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- // 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<OverscrollRefreshHandler> handler_;
- };
- } // namespace ui
- #endif // UI_ANDROID_OVERSCROLL_REFRESH_H_
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