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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsMathMLsemanticsFrame.h"
#include "nsMimeTypes.h"
#include "mozilla/PresShell.h"
#include "mozilla/dom/Element.h"
#include "mozilla/gfx/2D.h"
using namespace mozilla;
//
// <semantics> -- associate annotations with a MathML expression
//
nsIFrame* NS_NewMathMLsemanticsFrame(PresShell* aPresShell,
ComputedStyle* aStyle) {
return new (aPresShell)
nsMathMLsemanticsFrame(aStyle, aPresShell->GetPresContext());
}
NS_IMPL_FRAMEARENA_HELPERS(nsMathMLsemanticsFrame)
nsMathMLsemanticsFrame::~nsMathMLsemanticsFrame() = default;
nsIFrame* nsMathMLsemanticsFrame::GetSelectedFrame() {
// By default, we will display the first child of the <semantics> element.
nsIFrame* childFrame = mFrames.FirstChild();
mSelectedFrame = childFrame;
// An empty <semantics> is invalid
if (!childFrame) {
mInvalidMarkup = true;
return mSelectedFrame;
}
mInvalidMarkup = false;
// Using <annotation> or <annotation-xml> as a first child is invalid.
// However some people use this syntax so we take care of this case too.
bool firstChildIsAnnotation = false;
nsIContent* childContent = childFrame->GetContent();
if (childContent->IsAnyOfMathMLElements(nsGkAtoms::annotation_,
nsGkAtoms::annotation_xml_)) {
firstChildIsAnnotation = true;
}
// If the first child is a presentation MathML element other than
// <annotation> or <annotation-xml>, we are done.
if (!firstChildIsAnnotation && childFrame->IsFrameOfType(nsIFrame::eMathML)) {
nsIMathMLFrame* mathMLFrame = do_QueryFrame(childFrame);
if (mathMLFrame) {
TransmitAutomaticData();
return mSelectedFrame;
}
// The first child is not an annotation, so skip it.
childFrame = childFrame->GetNextSibling();
}
// Otherwise, we read the list of annotations and select the first one that
// could be displayed in place of the first child of <semantics>. If none is
// found, we fallback to this first child.
for (; childFrame; childFrame = childFrame->GetNextSibling()) {
nsIContent* childContent = childFrame->GetContent();
if (childContent->IsMathMLElement(nsGkAtoms::annotation_)) {
// If the <annotation> element has an src attribute we ignore it.
// XXXfredw Should annotation images be supported? See the related
// bug 297465 for mglyph.
if (childContent->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::src))
continue;
// Otherwise, we assume it is a text annotation that can always be
// displayed and stop here.
mSelectedFrame = childFrame;
break;
}
if (childContent->IsMathMLElement(nsGkAtoms::annotation_xml_)) {
// If the <annotation-xml> element has an src attribute we ignore it.
if (childContent->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::src))
continue;
// If the <annotation-xml> element has an encoding attribute
// describing presentation MathML, SVG or HTML we assume the content
// can be displayed and stop here.
//
// We recognize the following encoding values:
//
// - "MathML-Presentation", which is mentioned in the MathML3 REC
// - "SVG1.1" which is mentioned in the W3C note
// http://www.w3.org/Math/Documents/Notes/graphics.xml
// - Other mime Content-Types for SVG and HTML
//
// We exclude APPLICATION_MATHML_XML = "application/mathml+xml" which
// is ambiguous about whether it is Presentation or Content MathML.
// Authors must use a more explicit encoding value.
nsAutoString value;
childContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::encoding,
value);
if (value.EqualsLiteral("application/mathml-presentation+xml") ||
value.EqualsLiteral("MathML-Presentation") ||
value.EqualsLiteral(IMAGE_SVG_XML) || value.EqualsLiteral("SVG1.1") ||
value.EqualsLiteral(APPLICATION_XHTML_XML) ||
value.EqualsLiteral(TEXT_HTML)) {
mSelectedFrame = childFrame;
break;
}
}
}
TransmitAutomaticData();
return mSelectedFrame;
}
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