michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: 
michael@0: #include "nsMathMLsemanticsFrame.h"
michael@0: #include "nsMimeTypes.h"
michael@0: #include "mozilla/gfx/2D.h"
michael@0: 
michael@0: //
michael@0: // <semantics> -- associate annotations with a MathML expression
michael@0: //
michael@0: 
michael@0: nsIFrame*
michael@0: NS_NewMathMLsemanticsFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
michael@0: {
michael@0:   return new (aPresShell) nsMathMLsemanticsFrame(aContext);
michael@0: }
michael@0: 
michael@0: NS_IMPL_FRAMEARENA_HELPERS(nsMathMLsemanticsFrame)
michael@0: 
michael@0: nsMathMLsemanticsFrame::~nsMathMLsemanticsFrame()
michael@0: {
michael@0: }
michael@0: 
michael@0: nsIFrame* 
michael@0: nsMathMLsemanticsFrame::GetSelectedFrame()
michael@0: {
michael@0:   // By default, we will display the first child of the <semantics> element.
michael@0:   nsIFrame* childFrame = mFrames.FirstChild(); 
michael@0:   mSelectedFrame = childFrame;
michael@0: 
michael@0:   // An empty <semantics> is invalid
michael@0:   if (!childFrame) {
michael@0:     mInvalidMarkup = true;
michael@0:     return mSelectedFrame;
michael@0:   }
michael@0:   mInvalidMarkup = false;
michael@0: 
michael@0:   // Using <annotation> or <annotation-xml> as a first child is invalid.
michael@0:   // However some people use this syntax so we take care of this case too.
michael@0:   bool firstChildIsAnnotation = false;
michael@0:   nsIContent* childContent = childFrame->GetContent();
michael@0:   if (childContent->GetNameSpaceID() == kNameSpaceID_MathML &&
michael@0:       (childContent->Tag() == nsGkAtoms::annotation_ ||
michael@0:        childContent->Tag() == nsGkAtoms::annotation_xml_)) {
michael@0:     firstChildIsAnnotation = true;
michael@0:   }
michael@0: 
michael@0:   // If the first child is a presentation MathML element other than
michael@0:   // <annotation> or <annotation-xml>, we are done.
michael@0:   if (!firstChildIsAnnotation &&
michael@0:       childFrame->IsFrameOfType(nsIFrame::eMathML)) {
michael@0:     nsIMathMLFrame* mathMLFrame = do_QueryFrame(childFrame);
michael@0:     if (mathMLFrame) {
michael@0:       TransmitAutomaticData();
michael@0:       return mSelectedFrame;
michael@0:     }
michael@0:     // The first child is not an annotation, so skip it.
michael@0:     childFrame = childFrame->GetNextSibling();
michael@0:   }
michael@0: 
michael@0:   // Otherwise, we read the list of annotations and select the first one that
michael@0:   // could be displayed in place of the first child of <semantics>. If none is
michael@0:   // found, we fallback to this first child.
michael@0:   for ( ; childFrame; childFrame = childFrame->GetNextSibling()) {
michael@0:     nsIContent* childContent = childFrame->GetContent();
michael@0: 
michael@0:     if (childContent->GetNameSpaceID() != kNameSpaceID_MathML) continue;
michael@0: 
michael@0:     if (childContent->Tag() == nsGkAtoms::annotation_) {
michael@0: 
michael@0:       // If the <annotation> element has an src attribute we ignore it.
michael@0:       // XXXfredw Should annotation images be supported? See the related
michael@0:       // bug 297465 for mglyph.
michael@0:       if (childContent->HasAttr(kNameSpaceID_None, nsGkAtoms::src)) continue;
michael@0: 
michael@0:       // Otherwise, we assume it is a text annotation that can always be
michael@0:       // displayed and stop here.
michael@0:       mSelectedFrame = childFrame;
michael@0:       break;
michael@0:     }
michael@0: 
michael@0:     if (childContent->Tag() == nsGkAtoms::annotation_xml_) {
michael@0: 
michael@0:       // If the <annotation-xml> element has an src attribute we ignore it.
michael@0:       if (childContent->HasAttr(kNameSpaceID_None, nsGkAtoms::src)) continue;
michael@0: 
michael@0:       // If the <annotation-xml> element has an encoding attribute
michael@0:       // describing presentation MathML, SVG or HTML we assume the content
michael@0:       // can be displayed and stop here.
michael@0:       //
michael@0:       // We recognize the following encoding values:
michael@0:       //
michael@0:       // - "MathML-Presentation", which is mentioned in the MathML3 REC
michael@0:       // - "SVG1.1" which is mentioned in the W3C note
michael@0:       //                   http://www.w3.org/Math/Documents/Notes/graphics.xml
michael@0:       // - Other mime Content-Types for SVG and HTML
michael@0:       //
michael@0:       // We exclude APPLICATION_MATHML_XML = "application/mathml+xml" which
michael@0:       // is ambiguous about whether it is Presentation or Content MathML.
michael@0:       // Authors must use a more explicit encoding value.
michael@0:       nsAutoString value;
michael@0:       childContent->GetAttr(kNameSpaceID_None, nsGkAtoms::encoding, value);
michael@0:       if (value.EqualsLiteral("application/mathml-presentation+xml") ||
michael@0:           value.EqualsLiteral("MathML-Presentation") ||
michael@0:           value.EqualsLiteral(IMAGE_SVG_XML) ||
michael@0:           value.EqualsLiteral("SVG1.1") ||
michael@0:           value.EqualsLiteral(APPLICATION_XHTML_XML) ||
michael@0:           value.EqualsLiteral(TEXT_HTML)) {
michael@0:         mSelectedFrame = childFrame;
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   TransmitAutomaticData();
michael@0:   return mSelectedFrame;
michael@0: }