1 /*
2  * Copyright (c) 2021 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 
16 #include "core/pipeline/base/component_group_element.h"
17 
18 #include "core/pipeline/base/component_group.h"
19 
20 namespace OHOS::Ace {
21 
Create()22 RefPtr<Element> ComponentGroupElement::Create()
23 {
24     return AceType::MakeRefPtr<ComponentGroupElement>();
25 }
26 
PerformBuild()27 void ComponentGroupElement::PerformBuild()
28 {
29     RefPtr<ComponentGroup> componentGroup = AceType::DynamicCast<ComponentGroup>(component_);
30     if (!componentGroup) {
31         LOGW("Should be component group, but %s", AceType::TypeName(component_));
32         return;
33     }
34 
35     auto context = context_.Upgrade();
36     if (!context) {
37         LOGW("Pipeline context is invalid");
38         return;
39     }
40 
41     const auto& newComponents = componentGroup->GetChildren();
42     if (context->GetIsDeclarative() && componentGroup->GetUpdateType() != UpdateType::REBUILD) {
43         UpdateChildrenForDeclarative(newComponents);
44     } else {
45         UpdateChildren(newComponents);
46     }
47 }
48 
UpdateChildren(const std::list<RefPtr<Component>> & newComponents)49 void ComponentGroupElement::UpdateChildren(const std::list<RefPtr<Component>>& newComponents)
50 {
51     auto itChild = children_.begin();
52     auto itChildEnd = children_.end();
53     auto itComponent = newComponents.begin();
54     auto itComponentEnd = newComponents.end();
55 
56     while (itChild != itChildEnd && itComponent != itComponentEnd) {
57         const auto& child = *itChild;
58         const auto& component = *itComponent;
59         if (child->NeedUpdateWithComponent(component)) {
60             if (!child->CanUpdate(component)) {
61                 break;
62             }
63             UpdateChild(child, component);
64         }
65         ++itChild;
66         ++itComponent;
67     }
68 
69     // children_ will be modified during UpdateChild.(some items will be removed from children_)
70     while (itChild != itChildEnd) {
71         UpdateChild(*(itChild++), nullptr);
72     }
73 
74     while (itComponent != itComponentEnd) {
75         UpdateChild(nullptr, *(itComponent++));
76     }
77 }
78 
UpdateChildrenForDeclarative(const std::list<RefPtr<Component>> & newComponents)79 void ComponentGroupElement::UpdateChildrenForDeclarative(const std::list<RefPtr<Component>>& newComponents)
80 {
81     int32_t slot = 0;
82     int32_t renderSlot = 0;
83 #if defined(PREVIEW)
84     if (newComponents.empty()) {
85         auto itChild = children_.begin();
86         auto itChildEnd = children_.end();
87         while (itChild != itChildEnd) {
88             UpdateChild(*(itChild++), nullptr);
89         }
90     }
91 #endif
92     if (children_.empty()) {
93         for (const auto& component : newComponents) {
94             auto newChild = UpdateChildWithSlot(nullptr, component, slot++, renderSlot);
95             if (newChild) {
96                 renderSlot += newChild->CountRenderNode();
97             }
98         }
99         return;
100     }
101 
102     // For declarative frontend, the component tree is very stable,
103     // so size of children MUST be matched between elements and components
104     if (children_.size() != newComponents.size()) {
105         LOGW("Size of old children and new components are mismatched");
106         return;
107     }
108     auto itChild = children_.begin();
109     for (const auto& component : newComponents) {
110         auto newChild = UpdateChildWithSlot(*(itChild++), component, slot++, renderSlot);
111         renderSlot += newChild->CountRenderNode();
112     }
113 }
114 
115 } // namespace OHOS::Ace
116