1 /* 2 * Copyright (c) 2023 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_SCROLLABLE_NESTABLE_SCROLL_CONTAINER_H 17 #define FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_NG_PATTERNS_SCROLLABLE_NESTABLE_SCROLL_CONTAINER_H 18 19 #include "base/memory/ace_type.h" 20 #include "base/utils/noncopyable.h" 21 #include "core/components_ng/pattern/pattern.h" 22 #include "core/components_ng/pattern/scrollable/scrollable.h" 23 24 namespace OHOS::Ace::NG { 25 class NestableScrollContainer : public virtual Pattern { 26 DECLARE_ACE_TYPE(NestableScrollContainer, Pattern) 27 public: 28 NestableScrollContainer() = default; 29 ~NestableScrollContainer() override = default; 30 31 virtual Axis GetAxis() const = 0; 32 33 /** 34 * @brief Handle regular scroll motion. 35 * 36 * @param offset delta on the main axis. 37 * @param source scroll source type defined in scrollable_properties.h. 38 * @param state current nested state. Defines how this function is triggered. 39 * @return remaining offset and whether the edge is reached 40 */ 41 virtual ScrollResult HandleScroll(float offset, int32_t source, NestedState state) = 0; 42 43 /** 44 * @brief Handle drag end velocity, triggering a scroll animation or a bounce animation on overScroll. 45 * 46 * @param velocity drag end velocity. 47 * @return true if velocity is consumed 48 */ 49 virtual bool HandleScrollVelocity(float velocity) = 0; 50 51 /** 52 * @brief Called when the scroll starts, recursively pass upwards. 53 * 54 * @param position The global position of the first touch point. 55 */ 56 virtual void OnScrollStartRecursive(float position) = 0; 57 58 /** 59 * @brief This function is called when the scrolling ends, recursively pass upwards. 60 * 61 * @param velocity The velocity of the DragEnd event. Optionally passed to parent when the child won't call 62 * HandleScrollVelocity. 63 */ 64 virtual void OnScrollEndRecursive(const std::optional<float>& velocity) = 0; 65 66 protected: 67 /** 68 * @brief Helper function. Searches for the parent NestableScrollContainer of the current instance. 69 * 70 * @return RefPtr<NestableScrollContainer> A reference to the parent NestableScrollContainer. 71 */ 72 RefPtr<NestableScrollContainer> SearchParent(); 73 74 ACE_DISALLOW_COPY_AND_MOVE(NestableScrollContainer); 75 }; 76 } // namespace OHOS::Ace::NG 77 #endif // FOUNDATION_ACE_FRAMEWORKS_CORE_COMPONENTS_NG_PATTERNS_SCROLLABLE_NESTABLE_SCROLL_CONTAINER_H 78