cc/input/scroll_state.cc

// 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.

#include "cc/input/scroll_state.h"

#include "cc/layers/layer_impl.h"

namespace cc {

ScrollState::ScrollState(double delta_x,
                         double delta_y,
                         int start_position_x,
                         int start_position_y,
                         bool should_propagate,
                         bool delta_consumed_for_scroll_sequence,
                         bool is_direct_manipulation)
    : delta_x_(delta_x),
      delta_y_(delta_y),
      start_position_x_(start_position_x),
      start_position_y_(start_position_y),
      should_propagate_(should_propagate),
      delta_consumed_for_scroll_sequence_(delta_consumed_for_scroll_sequence),
      is_direct_manipulation_(is_direct_manipulation),
      caused_scroll_x_(false),
      caused_scroll_y_(false) {}

ScrollState::~ScrollState() {}

void ScrollState::ConsumeDelta(double x, double y) {
  delta_x_ -= x;
  delta_y_ -= y;

  if (x || y)
    delta_consumed_for_scroll_sequence_ = true;
}

void ScrollState::DistributeToScrollChainDescendant() {
  if (!scroll_chain_.empty()) {
    LayerImpl* next = scroll_chain_.front();
    scroll_chain_.pop_front();
    next->DistributeScroll(this);
  }
}

}  // namespace cc