1 /*

     2  * Copyright (C) 2007 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. ``AS IS'' AND ANY

    14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

    17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

    18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

    19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

    20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

    21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

    23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

    24  */

    25 

    26 #include "config.h"

    27 #include "LayoutState.h"

    28 

    29 #include "RenderArena.h"

    30 #include "RenderLayer.h"

    31 #include "RenderView.h"

    32 

    33 namespace WebCore {

    34 

    35 LayoutState::LayoutState(LayoutState* prev, RenderBox* renderer, const IntSize& offset)

    36 {

    37     ASSERT(prev);

    38 

    39     m_next = prev;

    40 

    41     bool fixed = renderer->isPositioned() && renderer->style()->position() == FixedPosition;

    42     if (fixed) {

    43         int fixedX = 0;

    44         int fixedY = 0;

    45         renderer->view()->absolutePosition(fixedX, fixedY, true);

    46         m_offset = IntSize(fixedX, fixedY) + offset;

    47     } else

    48         m_offset = prev->m_offset + offset;

    49 

    50     if (renderer->isRelPositioned()) {

    51         int relX = 0;

    52         int relY = 0;

    53         renderer->layer()->relativePositionOffset(relX, relY);

    54         m_offset += IntSize(relX, relY);

    55     } else if (renderer->isPositioned() && !fixed) {

    56         if (RenderObject* container = renderer->container())

    57             m_offset += renderer->offsetForPositionedInContainer(container);

    58     }

    59 

    60     m_clipped = !fixed && prev->m_clipped;

    61     if (m_clipped)

    62         m_clipRect = prev->m_clipRect;

    63     if (renderer->hasOverflowClip()) {

    64         int x = m_offset.width();

    65         int y = m_offset.height();

    66         RenderLayer* layer = renderer->layer();

    67         IntRect clipRect(x, y, layer->width(), layer->height());

    68         if (m_clipped)

    69             m_clipRect.intersect(clipRect);

    70         else {

    71             m_clipRect = clipRect;

    72             m_clipped = true;

    73         }

    74         layer->subtractScrollOffset(x, y);

    75         m_offset = IntSize(x, y);

    76     }

    77     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.

    78 }

    79 

    80 LayoutState::LayoutState(RenderObject* root)

    81 {

    82     RenderObject* container = root->container();

    83     m_clipped = true;

    84     m_clipRect = container->absoluteClippedOverflowRect();

    85     int x = 0;

    86     int y = 0;

    87     container->absolutePosition(x, y);

    88     m_offset = IntSize(x, y);

    89     m_next = 0;

    90 }

    91 

    92 #ifndef NDEBUG

    93 static bool inLayoutStateDestroy;

    94 #endif

    95 

    96 void LayoutState::destroy(RenderArena* renderArena)

    97 {

    98 #ifndef NDEBUG

    99     inLayoutStateDestroy = true;

   100 #endif

   101     delete this;

   102 #ifndef NDEBUG

   103     inLayoutStateDestroy = false;

   104 #endif

   105     renderArena->free(*(size_t*)this, this);

   106 }

   107 

   108 void* LayoutState::operator new(size_t sz, RenderArena* renderArena) throw()

   109 {

   110     return renderArena->allocate(sz);

   111 }

   112 

   113 void LayoutState::operator delete(void* ptr, size_t sz)

   114 {

   115     ASSERT(inLayoutStateDestroy);

   116     *(size_t*)ptr = sz;

   117 }

   118 

   119 } // namespace WebCore