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// Copyright 2013 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_LAYERS_LAYER_STICKY_POSITION_CONSTRAINT_H_
#define CC_LAYERS_LAYER_STICKY_POSITION_CONSTRAINT_H_
#include "cc/cc_export.h"
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/geometry/rect.h"
namespace cc {
struct CC_EXPORT LayerStickyPositionConstraint {
LayerStickyPositionConstraint();
LayerStickyPositionConstraint(const LayerStickyPositionConstraint& other);
bool is_sticky : 1;
bool is_anchored_left : 1;
bool is_anchored_right : 1;
bool is_anchored_top : 1;
bool is_anchored_bottom : 1;
// The offset from each edge of the ancestor scroller (or the viewport) to
// try to maintain to the sticky box as we scroll.
float left_offset;
float right_offset;
float top_offset;
float bottom_offset;
// The layout offset of the sticky box relative to its containing layer.
// This is used to detect the sticky offset the main thread has applied
// to the layer.
gfx::Point parent_relative_sticky_box_offset;
// The rectangle corresponding to original layout position of the sticky box
// relative to the scroll ancestor. The sticky box is only offset once the
// scroll has passed its initial position (e.g. top_offset will only push
// the element down from its original position).
gfx::Rect scroll_container_relative_sticky_box_rect;
// The layout rectangle of the sticky box's containing block relative to the
// scroll ancestor. The sticky box is only moved as far as its containing
// block boundary.
gfx::Rect scroll_container_relative_containing_block_rect;
// The nearest ancestor sticky layer ids that affect the sticky box constraint
// rect and the containing block constraint rect respectively. If no such
// layer exists, these are set to Layer::INVALID_ID.
int nearest_layer_shifting_sticky_box;
int nearest_layer_shifting_containing_block;
// Returns the nearest sticky ancestor layer, or Layer::INVALID_ID if no such
// layer exists.
int NearestStickyAncestor();
bool operator==(const LayerStickyPositionConstraint&) const;
bool operator!=(const LayerStickyPositionConstraint&) const;
};
} // namespace cc
#endif // CC_LAYERS_LAYER_STICKY_POSITION_CONSTRAINT_H_