging into
         NodeParam* comp_param = drop_item->node()->ParamAt(i);
 
-        // If so, we snap inside it
-        if (comp_rect.contains(drop_item->mapFromScene(event->scenePos()))) {
+        if (param_hitbox.contains(drop_item->mapFromScene(event->scenePos())) // See if we're dragging inside the hitbox
+            && NodeParam::AreDataTypesCompatible(drag_src_param_, comp_param)) { // Make sure the types are compatible
 
           drag_dest_param_ = comp_param;
           end_point = drop_item->mapToScene(drop_item->GetParameterConnectorRect(i).center());
@@ -361,18 +382,11 @@ void NodeViewItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 
     // FIXME: Make this undoable
 
-    // If this edge had an edge, we should disconnect it now
-    if (dragging_edge_->edge() != nullptr) {
-      NodeParam::DisconnectEdge(dragging_edge_->edge());
+    scene()->removeItem(dragging_edge_);
 
-      dragging_edge_->SetEdge(nullptr);
-    }
+    if (drag_dest_param_ != nullptr) {
+      // We dragged to somewhere, so we'll make a new connection
 
-    if (drag_dest_param_ == nullptr) {
-      // If we didn't drag to anywhere, just get rid of this edge
-      scene()->removeItem(dragging_edge_);
-    } else {
-      // If we did, create a new edge now
       NodeEdgePtr new_edge;
 
       if (drag_dest_param_->type() == NodeParam::kOutput) {
@@ -380,8 +394,6 @@ void NodeViewItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
       } else {
         new_edge = NodeParam::ConnectEdge(static_cast<NodeOutput*>(drag_src_param_), static_cast<NodeInput*>(drag_dest_param_));
       }
-
-      dragging_edge_->SetEdge(new_edge);
     }
 
     dragging_edge_ = nullptr;
@@ -397,27 +409,3 @@ void NodeViewItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
     QGraphicsRectItem::mouseReleaseEvent(event);
   }
 }
-
-NodeViewItemWidget::NodeViewItemWidget()
-{
-}
-
-QColor NodeViewItemWidget::TitleBarColor()
-{
-  return title_bar_color_;
-}
-
-void NodeViewItemWidget::SetTitleBarColor(QColor color)
-{
-  title_bar_color_ = color;
-}
-
-QColor NodeViewItemWidget::BorderColor()
-{
-  return border_color_;
-}
-
-void NodeViewItemWidget::SetBorderColor(QColor color)
-{
-  border_color_ = color;
-}

app/widget/nodeview/nodeviewitem.h

@@ -28,26 +28,7 @@
 
 #include "node/node.h"
 #include "nodeviewedge.h"
-
-/**
- * @brief A proxy object to allow NodeViewItem access to CSS functions
- */
-class NodeViewItemWidget : public QWidget {
-  Q_OBJECT
-  Q_PROPERTY(QColor titlebarColor READ TitleBarColor WRITE SetTitleBarColor DESIGNABLE true)
-  Q_PROPERTY(QColor borderColor READ BorderColor WRITE SetBorderColor DESIGNABLE true)
-public:
-  NodeViewItemWidget();
-
-  QColor TitleBarColor();
-  void SetTitleBarColor(QColor color);
-
-  QColor BorderColor();
-  void SetBorderColor(QColor color);
-private:
-  QColor title_bar_color_;
-  QColor border_color_;
-};
+#include "nodeviewitemwidgetproxy.h"
 
 class NodeViewItem : public QGraphicsRectItem
 {
@@ -76,7 +57,7 @@ private:
 
   Node* node_;
 
-  NodeViewItemWidget obj_proxy_;
+  NodeViewItemWidget css_proxy_;
 
   QRectF title_bar_rect_;
 
@@ -94,6 +75,9 @@ private:
   NodeViewItem* drag_source_;
 
   int node_connector_size_;
+  int node_text_padding_;
+  int node_icon_padding_;
+  int node_border_width_;
 
   bool expanded_;
 

app/widget/nodeview/nodeviewitemwidgetproxy.cpp

@@ -0,0 +1,25 @@
+#include "nodeviewitemwidgetproxy.h"
+
+NodeViewItemWidget::NodeViewItemWidget()
+{
+}
+
+QColor NodeViewItemWidget::TitleBarColor()
+{
+  return title_bar_color_;
+}
+
+void NodeViewItemWidget::SetTitleBarColor(QColor color)
+{
+  title_bar_color_ = color;
+}
+
+QColor NodeViewItemWidget::BorderColor()
+{
+  return border_color_;
+}
+
+void NodeViewItemWidget::SetBorderColor(QColor color)
+{
+  border_color_ = color;
+}

app/widget/nodeview/nodeviewitemwidgetproxy.h

@@ -0,0 +1,29 @@
+#ifndef NODEVIEWITEMWIDGETPROXY_H
+#define NODEVIEWITEMWIDGETPROXY_H
+
+#include <QWidget>
+
+/**
+ * @brief A proxy object to allow NodeViewItem access to CSS functions
+ *
+ * QGraphicsItems can't take Q_PROPERTYs for CSS stylesheet input, but QWidgets can. This is a hack to allow CSS
+ * properties to be set from CSS and then read by NodeViewItem.
+ */
+class NodeViewItemWidget : public QWidget {
+  Q_OBJECT
+  Q_PROPERTY(QColor titlebarColor READ TitleBarColor WRITE SetTitleBarColor DESIGNABLE true)
+  Q_PROPERTY(QColor borderColor READ BorderColor WRITE SetBorderColor DESIGNABLE true)
+public:
+  NodeViewItemWidget();
+
+  QColor TitleBarColor();
+  void SetTitleBarColor(QColor color);
+
+  QColor BorderColor();
+  void SetBorderColor(QColor color);
+private:
+  QColor title_bar_color_;
+  QColor border_color_;
+};
+
+#endif // NODEVIEWITEMWIDGETPROXY_H

app/window/mainwindow/mainwindow.cpp

@@ -83,10 +83,12 @@ void olive::MainWindow::ProjectOpen(Project* p)
   NodeGraph* graph = new NodeGraph();
   graph->setParent(this);
   graph->set_name("New Graph");
-  ViewerOutput* vo = new ViewerOutput(graph);
+  ViewerOutput* vo = new ViewerOutput();
   vo->AttachViewer(viewer_panel2);
-  SolidGenerator* sg = new SolidGenerator(graph);
+  graph->AddNode(vo);
+  SolidGenerator* sg = new SolidGenerator();
   NodeInput::ConnectEdge(sg->texture_output(), vo->texture_input());
+  graph->AddNode(sg);
   task_panel->SetGraph(graph);
   // End test code
 }