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/base/namespace.h>
21 #include <meta/ext/event_impl.h>
22 #include <meta/interface/builtin_objects.h>
23 #include <meta/interface/intf_container_observer.h>
24
25 #include "object.h"
26
META_BEGIN_NAMESPACE()27 META_BEGIN_NAMESPACE()
28
29 namespace Internal {
30
31 class ContainerChangeListener final {
32 public:
33 META_NO_COPY(ContainerChangeListener)
34 ~ContainerChangeListener();
35 ContainerChangeListener() = delete;
36 ContainerChangeListener(ContainerChangeListener&& other);
37 ContainerChangeListener& operator=(ContainerChangeListener&& other);
38
39 explicit ContainerChangeListener(const IContainer::Ptr& container);
40 // Note the copy assignment implementation which is not directly applicable to all use cases
41 bool operator==(const ContainerChangeListener& other) const noexcept;
42 bool Subscribe(const IOnChildChanged::InterfaceTypePtr& onChanged);
43 void Unsubscribe();
44
45 private:
46 mutable BASE_NS::pair<IEvent::Token, IOnChildChanged::InterfaceTypePtr> changed_;
47 mutable IContainer::WeakPtr container_;
48 };
49
50 class ContainerObserver : public IntroduceInterfaces<MetaObject, IContainerObserver> {
51 META_OBJECT(ContainerObserver, ClassId::ContainerObserver, IntroduceInterfaces)
52 protected: // LifeCycle
53 bool Build(const IMetadata::Ptr&) override;
54
55 public: // IContainerObjserver
56 void SetContainer(const IContainer::Ptr& container) override;
57
58 META_BEGIN_STATIC_DATA()
59 META_STATIC_EVENT_DATA(IContainerObserver, IOnChildChanged, OnDescendantChanged)
60 META_END_STATIC_DATA()
61 META_IMPLEMENT_EVENT(IOnChildChanged, OnDescendantChanged)
62
63 private:
64 void Subscribe(const IContainer::Ptr& base);
65 void Unsubscribe(const IContainer::Ptr& base);
66 void InvokeChanged(const ChildChangedInfo& info);
67
68 IContainer::Ptr container_;
69 IOnChildChanged::InterfaceTypePtr changedCallable_;
70
71 struct Subscription {
72 Subscription(IContainer::WeakPtr container, ContainerChangeListener&& listener)
73 : container(BASE_NS::move(container)), listener(BASE_NS::move(listener))
74 {}
75 IContainer::WeakPtr container;
76 ContainerChangeListener listener;
77 };
78
79 BASE_NS::vector<Subscription> subscriptions_;
80 };
81
82 } // namespace Internal
83
84 META_END_NAMESPACE()
85
86 #endif // META_SRC_CONTAINER_OBSERVER_H
87