blob: 151d88e267b6b05060db64335329cd0a10381a07 [file] [log] [blame]
/*
* Copyright (C) 2018 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "FloatAvoider.h"
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
#include "LayoutBox.h"
#include "LayoutContainer.h"
#include "LayoutState.h"
#include <wtf/IsoMallocInlines.h>
namespace WebCore {
namespace Layout {
WTF_MAKE_ISO_ALLOCATED_IMPL(FloatAvoider);
FloatAvoider::FloatAvoider(const Box& layoutBox, const FloatingState& floatingState, const LayoutState& layoutState)
: m_layoutBox(makeWeakPtr(layoutBox))
, m_floatingState(floatingState)
, m_absoluteDisplayBox(FormattingContext::mapBoxToAncestor(layoutState, layoutBox, downcast<Container>(floatingState.root())))
, m_containingBlockAbsoluteDisplayBox(layoutBox.containingBlock() == &floatingState.root() ? Display::Box(layoutState.displayBoxForLayoutBox(*layoutBox.containingBlock())) : FormattingContext::mapBoxToAncestor(layoutState, *layoutBox.containingBlock(), downcast<Container>(floatingState.root())))
{
ASSERT(m_layoutBox->establishesBlockFormattingContext());
m_absoluteDisplayBox.setLeft({ initialHorizontalPosition() });
}
void FloatAvoider::setHorizontalConstraints(HorizontalConstraints horizontalConstraints)
{
if ((isLeftAligned() && !horizontalConstraints.left) || (!isLeftAligned() && !horizontalConstraints.right)) {
// No constraints? Set horizontal position back to the inital value.
m_absoluteDisplayBox.setLeft(initialHorizontalPosition());
return;
}
auto constrainWithContainingBlock = [&](auto left) -> PositionInContextRoot {
// Horizontal position is constrained by the containing block's content box.
// Compute the horizontal position for the new floating by taking both the contining block and the current left/right floats into account.
auto containingBlockContentBoxLeft = m_containingBlockAbsoluteDisplayBox.left() + m_containingBlockAbsoluteDisplayBox.contentBoxLeft();
if (isLeftAligned())
return std::max<PositionInContextRoot>({ containingBlockContentBoxLeft + marginStart() }, left);
// Make sure it does not overflow the containing block on the right.
auto containingBlockContentBoxRight = containingBlockContentBoxLeft + m_containingBlockAbsoluteDisplayBox.contentBoxWidth();
return std::min<PositionInContextRoot>(left, { containingBlockContentBoxRight - marginBoxWidth() + marginStart() });
};
auto positionCandidate = horizontalPositionCandidate(horizontalConstraints);
m_absoluteDisplayBox.setLeft(constrainWithContainingBlock(positionCandidate));
}
void FloatAvoider::setVerticalConstraint(PositionInContextRoot verticalConstraint)
{
m_absoluteDisplayBox.setTop(verticalPositionCandidate(verticalConstraint));
}
PositionInContextRoot FloatAvoider::horizontalPositionCandidate(HorizontalConstraints horizontalConstraints)
{
return { isLeftAligned() ? *horizontalConstraints.left : *horizontalConstraints.right - rect().width() };
}
PositionInContextRoot FloatAvoider::verticalPositionCandidate(PositionInContextRoot verticalConstraint)
{
return verticalConstraint;
}
PositionInContextRoot FloatAvoider::initialHorizontalPosition() const
{
// Align the box with the containing block's content box.
auto containingBlockContentBoxLeft = m_containingBlockAbsoluteDisplayBox.left() + m_containingBlockAbsoluteDisplayBox.contentBoxLeft();
auto containingBlockContentBoxRight = containingBlockContentBoxLeft + m_containingBlockAbsoluteDisplayBox.contentBoxWidth();
auto left = isLeftAligned() ? containingBlockContentBoxLeft : containingBlockContentBoxRight - marginBoxWidth();
left += marginStart();
return { left };
}
bool FloatAvoider::overflowsContainingBlock() const
{
auto containingBlockContentBoxLeft = m_containingBlockAbsoluteDisplayBox.left() + m_containingBlockAbsoluteDisplayBox.contentBoxLeft();
auto left = displayBox().left() - marginStart();
if (containingBlockContentBoxLeft > left)
return true;
auto containingBlockContentBoxRight = containingBlockContentBoxLeft + m_containingBlockAbsoluteDisplayBox.contentBoxWidth();
auto right = displayBox().right() + marginEnd();
return containingBlockContentBoxRight < right;
}
Display::Box::Rect FloatAvoider::rectInContainingBlock() const
{
// From formatting root coordinate system back to containing block's.
if (layoutBox().containingBlock() == &floatingState().root())
return m_absoluteDisplayBox.rect();
return {
m_absoluteDisplayBox.top() - m_containingBlockAbsoluteDisplayBox.top(),
m_absoluteDisplayBox.left() - m_containingBlockAbsoluteDisplayBox.left(),
m_absoluteDisplayBox.width(),
m_absoluteDisplayBox.height()
};
}
}
}
#endif