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