third_party/WebKit/Source/web/ViewportAnchor.h

   1 /*
   2  * Copyright (C) 2013 Google 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 are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef ViewportAnchor_h
  32 #define ViewportAnchor_h
  33
  34 #include "platform/heap/Handle.h"
  35
  36 namespace blink {
  37
  38 class FrameView;
  39 class VisualViewport;
  40
  41 // Use derived ViewportAnchor classes to "anchor" the viewport to a location,
  42 // perform some operation that may move the viewport around, then restore
  43 // the viewport to the original location.
  44 // We support two kinds of anchors, a rotation anchor and a resize anchor.
  45 class ViewportAnchor {
  46     STACK_ALLOCATED();
  47 protected:
  48     ViewportAnchor(FrameView& rootFrameView, VisualViewport& visualViewport)
  49         : m_rootFrameView(&rootFrameView)
  50         , m_visualViewport(&visualViewport)
  51     {
  52     }
  53
  54     RawPtrWillBeMember<FrameView> m_rootFrameView;
  55     RawPtrWillBeMember<VisualViewport> m_visualViewport;
  56 };
  57
  58 } // namespace blink
  59
  60 #endif // ViewportAnchor_h