third_party/WebKit/Source/web/RotationViewportAnchor.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef RotationViewportAnchor_h
   6 #define RotationViewportAnchor_h
   7
   8 #include "platform/geometry/FloatSize.h"
   9 #include "platform/geometry/IntPoint.h"
  10 #include "platform/geometry/IntRect.h"
  11 #include "platform/geometry/LayoutRect.h"
  12 #include "platform/heap/Handle.h"
  13 #include "web/ViewportAnchor.h"
  14
  15 namespace blink {
  16
  17 class FrameView;
  18 class Node;
  19 class PageScaleConstraintsSet;
  20 class VisualViewport;
  21
  22 // The rotation anchor provides a way to anchor a viewport origin to a DOM node.
  23 // In particular, the user supplies an anchor point (in view coordinates, e.g.,
  24 // (0, 0) == viewport origin, (0.5, 0) == viewport top center). The anchor point
  25 // tracks the underlying DOM node; as the node moves or the view is resized, the
  26 // viewport anchor maintains its orientation relative to the node, and the
  27 // viewport origin maintains its orientation relative to the anchor. If there is
  28 // no node or it is lost during the resize, we fall back to the resize anchor
  29 // logic.
  30 class RotationViewportAnchor : public ViewportAnchor {
  31     STACK_ALLOCATED();
  32 public:
  33     RotationViewportAnchor(FrameView& rootFrameView, VisualViewport&, const FloatSize& anchorInInnerViewCoords, PageScaleConstraintsSet&);
  34     ~RotationViewportAnchor();
  35
  36 private:
  37     void setAnchor();
  38     void restoreToAnchor();
  39
  40     FloatPoint getInnerOrigin(const FloatSize& innerSize) const;
  41
  42     void computeOrigins(const FloatSize& innerSize, IntPoint& mainFrameOffset, FloatPoint& visualViewportOffset) const;
  43
  44     float m_oldPageScaleFactor;
  45     float m_oldMinimumPageScaleFactor;
  46
  47     // Inner viewport origin in the reference frame of the document in CSS pixels
  48     FloatPoint m_visualViewportInDocument;
  49
  50     // Inner viewport origin in the reference frame of the outer viewport
  51     // normalized to the outer viewport size.
  52     FloatSize m_normalizedVisualViewportOffset;
  53
  54     RefPtrWillBeMember<Node> m_anchorNode;
  55     LayoutRect m_anchorNodeBounds;
  56
  57     FloatSize m_anchorInInnerViewCoords;
  58     FloatSize m_anchorInNodeCoords;
  59
  60     PageScaleConstraintsSet& m_pageScaleConstraintsSet;
  61 };
  62
  63 } // namespace blink
  64
  65 #endif // RotationViewportAnchor_h