[Typed CSSOM] Get computed values for custom properties

third_party/WebKit/Source/core/css/cssom/ComputedStylePropertyMap.cpp

 // Copyright 2016 the Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/cssom/ComputedStylePropertyMap.h"
 
 #include "core/css/CSSComputedStyleDeclaration.h"
 #include "core/css/ComputedStyleCSSValueMapping.h"
+#include "core/css/PropertyRegistry.h"
 #include "core/css/cssom/CSSCalcLength.h"
 #include "core/css/cssom/CSSKeywordValue.h"
 #include "core/css/cssom/CSSNumberValue.h"
 #include "core/css/cssom/CSSSimpleLength.h"
 #include "core/css/cssom/CSSUnsupportedStyleValue.h"
 #include "core/css/cssom/StyleValueFactory.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/PseudoElement.h"
 #include "core/dom/StyleEngine.h"
 
@@ skipping 33 matching lines @@
     // Seems to only support before, after, backdrop, first-letter. See
     // PseudoElementData::pseudoElement.
     if (PseudoElement* element =
             (toElement(m_node))->pseudoElement(m_pseudoId)) {
       return element;
     }
   }
   return nullptr;
 }
 
-CSSStyleValueVector ComputedStylePropertyMap::getAllInternal(
-    CSSPropertyID propertyID) {
-  CSSStyleValueVector styleValueVector;
-
+const ComputedStyle* ComputedStylePropertyMap::updateStyle() const {
   Node* node = this->node();
   if (!node || !node->inActiveDocument()) {
-    return styleValueVector;
+    return nullptr;
   }
   node->document().updateStyleAndLayoutTreeForNode(node);
   node = this->node();
   if (!node) {
-    return styleValueVector;
+    return nullptr;
   }
   // I have copied this from
   // CSSComputedStyleDeclaration::computeComputedStyle(). I don't know if
   // there is any use in passing m_pseudoId if node is not already a
   // PseudoElement, but passing
   // pseudo_Id when it IS already a PseudoElement leads to disaster.
   const ComputedStyle* style = node->ensureComputedStyle(
       node->isPseudoElement() ? PseudoIdNone : m_pseudoId);
   node = this->node();
   if (!node || !node->inActiveDocument() || !style) {
+    return nullptr;
+  }
+  return style;
+}
+
+CSSStyleValueVector ComputedStylePropertyMap::getAllInternal(
+    CSSPropertyID propertyID) {
+  CSSStyleValueVector styleValueVector;
+  const ComputedStyle* style = this->updateStyle();

[alancutter (OOO until 2018), 2017/02/24 05:57:21]

No need for "this->" where it's not ambiguous. Style guide doesn't say anything
about it but I would avoid it for consistency with the rest of the code base.

+  if (!style)
     return styleValueVector;
-  }
 
   CSSStyleValue* styleValue = nullptr;
-
   switch (propertyID) {
     // TODO(rjwright): Generate this code.
     case CSSPropertyLeft:
       styleValue = styleValueForLength(style->left());
       break;
     case CSSPropertyRight:
       styleValue = styleValueForLength(style->right());
       break;
     case CSSPropertyTop:
       styleValue = styleValueForLength(style->top());
       break;
     case CSSPropertyBottom:
       styleValue = styleValueForLength(style->bottom());
       break;
     case CSSPropertyHeight:
       styleValue = styleValueForLength(style->height());
       break;
     case CSSPropertyWidth:
       styleValue = styleValueForLength(style->width());
       break;

[alancutter (OOO until 2018), 2017/02/24 05:57:21]

FYI there's a LengthPropertyFunctions class with a "static bool
getLength(CSSPropertyID, const ComputedStyle&, Length& result);" method that
could save a bit of repetition here.

     case CSSPropertyLineHeight: {
       // LineHeight is represented as a Length in ComputedStyle, even though it
       // can be a number or the "normal" keyword. "normal" is encoded as a
       // negative percent, and numbers (which must be positive) are encoded as
       // percents.
       Length lineHeight = style->lineHeight();
       if (lineHeight.isNegative()) {
         styleValue = CSSKeywordValue::create("normal");
         break;
       }
       if (lineHeight.isPercent()) {
         styleValue = CSSNumberValue::create(lineHeight.percent());
         break;
       }
       if (lineHeight.isFixed()) {
         styleValue = CSSSimpleLength::create(
             lineHeight.pixels(), CSSPrimitiveValue::UnitType::Pixels);
         break;
       }
       NOTREACHED();
       break;
     }
     default:
-      // TODO(rjwright): Add a flag argument to
-      // ComputedStyleCSSValyeMapping::get that makes it return
-      // just the raw value off the ComputedStyle, and not zoom adjusted or
-      // anything like that.
       const CSSValue* value = ComputedStyleCSSValueMapping::get(
-          propertyID, *style, nullptr, node, false);
+          propertyID, *style, nullptr, this->node(), false);

[alancutter (OOO until 2018), 2017/02/24 05:57:21]

I don't think it's necessary to pass in the node here, if I'm wrong then there
should be a TODO to remove the dependency. Everything you need should be on the
ComputedStyle.

       if (value) {
         return StyleValueFactory::cssValueToStyleValueVector(propertyID,
                                                              *value);
       }
       break;
   }
 
   if (styleValue) {
     styleValueVector.push_back(styleValue);
   }
   return styleValueVector;
 }
 
 CSSStyleValueVector ComputedStylePropertyMap::getAllInternal(
-    AtomicString customPropertyName) {
-  const CSSValue* cssValue =
-      m_computedStyleDeclaration->getPropertyCSSValue(customPropertyName);
+    AtomicString customPropertyName,
+    ExceptionState& exceptionState) {
+  const ComputedStyle* style = this->updateStyle();
+  if (!style)
+    return CSSStyleValueVector();
+  const PropertyRegistration* registration =
+      m_node->document().propertyRegistry()->registration(customPropertyName);

[alancutter (OOO until 2018), 2017/02/24 05:57:21]

The property registry is nullptr in stable Chrome.

+  if (!registration)
+    return CSSStyleValueVector();
+  const CSSValue* cssValue = style->getRegisteredVariable(
+      customPropertyName, registration->inherits());
   if (!cssValue)
     return CSSStyleValueVector();
   return StyleValueFactory::cssValueToStyleValueVector(CSSPropertyInvalid,

[alancutter (OOO until 2018), 2017/02/24 05:57:21]

No need to pass in CSSPropertyInvalid here, there's a single argument overload
of this function.

                                                        *cssValue);
 }
 
 Vector<String> ComputedStylePropertyMap::getProperties() {
   Vector<String> result;
   for (unsigned i = 0; i < m_computedStyleDeclaration->length(); i++) {
     result.push_back(m_computedStyleDeclaration->item(i));
   }
   return result;
 }
 
 }  // namespace blink