// Copyright 2014 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef UI_ANDROID_OVERSCROLL_REFRESH_H_ #define UI_ANDROID_OVERSCROLL_REFRESH_H_ #include "base/memory/raw_ptr.h" #include "ui/android/ui_android_export.h" #include "ui/gfx/geometry/size_f.h" #include "ui/gfx/geometry/vector2d_f.h" // A Java counterpart will be generated for this enum. // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.ui enum OverscrollAction { NONE = 0, PULL_TO_REFRESH = 1, HISTORY_NAVIGATION = 2 }; namespace cc { struct OverscrollBehavior; } namespace gfx { class PointF; } namespace ui { class OverscrollRefreshHandler; // Simple pull-to-refresh styled effect. Listens to scroll events, conditionally // activating when: // 1) The scroll begins when the page's root layer 1) has no vertical scroll // offset and 2) lacks the overflow-y:hidden property. // 2) The page doesn't consume the initial scroll events. // 3) The initial scroll direction is upward. // The actuall pull response, animation and action are delegated to the // provided refresh handler. class UI_ANDROID_EXPORT OverscrollRefresh { public: // The default distance in dp from a side of the device to start a navigation // from. static constexpr int kDefaultNavigationEdgeWidth = 24; OverscrollRefresh(OverscrollRefreshHandler* handler, float edge_width); OverscrollRefresh(const OverscrollRefresh&) = delete; OverscrollRefresh& operator=(const OverscrollRefresh&) = delete; virtual ~OverscrollRefresh(); // Scroll event stream listening methods. void OnScrollBegin(const gfx::PointF& pos); // Returns whether the refresh was activated. void OnScrollEnd(const gfx::Vector2dF& velocity); // Scroll ack listener. The effect will only be activated if |can_navigate| // is true which happens when the scroll update is not consumed and the // overscroll_behavior on y axis is 'auto'. // This method is made virtual for mocking. virtual void OnOverscrolled( const cc::OverscrollBehavior& overscroll_behavior); // Returns true if the effect has consumed the |scroll_delta|. bool WillHandleScrollUpdate(const gfx::Vector2dF& scroll_delta); // Release the effect (if active), preventing any associated refresh action. void ReleaseWithoutActivation(); // Notify the effect of the latest scroll offset and overflow properties. // The effect will be disabled when the offset is non-zero or overflow is // hidden. Note: All dimensions are in device pixels. void OnFrameUpdated(const gfx::SizeF& viewport_size, const gfx::PointF& content_scroll_offset, bool root_overflow_y_hidden); // Reset the effect to its inactive state, immediately detaching and // disabling any active effects. // This method is made virtual for mocking. virtual void Reset(); // Returns true if the refresh effect is either being manipulated or animated. // This method is made virtual for mocking. virtual bool IsActive() const; // Returns true if the effect is waiting for an unconsumed scroll to start. // This method is made virtual for mocking. virtual bool IsAwaitingScrollUpdateAck() const; protected: // This constructor is for mocking only. OverscrollRefresh(); private: void Release(bool allow_refresh); bool scrolled_to_top_; // True if the content y offset was zero before scroll began. Overscroll // should not be triggered for the scroll that started from non-zero offset. bool top_at_scroll_start_; bool overflow_y_hidden_; enum ScrollConsumptionState { DISABLED, AWAITING_SCROLL_UPDATE_ACK, ENABLED, } scroll_consumption_state_; float viewport_width_; float scroll_begin_x_; float scroll_begin_y_; const float edge_width_; // in px gfx::Vector2dF cumulative_scroll_; const raw_ptr handler_; }; } // namespace ui #endif // UI_ANDROID_OVERSCROLL_REFRESH_H_