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78 lines
2.9 KiB
C++
78 lines
2.9 KiB
C++
/*
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* Copyright (C) 2013 Google Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following disclaimer
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* in the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of Google Inc. nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef ViewportAnchor_h
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#define ViewportAnchor_h
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#include "platform/geometry/FloatSize.h"
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#include "platform/geometry/IntPoint.h"
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#include "platform/geometry/IntRect.h"
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#include "platform/geometry/LayoutRect.h"
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#include "platform/heap/Handle.h"
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#include "wtf/RefCounted.h"
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namespace blink {
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class EventHandler;
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class IntSize;
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class Node;
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// ViewportAnchor provides a way to anchor a viewport origin to a DOM node.
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// In particular, the user supplies the current viewport (in CSS coordinates)
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// and an anchor point (in view coordinates, e.g., (0, 0) == viewport origin,
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// (0.5, 0) == viewport top center). The anchor point tracks the underlying DOM
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// node; as the node moves or the view is resized, the viewport anchor maintains
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// its orientation relative to the node, and the viewport origin maintains its
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// orientation relative to the anchor.
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class ViewportAnchor {
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STACK_ALLOCATED();
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public:
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explicit ViewportAnchor(EventHandler*);
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void setAnchor(const IntRect& viewRect, const FloatSize& anchorInViewCoords);
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IntPoint computeOrigin(const IntSize& currentViewSize) const;
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private:
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RawPtrWillBeMember<EventHandler> m_eventHandler;
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IntRect m_viewRect;
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RefPtrWillBeMember<Node> m_anchorNode;
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LayoutRect m_anchorNodeBounds;
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FloatSize m_anchorInViewCoords;
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FloatSize m_anchorInNodeCoords;
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};
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} // namespace blink
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#endif
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