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// Copyright 2015 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 CC_INPUT_SCROLL_STATE_DATA_H_
#define CC_INPUT_SCROLL_STATE_DATA_H_
#include <stdint.h>
#include <list>
#include "cc/cc_export.h"
#include "cc/trees/property_tree.h"
namespace cc {
class CC_EXPORT ScrollStateData {
public:
ScrollStateData();
ScrollStateData(const ScrollStateData& other);
// Scroll delta in viewport coordinates (DIP).
double delta_x;
double delta_y;
// Scroll delta hint in viewport coordinates (DIP).
// Delta hints are equal to deltas of the first gesture scroll update event in
// a scroll sequence and are used for hittesting.
double delta_x_hint;
double delta_y_hint;
// Pointer (i.e. cursor/touch point) position in viewport coordinates (DIP).
int position_x;
int position_y;
// Scroll velocity in DIP/seconds.
double velocity_x;
double velocity_y;
bool is_beginning;
bool is_in_inertial_phase;
bool is_ending;
bool from_user_input;
// Whether the scroll sequence has had any delta consumed, in the
// current frame, or any child frames.
bool delta_consumed_for_scroll_sequence;
// True if the user interacts directly with the display, e.g., via
// touch.
bool is_direct_manipulation;
// Minimum amount this input device can scroll.
double delta_granularity;
// TODO(tdresser): ScrollState shouldn't need to keep track of whether or not
// this ScrollState object has caused a scroll. Ideally, any native scroller
// consuming delta has caused a scroll. Currently, there are some cases where
// we consume delta without scrolling, such as in
// |Viewport::AdjustOverscroll|. Once these cases are fixed, we should get rid
// of |caused_scroll_*_|. See crbug.com/510045 for details.
bool caused_scroll_x;
bool caused_scroll_y;
// Track if the scroll_chain has been cut by overscroll_behavior, in
// order to properly handle overscroll-effects.
// TODO(sunyunjia): overscroll should be handled at the top of scroll_chain,
// as implemented at blink side. This field should be removed after it's
// resolved. crbug.com/755164.
bool is_scroll_chain_cut;
ScrollNode* current_native_scrolling_node() const;
void set_current_native_scrolling_node(
ScrollNode* current_native_scrolling_node);
ElementId current_native_scrolling_element() const;
void set_current_native_scrolling_element(ElementId element_id);
private:
// Only one of current_native_scrolling_node_ and
// current_native_scrolling_element_ may be non-null at a time. Whenever
// possible, we should store the scroll node.
// The last scroll node to respond to a scroll, or null if none exists.
ScrollNode* current_native_scrolling_node_;
// The id of the last native element to respond to a scroll, or 0 if none
// exists.
ElementId current_native_scrolling_element_;
};
} // namespace cc
#endif // CC_INPUT_SCROLL_STATE_DATA_H_