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_PATTERNS_SCROLL_EFFECT_SCROLL_FADE_EFFECT_H
17 #define FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_NG_PATTERNS_SCROLL_EFFECT_SCROLL_FADE_EFFECT_H
18 
19 #include "base/utils/macros.h"
20 #include "core/components_ng/pattern/scroll/scroll_edge_effect.h"
21 #include "core/components_ng/pattern/scroll/effect/scroll_fade_controller.h"
22 #include "core/components_ng/pattern/scroll/effect/scroll_fade_painter.h"
23 
24 namespace OHOS::Ace::NG {
25 constexpr float SCALE_THRESHOLD = 0.3f;
26 constexpr float OVER_SCROLL_THRESHOLD = 2.0f;
27 
28 class ACE_EXPORT ScrollFadeEffect final : public ScrollEdgeEffect {
29     DECLARE_ACE_TYPE(ScrollFadeEffect, ScrollEdgeEffect);
30 
31 public:
32     explicit ScrollFadeEffect(const Color& color = Color::GRAY)
33         : ScrollEdgeEffect(EdgeEffect::FADE), fadeColor_(color) {}
34     ~ScrollFadeEffect() override = default;
35 
GetFadeColor()36     const Color& GetFadeColor() const
37     {
38         return fadeColor_;
39     }
40 
41     void InitialEdgeEffect() override;
42     double CalculateOverScroll(double oldPosition, bool isReachMax) override;
43     void Paint(RSCanvas& canvas, const SizeF& viewPort, const OffsetF& offset) override;
44     void HandleOverScroll(Axis axis, float overScroll, const SizeF& viewPort,
45         bool isScrollFromUpdate = false, bool isNotPositiveScrollableDistance = false) override;
46     void SetHandleOverScrollCallback(const HandleOverScrollCallback& callback) override;
47 
48 private:
49     void ResetFadeEffect(const Color& color);
50     void SetOpacityAndScale(float opacity, float scale);
51     void SetPaintDirection(Axis axis, float overScroll, bool isNotPositiveScrollableDistance);
52 
53     Color fadeColor_ = Color::GRAY;
54     RefPtr<ScrollFadePainter> fadePainter_;
55     RefPtr<ScrollFadeController> fadeController_;
56     HandleOverScrollCallback handleOverScrollCallback_ = nullptr;
57 };
58 } // namespace OHOS::Ace::NG
59 
60 #endif // FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_NG_PATTERNS_SCROLL_EFFECT_SCROLL_FADE_EFFECT_H
61