1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/mathml/nsMathMLsemanticsFrame.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,120 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +
1.10 +#include "nsMathMLsemanticsFrame.h"
1.11 +#include "nsMimeTypes.h"
1.12 +#include "mozilla/gfx/2D.h"
1.13 +
1.14 +//
1.15 +// <semantics> -- associate annotations with a MathML expression
1.16 +//
1.17 +
1.18 +nsIFrame*
1.19 +NS_NewMathMLsemanticsFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
1.20 +{
1.21 + return new (aPresShell) nsMathMLsemanticsFrame(aContext);
1.22 +}
1.23 +
1.24 +NS_IMPL_FRAMEARENA_HELPERS(nsMathMLsemanticsFrame)
1.25 +
1.26 +nsMathMLsemanticsFrame::~nsMathMLsemanticsFrame()
1.27 +{
1.28 +}
1.29 +
1.30 +nsIFrame*
1.31 +nsMathMLsemanticsFrame::GetSelectedFrame()
1.32 +{
1.33 + // By default, we will display the first child of the <semantics> element.
1.34 + nsIFrame* childFrame = mFrames.FirstChild();
1.35 + mSelectedFrame = childFrame;
1.36 +
1.37 + // An empty <semantics> is invalid
1.38 + if (!childFrame) {
1.39 + mInvalidMarkup = true;
1.40 + return mSelectedFrame;
1.41 + }
1.42 + mInvalidMarkup = false;
1.43 +
1.44 + // Using <annotation> or <annotation-xml> as a first child is invalid.
1.45 + // However some people use this syntax so we take care of this case too.
1.46 + bool firstChildIsAnnotation = false;
1.47 + nsIContent* childContent = childFrame->GetContent();
1.48 + if (childContent->GetNameSpaceID() == kNameSpaceID_MathML &&
1.49 + (childContent->Tag() == nsGkAtoms::annotation_ ||
1.50 + childContent->Tag() == nsGkAtoms::annotation_xml_)) {
1.51 + firstChildIsAnnotation = true;
1.52 + }
1.53 +
1.54 + // If the first child is a presentation MathML element other than
1.55 + // <annotation> or <annotation-xml>, we are done.
1.56 + if (!firstChildIsAnnotation &&
1.57 + childFrame->IsFrameOfType(nsIFrame::eMathML)) {
1.58 + nsIMathMLFrame* mathMLFrame = do_QueryFrame(childFrame);
1.59 + if (mathMLFrame) {
1.60 + TransmitAutomaticData();
1.61 + return mSelectedFrame;
1.62 + }
1.63 + // The first child is not an annotation, so skip it.
1.64 + childFrame = childFrame->GetNextSibling();
1.65 + }
1.66 +
1.67 + // Otherwise, we read the list of annotations and select the first one that
1.68 + // could be displayed in place of the first child of <semantics>. If none is
1.69 + // found, we fallback to this first child.
1.70 + for ( ; childFrame; childFrame = childFrame->GetNextSibling()) {
1.71 + nsIContent* childContent = childFrame->GetContent();
1.72 +
1.73 + if (childContent->GetNameSpaceID() != kNameSpaceID_MathML) continue;
1.74 +
1.75 + if (childContent->Tag() == nsGkAtoms::annotation_) {
1.76 +
1.77 + // If the <annotation> element has an src attribute we ignore it.
1.78 + // XXXfredw Should annotation images be supported? See the related
1.79 + // bug 297465 for mglyph.
1.80 + if (childContent->HasAttr(kNameSpaceID_None, nsGkAtoms::src)) continue;
1.81 +
1.82 + // Otherwise, we assume it is a text annotation that can always be
1.83 + // displayed and stop here.
1.84 + mSelectedFrame = childFrame;
1.85 + break;
1.86 + }
1.87 +
1.88 + if (childContent->Tag() == nsGkAtoms::annotation_xml_) {
1.89 +
1.90 + // If the <annotation-xml> element has an src attribute we ignore it.
1.91 + if (childContent->HasAttr(kNameSpaceID_None, nsGkAtoms::src)) continue;
1.92 +
1.93 + // If the <annotation-xml> element has an encoding attribute
1.94 + // describing presentation MathML, SVG or HTML we assume the content
1.95 + // can be displayed and stop here.
1.96 + //
1.97 + // We recognize the following encoding values:
1.98 + //
1.99 + // - "MathML-Presentation", which is mentioned in the MathML3 REC
1.100 + // - "SVG1.1" which is mentioned in the W3C note
1.101 + // http://www.w3.org/Math/Documents/Notes/graphics.xml
1.102 + // - Other mime Content-Types for SVG and HTML
1.103 + //
1.104 + // We exclude APPLICATION_MATHML_XML = "application/mathml+xml" which
1.105 + // is ambiguous about whether it is Presentation or Content MathML.
1.106 + // Authors must use a more explicit encoding value.
1.107 + nsAutoString value;
1.108 + childContent->GetAttr(kNameSpaceID_None, nsGkAtoms::encoding, value);
1.109 + if (value.EqualsLiteral("application/mathml-presentation+xml") ||
1.110 + value.EqualsLiteral("MathML-Presentation") ||
1.111 + value.EqualsLiteral(IMAGE_SVG_XML) ||
1.112 + value.EqualsLiteral("SVG1.1") ||
1.113 + value.EqualsLiteral(APPLICATION_XHTML_XML) ||
1.114 + value.EqualsLiteral(TEXT_HTML)) {
1.115 + mSelectedFrame = childFrame;
1.116 + break;
1.117 + }
1.118 + }
1.119 + }
1.120 +
1.121 + TransmitAutomaticData();
1.122 + return mSelectedFrame;
1.123 +}
