Changeset 201799 in webkit for trunk/Source/WebCore/css/StyleResolver.cpp

Timestamp:

Jun 8, 2016, 1:00:22 AM (9 years ago)

Author:

mmaxfield@apple.com

Message:

Extend CSSFontSelector's lifetime to be longer than the Document's lifetime
​https://bugs.webkit.org/show_bug.cgi?id=154101

Reviewed by Darin Adler.

Rather than destroying the Document's CSSFontSelector, instead, the object should
live for the lifetime of the document, and it should instead be asked to clear its
contents.

This is important for the CSS Font Loading API, where the identity of objects the
CSSFontSelector references needs to persist throughout the lifetime of the
Document. This patch represents the first step to implementing this correctly.
The second step is for the CSSFontSelector to perform a diff instead of a
wholesale clear of its contents. Once this is done, font loading objects can
survive through a call to Document::clearStyleResolver().

This patch gives the CSSFontSelector two states: building underway and building not
underway. The state is building underway in between calls to clearStyleResolver()
and when the style resolver gets built back up. Otherwise, the state is building
not underway. Because of this new design, creation of all FontFace objects can be
postponed until a state transition from building underway to building not underway.
A subsequent patch will perform the diff at this point. An ASSERT() makes sure that
we never service a font lookup request while Building.

No new tests because there is no behavior change.

• css/CSSFontFaceSet.cpp:

(WebCore::CSSFontFaceSet::clear):

• css/CSSFontSelector.cpp:

(WebCore::CSSFontSelector::buildStarted):
(WebCore::CSSFontSelector::buildCompleted):
(WebCore::CSSFontSelector::addFontFaceRule):
(WebCore::CSSFontSelector::fontRangesForFamily):
(WebCore::CSSFontSelector::CSSFontSelector): Deleted.
(WebCore::CSSFontSelector::clearDocument): Deleted.

• css/CSSFontSelector.h:
• css/StyleResolver.cpp:

(WebCore::StyleResolver::appendAuthorStyleSheets):

• dom/Document.cpp:

(WebCore::Document::Document):
(WebCore::Document::~Document):
(WebCore::Document::clearStyleResolver):
(WebCore::Document::fontSelector): Deleted.

• dom/Document.h:

(WebCore::Document::fontSelector):

File:

• trunk/Source/WebCore/css/StyleResolver.cpp (modified) (1 diff)

trunk/Source/WebCore/css/StyleResolver.cpp

@@ -297 +297 @@
 {
     m_ruleSets.appendAuthorStyleSheets(styleSheets, &m_mediaQueryEvaluator, m_inspectorCSSOMWrappers, this);
+
+    document().fontSelector().buildCompleted();
+
     if (auto renderView = document().renderView())
         renderView->style().fontCascade().update(&document().fontSelector());