Display MathML fallback content when it is specified and take into account inline/display modes for…

Source/core/css/mathml.css

 /*
+ * The default style sheet used to render MathML.
+ *
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer
  *    in the documentation and/or other materials provided with the
  *    distribution.
  * 3. Neither the name of Google Inc. nor the names of its contributors
  *    may be used to endorse or promote products derived from this
  *    software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
-#include "core/dom/custom/CustomElementMicrotaskElementStep.h"
+@namespace "http://www.w3.org/1998/Math/MathML";
 
-#include "core/dom/custom/CustomElementCallbackQueue.h"
-
-namespace WebCore {
-
-PassOwnPtr<CustomElementMicrotaskElementStep> CustomElementMicrotaskElementStep::create(CustomElementCallbackQueue* queue)
-{
-    ASSERT(queue);
-    return adoptPtr(new CustomElementMicrotaskElementStep(queue));
+/* By default, we only display the MathML formulas without any formatting other than the one specified by the display attribute. */
+math {
+    display: inline;
+}
+math[display="block"] {
+    display: block;
+    text-align: center;
 }
 
-static const CustomElementCallbackQueue::ElementQueueId kMicrotaskQueueId = 0;
-
-CustomElementMicrotaskElementStep::CustomElementMicrotaskElementStep(CustomElementCallbackQueue* queue)
-    : m_queue(queue)
-{
-    m_queue->setOwner(kMicrotaskQueueId);
+/* We only display the second child of a <semantics> element, which is its first annotation. */
+semantics > * {

[esprehn, 2014/01/15 20:59:59]

This is bad, it ends up in the universal rules so we have to match it all the
time.

+    display: none;
+}
+semantics > *:first-child + annotation,
+semantics > *:first-child + annotation-xml {

[esprehn, 2014/01/15 20:59:59]

This is bad, it means we will invalidate a sibling of every SubtreeStyleChange
all the time because of the + operator.

+    display: inline-block;
 }
 
-CustomElementMicrotaskStep::Result CustomElementMicrotaskElementStep::process()
-{
-    return m_queue->processInElementQueue(kMicrotaskQueueId) ? DidWork : Result(0);
+/* If an alttext attribute is specified, we replace the MathML formula with that text. */
+math[alttext] * {

[esprehn, 2014/01/15 20:59:59]

Another universal rule, it's going to add a rule to all elements in every page.

+    display: none;
 }
-
-} // namespace WebCore
+math[alttext]::after {

[esprehn, 2014/01/15 20:59:59]

This is another universal rule :(

+    content: attr(alttext);
+}