1 /*
2  * Copyright (c) 2022 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/components_ng/pattern/model/model_layout_algorithm.h"
17 
18 #include "core/components_ng/base/frame_node.h"
19 
20 namespace OHOS::Ace::NG {
21 
ModelLayoutAlgorithm(const WeakPtr<ModelAdapterWrapper> & adapter)22 ModelLayoutAlgorithm::ModelLayoutAlgorithm(const WeakPtr<ModelAdapterWrapper>& adapter) : modelAdapter_(adapter) {}
23 
MeasureContent(const LayoutConstraintF & contentConstraint,LayoutWrapper * layoutWrapper)24 std::optional<SizeF> ModelLayoutAlgorithm::MeasureContent(
25     const LayoutConstraintF& contentConstraint, LayoutWrapper* layoutWrapper)
26 {
27     auto modelLayoutProperty = layoutWrapper->GetLayoutProperty();
28     CHECK_NULL_RETURN(modelLayoutProperty, std::nullopt);
29 
30     // 1. Width and height are set properly - return content constraint as component size
31     if (contentConstraint.selfIdealSize.IsValid()) {
32         auto size = contentConstraint.selfIdealSize.ConvertToSizeT();
33         return size;
34     }
35 
36     SizeF componentSize(0.0f, 0.0f);
37     do {
38         // 2.1 Width and height are not set. Determine size from parent.
39         const auto& modelLayoutProperty = layoutWrapper->GetLayoutProperty();
40         SizeF layoutConstraintMaxSize = modelLayoutProperty->GetLayoutConstraint()->maxSize;
41         if (contentConstraint.selfIdealSize.IsNull()) {
42             componentSize.SetSizeT(layoutConstraintMaxSize);
43             break; // exit to return statement
44         }
45 
46         // 2.2 Either width or height are set. Set size based on aspect ratio.
47         auto sizeSet = contentConstraint.selfIdealSize.ConvertToSizeT();
48         componentSize.SetSizeT(sizeSet);
49         uint8_t sizeSetStatus = (Negative(sizeSet.Width()) << 1) | Negative(sizeSet.Height());
50         double aspectRatio = Size::CalcRatio(Size(4, 3)); // default aspect ratio os 4:3
51         switch (sizeSetStatus) {
52             case 0b01: // width is positive and height is negative
53                 componentSize.SetHeight(static_cast<float>(sizeSet.Width() / aspectRatio));
54                 break;
55             case 0b10: // width is negative and height is positive
56                 componentSize.SetWidth(static_cast<float>(sizeSet.Height() * aspectRatio));
57                 break;
58             case 0b11: // both width and height are negative
59             default:
60                 break;
61         }
62     } while (false);
63 
64     auto size = contentConstraint.Constrain(componentSize);
65     return size;
66 }
67 } // namespace OHOS::Ace::NG
68