blob: a539d684dcf77888fee02fd7843e3ecd18e4506f [file] [log] [blame]
// Copyright 2014 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "cobalt/dom/html_element.h"
#include <map>
#include "base/lazy_instance.h"
#include "base/string_number_conversions.h"
#include "cobalt/base/tokens.h"
#include "cobalt/base/user_log.h"
#include "cobalt/cssom/absolute_url_value.h"
#include "cobalt/cssom/cascaded_style.h"
#include "cobalt/cssom/computed_style.h"
#include "cobalt/cssom/css_parser.h"
#include "cobalt/cssom/css_style_sheet.h"
#include "cobalt/cssom/keyword_value.h"
#include "cobalt/cssom/property_list_value.h"
#include "cobalt/cssom/selector_tree.h"
#include "cobalt/dom/csp_delegate.h"
#include "cobalt/dom/document.h"
#include "cobalt/dom/dom_animatable.h"
#include "cobalt/dom/dom_string_map.h"
#include "cobalt/dom/focus_event.h"
#include "cobalt/dom/html_anchor_element.h"
#include "cobalt/dom/html_body_element.h"
#include "cobalt/dom/html_br_element.h"
#include "cobalt/dom/html_div_element.h"
#include "cobalt/dom/html_element_context.h"
#include "cobalt/dom/html_element_factory.h"
#include "cobalt/dom/html_head_element.h"
#include "cobalt/dom/html_heading_element.h"
#include "cobalt/dom/html_html_element.h"
#include "cobalt/dom/html_image_element.h"
#include "cobalt/dom/html_link_element.h"
#include "cobalt/dom/html_meta_element.h"
#include "cobalt/dom/html_paragraph_element.h"
#include "cobalt/dom/html_script_element.h"
#include "cobalt/dom/html_span_element.h"
#include "cobalt/dom/html_style_element.h"
#include "cobalt/dom/html_title_element.h"
#include "cobalt/dom/html_unknown_element.h"
#include "cobalt/dom/html_video_element.h"
#include "cobalt/dom/rule_matching.h"
#include "cobalt/loader/image/animated_image_tracker.h"
namespace cobalt {
namespace dom {
namespace {
// This struct manages the user log information for Node count.
struct HtmlElementCountLog {
public:
HtmlElementCountLog() : count(0) {
base::UserLog::Register(base::UserLog::kHtmlElementCountIndex,
"HtmlElementCnt", &count, sizeof(count));
}
~HtmlElementCountLog() {
base::UserLog::Deregister(base::UserLog::kHtmlElementCountIndex);
}
int count;
};
struct NonTrivialStaticFields {
NonTrivialStaticFields() {
cssom::PropertyKeyVector computed_style_invalidation_properties;
cssom::PropertyKeyVector layout_box_invalidation_properties;
cssom::PropertyKeyVector size_invalidation_properties;
cssom::PropertyKeyVector cross_references_invalidation_properties;
for (int i = 0; i <= cssom::kMaxLonghandPropertyKey; ++i) {
cssom::PropertyKey property_key = static_cast<cssom::PropertyKey>(i);
if (cssom::GetPropertyImpactsChildDeclaredStyle(property_key) ==
cssom::kImpactsChildDeclaredStyleYes) {
computed_style_invalidation_properties.push_back(property_key);
}
// TODO: Revisit inherited property handling. Currently, all boxes are
// invalidated if an inherited property changes, but now that inherited
// properties dynamically update, this is likely no longer necessary.
if (cssom::GetPropertyInheritance(property_key) == cssom::kInheritedYes ||
cssom::GetPropertyImpactsBoxGeneration(property_key) ==
cssom::kImpactsBoxGenerationYes) {
layout_box_invalidation_properties.push_back(property_key);
} else {
if (cssom::GetPropertyImpactsBoxSizes(property_key) ==
cssom::kImpactsBoxSizesYes) {
size_invalidation_properties.push_back(property_key);
}
if (cssom::GetPropertyImpactsBoxCrossReferences(property_key) ==
cssom::kImpactsBoxCrossReferencesYes) {
cross_references_invalidation_properties.push_back(property_key);
}
}
}
computed_style_invalidation_property_checker =
cssom::CSSComputedStyleData::PropertySetMatcher(
computed_style_invalidation_properties);
layout_box_invalidation_property_checker =
cssom::CSSComputedStyleData::PropertySetMatcher(
layout_box_invalidation_properties);
size_invalidation_property_checker =
cssom::CSSComputedStyleData::PropertySetMatcher(
size_invalidation_properties);
cross_references_invalidation_property_checker =
cssom::CSSComputedStyleData::PropertySetMatcher(
cross_references_invalidation_properties);
}
cssom::CSSComputedStyleData::PropertySetMatcher
computed_style_invalidation_property_checker;
cssom::CSSComputedStyleData::PropertySetMatcher
layout_box_invalidation_property_checker;
cssom::CSSComputedStyleData::PropertySetMatcher
size_invalidation_property_checker;
cssom::CSSComputedStyleData::PropertySetMatcher
cross_references_invalidation_property_checker;
HtmlElementCountLog html_element_count_log;
private:
DISALLOW_COPY_AND_ASSIGN(NonTrivialStaticFields);
};
base::LazyInstance<NonTrivialStaticFields> non_trivial_static_fields =
LAZY_INSTANCE_INITIALIZER;
} // namespace
std::string HTMLElement::dir() const {
// The dir attribute is limited to only known values. On getting, dir must
// return the conforming value associated with the state the attribute is in,
// or the empty string if the attribute is in a state with no associated
// keyword value.
// https://dev.w3.org/html5/spec-preview/global-attributes.html#the-directionality
// https://dev.w3.org/html5/spec-preview/common-dom-interfaces.html#limited-to-only-known-values
// NOTE: Value "auto" is not supported.
if (directionality_ == kLeftToRightDirectionality) {
return "ltr";
} else if (directionality_ == kRightToLeftDirectionality) {
return "rtl";
} else {
return "";
}
}
void HTMLElement::set_dir(const std::string& value) {
// The dir attribute is limited to only known values. On setting, the dir
// attribute must be set to the specified new value.
// https://dev.w3.org/html5/spec-preview/global-attributes.html#the-directionality
// https://dev.w3.org/html5/spec-preview/common-dom-interfaces.html#limited-to-only-known-values
SetAttribute("dir", value);
}
scoped_refptr<DOMStringMap> HTMLElement::dataset() {
scoped_refptr<DOMStringMap> dataset(dataset_);
if (!dataset) {
// Create a new instance and store a weak reference.
dataset = new DOMStringMap(this);
dataset_ = dataset->AsWeakPtr();
}
return dataset;
}
int32 HTMLElement::tab_index() const {
int32 tabindex;
bool success =
base::StringToInt32(GetAttribute("tabindex").value_or(""), &tabindex);
if (!success) {
LOG(WARNING) << "Element's tabindex is not an integer.";
}
return tabindex;
}
void HTMLElement::set_tab_index(int32 tab_index) {
SetAttribute("tabindex", base::Int32ToString(tab_index));
}
// Algorithm for Focus:
// https://www.w3.org/TR/html5/editing.html#dom-focus
void HTMLElement::Focus() {
// 1. If the element is marked as locked for focus, then abort these steps.
if (locked_for_focus_) {
return;
}
// 2. Mark the element as locked for focus.
locked_for_focus_ = true;
// 3. Run the focusing steps for the element.
RunFocusingSteps();
// 4. Unmark the element as locked for focus.
locked_for_focus_ = false;
// Custom, not in any spec.
Document* document = node_document();
if (document) {
document->OnFocusChange();
}
}
// Algorithm for Blur:
// https://www.w3.org/TR/html5/editing.html#dom-blur
void HTMLElement::Blur() {
// The blur() method, when invoked, should run the unfocusing steps for the
// element on which the method was called instead. User agents may selectively
// or uniformly ignore calls to this method for usability reasons.
RunUnFocusingSteps();
// Custom, not in any spec.
Document* document = node_document();
if (document) {
document->OnFocusChange();
}
}
// Algorithm for GetClientRects:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-element-getclientrects
scoped_refptr<DOMRectList> HTMLElement::GetClientRects() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element on which it was invoked does not have an associated
// layout box return an empty DOMRectList object and stop this algorithm.
if (!layout_boxes_) {
return make_scoped_refptr(new DOMRectList());
}
// The remaining steps are implemented in LayoutBoxes::GetClientRects().
return layout_boxes_->GetClientRects();
}
// Algorithm for client_top:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-element-clienttop
float HTMLElement::client_top() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element has no associated CSS layout box or if the CSS layout box
// is inline, return zero.
if (!layout_boxes_ || layout_boxes_->IsInline()) {
return 0.0f;
}
// 2. Return the computed value of the 'border-top-width' property plus the
// height of any scrollbar rendered between the top padding edge and the top
// border edge, ignoring any transforms that apply to the element and its
// ancestors.
return layout_boxes_->GetBorderTopWidth();
}
// Algorithm for client_left:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-element-clientleft
float HTMLElement::client_left() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element has no associated CSS layout box or if the CSS layout box
// is inline, return zero.
if (!layout_boxes_ || layout_boxes_->IsInline()) {
return 0.0f;
}
// 2. Return the computed value of the 'border-left-width' property plus the
// width of any scrollbar rendered between the left padding edge and the left
// border edge, ignoring any transforms that apply to the element and its
// ancestors.
return layout_boxes_->GetBorderLeftWidth();
}
// Algorithm for client_width:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-element-clientwidth
float HTMLElement::client_width() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element has no associated CSS layout box or if the CSS layout box
// is inline, return zero.
if (!layout_boxes_ || layout_boxes_->IsInline()) {
return 0.0f;
}
// 2. If the element is the root element, return the viewport width.
if (IsRootElement()) {
return layout_boxes_->GetMarginEdgeWidth();
}
// 3. Return the width of the padding edge, ignoring any transforms that apply
// to the element and its ancestors.
return layout_boxes_->GetPaddingEdgeWidth();
}
// Algorithm for client_height:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-element-clientheight
float HTMLElement::client_height() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element has no associated CSS layout box or if the CSS layout box
// is inline, return zero.
if (!layout_boxes_ || layout_boxes_->IsInline()) {
return 0.0f;
}
// 2. If the element is the root element, return the viewport height.
if (IsRootElement()) {
return layout_boxes_->GetMarginEdgeHeight();
}
// Return the height of the padding edge, ignoring any transforms that apply
// to the element and its ancestors.
return layout_boxes_->GetPaddingEdgeHeight();
}
// Algorithm for offsetParent:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-htmlelement-offsetparent
Element* HTMLElement::offset_parent() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If any of the following holds true return null and terminate this
// algorithm:
// . The element does not have an associated CSS layout box.
// . The element is the root element.
// . The element is the HTML body element.
// . The element's computed value of the 'position' property is 'fixed'.
if (!layout_boxes_ || IsRootElement() || AsHTMLBodyElement() ||
!computed_style() ||
computed_style()->position() == cssom::KeywordValue::GetFixed()) {
return NULL;
}
// 2. Return the nearest ancestor element of the element for which at least
// one of the following is true and terminate this algorithm if such an
// ancestor is found:
// . The computed value of the 'position' property is not 'static'.
// . It is the HTML body element.
for (Node* ancestor_node = parent_node(); ancestor_node;
ancestor_node = ancestor_node->parent_node()) {
Element* ancestor_element = ancestor_node->AsElement();
if (!ancestor_element) {
continue;
}
HTMLElement* ancestor_html_element = ancestor_element->AsHTMLElement();
if (!ancestor_html_element) {
continue;
}
DCHECK(ancestor_html_element->computed_style());
if (ancestor_html_element->AsHTMLBodyElement() ||
ancestor_html_element->computed_style()->position() !=
cssom::KeywordValue::GetStatic()) {
return ancestor_element;
}
}
// 3. Return null.
return NULL;
}
// Algorithm for offset_top:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-htmlelement-offsettop
float HTMLElement::offset_top() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element is the HTML body element or does not have any associated
// CSS layout box return zero and terminate this algorithm.
if (!layout_boxes_ || AsHTMLBodyElement()) {
return 0.0f;
}
// 2. If the offsetParent of the element is null return the y-coordinate of
// the top border edge of the first CSS layout box associated with the
// element, relative to the initial containing block origin, ignoring any
// transforms that apply to the element and its ancestors, and terminate this
// algorithm.
scoped_refptr<Element> offset_parent_element = offset_parent();
if (!offset_parent_element) {
return layout_boxes_->GetBorderEdgeTop();
}
// 3. Return the result of subtracting the y-coordinate of the top padding
// edge of the first CSS layout box associated with the offsetParent of the
// element from the y-coordinate of the top border edge of the first CSS
// layout box associated with the element, relative to the initial containing
// block origin, ignoring any transforms that apply to the element and its
// ancestors.
scoped_refptr<HTMLElement> offset_parent_html_element =
offset_parent_element->AsHTMLElement();
if (!offset_parent_html_element) {
return layout_boxes_->GetBorderEdgeTop();
}
DCHECK(offset_parent_html_element->layout_boxes());
return layout_boxes_->GetBorderEdgeTop() -
offset_parent_html_element->layout_boxes()->GetPaddingEdgeTop();
}
// Algorithm for offset_left:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-htmlelement-offsetleft
float HTMLElement::offset_left() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element is the HTML body element or does not have any associated
// CSS layout box return zero and terminate this algorithm.
if (!layout_boxes_ || AsHTMLBodyElement()) {
return 0.0f;
}
// 2. If the offsetParent of the element is null return the x-coordinate of
// the left border edge of the first CSS layout box associated with the
// element, relative to the initial containing block origin, ignoring any
// transforms that apply to the element and its ancestors, and terminate this
// algorithm.
scoped_refptr<Element> offset_parent_element = offset_parent();
if (!offset_parent_element) {
return layout_boxes_->GetBorderEdgeLeft();
}
// 3. Return the result of subtracting the x-coordinate of the left padding
// edge of the first CSS layout box associated with the offsetParent of the
// element from the x-coordinate of the left border edge of the first CSS
// layout box associated with the element, relative to the initial containing
// block origin, ignoring any transforms that apply to the element and its
// ancestors.
scoped_refptr<HTMLElement> offset_parent_html_element =
offset_parent_element->AsHTMLElement();
if (!offset_parent_html_element) {
return layout_boxes_->GetBorderEdgeLeft();
}
DCHECK(offset_parent_html_element->layout_boxes());
return layout_boxes_->GetBorderEdgeLeft() -
offset_parent_html_element->layout_boxes()->GetPaddingEdgeLeft();
}
// Algorithm for offset_width:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-htmlelement-offsetwidth
float HTMLElement::offset_width() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element does not have any associated CSS layout box return zero
// and terminate this algorithm.
if (!layout_boxes_) {
return 0.0f;
}
// 2. Return the border edge width of the first CSS layout box associated with
// the element, ignoring any transforms that apply to the element and its
// ancestors.
return layout_boxes_->GetBorderEdgeWidth();
}
// Algorithm for offset_height:
// https://www.w3.org/TR/2013/WD-cssom-view-20131217/#dom-htmlelement-offsetheight
float HTMLElement::offset_height() {
DCHECK(node_document());
node_document()->DoSynchronousLayout();
// 1. If the element does not have any associated CSS layout box return zero
// and terminate this algorithm.
if (!layout_boxes_) {
return 0.0f;
}
// 2. Return the border edge height of the first CSS layout box associated
// with the element, ignoring any transforms that apply to the element and its
// ancestors.
return layout_boxes_->GetBorderEdgeHeight();
}
scoped_refptr<Node> HTMLElement::Duplicate() const {
Document* document = node_document();
DCHECK(document->html_element_context()->html_element_factory());
scoped_refptr<HTMLElement> new_html_element =
document->html_element_context()
->html_element_factory()
->CreateHTMLElement(document, local_name());
new_html_element->CopyAttributes(*this);
new_html_element->CopyDirectionality(*this);
new_html_element->style_->AssignFrom(*this->style_);
return new_html_element;
}
base::optional<std::string> HTMLElement::GetStyleAttribute() const {
base::optional<std::string> value = Element::GetStyleAttribute();
return value.value_or(style_->css_text(NULL));
}
void HTMLElement::SetStyleAttribute(const std::string& value) {
Document* document = node_document();
CspDelegate* csp_delegate = document->csp_delegate();
if (value.empty() ||
csp_delegate->AllowInline(
CspDelegate::kStyle,
base::SourceLocation(GetSourceLocationName(), 1, 1), value)) {
style_->set_css_text(value, NULL);
Element::SetStyleAttribute(value);
} else {
// Report a violation.
PostToDispatchEvent(FROM_HERE, base::Tokens::error());
}
}
void HTMLElement::RemoveStyleAttribute() {
style_->set_css_text("", NULL);
Element::RemoveStyleAttribute();
}
void HTMLElement::OnCSSMutation() {
// Invalidate the computed style of this node.
computed_style_valid_ = false;
descendant_computed_styles_valid_ = false;
// Remove the style attribute value from the Element.
Element::RemoveStyleAttribute();
node_document()->OnElementInlineStyleMutation();
}
scoped_refptr<HTMLAnchorElement> HTMLElement::AsHTMLAnchorElement() {
return NULL;
}
scoped_refptr<HTMLBodyElement> HTMLElement::AsHTMLBodyElement() { return NULL; }
scoped_refptr<HTMLBRElement> HTMLElement::AsHTMLBRElement() { return NULL; }
scoped_refptr<HTMLDivElement> HTMLElement::AsHTMLDivElement() { return NULL; }
scoped_refptr<HTMLHeadElement> HTMLElement::AsHTMLHeadElement() { return NULL; }
scoped_refptr<HTMLHeadingElement> HTMLElement::AsHTMLHeadingElement() {
return NULL;
}
scoped_refptr<HTMLHtmlElement> HTMLElement::AsHTMLHtmlElement() { return NULL; }
scoped_refptr<HTMLImageElement> HTMLElement::AsHTMLImageElement() {
return NULL;
}
scoped_refptr<HTMLLinkElement> HTMLElement::AsHTMLLinkElement() { return NULL; }
scoped_refptr<HTMLMetaElement> HTMLElement::AsHTMLMetaElement() { return NULL; }
scoped_refptr<HTMLParagraphElement> HTMLElement::AsHTMLParagraphElement() {
return NULL;
}
scoped_refptr<HTMLScriptElement> HTMLElement::AsHTMLScriptElement() {
return NULL;
}
scoped_refptr<HTMLSpanElement> HTMLElement::AsHTMLSpanElement() { return NULL; }
scoped_refptr<HTMLStyleElement> HTMLElement::AsHTMLStyleElement() {
return NULL;
}
scoped_refptr<HTMLTitleElement> HTMLElement::AsHTMLTitleElement() {
return NULL;
}
scoped_refptr<HTMLUnknownElement> HTMLElement::AsHTMLUnknownElement() {
return NULL;
}
scoped_refptr<HTMLVideoElement> HTMLElement::AsHTMLVideoElement() {
return NULL;
}
void HTMLElement::InvalidateMatchingRulesRecursively() {
if (!matching_rules_valid_) {
return;
}
matching_rules_valid_ = false;
// Move |matching_rules_| into |old_matching_rules_|. This is used for
// determining whether or not the matching rules actually changed when they
// are updated.
old_matching_rules_.swap(matching_rules_);
matching_rules_.clear();
rule_matching_state_.matching_nodes.clear();
rule_matching_state_.descendant_potential_nodes.clear();
rule_matching_state_.following_sibling_potential_nodes.clear();
for (int pseudo_element_type = 0; pseudo_element_type < kMaxPseudoElementType;
++pseudo_element_type) {
if (pseudo_elements_[pseudo_element_type]) {
pseudo_elements_[pseudo_element_type]->ClearMatchingRules();
}
}
// Invalidate matching rules on all children.
for (Element* element = first_element_child(); element;
element = element->next_element_sibling()) {
HTMLElement* html_element = element->AsHTMLElement();
if (html_element) {
html_element->InvalidateMatchingRulesRecursively();
}
}
// Invalidate matching rules on all following siblings if sibling combinators
// are used.
if (node_document()->selector_tree()->has_sibling_combinators()) {
for (Element* element = next_element_sibling(); element;
element = element->next_element_sibling()) {
HTMLElement* html_element = element->AsHTMLElement();
if (html_element) {
html_element->InvalidateMatchingRulesRecursively();
}
}
}
}
void HTMLElement::UpdateComputedStyleRecursively(
const scoped_refptr<cssom::CSSComputedStyleDeclaration>&
parent_computed_style_declaration,
const scoped_refptr<const cssom::CSSComputedStyleData>& root_computed_style,
const base::TimeDelta& style_change_event_time, bool ancestors_were_valid,
int current_element_depth) {
int max_depth = node_document()->dom_max_element_depth();
if (max_depth > 0 && current_element_depth >= max_depth) {
return;
}
// Update computed style for this element.
bool is_valid =
ancestors_were_valid && matching_rules_valid_ && computed_style_valid_;
if (!is_valid) {
UpdateComputedStyle(parent_computed_style_declaration, root_computed_style,
style_change_event_time, kAncestorsAreDisplayed);
}
// Do not update computed style for descendants of "display: none" elements,
// since they do not participate in layout. Note the "display: node" elements
// themselves still need to have their computed style updated, in case the
// value of display is changed.
if (computed_style()->display() == cssom::KeywordValue::GetNone()) {
return;
}
// Update computed style for this element's descendants. Note that if
// descendant_computed_styles_valid_ flag is not set, the ancestors should
// still be considered invalid, which forces the computes styles to be updated
// on all children.
for (Element* element = first_element_child(); element;
element = element->next_element_sibling()) {
HTMLElement* html_element = element->AsHTMLElement();
if (html_element) {
html_element->UpdateComputedStyleRecursively(
css_computed_style_declaration(), root_computed_style,
style_change_event_time,
is_valid && descendant_computed_styles_valid_,
current_element_depth + 1);
}
}
descendant_computed_styles_valid_ = true;
}
void HTMLElement::MarkDisplayNoneOnNodeAndDescendants() {
// While we do want to clear the animations immediately, we also want to
// ensure that they are also reset starting with the next computed style
// update. This ensures that for example a transition will not be triggered
// on the next computed style update.
ancestors_are_displayed_ = kAncestorsAreNotDisplayed;
PurgeCachedBackgroundImages();
if (!css_animations_.empty() || !css_transitions_.empty()) {
css_transitions_.Clear();
css_animations_.Clear();
computed_style_valid_ = false;
descendant_computed_styles_valid_ = false;
}
MarkDisplayNoneOnDescendants();
}
void HTMLElement::PurgeCachedBackgroundImagesOfNodeAndDescendants() {
PurgeCachedBackgroundImages();
PurgeCachedBackgroundImagesOfDescendants();
}
void HTMLElement::PurgeCachedBackgroundImages() {
ClearActiveBackgroundImages();
if (!cached_background_images_.empty()) {
cached_background_images_.clear();
computed_style_valid_ = false;
descendant_computed_styles_valid_ = false;
}
}
bool HTMLElement::IsDisplayed() const {
return ancestors_are_displayed_ == kAncestorsAreDisplayed &&
computed_style()->display() != cssom::KeywordValue::GetNone();
}
void HTMLElement::InvalidateComputedStylesOfNodeAndDescendants() {
computed_style_valid_ = false;
descendant_computed_styles_valid_ = false;
InvalidateComputedStylesOfDescendants();
}
void HTMLElement::InvalidateLayoutBoxesOfNodeAndAncestors() {
layout_boxes_.reset();
InvalidateLayoutBoxesOfAncestors();
}
void HTMLElement::InvalidateLayoutBoxesOfNodeAndDescendants() {
layout_boxes_.reset();
InvalidateLayoutBoxesOfDescendants();
}
void HTMLElement::InvalidateLayoutBoxSizes() {
if (layout_boxes_) {
layout_boxes_->InvalidateSizes();
}
}
void HTMLElement::InvalidateLayoutBoxCrossReferences() {
if (layout_boxes_) {
layout_boxes_->InvalidateCrossReferences();
}
}
void HTMLElement::InvalidateLayoutBoxRenderTreeNodes() {
if (layout_boxes_) {
layout_boxes_->InvalidateRenderTreeNodes();
}
}
HTMLElement::HTMLElement(Document* document, base::Token local_name)
: Element(document, local_name),
dom_stat_tracker_(document->html_element_context()->dom_stat_tracker()),
locked_for_focus_(false),
directionality_(kNoExplicitDirectionality),
style_(new cssom::CSSDeclaredStyleDeclaration(
document->html_element_context()->css_parser())),
computed_style_valid_(false),
descendant_computed_styles_valid_(false),
ancestors_are_displayed_(kAncestorsAreDisplayed),
css_computed_style_declaration_(new cssom::CSSComputedStyleDeclaration()),
ALLOW_THIS_IN_INITIALIZER_LIST(
transitions_adapter_(new DOMAnimatable(this))),
css_transitions_(&transitions_adapter_),
ALLOW_THIS_IN_INITIALIZER_LIST(
animations_adapter_(new DOMAnimatable(this))),
css_animations_(&animations_adapter_),
matching_rules_valid_(false) {
css_computed_style_declaration_->set_animations(animations());
style_->set_mutation_observer(this);
++(non_trivial_static_fields.Get().html_element_count_log.count);
dom_stat_tracker_->OnHtmlElementCreated();
}
HTMLElement::~HTMLElement() {
--(non_trivial_static_fields.Get().html_element_count_log.count);
if (IsInDocument()) {
dom_stat_tracker_->OnHtmlElementRemovedFromDocument();
}
dom_stat_tracker_->OnHtmlElementDestroyed();
style_->set_mutation_observer(NULL);
}
void HTMLElement::CopyDirectionality(const HTMLElement& other) {
directionality_ = other.directionality_;
}
void HTMLElement::OnInsertedIntoDocument() {
Node::OnInsertedIntoDocument();
dom_stat_tracker_->OnHtmlElementInsertedIntoDocument();
}
void HTMLElement::OnRemovedFromDocument() {
Node::OnRemovedFromDocument();
dom_stat_tracker_->OnHtmlElementRemovedFromDocument();
// When an element that is focused stops being a focusable element, or stops
// being focused without another element being explicitly focused in its
// stead, the user agent should synchronously run the unfocusing steps for the
// affected element only.
// For example, this might happen because the element is removed from its
// Document, or has a hidden attribute added. It would also happen to an input
// element when the element gets disabled.
// https://www.w3.org/TR/html5/editing.html#unfocusing-steps
Document* document = node_document();
DCHECK(document);
if (document->active_element() == this->AsElement()) {
RunUnFocusingSteps();
document->OnFocusChange();
}
}
void HTMLElement::OnMutation() { InvalidateMatchingRulesRecursively(); }
void HTMLElement::OnSetAttribute(const std::string& name,
const std::string& value) {
if (name == "class" || name == "id") {
InvalidateMatchingRulesRecursively();
} else if (name == "dir") {
SetDirectionality(value);
}
}
void HTMLElement::OnRemoveAttribute(const std::string& name) {
if (name == "class" || name == "id") {
InvalidateMatchingRulesRecursively();
} else if (name == "dir") {
SetDirectionality("");
}
}
// Algorithm for IsFocusable:
// https://www.w3.org/TR/html5/editing.html#focusable
bool HTMLElement::IsFocusable() {
return HasTabindexFocusFlag() && IsBeingRendered();
}
// Algorithm for HasTabindexFocusFlag:
// https://www.w3.org/TR/html5/editing.html#specially-focusable
bool HTMLElement::HasTabindexFocusFlag() const {
int32 tabindex;
return base::StringToInt32(GetAttribute("tabindex").value_or(""), &tabindex);
}
// An element is being rendered if it has any associated CSS layout boxes, SVG
// layout boxes, or some equivalent in other styling languages.
// https://www.w3.org/TR/html5/rendering.html#being-rendered
bool HTMLElement::IsBeingRendered() {
Document* document = node_document();
if (!document) {
return false;
}
if (!document->UpdateComputedStyleOnElementAndAncestor(this)) {
return false;
}
DCHECK(computed_style());
return IsDisplayed() &&
computed_style()->visibility() == cssom::KeywordValue::GetVisible();
}
// Algorithm for RunFocusingSteps:
// https://www.w3.org/TR/html5/editing.html#focusing-steps
void HTMLElement::RunFocusingSteps() {
// 1. If the element is not in a Document, or if the element's Document has
// no browsing context, or if the element's Document's browsing context has no
// top-level browsing context, or if the element is not focusable, or if the
// element is already focused, then abort these steps.
Document* document = node_document();
if (!document || !document->HasBrowsingContext() || !IsFocusable()) {
return;
}
Element* old_active_element = document->active_element();
if (old_active_element == this) {
return;
}
// 2. If focusing the element will remove the focus from another element,
// then run the unfocusing steps for that element.
if (old_active_element && old_active_element->AsHTMLElement()) {
old_active_element->AsHTMLElement()->RunUnFocusingSteps();
}
// focusin: A user agent MUST dispatch this event when an event target is
// about to receive focus. This event type MUST be dispatched before the
// element is given focus. The event target MUST be the element which is about
// to receive focus. This event type is similar to focus, but is dispatched
// before focus is shifted, and does bubble.
// https://www.w3.org/TR/2016/WD-uievents-20160804/#event-type-focusin
DispatchEvent(new FocusEvent(base::Tokens::focusin(), Event::kBubbles,
Event::kNotCancelable, document->window(),
this));
// 3. Make the element the currently focused element in its top-level browsing
// context.
document->SetActiveElement(this);
// 4. Not needed by Cobalt.
// 5. Fire a simple event named focus at the element.
// focus: A user agent MUST dispatch this event when an event target receives
// focus. The focus MUST be given to the element before the dispatch of this
// event type. This event type is similar to focusin, but is dispatched after
// focus is shifted, and does not bubble.
// https://www.w3.org/TR/2016/WD-uievents-20160804/#event-type-focus
DispatchEvent(new FocusEvent(base::Tokens::focus(), Event::kNotBubbles,
Event::kNotCancelable, document->window(),
this));
// Custom, not in any sepc.
InvalidateMatchingRulesRecursively();
}
// Algorithm for RunUnFocusingSteps:
// https://www.w3.org/TR/html5/editing.html#unfocusing-steps
void HTMLElement::RunUnFocusingSteps() {
// 1. Not needed by Cobalt.
// focusout: A user agent MUST dispatch this event when an event target is
// about to lose focus. This event type MUST be dispatched before the element
// loses focus. The event target MUST be the element which is about to lose
// focus. This event type is similar to blur, but is dispatched before focus
// is shifted, and does bubble.
// https://www.w3.org/TR/2016/WD-uievents-20160804/#event-type-focusout
Document* document = node_document();
scoped_refptr<Window> window(document ? document->window() : NULL);
DispatchEvent(new FocusEvent(base::Tokens::focusout(), Event::kBubbles,
Event::kNotCancelable, window, this));
// 2. Unfocus the element.
if (document && document->active_element() == this->AsElement()) {
document->SetActiveElement(NULL);
}
// 3. Fire a simple event named blur at the element.
// blur: A user agent MUST dispatch this event when an event target loses
// focus. The focus MUST be taken from the element before the dispatch of this
// event type. This event type is similar to focusout, but is dispatched after
// focus is shifted, and does not bubble.
// https://www.w3.org/TR/2016/WD-uievents-20160804/#event-type-blur
DispatchEvent(new FocusEvent(base::Tokens::blur(), Event::kNotBubbles,
Event::kNotCancelable, document->window(),
this));
// Custom, not in any sepc.
InvalidateMatchingRulesRecursively();
}
void HTMLElement::SetDirectionality(const std::string& value) {
// NOTE: Value "auto" is not supported.
Directionality previous_directionality = directionality_;
if (value == "ltr") {
directionality_ = kLeftToRightDirectionality;
} else if (value == "rtl") {
directionality_ = kRightToLeftDirectionality;
} else {
directionality_ = kNoExplicitDirectionality;
}
if (directionality_ != previous_directionality) {
InvalidateLayoutBoxesOfNodeAndAncestors();
InvalidateLayoutBoxesOfDescendants();
}
}
namespace {
scoped_refptr<cssom::CSSComputedStyleData> PromoteMatchingRulesToComputedStyle(
cssom::RulesWithCascadePrecedence* matching_rules,
cssom::GURLMap* property_key_to_base_url_map,
const scoped_refptr<const cssom::CSSDeclaredStyleData>& inline_style,
const scoped_refptr<cssom::CSSComputedStyleDeclaration>&
parent_computed_style_declaration,
const scoped_refptr<const cssom::CSSComputedStyleData>& root_computed_style,
const math::Size& viewport_size) {
// Select the winning value for each property by performing the cascade,
// that is, apply values from matching rules on top of inline style, taking
// into account rule specificity and location in the source file, as well as
// property declaration importance.
scoped_refptr<cssom::CSSComputedStyleData> computed_style =
PromoteToCascadedStyle(inline_style, matching_rules,
property_key_to_base_url_map);
// Lastly, absolutize the values, if possible. Start by resolving "initial"
// and "inherit" keywords (which gives us what the specification refers to
// as "specified style"). Then, convert length units and percentages into
// pixels, convert color keywords into RGB triplets, and so on. For certain
// properties, like "font-family", computed value is the same as specified
// value. Declarations that cannot be absolutized easily, like "width: auto;",
// will be resolved during layout.
cssom::PromoteToComputedStyle(
computed_style, parent_computed_style_declaration, root_computed_style,
viewport_size, property_key_to_base_url_map);
return computed_style;
}
void PossiblyActivateAnimations(
const scoped_refptr<const cssom::CSSComputedStyleData>&
previous_computed_style,
const scoped_refptr<const cssom::CSSComputedStyleData>& new_computed_style,
const base::TimeDelta& style_change_event_time,
cssom::TransitionSet* css_transitions, cssom::AnimationSet* css_animations,
const cssom::CSSKeyframesRule::NameMap& keyframes_map,
HTMLElement::AncestorsAreDisplayed old_ancestors_are_displayed,
HTMLElement::AncestorsAreDisplayed new_ancestors_are_displayed,
bool* animations_modified) {
// Calculate some helper values to help determine if we are transitioning from
// not being displayed to being displayed, or vice-versa. Animations should
// not be playing if we are not being displayed.
bool old_is_displayed =
old_ancestors_are_displayed == HTMLElement::kAncestorsAreDisplayed &&
(previous_computed_style &&
previous_computed_style->display() != cssom::KeywordValue::GetNone());
bool new_is_displayed =
new_ancestors_are_displayed == HTMLElement::kAncestorsAreDisplayed &&
new_computed_style->display() != cssom::KeywordValue::GetNone();
if (new_is_displayed) {
// Don't start any transitions if we are transitioning from display: none.
if (previous_computed_style && old_is_displayed) {
// Now that we have updated our computed style, compare it to the previous
// style and see if we need to adjust our animations.
css_transitions->UpdateTransitions(style_change_event_time,
*previous_computed_style,
*new_computed_style);
}
// Update the set of currently running animations and track whether or not
// the animations changed.
*animations_modified = css_animations->Update(
style_change_event_time, *new_computed_style, keyframes_map);
} else {
if (old_is_displayed) {
css_transitions->Clear();
css_animations->Clear();
} else {
DCHECK(css_transitions->empty());
DCHECK(css_animations->empty());
}
}
}
// Flags tracking which cached values must be invalidated.
struct UpdateComputedStyleInvalidationFlags {
UpdateComputedStyleInvalidationFlags()
: mark_descendants_as_display_none(false),
invalidate_computed_styles_of_descendants(false),
invalidate_layout_boxes(false),
invalidate_sizes(false),
invalidate_cross_references(false),
invalidate_render_tree_nodes(false) {}
bool mark_descendants_as_display_none;
bool invalidate_computed_styles_of_descendants;
bool invalidate_layout_boxes;
bool invalidate_sizes;
bool invalidate_cross_references;
bool invalidate_render_tree_nodes;
};
bool NewComputedStyleMarksDescendantsAsDisplayNone(
const scoped_refptr<const cssom::CSSComputedStyleData>& old_computed_style,
const scoped_refptr<cssom::CSSComputedStyleData>& new_computed_style) {
return old_computed_style->display() != cssom::KeywordValue::GetNone() &&
new_computed_style->display() == cssom::KeywordValue::GetNone();
}
bool NewComputedStyleInvalidatesComputedStylesOfDescendants(
const scoped_refptr<const cssom::CSSComputedStyleData>& old_computed_style,
const scoped_refptr<cssom::CSSComputedStyleData>& new_computed_style) {
return !non_trivial_static_fields.Get()
.computed_style_invalidation_property_checker
.DoDeclaredPropertiesMatch(old_computed_style,
new_computed_style);
}
bool NewComputedStyleInvalidatesLayoutBoxes(
const scoped_refptr<const cssom::CSSComputedStyleData>& old_computed_style,
const scoped_refptr<cssom::CSSComputedStyleData>& new_computed_style) {
return !non_trivial_static_fields.Get()
.layout_box_invalidation_property_checker
.DoDeclaredPropertiesMatch(old_computed_style,
new_computed_style);
}
bool NewComputedStyleInvalidatesSizes(
const scoped_refptr<const cssom::CSSComputedStyleData>& old_computed_style,
const scoped_refptr<cssom::CSSComputedStyleData>& new_computed_style) {
return !non_trivial_static_fields.Get()
.size_invalidation_property_checker.DoDeclaredPropertiesMatch(
old_computed_style, new_computed_style);
}
bool NewComputedStyleInvalidatesCrossReferences(
const scoped_refptr<const cssom::CSSComputedStyleData>& old_computed_style,
const scoped_refptr<cssom::CSSComputedStyleData>& new_computed_style) {
return !non_trivial_static_fields.Get()
.cross_references_invalidation_property_checker
.DoDeclaredPropertiesMatch(old_computed_style,
new_computed_style);
}
enum IsPseudoElement {
kIsNotPseudoElement,
kIsPseudoElement,
};
void UpdateInvalidationFlagsFromNewComputedStyle(
const scoped_refptr<const cssom::CSSComputedStyleData>& old_computed_style,
const scoped_refptr<cssom::CSSComputedStyleData>& new_computed_style,
bool animations_modified, IsPseudoElement is_pseudo_element,
UpdateComputedStyleInvalidationFlags* flags) {
if (old_computed_style) {
if (!flags->mark_descendants_as_display_none &&
is_pseudo_element == kIsNotPseudoElement &&
NewComputedStyleMarksDescendantsAsDisplayNone(old_computed_style,
new_computed_style)) {
flags->mark_descendants_as_display_none = true;
}
if (!flags->invalidate_computed_styles_of_descendants &&
NewComputedStyleInvalidatesComputedStylesOfDescendants(
old_computed_style, new_computed_style)) {
flags->invalidate_computed_styles_of_descendants = true;
flags->invalidate_layout_boxes = true;
} else if (!flags->invalidate_layout_boxes) {
if (NewComputedStyleInvalidatesLayoutBoxes(old_computed_style,
new_computed_style)) {
flags->invalidate_layout_boxes = true;
} else {
if (!flags->invalidate_sizes &&
NewComputedStyleInvalidatesSizes(old_computed_style,
new_computed_style)) {
flags->invalidate_sizes = true;
flags->invalidate_render_tree_nodes = true;
}
if (!flags->invalidate_cross_references &&
NewComputedStyleInvalidatesCrossReferences(old_computed_style,
new_computed_style)) {
flags->invalidate_cross_references = true;
flags->invalidate_render_tree_nodes = true;
}
flags->invalidate_render_tree_nodes =
flags->invalidate_render_tree_nodes || animations_modified ||
!new_computed_style->DoDeclaredPropertiesMatch(old_computed_style);
}
}
}
}
void DoComputedStyleUpdate(
cssom::RulesWithCascadePrecedence* matching_rules,
cssom::GURLMap* property_key_to_base_url_map,
const scoped_refptr<const cssom::CSSDeclaredStyleData>& inline_style,
const scoped_refptr<cssom::CSSComputedStyleDeclaration>&
parent_computed_style_declaration,
const scoped_refptr<const cssom::CSSComputedStyleData>& root_computed_style,
const math::Size& viewport_size,
const scoped_refptr<const cssom::CSSComputedStyleData>&
previous_computed_style,
const base::TimeDelta& style_change_event_time,
cssom::TransitionSet* css_transitions, cssom::AnimationSet* css_animations,
const cssom::CSSKeyframesRule::NameMap& keyframes_map,
HTMLElement::AncestorsAreDisplayed old_ancestors_are_displayed,
HTMLElement::AncestorsAreDisplayed new_ancestors_are_displayed,
IsPseudoElement is_pseudo_element,
UpdateComputedStyleInvalidationFlags* invalidation_flags,
cssom::CSSComputedStyleDeclaration* css_computed_style_declaration) {
bool animations_modified = false;
scoped_refptr<cssom::CSSComputedStyleData> new_computed_style =
PromoteMatchingRulesToComputedStyle(
matching_rules, property_key_to_base_url_map, inline_style,
parent_computed_style_declaration, root_computed_style,
viewport_size);
PossiblyActivateAnimations(previous_computed_style, new_computed_style,
style_change_event_time, css_transitions,
css_animations, keyframes_map,
old_ancestors_are_displayed,
new_ancestors_are_displayed, &animations_modified);
UpdateInvalidationFlagsFromNewComputedStyle(
previous_computed_style, new_computed_style, animations_modified,
is_pseudo_element, invalidation_flags);
css_computed_style_declaration->SetData(new_computed_style);
}
} // namespace
void HTMLElement::UpdateComputedStyle(
const scoped_refptr<cssom::CSSComputedStyleDeclaration>&
parent_computed_style_declaration,
const scoped_refptr<const cssom::CSSComputedStyleData>& root_computed_style,
const base::TimeDelta& style_change_event_time,
AncestorsAreDisplayed ancestors_are_displayed) {
Document* document = node_document();
DCHECK(document) << "Element should be attached to document in order to "
"participate in layout.";
// If there is no previous computed style, there should also be no layout
// boxes.
DCHECK(computed_style() || NULL == layout_boxes());
dom_stat_tracker_->OnUpdateComputedStyle();
// The computed style must be generated if either the computed style is
// invalid or no computed style has been created yet.
bool generate_computed_style = !computed_style_valid_ || !computed_style();
// Update matching rules if necessary.
if (!matching_rules_valid_) {
dom_stat_tracker_->OnUpdateMatchingRules();
UpdateMatchingRules(this);
matching_rules_valid_ = true;
// Check for whether the matching rules have changed. If they have, then a
// new computed style must be generated from them.
if (!generate_computed_style && old_matching_rules_ != matching_rules_) {
generate_computed_style = true;
}
}
// If any declared properties inherited from the parent are no longer valid,
// then a new computed style must be generated with the updated inherited
// values.
if (!generate_computed_style &&
!computed_style()->AreDeclaredPropertiesInheritedFromParentValid()) {
generate_computed_style = true;
}
// It is possible for computed style to have been updated on this element even
// if its ancestors were set to display: none. If this has changed, we would
// need to update our computed style again, even if nothing else has changed.
if (!generate_computed_style &&
ancestors_are_displayed_ == kAncestorsAreNotDisplayed &&
ancestors_are_displayed == kAncestorsAreDisplayed) {
generate_computed_style = true;
}
// TODO: It maybe helpful to generalize this mapping framework in the
// future to allow more data and context about where a cssom::PropertyValue
// came from.
cssom::GURLMap property_key_to_base_url_map;
property_key_to_base_url_map[cssom::kBackgroundImageProperty] =
document->url_as_gurl();
// Flags tracking which cached values must be invalidated.
UpdateComputedStyleInvalidationFlags invalidation_flags;
// We record this now before we make changes to the computed style and use
// it later for the pseudo element computed style updates.
bool old_is_displayed = computed_style() && IsDisplayed();
if (generate_computed_style) {
dom_stat_tracker_->OnGenerateHtmlElementComputedStyle();
DoComputedStyleUpdate(
matching_rules(), &property_key_to_base_url_map, style_->data(),
parent_computed_style_declaration, root_computed_style,
document->viewport_size(), computed_style(), style_change_event_time,
&css_transitions_, &css_animations_, document->keyframes_map(),
ancestors_are_displayed_, ancestors_are_displayed, kIsNotPseudoElement,
&invalidation_flags, css_computed_style_declaration_);
// Update cached background images after resolving the urls in
// background_image CSS property of the computed style, so we have all the
// information to get the cached background images.
UpdateCachedBackgroundImagesFromComputedStyle();
} else {
// Update the inherited data if a new style was not generated. The ancestor
// data with inherited properties may have changed.
css_computed_style_declaration_->UpdateInheritedData();
}
// Update the displayed status of our ancestors.
ancestors_are_displayed_ = ancestors_are_displayed;
// NOTE: Currently, pseudo element's computed styles are always generated. If
// this becomes a performance bottleneck, change the logic so that it only
// occurs when needed.
// Promote the matching rules for all known pseudo elements.
for (int pseudo_element_type = 0; pseudo_element_type < kMaxPseudoElementType;
++pseudo_element_type) {
if (pseudo_elements_[pseudo_element_type]) {
dom_stat_tracker_->OnGeneratePseudoElementComputedStyle();
DoComputedStyleUpdate(
pseudo_elements_[pseudo_element_type]->matching_rules(),
&property_key_to_base_url_map, NULL, css_computed_style_declaration(),
root_computed_style, document->viewport_size(),
pseudo_elements_[pseudo_element_type]->computed_style(),
style_change_event_time,
pseudo_elements_[pseudo_element_type]->css_transitions(),
pseudo_elements_[pseudo_element_type]->css_animations(),
document->keyframes_map(),
old_is_displayed ? kAncestorsAreDisplayed : kAncestorsAreNotDisplayed,
IsDisplayed() ? kAncestorsAreDisplayed : kAncestorsAreNotDisplayed,
kIsPseudoElement, &invalidation_flags,
pseudo_elements_[pseudo_element_type]
->css_computed_style_declaration());
}
}
if (invalidation_flags.mark_descendants_as_display_none) {
MarkDisplayNoneOnDescendants();
}
if (invalidation_flags.invalidate_computed_styles_of_descendants) {
InvalidateComputedStylesOfDescendants();
}
if (invalidation_flags.invalidate_layout_boxes) {
InvalidateLayoutBoxesOfNodeAndAncestors();
InvalidateLayoutBoxesOfDescendants();
} else {
if (invalidation_flags.invalidate_sizes) {
InvalidateLayoutBoxSizes();
}
if (invalidation_flags.invalidate_cross_references) {
InvalidateLayoutBoxCrossReferences();
}
if (invalidation_flags.invalidate_render_tree_nodes) {
InvalidateLayoutBoxRenderTreeNodes();
}
}
computed_style_valid_ = true;
}
bool HTMLElement::IsDesignated() const {
Document* document = node_document();
if (document) {
scoped_refptr<Element> element = document->indicated_element();
while (element) {
if (element.get() == this) {
return true;
}
// The parent of an element that is :hover is also in that state.
// https://www.w3.org/TR/selectors4/#hover-pseudo
element = element->parent_element();
}
}
return false;
}
bool HTMLElement::CanbeDesignatedByPointerIfDisplayed() const {
return computed_style()->pointer_events() != cssom::KeywordValue::GetNone() &&
computed_style()->visibility() == cssom::KeywordValue::GetVisible();
}
void HTMLElement::ClearActiveBackgroundImages() {
if (html_element_context() &&
html_element_context()->animated_image_tracker()) {
for (std::vector<GURL>::iterator it = active_background_images_.begin();
it != active_background_images_.end(); ++it) {
html_element_context()->animated_image_tracker()->DecreaseURLCount(*it);
}
}
active_background_images_.clear();
}
void HTMLElement::UpdateCachedBackgroundImagesFromComputedStyle() {
ClearActiveBackgroundImages();
// Don't fetch or cache the image if the display of this element is turned
// off.
if (computed_style()->display() != cssom::KeywordValue::GetNone()) {
scoped_refptr<cssom::PropertyValue> background_image =
computed_style()->background_image();
cssom::PropertyListValue* property_list_value =
base::polymorphic_downcast<cssom::PropertyListValue*>(
background_image.get());
loader::image::CachedImageReferenceVector cached_images;
for (size_t i = 0; i < property_list_value->value().size(); ++i) {
// Skip this image if it is not an absolute URL.
if (property_list_value->value()[i]->GetTypeId() !=
base::GetTypeId<cssom::AbsoluteURLValue>()) {
continue;
}
// Skip invalid URL.
GURL absolute_url = base::polymorphic_downcast<cssom::AbsoluteURLValue*>(
property_list_value->value()[i].get())
->value();
if (!absolute_url.is_valid()) {
continue;
}
active_background_images_.push_back(absolute_url);
html_element_context()->animated_image_tracker()->IncreaseURLCount(
absolute_url);
scoped_refptr<loader::image::CachedImage> cached_image =
html_element_context()->image_cache()->CreateCachedResource(
absolute_url);
base::Closure loaded_callback = base::Bind(
&HTMLElement::OnBackgroundImageLoaded, base::Unretained(this));
cached_images.push_back(
new loader::image::CachedImageReferenceWithCallbacks(
cached_image, loaded_callback, base::Closure()));
}
cached_background_images_ = cached_images.Pass();
} else {
// Clear the previous cached background image if the display is "none".
cached_background_images_.clear();
}
}
void HTMLElement::OnBackgroundImageLoaded() {
node_document()->RecordMutation();
InvalidateLayoutBoxRenderTreeNodes();
}
bool HTMLElement::IsRootElement() {
// The html element represents the root of an HTML document.
// https://www.w3.org/TR/2014/REC-html5-20141028/semantics.html#the-root-element
return AsHTMLHtmlElement() != NULL;
}
} // namespace dom
} // namespace cobalt