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 #ifndef FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_NG_PATTERN_FLEX_FLEX_LAYOUT_ALGORITHM_H
17 #define FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_NG_PATTERN_FLEX_FLEX_LAYOUT_ALGORITHM_H
18 
19 #include "core/components/common/layout/constants.h"
20 #include "core/components_ng/layout/layout_algorithm.h"
21 #include "core/components_ng/layout/layout_wrapper.h"
22 #include "core/components_ng/pattern/flex/flex_layout_styles.h"
23 
24 namespace OHOS::Ace::NG {
25 
26 struct FlexItemProperties {
27     float totalShrink = 0.0f;
28     float totalGrow = 0.0f;
29     RefPtr<LayoutWrapper> lastShrinkChild;
30     RefPtr<LayoutWrapper> lastGrowChild;
31 };
32 
33 struct MagicLayoutNode {
34     LayoutConstraintF layoutConstraint;
35     RefPtr<LayoutWrapper> layoutWrapper;
36     OptionalSizeF calcSize;
37     bool needSecondMeasure = false;
38     bool needKeepMinCalcSize = false;
39 };
40 
41 struct BaselineProperties {
42     float maxBaselineDistance = 0.0f;
43     float maxDistanceAboveBaseline = 0.0f;
44     float maxDistanceBelowBaseline = 0.0f;
45 
ResetBaselineProperties46     void Reset()
47     {
48         maxBaselineDistance = 0.0f;
49         maxDistanceAboveBaseline = 0.0f;
50         maxDistanceBelowBaseline = 0.0f;
51     }
52 };
53 
54 class ACE_FORCE_EXPORT FlexLayoutAlgorithm : public LayoutAlgorithm {
55     DECLARE_ACE_TYPE(FlexLayoutAlgorithm, LayoutAlgorithm);
56 
57 public:
58     FlexLayoutAlgorithm() = default;
59     ~FlexLayoutAlgorithm() override = default;
60 
61     void Measure(LayoutWrapper* layoutWrapper) override;
62 
63     void Layout(LayoutWrapper* layoutWrapper) override;
64 
SetLinearLayoutFeature()65     void SetLinearLayoutFeature()
66     {
67         isLinearLayoutFeature_ = true;
68     }
69 
70 private:
71     void InitFlexProperties(LayoutWrapper* layoutWrapper);
72     void TravelChildrenFlexProps(LayoutWrapper* layoutWrapper, const SizeF& realSize);
73     void UpdateAllocatedSize(const RefPtr<LayoutWrapper>& layoutWrapper, float& crossAxisSize);
74     float GetChildMainAxisSize(const RefPtr<LayoutWrapper>& layoutWrapper) const;
75     float GetChildCrossAxisSize(const RefPtr<LayoutWrapper>& layoutWrapper) const;
76     float GetSelfCrossAxisSize(const RefPtr<LayoutWrapper>& layoutWrapper) const;
77     void CheckSizeValidity(const RefPtr<LayoutWrapper>& layoutWrapper);
78     void CheckBaselineProperties(const RefPtr<LayoutWrapper>& layoutWrapper);
79     void CalculateSpace(float remainSpace, float& frontSpace, float& betweenSpace) const;
80     void PlaceChildren(
81         LayoutWrapper* layoutWrapper, float frontSpace, float betweenSpace, const OffsetF& paddingOffset);
82     FlexAlign GetSelfAlign(const RefPtr<LayoutWrapper>& layoutWrapper) const;
83     float GetStretchCrossAxisLimit() const;
84     void MeasureOutOfLayoutChildren(LayoutWrapper* layoutWrapper);
85     void MeasureAndCleanMagicNodes(LayoutWrapper* containerLayoutWrapper, FlexItemProperties& flexItemProperties);
86     bool HandleBlankFirstTimeMeasure(const MagicLayoutNode& child, FlexItemProperties& flexItemProperties);
87     void UpdateFlexProperties(FlexItemProperties& flexItemProperties, const RefPtr<LayoutWrapper>& layoutWrapper);
88     void SecondaryMeasureByProperty(FlexItemProperties& flexItemProperties, LayoutWrapper* layoutWrapper);
89     void UpdateLayoutConstraintOnMainAxis(LayoutConstraintF& layoutConstraint, float size);
90     void UpdateLayoutConstraintOnCrossAxis(LayoutConstraintF& layoutConstraint, float size);
91     void AdjustTotalAllocatedSize(LayoutWrapper* layoutWrapper);
92     void CheckIsGrowOrShrink(std::function<float(const RefPtr<LayoutWrapper>&)>& getFlex, float remainSpace,
93         float& spacePerFlex, FlexItemProperties& flexItemProperties, RefPtr<LayoutWrapper>& lastChild);
94     void CheckBlankAndKeepMin(const RefPtr<LayoutWrapper>& childLayoutWrapper, float& flexSize);
95     float MainAxisMinValue(LayoutWrapper* layoutWrapper);
96     bool MarginOnMainAxisNegative(LayoutWrapper* layoutWrapper);
97     bool IsKeepMinSize(const RefPtr<LayoutWrapper>& childLayoutWrapper, float& flexSize);
98     bool CheckSetConstraint(const std::unique_ptr<MeasureProperty>& propertyPtr);
99     void CheckMainAxisSizeAuto(const std::unique_ptr<MeasureProperty>& calcLayoutConstraint);
100 
101     OptionalSizeF realSize_;
102     float mainAxisSize_ = 0.0f;
103     float crossAxisSize_ = 0.0f;
104     float selfIdealCrossAxisSize_ = -1.0f;
105     float allocatedSize_ = 0.0f;
106     float space_ = 0.0f;
107     float totalFlexWeight_ = 0.0f;
108     int32_t maxDisplayPriority_ = 0;
109     int32_t validSizeCount_ = 0;
110     FlexAlign crossAxisAlign_ = FlexAlign::FLEX_START;
111     FlexAlign mainAxisAlign_ = FlexAlign::FLEX_START;
112 
113     std::map<int32_t, std::list<MagicLayoutNode>> magicNodes_;
114     std::map<int32_t, float> magicNodeWeights_;
115     std::list<MagicLayoutNode> secondaryMeasureList_;
116     std::list<RefPtr<LayoutWrapper>> outOfLayoutChildren_;
117 
118     FlexDirection direction_ = FlexDirection::ROW;
119     friend class LinearLayoutUtils;
120     BaselineProperties baselineProperties_;
121     bool isLinearLayoutFeature_ = false;
122     bool isInfiniteLayout_ = false;
123     bool selfAdaptive_ = false;
124     TextDirection textDir_ = TextDirection::LTR;
125     bool childrenHasAlignSelfBaseLine_ = false;
126 
127     ACE_DISALLOW_COPY_AND_MOVE(FlexLayoutAlgorithm);
128 };
129 } // namespace OHOS::Ace::NG
130 
131 #endif // FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_NG_PATTERN_FLEX_FLEX_LAYOUT_ALGORITHM_H
132