1 /*
2 * Copyright (c) 2024 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15 #ifndef META_SRC_CONTAINER_OBSERVER_H
16 #define META_SRC_CONTAINER_OBSERVER_H
17
18 #include <base/containers/unordered_map.h>
19
20 #include <meta/ext/event_impl.h>
21 #include <meta/interface/builtin_objects.h>
22 #include <meta/interface/intf_container_observer.h>
23
24 #include "object.h"
25
META_BEGIN_NAMESPACE()26 META_BEGIN_NAMESPACE()
27
28 class ContainerChangeListener final {
29 public:
30 META_NO_COPY(ContainerChangeListener)
31 ~ContainerChangeListener();
32 ContainerChangeListener() = delete;
33 ContainerChangeListener(ContainerChangeListener&& other);
34 ContainerChangeListener& operator=(ContainerChangeListener&& other);
35
36 explicit ContainerChangeListener(const IContainer::Ptr& container);
37 // Note the copy assignment implementation which is not directly applicable to all use cases
38 bool operator==(const ContainerChangeListener& other) const noexcept;
39 bool Subscribe(const IOnChildChanged::InterfaceTypePtr& onAdded, const IOnChildChanged::InterfaceTypePtr& onRemoved,
40 const IOnChildMoved::InterfaceTypePtr& onMoved);
41 void Unsubscribe();
42
43 private:
44 mutable BASE_NS::pair<IEvent::Token, IOnChildChanged::InterfaceTypePtr> added_;
45 mutable BASE_NS::pair<IEvent::Token, IOnChildChanged::InterfaceTypePtr> removed_;
46 mutable BASE_NS::pair<IEvent::Token, IOnChildMoved::InterfaceTypePtr> moved_;
47 mutable IContainer::WeakPtr container_;
48 };
49
50 class ContainerObserver
51 : public Internal::MetaObjectFwd<ContainerObserver, ClassId::ContainerObserver, IContainerObserver> {
52 using Super = Internal::MetaObjectFwd<ContainerObserver, ClassId::ContainerObserver, IContainerObserver>;
53 using Super::Super;
54
55 protected: // LifeCycle
56 bool Build(const IMetadata::Ptr&) override;
57
58 protected: // IContainerObjserver
59 void SetContainer(const IContainer::Ptr& container) override;
60
61 META_IMPLEMENT_INTERFACE_EVENT(IContainerObserver, IOnChildChanged, OnDescendantAdded)
62 META_IMPLEMENT_INTERFACE_EVENT(IContainerObserver, IOnChildChanged, OnDescendantRemoved)
63 META_IMPLEMENT_INTERFACE_EVENT(IContainerObserver, IOnChildMoved, OnDescendantMoved)
64
65 private:
66 void Subscribe(const IContainer::Ptr& base);
67 void Unsubscribe(const IContainer::Ptr& base);
68 void InvokeAdded(const ChildChangedInfo& info);
69 void InvokeRemoved(const ChildChangedInfo& info);
70 void InvokeMoved(const ChildMovedInfo& info);
71 IContainer::Ptr container_;
72 IOnChildChanged::InterfaceTypePtr addedCallable_;
73 IOnChildChanged::InterfaceTypePtr removedCallable_;
74 IOnChildMoved::InterfaceTypePtr movedCallable_;
75
76 struct Subscription {
SubscriptionSubscription77 Subscription(IContainer::WeakPtr container, ContainerChangeListener&& listener)
78 : container(BASE_NS::move(container)), listener(BASE_NS::move(listener))
79 {}
80 IContainer::WeakPtr container;
81 ContainerChangeListener listener;
82 };
83
84 BASE_NS::vector<Subscription> subscriptions_;
85 };
86
87 META_END_NAMESPACE()
88
89 #endif // META_SRC_CONTAINER_OBSERVER_H
90