implement context_menu_prompt signal.

Author: jchanvfx

NodeGraphQt/base/graph.py

@@ -122,9 +122,18 @@ class NodeGraph(QtCore.QObject):
     """
     Signal is triggered when session has been changed.
 
-    :parameters: :str
+    :parameters: str
     :emits: new session path
     """
+    context_menu_prompt = QtCore.Signal(object, object)
+    """
+    Signal is triggered just before a context menu is shown.
+
+    :parameters: 
+        :class:`NodeGraphQt.NodeGraphMenu` or :class:`NodeGraphQt.NodesMenu`, 
+        :class:`NodeGraphQt.BaseNode`
+    :emits: triggered context menu, node object.
+    """
 
     def __init__(self, parent=None, **kwargs):
         """
@@ -220,6 +229,19 @@ def _wire_signals(self):
         self._viewer.node_selection_changed.connect(
             self._on_node_selection_changed)
         self._viewer.data_dropped.connect(self._on_node_data_dropped)
+        self._viewer.context_menu_prompt.connect(self._on_context_menu_prompt)
+
+    def _on_context_menu_prompt(self, menu_name, node_id):
+        """
+        Slot function triggered just before a context menu is shown.
+
+        Args:
+            menu_name (str): context menu name.
+            node_id (str): node id if triggered from the nodes context menu.
+        """
+        node = self.get_node_by_id(node_id)
+        menu = self.get_context_menu(menu_name)
+        self.context_menu_prompt.emit(menu, node)
 
     def _on_insert_node(self, pipe, node_id, prev_node_pos):
         """

NodeGraphQt/widgets/viewer.py

@@ -51,6 +51,7 @@ class NodeViewer(QtWidgets.QGraphicsView):
     node_selection_changed = QtCore.Signal(list, list)
     node_double_clicked = QtCore.Signal(str)
     data_dropped = QtCore.Signal(QtCore.QMimeData, QtCore.QPoint)
+    context_menu_prompt = QtCore.Signal(str, object)
 
     def __init__(self, parent=None, undo_stack=None):
         """
@@ -354,6 +355,8 @@ def contextMenuEvent(self, event):
         ctx_menu = None
         ctx_menus = self.context_menus()
 
+        prompted_data = None, None
+
         if ctx_menus['nodes'].isEnabled():
             pos = self.mapToScene(self._previous_pos)
             items = self._items_near(pos)
@@ -365,10 +368,17 @@ def contextMenuEvent(self, event):
                     for action in ctx_menu.actions():
                         if not action.menu():
                             action.node_id = node.id
+                    prompted_data = 'nodes', node.id
+
+        if not ctx_menu:
+            ctx_menu = ctx_menus['graph']
+            prompted_data = 'graph', None
 
-        ctx_menu = ctx_menu or ctx_menus['graph']
         if len(ctx_menu.actions()) > 0:
             if ctx_menu.isEnabled():
+                self.context_menu_prompt.emit(
+                    prompted_data[0], prompted_data[1]
+                )
                 ctx_menu.exec_(event.globalPos())
             else:
                 return super(NodeViewer, self).contextMenuEvent(event)