Add node to graph with Ctrl+V if valid node content is in the clipboard

Attempt to paste the clipboard's content in the graph when Ctrl+V is
pressed. If the clipboard contains a valid node description, add the
corresponding node to the graph.
Otherwise, do nothing.

meshroom/core/graph.py

@@ -396,6 +396,15 @@ class Graph(BaseObject):
 
         return duplicates
 
+    def pasteNode(self, nodeType, **kwargs):
+        name = self._createUniqueNodeName(nodeType)
+        node = None
+        with GraphModification(self):
+            node = Node(nodeType, **kwargs)
+            self._addNode(node, name)
+            self._applyExpr()
+        return node
+
     def outEdges(self, attribute):
         """ Return the list of edges starting from the given attribute """
         # type: (Attribute,) -> [Edge]

meshroom/ui/commands.py

@@ -195,6 +195,26 @@ class DuplicateNodesCommand(GraphCommand):
             self.graph.removeNode(duplicate)
 
 
+class PasteNodeCommand(GraphCommand):
+    """
+    Handle node pasting in a Graph.
+    """
+    def __init__(self, graph, nodeType, parent=None, **kwargs):
+        super(PasteNodeCommand, self).__init__(graph, parent)
+        self.nodeType = nodeType
+        self.nodeName = None
+        self.kwargs = kwargs
+
+    def redoImpl(self):
+        node = self.graph.pasteNode(self.nodeType, **self.kwargs)
+        self.nodeName = node.name
+        self.setText("Paste Node {}".format(self.nodeName))
+        return node
+
+    def undoImpl(self):
+        self.graph.removeNode(self.nodeName)
+
+
 class SetAttributeCommand(GraphCommand):
     def __init__(self, graph, attribute, value, parent=None):
         super(SetAttributeCommand, self).__init__(graph, parent)

meshroom/ui/components/clipboard.py

@@ -15,6 +15,10 @@ class ClipboardHelper(QObject):
     def setText(self, value):
         self._clipboard.setText(value)
 
+    @Slot(result=str)
+    def getText(self):
+        return self._clipboard.text()
+
     @Slot()
     def clear(self):
         self._clipboard.clear()

meshroom/ui/graph.py

@@ -766,6 +766,44 @@ class UIGraph(QObject):
             return json.dumps(node, indent=4)
         return ''
 
+    @Slot(str)
+    def pasteNode(self, clipboardContent):
+        """
+        Parse the content of the clipboard to see whether it contains
+        a valid node description. If that is the case, the node described
+        in the clipboard is built with the available information.
+        Otherwise, nothing is done.
+
+        This function does not need to be preceded by a call to "copyNodeContent".
+        Any clipboard content that contains at least a node type with a valid JSON
+        formatting (dictionary form with double quotes around the keys and values)
+        can be used to generate a node.
+
+        For example, it is enough to have:
+        {"nodeType":"CameraInit"}
+        in the clipboard to create a default CameraInit node.
+        """
+        if not clipboardContent:
+            return
+        d = {}
+        try:
+            d = json.loads(clipboardContent)
+        except ValueError as e:
+            raise ValueError(e)
+
+        if not isinstance(d, dict):
+            raise ValueError("The clipboard does not contain a valid node. Cannot paste it.")
+
+        nodeType = d.get("nodeType", None)
+        if not nodeType:
+            raise ValueError("The clipboard does not contain a valid node. Cannot paste it.")
+
+        attributes = {}
+        attributes.update(d.get("inputs", {}))
+        attributes.update(d.get("outputs", {}))
+
+        self.push(commands.PasteNodeCommand(self._graph, nodeType, **attributes))
+
     undoStack = Property(QObject, lambda self: self._undoStack, constant=True)
     graphChanged = Signal()
     graph = Property(Graph, lambda self: self._graph, notify=graphChanged)

meshroom/ui/qml/GraphEditor/GraphEditor.qml

@@ -85,6 +85,12 @@ Item {
         }
     }
 
+    /// Paste content of clipboard to graph editor and create new node if valid
+    function pasteNode()
+    {
+        var copiedContent = Clipboard.getText()
+        uigraph.pasteNode(copiedContent)
+    }
 
     Keys.onPressed: {
         if (event.key === Qt.Key_F)
@@ -100,6 +106,9 @@ Item {
         if (event.key === Qt.Key_C)
             if (event.modifiers == Qt.ControlModifier)
                 copyNode()
+        if (event.key === Qt.Key_V)
+            if (event.modifiers == Qt.ControlModifier)
+                pasteNode()
     }
 
     MouseArea {