The Tor Browser: layout/mathml/nsMathMLsemanticsFrame.cpp@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include "nsMathMLsemanticsFrame.h"

     8 #include "nsMimeTypes.h"

     9 #include "mozilla/gfx/2D.h"

    11 //

    12 // <semantics> -- associate annotations with a MathML expression

    13 //

    15 nsIFrame*

    16 NS_NewMathMLsemanticsFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)

    17 {

    18   return new (aPresShell) nsMathMLsemanticsFrame(aContext);

    19 }

    21 NS_IMPL_FRAMEARENA_HELPERS(nsMathMLsemanticsFrame)

    23 nsMathMLsemanticsFrame::~nsMathMLsemanticsFrame()

    24 {

    25 }

    27 nsIFrame*

    28 nsMathMLsemanticsFrame::GetSelectedFrame()

    29 {

    30   // By default, we will display the first child of the <semantics> element.

    31   nsIFrame* childFrame = mFrames.FirstChild();

    32   mSelectedFrame = childFrame;

    34   // An empty <semantics> is invalid

    35   if (!childFrame) {

    36     mInvalidMarkup = true;

    37     return mSelectedFrame;

    38   }

    39   mInvalidMarkup = false;

    41   // Using <annotation> or <annotation-xml> as a first child is invalid.

    42   // However some people use this syntax so we take care of this case too.

    43   bool firstChildIsAnnotation = false;

    44   nsIContent* childContent = childFrame->GetContent();

    45   if (childContent->GetNameSpaceID() == kNameSpaceID_MathML &&

    46       (childContent->Tag() == nsGkAtoms::annotation_ ||

    47        childContent->Tag() == nsGkAtoms::annotation_xml_)) {

    48     firstChildIsAnnotation = true;

    49   }

    51   // If the first child is a presentation MathML element other than

    52   // <annotation> or <annotation-xml>, we are done.

    53   if (!firstChildIsAnnotation &&

    54       childFrame->IsFrameOfType(nsIFrame::eMathML)) {

    55     nsIMathMLFrame* mathMLFrame = do_QueryFrame(childFrame);

    56     if (mathMLFrame) {

    57       TransmitAutomaticData();

    58       return mSelectedFrame;

    59     }

    60     // The first child is not an annotation, so skip it.

    61     childFrame = childFrame->GetNextSibling();

    62   }

    64   // Otherwise, we read the list of annotations and select the first one that

    65   // could be displayed in place of the first child of <semantics>. If none is

    66   // found, we fallback to this first child.

    67   for ( ; childFrame; childFrame = childFrame->GetNextSibling()) {

    68     nsIContent* childContent = childFrame->GetContent();

    70     if (childContent->GetNameSpaceID() != kNameSpaceID_MathML) continue;

    72     if (childContent->Tag() == nsGkAtoms::annotation_) {

    74       // If the <annotation> element has an src attribute we ignore it.

    75       // XXXfredw Should annotation images be supported? See the related

    76       // bug 297465 for mglyph.

    77       if (childContent->HasAttr(kNameSpaceID_None, nsGkAtoms::src)) continue;

    79       // Otherwise, we assume it is a text annotation that can always be

    80       // displayed and stop here.

    81       mSelectedFrame = childFrame;

    82       break;

    83     }

    85     if (childContent->Tag() == nsGkAtoms::annotation_xml_) {

    87       // If the <annotation-xml> element has an src attribute we ignore it.

    88       if (childContent->HasAttr(kNameSpaceID_None, nsGkAtoms::src)) continue;

    90       // If the <annotation-xml> element has an encoding attribute

    91       // describing presentation MathML, SVG or HTML we assume the content

    92       // can be displayed and stop here.

    93       //

    94       // We recognize the following encoding values:

    95       //

    96       // - "MathML-Presentation", which is mentioned in the MathML3 REC

    97       // - "SVG1.1" which is mentioned in the W3C note

    98       //                   http://www.w3.org/Math/Documents/Notes/graphics.xml

    99       // - Other mime Content-Types for SVG and HTML

   100       //

   101       // We exclude APPLICATION_MATHML_XML = "application/mathml+xml" which

   102       // is ambiguous about whether it is Presentation or Content MathML.

   103       // Authors must use a more explicit encoding value.

   104       nsAutoString value;

   105       childContent->GetAttr(kNameSpaceID_None, nsGkAtoms::encoding, value);

   106       if (value.EqualsLiteral("application/mathml-presentation+xml") ||

   107           value.EqualsLiteral("MathML-Presentation") ||

   108           value.EqualsLiteral(IMAGE_SVG_XML) ||

   109           value.EqualsLiteral("SVG1.1") ||

   110           value.EqualsLiteral(APPLICATION_XHTML_XML) ||

   111           value.EqualsLiteral(TEXT_HTML)) {

   112         mSelectedFrame = childFrame;

   113         break;

   114       }

   115     }

   116   }

   118   TransmitAutomaticData();

   119   return mSelectedFrame;

   120 }

The Tor Browser / file revision

layout/mathml/nsMathMLsemanticsFrame.cpp@97036ab72558

layout/mathml/nsMathMLsemanticsFrame.cpp