Adds Node Group functionality (#514)

The node group feature allows nodes to be grouped, giving users the flexibility to organize their workspace. Groups can be locked, making the constituent nodes inaccessible via the mouse, or unlocked for easy access. Saving and loading groups further empower users to tailor their setup to their needs, enhancing control over their workflow. 

Co-authored-by: Taiguara Tupinambás <tatatupi@gmail.com>
Co-authored-by: Hudson Miranda <hudsonmiranda291@gmail.com>
Co-authored-by: Gabrielnmds <gabrielnmds21@gmail.com>

Author: 4 people

CMakeLists.txt

@@ -87,6 +87,8 @@ set(CPP_SOURCE_FILES
   src/StyleCollection.cpp
   src/UndoCommands.cpp
   src/locateNode.cpp
+  src/GroupGraphicsObject.cpp
+  src/NodeGroup.cpp
   resources/resources.qrc
 )
 
@@ -127,6 +129,8 @@ set(HPP_HEADER_FILES
   include/QtNodes/internal/DefaultVerticalNodeGeometry.hpp
   include/QtNodes/internal/NodeConnectionInteraction.hpp
   include/QtNodes/internal/UndoCommands.hpp
+  include/QtNodes/internal/NodeGroup.hpp
+  include/QtNodes/internal/GroupGraphicsObject.hpp
 )
 
 # If we want to give the option to build a static library,

examples/calculator/main.cpp

@@ -112,6 +112,11 @@ int main(int argc, char *argv[])
         mainWidget.setWindowModified(true);
     });
 
+    if (scene->groupingEnabled()) {
+        auto loadGroupAction = menu->addAction("Load Group...");
+        QObject::connect(loadGroupAction, &QAction::triggered, [scene] { scene->loadGroupFile(); });
+    }
+
     mainWidget.setWindowTitle("[*]Data Flow: simplest calculator");
     mainWidget.resize(800, 600);
     // Center window.

include/QtNodes/GroupGraphicsObject

@@ -0,0 +1 @@
+#include "internal/GroupGraphicsObject.hpp"

include/QtNodes/NodeGroup

@@ -0,0 +1 @@
+#include "internal/NodeGroup.hpp"

include/QtNodes/internal/BasicGraphicsScene.hpp

@@ -5,10 +5,11 @@
 #include "ConnectionIdHash.hpp"
 #include "Definitions.hpp"
 #include "Export.hpp"
+#include "GroupGraphicsObject.hpp"
+#include "NodeGroup.hpp"
+#include "UndoCommands.hpp"
 
-#include "QUuidStdHash.hpp"
-
-#include <QtCore/QUuid>
+#include <QtCore/QJsonObject>
 #include <QtWidgets/QGraphicsScene>
 #include <QtWidgets/QMenu>
 
@@ -27,6 +28,11 @@ class AbstractNodePainter;
 class ConnectionGraphicsObject;
 class NodeGraphicsObject;
 class NodeStyle;
+class DeleteCommand;
+class CopyCommand;
+class NodeGroup;
+class GroupGraphicsObject;
+struct ConnectionId;
 
 /// An instance of QGraphicsScene, holds connections and nodes.
 class NODE_EDITOR_PUBLIC BasicGraphicsScene : public QGraphicsScene
@@ -62,6 +68,17 @@ class NODE_EDITOR_PUBLIC BasicGraphicsScene : public QGraphicsScene
 
     QUndoStack &undoStack();
 
+    /**
+     * @brief Setter for the _groupingEnabled flag.
+     * @param boolean to set or not the flag.
+     */
+    void setGroupingEnabled(bool enabled);
+
+    /**
+     * @brief Getter for the _groupingEnabled flag.
+     */
+    bool groupingEnabled() const { return _groupingEnabled; }
+
 public:
     /**
      * @brief Creates a "draft" instance of ConnectionGraphicsObject.
@@ -87,6 +104,83 @@ class NODE_EDITOR_PUBLIC BasicGraphicsScene : public QGraphicsScene
     /// Deletes all the nodes. Connections are removed automatically.
     void clearScene();
 
+    /**
+     * @brief Creates a list of the connections that are incident only to nodes within a
+     * given group.
+     * @param groupID ID of the desired group.
+     * @return List of (pointers of) connections whose both endpoints belong to members of
+     * the specified group.
+     */
+    std::vector<std::shared_ptr<ConnectionId>> connectionsWithinGroup(GroupId groupID);
+    /**
+     * @brief Creates a group in the scene containing the given nodes.
+     * @param nodes Reference to the list of nodes to be included in the group.
+     * @param name Group's name.
+     * @param groupId Group's id.
+     * @return Pointer to the newly-created group.
+     */
+    std::weak_ptr<NodeGroup> createGroup(std::vector<NodeGraphicsObject *> &nodes,
+                                         QString name = QStringLiteral(""),
+                                         GroupId groupId = InvalidGroupId);
+
+    /**
+     * @brief Creates a group in the scene containing the currently selected nodes.
+     * @param name Group's name
+     * @return Pointer to the newly-created group.
+     */
+    std::weak_ptr<NodeGroup> createGroupFromSelection(QString groupName = QStringLiteral(""));
+
+    /**
+     * @brief Restores a group from a JSON object.
+     * @param groupJson JSON object containing the group data.
+     * @return Pair consisting of a pointer to the newly-created group and the mapping
+     * between old and new nodes.
+     */
+    std::pair<std::weak_ptr<NodeGroup>, std::unordered_map<GroupId, GroupId>> restoreGroup(
+        QJsonObject const &groupJson);
+
+    /**
+     * @brief Returns a const reference to the mapping of existing groups.
+     */
+    std::unordered_map<GroupId, std::shared_ptr<NodeGroup>> const &groups() const;
+
+    /**
+     * @brief Loads a group from a file specified by the user.
+     * @return Pointer to the newly-created group.
+     */
+    std::weak_ptr<NodeGroup> loadGroupFile();
+
+    /**
+     * @brief Saves a group in a .group file.
+     * @param groupID Group's id.
+     */
+    void saveGroupFile(GroupId groupID);
+
+    /**
+     * @brief Calculates the selected nodes.
+     * @return Vector containing the NodeGraphicsObject pointers related to the selected nodes.
+     */
+    std::vector<NodeGraphicsObject *> selectedNodes() const;
+
+    /**
+     * @brief Calculates the selected groups.
+     * @return Vector containing the GroupGraphicsObject pointers related to the selected groups.
+     */
+    std::vector<GroupGraphicsObject *> selectedGroups() const;
+
+    /**
+     * @brief Adds a node to a group, if both node and group exists.
+     * @param nodeId Node's id.
+     * @param groupId Group's id.
+     */
+    void addNodeToGroup(NodeId nodeId, GroupId groupId);
+
+    /**
+     * @brief Removes a node from a group, if the node exists and is within a group.
+     * @param nodeId Node's id.
+     */
+    void removeNodeFromGroup(NodeId nodeId);
+
 public:
     /**
      * @returns NodeGraphicsObject associated with the given nodeId.
@@ -111,6 +205,17 @@ class NODE_EDITOR_PUBLIC BasicGraphicsScene : public QGraphicsScene
      */
     virtual QMenu *createSceneMenu(QPointF const scenePos);
 
+    /**
+     * @brief Creates the default menu when a node is selected.
+     */
+    QMenu *createStdMenu(QPointF const scenePos);
+
+    /**
+     * @brief Creates the menu when a group is selected.
+     * @param groupGo reference to the GroupGraphicsObject related to the selected group.
+     */
+    QMenu *createGroupMenu(QPointF const scenePos, GroupGraphicsObject *groupGo);
+
 Q_SIGNALS:
     void modified(BasicGraphicsScene *);
     void nodeMoved(NodeId const nodeId, QPointF const &newLocation);
@@ -141,6 +246,24 @@ class NODE_EDITOR_PUBLIC BasicGraphicsScene : public QGraphicsScene
     /// Redraws adjacent nodes for given `connectionId`
     void updateAttachedNodes(ConnectionId const connectionId, PortType const portType);
 
+    /**
+     * @brief Loads a JSON object that represents a node, with the option
+     * to keep the stored node id or generate a new one.
+     * @param nodeJson The JSON object representing a node.
+     * @param keepOriginalId If true, the loaded node will have the same id as the one stored in
+     * the file; otherwise, a new id will be generated
+     * @return A reference to the NodeGraphicsObject related to the loaded node.
+     */
+    NodeGraphicsObject &loadNodeToMap(QJsonObject nodeJson, bool keepOriginalId = false);
+
+    /**
+     * @brief Loads a connection between nodes from a JSON file.
+     * @param connectionJson JSON object that stores the connection's endpoints.
+     * @param nodeIdMap Map of nodes (i.e. all possible endpoints).
+     */
+    void loadConnectionToMap(QJsonObject const &connectionJson,
+                             std::unordered_map<NodeId, NodeId> const &nodeIdMap);
+
 public Q_SLOTS:
     /// Slot called when the `connectionId` is erased form the AbstractGraphModel.
     virtual void onConnectionDeleted(ConnectionId const connectionId);
@@ -155,21 +278,37 @@ public Q_SLOTS:
     virtual void onNodeClicked(NodeId const nodeId);
     virtual void onModelReset();
 
+    /**
+     * @brief Slot called to trigger the copy command action.
+     */
+    void onCopySelectedObjects() { undoStack().push(new CopyCommand(this)); }
+
+    /**
+     * @brief Slot called to trigger the delete command action.
+     */
+    void onDeleteSelectedObjects() { undoStack().push(new DeleteCommand(this)); }
+
 private:
     AbstractGraphModel &_graphModel;
 
     using UniqueNodeGraphicsObject = std::unique_ptr<NodeGraphicsObject>;
     using UniqueConnectionGraphicsObject = std::unique_ptr<ConnectionGraphicsObject>;
+    using SharedGroup = std::shared_ptr<NodeGroup>;
 
     std::unordered_map<NodeId, UniqueNodeGraphicsObject> _nodeGraphicsObjects;
     std::unordered_map<ConnectionId, UniqueConnectionGraphicsObject> _connectionGraphicsObjects;
+    GroupId nextGroupId();
+
+    std::unordered_map<GroupId, SharedGroup> _groups{};
+    GroupId _nextGroupId{0};
     std::unique_ptr<ConnectionGraphicsObject> _draftConnection;
     std::unique_ptr<AbstractNodeGeometry> _nodeGeometry;
     std::unique_ptr<AbstractNodePainter> _nodePainter;
     std::unique_ptr<AbstractConnectionPainter> _connectionPainter;
     bool _nodeDrag;
     QUndoStack *_undoStack;
     Qt::Orientation _orientation;
+    bool _groupingEnabled;
 };
 
 } // namespace QtNodes

include/QtNodes/internal/Definitions.hpp

@@ -18,23 +18,23 @@ NODE_EDITOR_PUBLIC Q_NAMESPACE
 Q_NAMESPACE_EXPORT(NODE_EDITOR_PUBLIC)
 #endif
 
-/**
+    /**
  * Constants used for fetching QVariant data from GraphModel.
  */
-enum class NodeRole {
-    Type = 0,             ///< Type of the current node, usually a string.
-    Position = 1,         ///< `QPointF` positon of the node on the scene.
-    Size = 2,             ///< `QSize` for resizable nodes.
-    CaptionVisible = 3,   ///< `bool` for caption visibility.
-    Caption = 4,          ///< `QString` for node caption.
-    Style = 5,            ///< Custom NodeStyle as QJsonDocument
-    InternalData = 6,     ///< Node-stecific user data as QJsonObject
-    InPortCount = 7,      ///< `unsigned int`
-    OutPortCount = 9,     ///< `unsigned int`
-    Widget = 10,          ///< Optional `QWidget*` or `nullptr`
-    ValidationState = 11, ///< Enum NodeValidationState of the node
-    ProcessingStatus = 12 ///< Enum NodeProcessingStatus of the node
-};
+    enum class NodeRole {
+        Type = 0,             ///< Type of the current node, usually a string.
+        Position = 1,         ///< `QPointF` positon of the node on the scene.
+        Size = 2,             ///< `QSize` for resizable nodes.
+        CaptionVisible = 3,   ///< `bool` for caption visibility.
+        Caption = 4,          ///< `QString` for node caption.
+        Style = 5,            ///< Custom NodeStyle as QJsonDocument
+        InternalData = 6,     ///< Node-stecific user data as QJsonObject
+        InPortCount = 7,      ///< `unsigned int`
+        OutPortCount = 9,     ///< `unsigned int`
+        Widget = 10,          ///< Optional `QWidget*` or `nullptr`
+        ValidationState = 11, ///< Enum NodeValidationState of the node
+        ProcessingStatus = 12 ///< Enum NodeProcessingStatus of the node
+    };
 Q_ENUM_NS(NodeRole)
 
 /**
@@ -94,6 +94,11 @@ using NodeId = unsigned int;
 
 static constexpr NodeId InvalidNodeId = std::numeric_limits<NodeId>::max();
 
+/// Unique Id associated with each node group.
+using GroupId = unsigned int;
+
+static constexpr GroupId InvalidGroupId = std::numeric_limits<GroupId>::max();
+
 /**
  * A unique connection identificator that stores
  * out `NodeId`, out `PortIndex`, in `NodeId`, in `PortIndex`

include/QtNodes/internal/GraphicsView.hpp

@@ -91,6 +91,7 @@ public Q_SLOTS:
 private:
     QAction *_clearSelectionAction = nullptr;
     QAction *_deleteSelectionAction = nullptr;
+    QAction *_cutSelectionAction = nullptr;
     QAction *_duplicateSelectionAction = nullptr;
     QAction *_copySelectionAction = nullptr;
     QAction *_pasteAction = nullptr;