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// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CC_TREES_STICKY_POSITION_CONSTRAINT_H_
#define CC_TREES_STICKY_POSITION_CONSTRAINT_H_
#include "cc/cc_export.h"
#include "cc/paint/element_id.h"
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/rect_f.h"
namespace cc {
struct CC_EXPORT StickyPositionConstraint {
StickyPositionConstraint();
StickyPositionConstraint(const StickyPositionConstraint& other);
StickyPositionConstraint& operator=(const StickyPositionConstraint& other);
bool is_anchored_left : 1 = false;
bool is_anchored_right : 1 = false;
bool is_anchored_top : 1 = false;
bool is_anchored_bottom : 1 = false;
// 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 = 0;
float right_offset = 0;
float top_offset = 0;
float bottom_offset = 0;
// The rectangle in which the sticky box is able to be positioned. This may be
// smaller than the scroller viewport due to things like padding.
gfx::RectF constraint_box_rect;
// 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::RectF 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::RectF scroll_container_relative_containing_block_rect;
// Extra offset to account for pixel snapping of the sticky layout object.
// The above rects are sufficient to compute the un-snapped sticky offset
// but need to be adjusted by this for pixel snapping.
gfx::Vector2dF pixel_snap_offset;
// The nearest ancestor sticky element ids that affect the sticky box
// constraint rect and the containing block constraint rect respectively.
// They are used to generate nearest_node_shifting_sticky_box and
// nearest_node_shifting_containing_block in StickyPositionNodeData when the
// property trees are generated. They are useless after the property trees
// are generated.
ElementId nearest_element_shifting_sticky_box;
ElementId nearest_element_shifting_containing_block;
bool operator==(const StickyPositionConstraint&) const;
bool operator!=(const StickyPositionConstraint&) const;
};
} // namespace cc
#endif // CC_TREES_STICKY_POSITION_CONSTRAINT_H_
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