Merge pull request #676 from dfb/pr_unbind_event

Add support for unbind_event

Author: rdeioris

Source/UnrealEnginePython/Private/PythonDelegate.cpp

@@ -1,6 +1,7 @@
 
 #include "PythonDelegate.h"
 #include "UEPyModule.h"
+#include "UEPyCallable.h"
 
 UPythonDelegate::UPythonDelegate()
 {
@@ -101,6 +102,12 @@ void UPythonDelegate::PyInputAxisHandler(float value)
 	Py_DECREF(ret);
 }
 
+bool UPythonDelegate::UsesPyCallable(PyObject *other)
+{
+    ue_PyCallable *other_callable = (ue_PyCallable*)other;
+    ue_PyCallable *this_callable = (ue_PyCallable*)py_callable;
+    return other_callable->u_function == this_callable->u_function && other_callable->u_target == this_callable->u_target;
+}
 
 UPythonDelegate::~UPythonDelegate()
 {
@@ -110,4 +117,4 @@ UPythonDelegate::~UPythonDelegate()
 #if defined(UEPY_MEMORY_DEBUG)
 	UE_LOG(LogPython, Warning, TEXT("PythonDelegate %p callable XDECREF'ed"), this);
 #endif
-}
+}

Source/UnrealEnginePython/Private/UEPyModule.cpp

@@ -607,6 +607,7 @@ static PyMethodDef ue_PyUObject_methods[] = {
 	{ "set_name", (PyCFunction)py_ue_set_name, METH_VARARGS, "" },
 
 	{ "bind_event", (PyCFunction)py_ue_bind_event, METH_VARARGS, "" },
+	{ "unbind_event", (PyCFunction)py_ue_unbind_event, METH_VARARGS, "" },
 	{ "delegate_bind_ufunction", (PyCFunction)py_ue_delegate_bind_ufunction, METH_VARARGS, "" },
 
 	{ "get_py_proxy", (PyCFunction)py_ue_get_py_proxy, METH_VARARGS, "" },
@@ -3044,6 +3045,45 @@ PyObject *py_ue_ufunction_call(UFunction *u_function, UObject *u_obj, PyObject *
 	Py_RETURN_NONE;
 }
 
+PyObject *ue_unbind_pyevent(ue_PyUObject *u_obj, FString event_name, PyObject *py_callable, bool fail_on_wrong_property)
+{
+	UProperty *u_property = u_obj->ue_object->GetClass()->FindPropertyByName(FName(*event_name));
+	if (!u_property)
+	{
+		if (fail_on_wrong_property)
+			return PyErr_Format(PyExc_Exception, "unable to find event property %s", TCHAR_TO_UTF8(*event_name));
+		Py_RETURN_NONE;
+	}
+
+	if (auto casted_prop = Cast<UMulticastDelegateProperty>(u_property))
+	{
+        UPythonDelegate *py_delegate = FUnrealEnginePythonHouseKeeper::Get()->FindDelegate(u_obj->ue_object, py_callable);
+        if (py_delegate != nullptr)
+        {
+            FMulticastScriptDelegate multiscript_delegate = casted_prop->GetPropertyValue_InContainer(u_obj->ue_object);
+            multiscript_delegate.Remove(py_delegate, FName("PyFakeCallable"));
+
+            // re-assign multicast delegate
+            casted_prop->SetPropertyValue_InContainer(u_obj->ue_object, multiscript_delegate);
+        }
+	}
+	else if (auto casted_prop_delegate = Cast<UDelegateProperty>(u_property))
+	{
+		FScriptDelegate script_delegate = casted_prop_delegate->GetPropertyValue_InContainer(u_obj->ue_object);
+        script_delegate.Unbind();
+
+		// re-assign multicast delegate
+		casted_prop_delegate->SetPropertyValue_InContainer(u_obj->ue_object, script_delegate);
+	}
+	else
+	{
+		if (fail_on_wrong_property)
+			return PyErr_Format(PyExc_Exception, "property %s is not an event", TCHAR_TO_UTF8(*event_name));
+	}
+
+	Py_RETURN_NONE;
+}
+
 PyObject *ue_bind_pyevent(ue_PyUObject *u_obj, FString event_name, PyObject *py_callable, bool fail_on_wrong_property)
 {
 

Source/UnrealEnginePython/Private/UEPyModule.h

@@ -35,6 +35,7 @@ void ue_bind_events_for_py_class_by_attribute(UObject *, PyObject *);
 
 void ue_autobind_events_for_pyclass(ue_PyUObject *, PyObject *);
 PyObject *ue_bind_pyevent(ue_PyUObject *, FString, PyObject *, bool);
+PyObject *ue_unbind_pyevent(ue_PyUObject *, FString, PyObject *, bool);
 
 PyObject *py_ue_ufunction_call(UFunction *, UObject *, PyObject *, int, PyObject *);
 

Source/UnrealEnginePython/Private/UObject/UEPyObject.cpp

@@ -1517,6 +1517,25 @@ PyObject *py_ue_bind_event(ue_PyUObject * self, PyObject * args)
 	return ue_bind_pyevent(self, FString(event_name), py_callable, true);
 }
 
+PyObject *py_ue_unbind_event(ue_PyUObject * self, PyObject * args)
+{
+	ue_py_check(self);
+
+	char *event_name;
+	PyObject *py_callable;
+	if (!PyArg_ParseTuple(args, "sO:bind_event", &event_name, &py_callable))
+	{
+		return NULL;
+	}
+
+	if (!PyCallable_Check(py_callable))
+	{
+		return PyErr_Format(PyExc_Exception, "object is not callable");
+	}
+
+	return ue_unbind_pyevent(self, FString(event_name), py_callable, true);
+}
+
 PyObject *py_ue_delegate_bind_ufunction(ue_PyUObject * self, PyObject * args)
 {
 	ue_py_check(self);

Source/UnrealEnginePython/Private/UObject/UEPyObject.h

@@ -51,6 +51,7 @@ PyObject *py_ue_enum_user_defined_names(ue_PyUObject *, PyObject *);
 
 
 PyObject *py_ue_bind_event(ue_PyUObject *, PyObject *);
+PyObject *py_ue_unbind_event(ue_PyUObject *, PyObject *);
 PyObject *py_ue_add_function(ue_PyUObject *, PyObject *);
 PyObject *py_ue_add_property(ue_PyUObject *, PyObject *);
 
@@ -111,4 +112,4 @@ PyObject *py_ue_render_thumbnail(ue_PyUObject *, PyObject *);
 
 PyObject *py_ue_to_bytes(ue_PyUObject *, PyObject *);
 PyObject *py_ue_to_bytearray(ue_PyUObject *, PyObject *);
-PyObject *py_ue_from_bytes(ue_PyUObject *, PyObject *);
+PyObject *py_ue_from_bytes(ue_PyUObject *, PyObject *);

Source/UnrealEnginePython/Public/PythonDelegate.h

@@ -13,6 +13,7 @@ class UPythonDelegate : public UObject
 	~UPythonDelegate();
 	virtual void ProcessEvent(UFunction *function, void *Parms) override;
 	void SetPyCallable(PyObject *callable);
+    bool UsesPyCallable(PyObject *callable);
 	void SetSignature(UFunction *original_signature);
 
 	void PyInputHandler();

Source/UnrealEnginePython/Public/PythonHouseKeeper.h

@@ -238,6 +238,17 @@ class FUnrealEnginePythonHouseKeeper : public FGCObject
 		return Garbaged;
 		}
 
+    UPythonDelegate *FindDelegate(UObject *Owner, PyObject *PyCallable)
+    {
+		for (int32 i = PyDelegatesTracker.Num() - 1; i >= 0; --i)
+		{
+			FPythonDelegateTracker &Tracker = PyDelegatesTracker[i];
+            if (Tracker.Owner.Get() == Owner && Tracker.Delegate->UsesPyCallable(PyCallable))
+                return Tracker.Delegate;
+        }
+        return nullptr;
+    }
+
 	UPythonDelegate *NewDelegate(UObject *Owner, PyObject *PyCallable, UFunction *Signature)
 	{
 		UPythonDelegate *Delegate = NewObject<UPythonDelegate>();