implemented BaseNode.on_input_connected callback func.

Author: jchanvfx

NodeGraphQt/base/graph.py

@@ -16,7 +16,9 @@
 from NodeGraphQt.base.port import Port
 from NodeGraphQt.constants import (DRAG_DROP_ID,
                                    PIPE_LAYOUT_CURVED,
-                                   PIPE_LAYOUT_STRAIGHT, PIPE_LAYOUT_ANGLE)
+                                   PIPE_LAYOUT_STRAIGHT,
+                                   PIPE_LAYOUT_ANGLE,
+                                   IN_PORT, OUT_PORT)
 from NodeGraphQt.widgets.viewer import NodeViewer
 
 
@@ -73,6 +75,9 @@ def _wire_signals(self):
         self._viewer.node_selected.connect(self._on_node_selected)
         self._viewer.data_dropped.connect(self._on_node_data_dropped)
 
+        # node events.
+        self.port_connected.connect(self._on_port_connected)
+
     def _toggle_tab_search(self):
         """
         toggle the tab search widget.
@@ -96,6 +101,22 @@ def _on_property_bin_changed(self, node_id, prop_name, prop_value):
         if node.get_property(prop_name) != prop_value:
             node.set_property(prop_name, prop_value)
 
+    def _on_port_connected(self, src_port, tgt_port):
+        """
+        called when a port connection has been made.
+        (executes the "on_input_connected" method on the node.)
+
+        Args:
+            src_port (NodeGraphQt.Port): source port.
+            tgt_port (NodeGraphQt.Port): target port.
+        """
+        if tgt_port.type_() == IN_PORT:
+            node = tgt_port.node()
+            node.on_input_connected(tgt_port, src_port)
+        elif tgt_port.type_() == OUT_PORT:
+            node = src_port.node()
+            node.on_input_connected(src_port, tgt_port)
+
     def _on_node_double_clicked(self, node_id):
         """
         called when a node in the viewer is double click.
@@ -177,7 +198,7 @@ def _on_connection_changed(self, disconnected, connected):
             return
 
         label = 'connect node(s)' if connected else 'disconnect node(s)'
-        ptypes = {'in': 'inputs', 'out': 'outputs'}
+        ptypes = {IN_PORT: 'inputs', OUT_PORT: 'outputs'}
 
         self._undo_stack.beginMacro(label)
         for p1_view, p2_view in disconnected:
@@ -204,7 +225,7 @@ def _on_connection_sliced(self, ports):
         """
         if not ports:
             return
-        ptypes = {'in': 'inputs', 'out': 'outputs'}
+        ptypes = {IN_PORT: 'inputs', OUT_PORT: 'outputs'}
         self._undo_stack.beginMacro('slice connections')
         for p1_view, p2_view in ports:
             node1 = self._model.nodes[p1_view.node.id]

NodeGraphQt/base/node.py

@@ -33,7 +33,7 @@ class NodeObject(object):
         qgraphics_item (AbstractNodeItem): graphic item used for drawing.
     """
 
-    #: (str) unique node identifier domain.
+    #: (str) unique node identifier domain. (default: "nodeGraphQt.nodes")
     __identifier__ = 'nodeGraphQt.nodes'
 
     #: (str) base node name.
@@ -602,6 +602,44 @@ def set_output(self, index, port):
         src_port = self.output(index)
         src_port.connect_to(port)
 
+    def connected_input_nodes(self):
+        """
+        Returns all nodes connected from the input ports.
+
+        Returns:
+            dict: {<input_port>: <node_list>}
+        """
+        nodes = {}
+        for p in self.input_ports():
+            nodes[p] = [cp.node() for cp in p.connected_ports()]
+        return nodes
+
+    def connected_output_nodes(self):
+        """
+        Returns all nodes connected from the output ports.
+
+        Returns:
+            dict: {<output_port>: <node_list>}
+        """
+        nodes = {}
+        for p in self.output_ports():
+            nodes[p] = [cp.node() for cp in p.connected_ports()]
+        return nodes
+
+    def on_input_connected(self, in_port, out_port):
+        """
+        Callback function that is triggered when a OUTPUT port from another
+        node has connected to a INPUT port for this node.
+
+        Note:
+            re-implement this function if you require logic to run for this event.
+
+        Args:
+            in_port (NodeGraphQt.Port): input port from this node.
+            out_port (NodeGraphQt.Port): output port connecting to this node.
+        """
+        return
+
 
 class BackdropNode(NodeObject):
     """

NodeGraphQt/base/port.py

@@ -66,7 +66,7 @@ def node(self):
         Return the parent node.
 
         Returns:
-            NodeGraphQt.NodeObject: parent node object.
+            NodeGraphQt.BaseNode: parent node object.
         """
         return self.model.node
 

NodeGraphQt/constants.py

@@ -9,9 +9,9 @@
 # === PIPE ===
 
 PIPE_WIDTH = 1.2
-PIPE_STYLE_DEFAULT = 'line'
-PIPE_STYLE_DASHED = 'dashed'
-PIPE_STYLE_DOTTED = 'dotted'
+PIPE_STYLE_DEFAULT = 0
+PIPE_STYLE_DASHED = 1
+PIPE_STYLE_DOTTED = 2
 PIPE_DEFAULT_COLOR = (175, 95, 30, 255)
 PIPE_DISABLED_COLOR = (190, 20, 20, 255)
 PIPE_ACTIVE_COLOR = (70, 255, 220, 255)