1/*
2 * Copyright (C) 2012 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "core/page/scrolling/ScrollingConstraints.h"
28
29namespace blink {
30
31FloatPoint FixedPositionViewportConstraints::layerPositionForViewportRect(const FloatRect& viewportRect) const
32{
33    FloatSize offset;
34
35    if (hasAnchorEdge(AnchorEdgeLeft))
36        offset.setWidth(viewportRect.x() - m_viewportRectAtLastLayout.x());
37    else if (hasAnchorEdge(AnchorEdgeRight))
38        offset.setWidth(viewportRect.maxX() - m_viewportRectAtLastLayout.maxX());
39
40    if (hasAnchorEdge(AnchorEdgeTop))
41        offset.setHeight(viewportRect.y() - m_viewportRectAtLastLayout.y());
42    else if (hasAnchorEdge(AnchorEdgeBottom))
43        offset.setHeight(viewportRect.maxY() - m_viewportRectAtLastLayout.maxY());
44
45    return m_layerPositionAtLastLayout + offset;
46}
47
48} // namespace blink
49