blob: 72ded3956e43923afaf6aa667165703d45ccfe4f [file] [log] [blame]
/*
* Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
* Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
* Copyright (C) 2007-2019 Apple Inc. All rights reserved.
* Copyright (C) Research In Motion Limited 2011. All rights reserved.
* Copyright (C) 2014 Adobe Systems Incorporated. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "SVGLengthContext.h"
#include "CSSHelper.h"
#include "FontMetrics.h"
#include "Frame.h"
#include "LegacyRenderSVGRoot.h"
#include "LengthFunctions.h"
#include "RenderSVGViewportContainer.h"
#include "RenderView.h"
#include "SVGElementTypeHelpers.h"
#include "SVGSVGElement.h"
#include <wtf/MathExtras.h>
namespace WebCore {
SVGLengthContext::SVGLengthContext(const SVGElement* context)
: m_context(context)
{
}
SVGLengthContext::SVGLengthContext(const SVGElement* context, const FloatRect& viewport)
: m_context(context)
, m_overriddenViewport(viewport)
{
}
FloatRect SVGLengthContext::resolveRectangle(const SVGElement* context, SVGUnitTypes::SVGUnitType type, const FloatRect& viewport, const SVGLengthValue& x, const SVGLengthValue& y, const SVGLengthValue& width, const SVGLengthValue& height)
{
ASSERT(type != SVGUnitTypes::SVG_UNIT_TYPE_UNKNOWN);
if (type == SVGUnitTypes::SVG_UNIT_TYPE_USERSPACEONUSE) {
SVGLengthContext lengthContext(context);
return FloatRect(x.value(lengthContext), y.value(lengthContext), width.value(lengthContext), height.value(lengthContext));
}
SVGLengthContext lengthContext(context, viewport);
return FloatRect(x.value(lengthContext) + viewport.x(),
y.value(lengthContext) + viewport.y(),
width.value(lengthContext),
height.value(lengthContext));
}
FloatPoint SVGLengthContext::resolvePoint(const SVGElement* context, SVGUnitTypes::SVGUnitType type, const SVGLengthValue& x, const SVGLengthValue& y)
{
ASSERT(type != SVGUnitTypes::SVG_UNIT_TYPE_UNKNOWN);
if (type == SVGUnitTypes::SVG_UNIT_TYPE_USERSPACEONUSE) {
SVGLengthContext lengthContext(context);
return FloatPoint(x.value(lengthContext), y.value(lengthContext));
}
// FIXME: valueAsPercentage() won't be correct for eg. cm units. They need to be resolved in user space and then be considered in objectBoundingBox space.
return FloatPoint(x.valueAsPercentage(), y.valueAsPercentage());
}
float SVGLengthContext::resolveLength(const SVGElement* context, SVGUnitTypes::SVGUnitType type, const SVGLengthValue& x)
{
ASSERT(type != SVGUnitTypes::SVG_UNIT_TYPE_UNKNOWN);
if (type == SVGUnitTypes::SVG_UNIT_TYPE_USERSPACEONUSE) {
SVGLengthContext lengthContext(context);
return x.value(lengthContext);
}
// FIXME: valueAsPercentage() won't be correct for eg. cm units. They need to be resolved in user space and then be considered in objectBoundingBox space.
return x.valueAsPercentage();
}
float SVGLengthContext::valueForLength(const Length& length, SVGLengthMode lengthMode)
{
if (length.isPercent()) {
auto result = convertValueFromPercentageToUserUnits(length.value() / 100, lengthMode);
if (result.hasException())
return 0;
return result.releaseReturnValue();
}
if (length.isAuto() || !length.isSpecified())
return 0;
auto viewportSize = this->viewportSize().value_or(FloatSize { });
switch (lengthMode) {
case SVGLengthMode::Width:
return floatValueForLength(length, viewportSize.width());
case SVGLengthMode::Height:
return floatValueForLength(length, viewportSize.height());
case SVGLengthMode::Other:
return floatValueForLength(length, viewportSize.diagonalLength() / sqrtOfTwoFloat);
};
return 0;
}
ExceptionOr<float> SVGLengthContext::convertValueToUserUnits(float value, SVGLengthType lengthType, SVGLengthMode lengthMode) const
{
// If the SVGLengthContext carries a custom viewport, force resolving against it.
if (!m_overriddenViewport.isZero()) {
// 100% = 100.0 instead of 1.0 for historical reasons, this could eventually be changed
if (lengthType == SVGLengthType::Percentage)
value /= 100;
return convertValueFromPercentageToUserUnits(value, lengthMode);
}
switch (lengthType) {
case SVGLengthType::Unknown:
return Exception { NotSupportedError };
case SVGLengthType::Number:
return value;
case SVGLengthType::Pixels:
return value;
case SVGLengthType::Percentage:
return convertValueFromPercentageToUserUnits(value / 100, lengthMode);
case SVGLengthType::Ems:
return convertValueFromEMSToUserUnits(value);
case SVGLengthType::Exs:
return convertValueFromEXSToUserUnits(value);
case SVGLengthType::Centimeters:
return value * cssPixelsPerInch / 2.54f;
case SVGLengthType::Millimeters:
return value * cssPixelsPerInch / 25.4f;
case SVGLengthType::Inches:
return value * cssPixelsPerInch;
case SVGLengthType::Points:
return value * cssPixelsPerInch / 72;
case SVGLengthType::Picas:
return value * cssPixelsPerInch / 6;
}
ASSERT_NOT_REACHED();
return 0;
}
ExceptionOr<float> SVGLengthContext::convertValueFromUserUnits(float value, SVGLengthType lengthType, SVGLengthMode lengthMode) const
{
switch (lengthType) {
case SVGLengthType::Unknown:
return Exception { NotSupportedError };
case SVGLengthType::Number:
return value;
case SVGLengthType::Percentage:
return convertValueFromUserUnitsToPercentage(value * 100, lengthMode);
case SVGLengthType::Ems:
return convertValueFromUserUnitsToEMS(value);
case SVGLengthType::Exs:
return convertValueFromUserUnitsToEXS(value);
case SVGLengthType::Pixels:
return value;
case SVGLengthType::Centimeters:
return value * 2.54f / cssPixelsPerInch;
case SVGLengthType::Millimeters:
return value * 25.4f / cssPixelsPerInch;
case SVGLengthType::Inches:
return value / cssPixelsPerInch;
case SVGLengthType::Points:
return value * 72 / cssPixelsPerInch;
case SVGLengthType::Picas:
return value * 6 / cssPixelsPerInch;
}
ASSERT_NOT_REACHED();
return 0;
}
ExceptionOr<float> SVGLengthContext::convertValueFromUserUnitsToPercentage(float value, SVGLengthMode lengthMode) const
{
auto viewportSize = this->viewportSize();
if (!viewportSize)
return Exception { NotSupportedError };
switch (lengthMode) {
case SVGLengthMode::Width:
return value / viewportSize->width() * 100;
case SVGLengthMode::Height:
return value / viewportSize->height() * 100;
case SVGLengthMode::Other:
return value / (viewportSize->diagonalLength() / sqrtOfTwoFloat) * 100;
};
ASSERT_NOT_REACHED();
return 0;
}
ExceptionOr<float> SVGLengthContext::convertValueFromPercentageToUserUnits(float value, SVGLengthMode lengthMode) const
{
auto viewportSize = this->viewportSize();
if (!viewportSize)
return Exception { NotSupportedError };
switch (lengthMode) {
case SVGLengthMode::Width:
return value * viewportSize->width();
case SVGLengthMode::Height:
return value * viewportSize->height();
case SVGLengthMode::Other:
return value * viewportSize->diagonalLength() / sqrtOfTwoFloat;
};
ASSERT_NOT_REACHED();
return 0;
}
static inline const RenderStyle* renderStyleForLengthResolving(const SVGElement* context)
{
if (!context)
return nullptr;
const ContainerNode* currentContext = context;
do {
if (currentContext->renderer())
return &currentContext->renderer()->style();
currentContext = currentContext->parentNode();
} while (currentContext);
// There must be at least a LegacyRenderSVGRoot renderer, carrying a style.
ASSERT_NOT_REACHED();
return nullptr;
}
ExceptionOr<float> SVGLengthContext::convertValueFromUserUnitsToEMS(float value) const
{
auto* style = renderStyleForLengthResolving(m_context);
if (!style)
return Exception { NotSupportedError };
float fontSize = style->computedFontPixelSize();
if (!fontSize)
return Exception { NotSupportedError };
return value / fontSize;
}
ExceptionOr<float> SVGLengthContext::convertValueFromEMSToUserUnits(float value) const
{
auto* style = renderStyleForLengthResolving(m_context);
if (!style)
return Exception { NotSupportedError };
return value * style->computedFontPixelSize();
}
ExceptionOr<float> SVGLengthContext::convertValueFromUserUnitsToEXS(float value) const
{
auto* style = renderStyleForLengthResolving(m_context);
if (!style)
return Exception { NotSupportedError };
// Use of ceil allows a pixel match to the W3Cs expected output of coords-units-03-b.svg
// if this causes problems in real world cases maybe it would be best to remove this
float xHeight = std::ceil(style->metricsOfPrimaryFont().xHeight());
if (!xHeight)
return Exception { NotSupportedError };
return value / xHeight;
}
ExceptionOr<float> SVGLengthContext::convertValueFromEXSToUserUnits(float value) const
{
auto* style = renderStyleForLengthResolving(m_context);
if (!style)
return Exception { NotSupportedError };
// Use of ceil allows a pixel match to the W3Cs expected output of coords-units-03-b.svg
// if this causes problems in real world cases maybe it would be best to remove this
return value * std::ceil(style->metricsOfPrimaryFont().xHeight());
}
std::optional<FloatSize> SVGLengthContext::viewportSize() const
{
if (!m_context)
return std::nullopt;
// If an overridden viewport is given, it has precedence.
if (!m_overriddenViewport.isZero())
return m_overriddenViewport.size();
if (!m_viewportSize)
m_viewportSize = computeViewportSize();
return m_viewportSize;
}
std::optional<FloatSize> SVGLengthContext::computeViewportSize() const
{
ASSERT(m_overriddenViewport.isZero());
ASSERT(m_context);
// Root <svg> element lengths are resolved against the top level viewport.
if (m_context->isOutermostSVGSVGElement())
return downcast<SVGSVGElement>(*m_context).currentViewportSize();
// Take size from nearest viewport element.
RefPtr viewportElement = m_context->viewportElement();
if (!is<SVGSVGElement>(viewportElement))
return std::nullopt;
const SVGSVGElement& svg = downcast<SVGSVGElement>(*viewportElement);
auto viewportSize = svg.currentViewBoxRect().size();
if (viewportSize.isEmpty())
viewportSize = svg.currentViewportSize();
return viewportSize;
}
}