Merge pull request #239 from ales-erjavec/fixes/new-signals-on-link-e…

…nable

[FIX] signalmanager: Dispatch `Signal.New` in `send` when link is disabled

orangecanvas/scheme/signalmanager.py

@@ -112,6 +112,15 @@ def __repr__(self):
     __str__ = __repr__
 
 
+class _LinkExtra:
+    """Extra data tracked for a SchemeLink"""
+    __slots__ = ("flags",)
+    DidScheduleNew = 1
+
+    def __init__(self, flags=0):
+        self.flags = flags
+
+
 class SignalManager(QObject):
     """
     SignalManager handles the runtime signal propagation for a :class:`.Scheme`
@@ -196,6 +205,8 @@ def __init__(self, parent=None, *, max_running=None, **kwargs):
         # mapping a node to its current outputs
         self.__node_outputs = {}  # type: Dict[SchemeNode, DefaultDict[OutputSignal, _OutputState]]
 
+        #: Extra link state
+        self.__link_extra = defaultdict(_LinkExtra)  # type: DefaultDict[SchemeLink, _LinkExtra]
         self.__state = SignalManager.Running
         self.__runtime_state = SignalManager.Waiting
 
@@ -406,6 +417,7 @@ def __on_link_added(self, link):
     def __on_link_removed(self, link):
         # type: (SchemeLink) -> None
         link.enabled_changed.disconnect(self.__on_link_enabled_changed)
+        self.__link_extra.pop(link, None)
 
     def eventFilter(self, recv: QObject, event: QEvent) -> bool:
         etype = event.type()
@@ -519,15 +531,21 @@ def _id_(id):
                       node.title, channel.name)
             state.flags &= ~_OutputState.Invalidated
 
-        links = filter(
-            is_enabled,
-            scheme.find_links(source_node=node, source_channel=channel)
-        )
+        links = scheme.find_links(source_node=node, source_channel=channel)
         signals = []
         for link in links:
+            extra = self.__link_extra[link]
             links_in = scheme.find_links(sink_node=link.sink_node)
             index = links_in.index(link)
-            signals.append(sigtype(link, value, id, index=index))
+            if not link.is_enabled() and not extra.flags & _LinkExtra.DidScheduleNew:
+                # Send Signal.New with None value. Proper update will be done
+                # when/if the link is re-enabled.
+                signal = Signal.New(link, None, id, index=index)
+            elif link.is_enabled():
+                signal = sigtype(link, value, id, index=index)
+            else:
+                continue
+            signals.append(signal)
             link.set_runtime_state_flag(SchemeLink.Invalidated, False)
 
         self._schedule(signals)
@@ -584,6 +602,11 @@ def _schedule(self, signals):
         """
         self.__input_queue.extend(signals)
 
+        for sig in signals:
+            if isinstance(sig, Signal.New):
+                extra = self.__link_extra[sig.link]
+                extra.flags |= _LinkExtra.DidScheduleNew
+
         for link in {sig.link for sig in signals}:
             # update the SchemeLink's runtime state flags
             contents = self.link_contents(link)

orangecanvas/scheme/tests/test_signalmanager.py

@@ -1,9 +1,6 @@
-import unittest
-
 from AnyQt.QtTest import QSignalSpy
 
 from orangecanvas.scheme import Scheme, SchemeNode, SchemeLink
-from orangecanvas.scheme import signalmanager
 from orangecanvas.scheme.signalmanager import (
     SignalManager, Signal, compress_signals, compress_single
 )
@@ -34,8 +31,12 @@ def setUp(self):
         add = scheme.new_node(reg.widget("add"))
         scheme.new_link(zero, "value", add, "left")
         scheme.new_link(one, "value", add, "right")
+        sm = TestingSignalManager()
+        sm.set_workflow(scheme)
+        sm.start()
         self.reg = reg
         self.scheme = scheme
+        self.signal_manager = sm
 
     def test(self):
         workflow = self.scheme
@@ -73,9 +74,7 @@ def test(self):
 
     def test_add_link_disabled(self):
         workflow = self.scheme
-        sm = TestingSignalManager()
-        sm.set_workflow(workflow)
-        sm.start()
+        sm = self.signal_manager
         n0, n1, n2 = workflow.nodes
         l0, l1 = workflow.links
         workflow.remove_link(l0)
@@ -98,12 +97,27 @@ def test_add_link_disabled(self):
             ]
         )
 
-    def test_invalidated_flags(self):
+    def test_link_new_dispatch_after_enable(self):
         workflow = self.scheme
-        sm = TestingSignalManager()
-        sm.set_workflow(workflow)
-        sm.start()
+        sm = self.signal_manager
+        n0, n1, n2 = workflow.nodes
+        l0, l1 = workflow.links
+        l0.set_enabled(False)
+        sm.send(n0, n0.description.outputs[0], -42)
+        sm.send(n0, n0.description.outputs[0], 42)
+        self.assertSequenceEqual(
+            sm.pending_input_signals(n2), [Signal.New(l0, None, None, 0)]
+        )
+        sm.process_queued()
+        l0.set_enabled(True)
+        self.assertSequenceEqual(
+            sm.pending_input_signals(n2), [Signal.Update(l0, 42, None, 0)]
+        )
+        sm.process_queued()
 
+    def test_invalidated_flags(self):
+        workflow = self.scheme
+        sm = self.signal_manager
         n0, n1, n2 = workflow.nodes[:3]
         l0, l1 = workflow.links[:2]
 
@@ -149,9 +163,7 @@ def test_invalidated_flags(self):
 
     def test_pending_flags(self):
         workflow = self.scheme
-        sm = TestingSignalManager()
-        sm.set_workflow(workflow)
-        sm.start()
+        sm = self.signal_manager
         n0, n1, n3 = workflow.nodes[:3]
         l0, l1 = workflow.links[:2]
 
@@ -169,10 +181,7 @@ def test_pending_flags(self):
 
     def test_ready_flags(self):
         workflow = self.scheme
-        sm = TestingSignalManager()
-        sm.set_workflow(workflow)
-        sm.start()
-
+        sm = self.signal_manager
         n0, n1, n3 = workflow.nodes[:3]
         sm.send(n0, n0.output_channel("value"), 'hello')
         sm.send(n1, n1.output_channel("value"), 'hello')
@@ -187,10 +196,7 @@ def test_ready_flags(self):
 
     def test_start_finished(self):
         workflow = self.scheme
-        sm = TestingSignalManager()
-        sm.set_workflow(workflow)
-        sm.start()
-
+        sm = self.signal_manager
         n0, n1, n3 = workflow.nodes[:3]
         start_spy = QSignalSpy(sm.started)
         fin_spy = QSignalSpy(sm.finished)