[Typed CSSOM] New design for computed styles which includes 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"

[alancutter (OOO until 2018), 2017/04/05 04:54:09]

I don't think this include is required.

 #include "core/css/cssom/CSSCalcLength.h"
 #include "core/css/cssom/CSSKeywordValue.h"
 #include "core/css/cssom/CSSNumberValue.h"
 #include "core/css/cssom/CSSSimpleLength.h"

[meade_UTC10, 2017/04/06 03:47:32]

These other specific types probably aren't required any more either now.

 #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"
 
 namespace blink {
 
-namespace {
-
-CSSStyleValue* styleValueForLength(const Length& length) {
-  if (length.isAuto()) {
-    return CSSKeywordValue::create("auto");
-  }
-  if (length.isFixed()) {
-    return CSSSimpleLength::create(length.pixels(),
-                                   CSSPrimitiveValue::UnitType::Pixels);
-  }
-  if (length.isPercent()) {
-    return CSSSimpleLength::create(length.percent(),
-                                   CSSPrimitiveValue::UnitType::Percentage);
-  }
-  if (length.isCalculated()) {
-    return CSSCalcLength::fromLength(length);
-  }
-  NOTREACHED();
-  return nullptr;
-}
-
-}  // namespace
-
-Node* ComputedStylePropertyMap::node() const {
-  if (!m_node) {
+Node* ComputedStylePropertyMap::styledNode() const {
+  if (!m_node)
     return nullptr;
-  }
-  if (!m_pseudoId) {
+  if (!m_pseudoId)
     return m_node;
-  }
   if (m_node->isElementNode()) {
     // 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;
 }
 
-// ComputedStylePropertyMap::getAllInternal/get should return computed styles
-// (as opposed to resolved styles a la getComputedStyle()).
-//
-// Property values are read from an up-to-date ComputedStyle and converted into
-// CSSStyleValues. This has not been implemented for all properties yet.
-// Unsupported properties fall back to using resolved styles & converting them
-// to CSSStyleValues via StyleValueFactory. For some types of values, such as
-// images, the difference between the two is minor.
+const ComputedStyle* ComputedStylePropertyMap::updateStyle() const {
+  Node* node = styledNode();
+  if (!node || !node->inActiveDocument())
+    return nullptr;
+
+  // Update style before getting the value for the property
+  // This could cause the node to be blown away.

[alancutter (OOO until 2018), 2017/04/05 04:54:09]

Add test case for this. (Set display to none).

+  node->document().updateStyleAndLayoutTreeForNode(node);
+  node = styledNode();
+  if (!node)
+    return nullptr;
+  // This is copied from CSSComputedStyleDeclaration::computeComputedStyle().
+  // PseudoIdNone must be used if node() is a PseudoElement.
+  const ComputedStyle* style = node->ensureComputedStyle(
+      node->isPseudoElement() ? PseudoIdNone : m_pseudoId);
+  node = styledNode();
+  if (!node || !node->inActiveDocument() || !style)
+    return nullptr;
+  return style;
+}
+
 CSSStyleValueVector ComputedStylePropertyMap::getAllInternal(
     CSSPropertyID propertyID) {
   CSSStyleValueVector styleValueVector;
-
-  Node* node = this->node();
-  if (!node || !node->inActiveDocument()) {
-    return styleValueVector;
-  }
-
-  // Update style before getting the value for the property
-  node->document().updateStyleAndLayoutTreeForNode(node);
-  node = this->node();
-  if (!node) {
-    return styleValueVector;
-  }
-  // 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 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;
-    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:
-      // For properties not yet handled above, fall back to using resolved
-      // style.
-      const CSSValue* value = ComputedStyleCSSValueMapping::get(
-          propertyID, *style, nullptr, node, false);
-      if (value) {
-        return StyleValueFactory::cssValueToStyleValueVector(propertyID,
-                                                             *value);
-      }
-      break;
-  }
-
-  if (styleValue) {
-    styleValueVector.push_back(styleValue);
-  }
-  return styleValueVector;
+  const ComputedStyle* style = updateStyle();
+  if (!style)
+    return CSSStyleValueVector();
+  const CSSValue* cssValue = ComputedStyleCSSValueMapping::get(
+      propertyID, *style, nullptr /* layoutObject */);
+  if (!cssValue)
+    return CSSStyleValueVector();
+  return StyleValueFactory::cssValueToStyleValueVector(propertyID, *cssValue);
 }
 
 CSSStyleValueVector ComputedStylePropertyMap::getAllInternal(
-    AtomicString customPropertyName) {
-  const CSSValue* cssValue =
-      m_computedStyleDeclaration->getPropertyCSSValue(customPropertyName);
+    AtomicString customPropertyName,
+    ExceptionState& exceptionState) {

[meade_UTC10, 2017/04/06 03:47:32]

You're not using the exception state - no need to add it here. Removing will let
you revert some of the other files in this CL.

+  const ComputedStyle* style = updateStyle();
+  if (!style)
+    return CSSStyleValueVector();
+  // FIXME(rjwright): propertyRegistry is nullptr in stable Chrome.

[alancutter (OOO until 2018), 2017/04/05 04:54:08]

I don't think anything will change here, no need for FIXME.

+  const CSSValue* cssValue = ComputedStyleCSSValueMapping::get(
+      customPropertyName, *style, m_node->document().propertyRegistry());
   if (!cssValue)
     return CSSStyleValueVector();
-  return StyleValueFactory::cssValueToStyleValueVector(CSSPropertyInvalid,
-                                                       *cssValue);
+  return StyleValueFactory::cssValueToStyleValueVector(*cssValue);
 }
 
 Vector<String> ComputedStylePropertyMap::getProperties() {
   Vector<String> result;
   for (CSSPropertyID propertyID :
        CSSComputedStyleDeclaration::computableProperties()) {
     result.push_back(getPropertyNameString(propertyID));
   }
   return result;
 }
 
 }  // namespace blink