use topological sort for node stream update

Author: ArnoChenFx

NodeGraphQt/base/graph.py

@@ -148,6 +148,7 @@ def __init__(self, parent=None):
 
         self._wire_signals()
         self._node_space_bar = node_space_bar(self)
+        self._auto_update = True
 
     def __repr__(self):
         return '<{} object at {}>'.format(self.__class__.__name__, hex(id(self)))
@@ -376,6 +377,15 @@ def widget(self):
             layout.addWidget(self._viewer)
         return self._widget
 
+    @property
+    def auto_update(self):
+        """
+
+        Returns:
+            if the graph can run node automatically.
+        """
+        return self._auto_update
+
     def show(self):
         """
         Show node graph widget this is just a convenience
@@ -1251,7 +1261,8 @@ def import_session(self, file_path):
         Args:
             file_path (str): path to the serialized layout file.
         """
-
+        _temp_auto_update = self._auto_update
+        self._auto_update = False
         file_path = file_path.strip()
         if not os.path.isfile(file_path):
             raise IOError('file does not exist.')
@@ -1277,6 +1288,7 @@ def import_session(self, file_path):
         self._undo_stack.clear()
         self._model.session = file_path
         self.session_changed.emit(file_path)
+        self._auto_update = _temp_auto_update
 
     def copy_nodes(self, nodes=None):
         """

NodeGraphQt/base/node.py

@@ -1183,13 +1183,13 @@ class SubGraph(object):
     """
 
     def __init__(self):
-        self._children = []
+        self._children = set()
 
     def children(self):
         """
         Returns the children of the sub graph.
         """
-        return self._children
+        return list(self._children)
 
     def create_from_nodes(self, nodes):
         """
@@ -1207,8 +1207,7 @@ def add_child(self, node):
         Args:
             node(NodeGraphQt.BaseNode).
         """
-        if node not in self._children:
-            self._children.append(node)
+        self._children.add(node)
 
     def remove_child(self, node):
         """

NodeGraphQt/base/utils.py

@@ -8,6 +8,7 @@
                          PIPE_LAYOUT_ANGLE)
 
 
+# menu
 def setup_context_menu(graph):
     """
     populate the specified graph's context menu with essential menus commands.
@@ -275,3 +276,87 @@ def _angle_pipe(graph):
 
 def _toggle_grid(graph):
     graph.display_grid(not graph.scene().grid)
+
+
+# topological_sort
+
+def get_input_nodes(node):
+    nodes = {}
+    for p in node.input_ports():
+        for cp in p.connected_ports():
+            n = cp.node()
+            nodes[n.id] = n
+    return list(nodes.values())
+
+
+def get_output_nodes(node):
+    nodes = {}
+    for p in node.output_ports():
+        for cp in p.connected_ports():
+            n = cp.node()
+            nodes[n.id] = n
+    return list(nodes.values())
+
+
+def _has_input_node(node):
+    for p in node.input_ports():
+        if p.view.connected_pipes:
+            return True
+    return False
+
+
+def _has_output_node(node):
+    for p in node.output_ports():
+        if p.view.connected_pipes:
+            return True
+    return False
+
+
+def _build_graph(start_nodes):
+    graph = {}
+    for node in start_nodes:
+        output_nodes = get_output_nodes(node)
+        graph[node] = output_nodes
+        while output_nodes:
+            _output_nodes = []
+            for n in output_nodes:
+                if n not in graph:
+                    nodes = get_output_nodes(n)
+                    graph[n] = nodes
+                    _output_nodes.extend(nodes)
+            output_nodes = _output_nodes
+
+    return graph
+
+
+def topological_sort(start_nodes=[], all_nodes=[]):
+    if not start_nodes:
+        start_nodes = [n for n in all_nodes if not _has_input_node(n)]
+    if not start_nodes:
+        return []
+    if not [n for n in start_nodes if _has_output_node(n)]:
+        return start_nodes
+
+    graph = _build_graph(start_nodes)
+    if not graph:
+        return []
+
+    visit = dict((node, False) for node in graph.keys())
+
+    sorted_nodes = []
+
+    def dfs(graph, start_node):
+        for end_node in graph[start_node]:
+            if not visit[end_node]:
+                visit[end_node] = True
+                dfs(graph, end_node)
+        sorted_nodes.append(start_node)
+
+    for start_node in start_nodes:
+        if not visit[start_node]:
+            visit[start_node] = True
+            dfs(graph, start_node)
+
+    sorted_nodes.reverse()
+
+    return sorted_nodes

NodeGraphQt/widgets/viewer.py

@@ -672,7 +672,8 @@ def establish_connection(self, start_port, end_port):
         if not start_port.node.visible or not end_port.node.visible:
             pipe.hide()
 
-    def acyclic_check(self, start_port, end_port):
+    @staticmethod
+    def acyclic_check(start_port, end_port):
         """
         validate the connection so it doesn't loop itself.
 
@@ -724,11 +725,13 @@ def context_menus(self):
         return {'graph': self._ctx_menu,
                 'nodes': self._ctx_node_menu}
 
-    def question_dialog(self, text, title='Node Graph'):
+    @staticmethod
+    def question_dialog(text, title='Node Graph'):
         dlg = messageBox(text, title, QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No)
         return dlg == QtWidgets.QMessageBox.Yes
 
-    def message_dialog(self, text, title='Node Graph'):
+    @staticmethod
+    def message_dialog(text, title='Node Graph'):
         messageBox(text, title, QtWidgets.QMessageBox.Ok)
 
     def load_dialog(self, current_dir=None, ext=None):
@@ -798,7 +801,8 @@ def add_node(self, node, pos=None):
         self.scene().addItem(node)
         node.post_init(self, pos)
 
-    def remove_node(self, node):
+    @staticmethod
+    def remove_node(node):
         if isinstance(node, AbstractNodeItem):
             node.delete()
 

example_auto_nodes.py

@@ -5,6 +5,7 @@
 from NodeGraphQt import NodeGraph, setup_context_menu
 from NodeGraphQt import QtWidgets, QtCore, PropertiesBinWidget, \
     NodeTreeWidget, BackdropNode, NodePublishWidget
+from NodeGraphQt.base.utils import topological_sort
 import os
 import sys
 import inspect
@@ -51,7 +52,7 @@ def get_published_nodes_from_folder(folder_path):
 
 
 def cook_node(graph, node):
-    node.cook()
+    node.cook(forceCook=True)
 
 
 def print_functions(graph, node):
@@ -85,6 +86,14 @@ def publish_node(graph, node):
     wid.show()
 
 
+def cook_nodes(nodes):
+    nodes = topological_sort(all_nodes=nodes)
+    for node in nodes:
+        node.cook(stream=True)
+        if node.error():
+            break
+
+
 if __name__ == '__main__':
     app = QtWidgets.QApplication([])
 
@@ -136,9 +145,7 @@ def show_nodes_list(node):
 
     # create test nodes
     graph.load_session(r'example_auto_nodes/networks/example_SubGraph.json')
-    graph.get_node_by_path('/root/Distance').cook()
-    graph.get_node_by_path('/root/Cross Product').cook()
-    graph.get_node_by_path('/root/Dot Product').cook()
+    cook_nodes(graph.root_node().children())
 
     # widget used for the node graph.
     graph_widget = graph.widget