+2013-12-18 Andreas Kling <akling@apple.com>
+
+ CSS: Add a property cascading pass to style application.
+ <https://webkit.org/b/125213>
+
+ Add an intermediate pass to style application where we cascade all
+ style properties to figure out their final values before starting
+ to build RenderStyles.
+
+ This opens up various opportunities for further optimization.
+
+ Reviewed by Antti Koivisto.
+
+ * css/StyleResolver.cpp:
+ (WebCore::StyleResolver::CascadedProperties::Property::Property):
+ (WebCore::StyleResolver::CascadedProperties::CascadedProperties):
+ (WebCore::StyleResolver::CascadedProperties::property):
+ (WebCore::StyleResolver::CascadedProperties::set):
+ (WebCore::StyleResolver::CascadedProperties::addStyleProperties):
+ (WebCore::StyleResolver::CascadedProperties::addMatches):
+ (WebCore::StyleResolver::CascadedProperties::Property::apply):
+
+ Added. CascadedProperties is something of a container class
+ that takes CSS property/value/linkMatchType as input and boils
+ them down to the final values that will actually be used.
+
+ Most properties are poked into an unfancy array where latest
+ is greatest (unless !important, of course.) Some properties are
+ queued up to be applied in parse order, more on that below.
+
+ (WebCore::StyleResolver::applyCascadedProperties):
+ (WebCore::StyleResolver::applyMatchedProperties):
+
+ The brains of this patch. applyMatchedProperties() now creates
+ a CascadedProperties and uses it to figure out the final values
+ and uses applyCascadedProperties() to apply them. Deferred
+ properties (parse order) are applied last.
+
+ We may discover during property application that we won't be
+ able to use a matched properties cache item. This happens if
+ the effective zoom or font changes. If that happens, we start
+ the process over, now with the cache disabled. This may need
+ some optimization work.
+
+ (WebCore::extractDirectionAndWritingMode):
+
+ Directional properties ending in e.g -before or -after depend on
+ the direction and writing mode in effect, so we must begin with
+ resolving those properties before doing the full cascade.
+
+ This is done by simply walking the set of matched properties and
+ manually applying '-webkit-writing-mode' and 'direction'.
+
+ If this starts showing up in profiles, we can easily cache some
+ of the information in e.g RuleData to avoid the traversal here.
+
+ (WebCore::elementTypeHasAppearanceFromUAStyle):
+
+ To determine whether a form element is styled beyond the default
+ UA style sheet, StyleResolver caches the border and background
+ values from RenderStyle after applying the UA style sheet.
+
+ Those values are then compared against after all style is applied
+ and if some (platform-dependent) values differ, the element is
+ considered "styled."
+
+ This really only affects elements with -webkit-appearance values
+ in the default UA style sheet, so this function determines if an
+ element should take the goofy slow path for this.
+
+ (WebCore::shouldApplyPropertyInParseOrder):
+ (WebCore::StyleResolver::CascadedProperties::setDeferred):
+ (WebCore::StyleResolver::CascadedProperties::applyDeferredProperties):
+
+ Some CSS properties will write to the same RenderStyle fields when
+ applied, so in order to maintain previous behavior, we must apply
+ them in the order they were parsed.
+
+ We accomplish this by keeping an ordered queue of such properties
+ to apply separately after all the other properties.
+
+ (WebCore::StyleResolver::CascadedProperties::setPropertyInternal):
+
+ Helper for poking values into a CascadedProperties::Property.
+
+ * css/StyleResolver.h:
+ (WebCore::StyleResolver::state):
+
+ Expose the StyleResolver::State so CascadedProperties can access it.
+
2013-12-16 Martin Robinson <mrobinson@igalia.com>
[GTK] [CMake] Add support for building WebKit1
git://git.webkit.org / WebKit-https.git / blobdiff