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CSS

Experimental

This domain exposes CSS read/write operations. All CSS objects (stylesheets, rules, and styles) have an associated `id` used in subsequent operations on the related object. Each object type has a specific `id` structure, and those are not interchangeable between objects of different kinds. CSS objects can be loaded using the `get*ForNode()` calls (which accept a DOM node id). A client can also keep track of stylesheets via the `styleSheetAdded`/`styleSheetRemoved` events and subsequently load the required stylesheet contents using the `getStyleSheet[Text]()` methods.

Dependencies: DOM, Page

Commands

CSS.addRule

Inserts a new rule with the given `ruleText` in a stylesheet with given `styleSheetId`, at the
position specified by `location`.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId The css style sheet identifier where a new rule should be inserted.
ruleText string The text of a new rule.
location SourceRange Text position of a new rule in the target style sheet.
nodeForPropertySyntaxValidation (optional) Experimental DOM.NodeId NodeId for the DOM node in whose context custom property declarations for registered properties should be
validated. If omitted, declarations in the new rule text can only be validated statically, which may produce
incorrect results if the declaration contains a var() for example.
Return Object
Name Type Description
rule CSSRule The newly created rule.

CSS.collectClassNames

Returns all class names from specified stylesheet.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
Return Object
Name Type Description
classNames array<string> Class name list.

CSS.createStyleSheet

Creates a new special "via-inspector" stylesheet in the frame with given `frameId`.

Parameters
Name Type Description
frameId Page.FrameId Identifier of the frame where "via-inspector" stylesheet should be created.
force (optional) boolean If true, creates a new stylesheet for every call. If false,
returns a stylesheet previously created by a call with force=false
for the frame's document if it exists or creates a new stylesheet
(default: false).
Return Object
Name Type Description
styleSheetId DOM.StyleSheetId Identifier of the created "via-inspector" stylesheet.

CSS.disable

Disables the CSS agent for the given page.

CSS.enable

Enables the CSS agent for the given page. Clients should not assume that the CSS agent has been
enabled until the result of this command is received.

CSS.forcePseudoState

Ensures that the given node will have specified pseudo-classes whenever its style is computed by
the browser.

Parameters
Name Type Description
nodeId DOM.NodeId The element id for which to force the pseudo state.
forcedPseudoClasses array<string> Element pseudo classes to force when computing the element's style.

CSS.forceStartingStyle

Ensures that the given node is in its starting-style state.

Parameters
Name Type Description
nodeId DOM.NodeId The element id for which to force the starting-style state.
forced boolean Boolean indicating if this is on or off.

CSS.getBackgroundColors

Parameters
Name Type Description
nodeId DOM.NodeId Id of the node to get background colors for.
Return Object
Name Type Description
backgroundColors (optional) array<string> The range of background colors behind this element, if it contains any visible text. If no
visible text is present, this will be undefined. In the case of a flat background color,
this will consist of simply that color. In the case of a gradient, this will consist of each
of the color stops. For anything more complicated, this will be an empty array. Images will
be ignored (as if the image had failed to load).
computedFontSize (optional) string The computed font size for this node, as a CSS computed value string (e.g. '12px').
computedFontWeight (optional) string The computed font weight for this node, as a CSS computed value string (e.g. 'normal' or
'100').

CSS.getComputedStyleForNode

Returns the computed style for a DOM node identified by `nodeId`.

Parameters
Name Type Description
nodeId DOM.NodeId
Return Object
Name Type Description
computedStyle array<CSSComputedStyleProperty> Computed style for the specified DOM node.
extraFields Experimental ComputedStyleExtraFields A list of non-standard "extra fields" which blink stores alongside each
computed style.

CSS.resolveValues

Experimental

Resolve the specified values in the context of the provided element.
For example, a value of '1em' is evaluated according to the computed
'font-size' of the element and a value 'calc(1px + 2px)' will be
resolved to '3px'.
If the `propertyName` was specified the `values` are resolved as if
they were property's declaration. If a value cannot be parsed according
to the provided property syntax, the value is parsed using combined
syntax as if null `propertyName` was provided. If the value cannot be
resolved even then, return the provided value without any changes.
Note: this function currently does not resolve CSS random() function,
it returns unmodified random() function parts.`

Parameters
Name Type Description
values array<string> Cascade-dependent keywords (revert/revert-layer) do not work.
nodeId DOM.NodeId Id of the node in whose context the expression is evaluated
propertyName (optional) string Only longhands and custom property names are accepted.
pseudoType (optional) DOM.PseudoType Pseudo element type, only works for pseudo elements that generate
elements in the tree, such as ::before and ::after.
pseudoIdentifier (optional) string Pseudo element custom ident.
Return Object
Name Type Description
results array<string>

CSS.getLonghandProperties

Experimental
Parameters
Name Type Description
shorthandName string
value string
Return Object
Name Type Description
longhandProperties array<CSSProperty>

CSS.getInlineStylesForNode

Returns the styles defined inline (explicitly in the "style" attribute and implicitly, using DOM
attributes) for a DOM node identified by `nodeId`.

Parameters
Name Type Description
nodeId DOM.NodeId
Return Object
Name Type Description
inlineStyle (optional) CSSStyle Inline style for the specified DOM node.
attributesStyle (optional) CSSStyle Attribute-defined element style (e.g. resulting from "width=20 height=100%").

CSS.getAnimatedStylesForNode

Experimental

Returns the styles coming from animations & transitions
including the animation & transition styles coming from inheritance chain.

Parameters
Name Type Description
nodeId DOM.NodeId
Return Object
Name Type Description
animationStyles (optional) array<CSSAnimationStyle> Styles coming from animations.
transitionsStyle (optional) CSSStyle Style coming from transitions.
inherited (optional) array<InheritedAnimatedStyleEntry> Inherited style entries for animationsStyle and transitionsStyle from
the inheritance chain of the element.

CSS.getMatchedStylesForNode

Returns requested styles for a DOM node identified by `nodeId`.

Parameters
Name Type Description
nodeId DOM.NodeId
Return Object
Name Type Description
inlineStyle (optional) CSSStyle Inline style for the specified DOM node.
attributesStyle (optional) CSSStyle Attribute-defined element style (e.g. resulting from "width=20 height=100%").
matchedCSSRules (optional) array<RuleMatch> CSS rules matching this node, from all applicable stylesheets.
pseudoElements (optional) array<PseudoElementMatches> Pseudo style matches for this node.
inherited (optional) array<InheritedStyleEntry> A chain of inherited styles (from the immediate node parent up to the DOM tree root).
inheritedPseudoElements (optional) array<InheritedPseudoElementMatches> A chain of inherited pseudo element styles (from the immediate node parent up to the DOM tree root).
cssKeyframesRules (optional) array<CSSKeyframesRule> A list of CSS keyframed animations matching this node.
cssPositionTryRules (optional) array<CSSPositionTryRule> A list of CSS @position-try rules matching this node, based on the position-try-fallbacks property.
activePositionFallbackIndex (optional) integer Index of the active fallback in the applied position-try-fallback property,
will not be set if there is no active position-try fallback.
cssPropertyRules (optional) array<CSSPropertyRule> A list of CSS at-property rules matching this node.
cssPropertyRegistrations (optional) array<CSSPropertyRegistration> A list of CSS property registrations matching this node.
cssAtRules (optional) array<CSSAtRule> A list of simple @rules matching this node or its pseudo-elements.
parentLayoutNodeId (optional) Experimental DOM.NodeId Id of the first parent element that does not have display: contents.
cssFunctionRules (optional) Experimental array<CSSFunctionRule> A list of CSS at-function rules referenced by styles of this node.

CSS.getEnvironmentVariables

Experimental

Returns the values of the default UA-defined environment variables used in env()

Return Object
Name Type Description
environmentVariables object

CSS.getMediaQueries

Returns all media queries parsed by the rendering engine.

Return Object
Name Type Description
medias array<CSSMedia>

CSS.getPlatformFontsForNode

Requests information about platform fonts which we used to render child TextNodes in the given
node.

Parameters
Name Type Description
nodeId DOM.NodeId
Return Object
Name Type Description
fonts array<PlatformFontUsage> Usage statistics for every employed platform font.

CSS.getStyleSheetText

Returns the current textual content for a stylesheet.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
Return Object
Name Type Description
text string The stylesheet text.

CSS.getLayersForNode

Experimental

Returns all layers parsed by the rendering engine for the tree scope of a node.
Given a DOM element identified by nodeId, getLayersForNode returns the root
layer for the nearest ancestor document or shadow root. The layer root contains
the full layer tree for the tree scope and their ordering.

Parameters
Name Type Description
nodeId DOM.NodeId
Return Object
Name Type Description
rootLayer CSSLayerData

CSS.getLocationForSelector

Experimental

Given a CSS selector text and a style sheet ID, getLocationForSelector
returns an array of locations of the CSS selector in the style sheet.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
selectorText string
Return Object
Name Type Description
ranges array<SourceRange>

CSS.trackComputedStyleUpdatesForNode

Experimental

Starts tracking the given node for the computed style updates
and whenever the computed style is updated for node, it queues
a `computedStyleUpdated` event with throttling.
There can only be 1 node tracked for computed style updates
so passing a new node id removes tracking from the previous node.
Pass `undefined` to disable tracking.

Parameters
Name Type Description
nodeId (optional) DOM.NodeId

CSS.trackComputedStyleUpdates

Experimental

Starts tracking the given computed styles for updates. The specified array of properties
replaces the one previously specified. Pass empty array to disable tracking.
Use takeComputedStyleUpdates to retrieve the list of nodes that had properties modified.
The changes to computed style properties are only tracked for nodes pushed to the front-end
by the DOM agent. If no changes to the tracked properties occur after the node has been pushed
to the front-end, no updates will be issued for the node.

Parameters
Name Type Description
propertiesToTrack array<CSSComputedStyleProperty>

CSS.takeComputedStyleUpdates

Experimental

Polls the next batch of computed style updates.

Return Object
Name Type Description
nodeIds array<DOM.NodeId> The list of node Ids that have their tracked computed styles updated.

CSS.setEffectivePropertyValueForNode

Find a rule with the given active property for the given node and set the new value for this
property

Parameters
Name Type Description
nodeId DOM.NodeId The element id for which to set property.
propertyName string
value string

CSS.setPropertyRulePropertyName

Modifies the property rule property name.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
propertyName string
Return Object
Name Type Description
propertyName Value The resulting key text after modification.

CSS.setKeyframeKey

Modifies the keyframe rule key text.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
keyText string
Return Object
Name Type Description
keyText Value The resulting key text after modification.

CSS.setMediaText

Modifies the rule selector.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
text string
Return Object
Name Type Description
media CSSMedia The resulting CSS media rule after modification.

CSS.setContainerQueryText

Experimental

Modifies the expression of a container query.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
text string
Return Object
Name Type Description
containerQuery CSSContainerQuery The resulting CSS container query rule after modification.

CSS.setSupportsText

Experimental

Modifies the expression of a supports at-rule.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
text string
Return Object
Name Type Description
supports CSSSupports The resulting CSS Supports rule after modification.

CSS.setNavigationText

Experimental

Modifies the expression of a navigation at-rule.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
text string
Return Object
Name Type Description
navigation CSSNavigation The resulting CSS Navigation rule after modification.

CSS.setScopeText

Experimental

Modifies the expression of a scope at-rule.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
text string
Return Object
Name Type Description
scope CSSScope The resulting CSS Scope rule after modification.

CSS.setRuleSelector

Modifies the rule selector.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
range SourceRange
selector string
Return Object
Name Type Description
selectorList SelectorList The resulting selector list after modification.

CSS.setStyleSheetText

Sets the new stylesheet text.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId
text string
Return Object
Name Type Description
sourceMapURL (optional) string URL of source map associated with script (if any).

CSS.setStyleTexts

Applies specified style edits one after another in the given order.

Parameters
Name Type Description
edits array<StyleDeclarationEdit>
nodeForPropertySyntaxValidation (optional) Experimental DOM.NodeId NodeId for the DOM node in whose context custom property declarations for registered properties should be
validated. If omitted, declarations in the new rule text can only be validated statically, which may produce
incorrect results if the declaration contains a var() for example.
Return Object
Name Type Description
styles array<CSSStyle> The resulting styles after modification.

CSS.startRuleUsageTracking

Enables the selector recording.

CSS.stopRuleUsageTracking

Stop tracking rule usage and return the list of rules that were used since last call to
`takeCoverageDelta` (or since start of coverage instrumentation).

Return Object
Name Type Description
ruleUsage array<RuleUsage>

CSS.takeCoverageDelta

Obtain list of rules that became used since last call to this method (or since start of coverage
instrumentation).

Return Object
Name Type Description
coverage array<RuleUsage>
timestamp number Monotonically increasing time, in seconds.

CSS.setLocalFontsEnabled

Experimental

Enables/disables rendering of local CSS fonts (enabled by default).

Parameters
Name Type Description
enabled boolean Whether rendering of local fonts is enabled.

Events

CSS.fontsUpdated

Fires whenever a web font is updated. A non-empty font parameter indicates a successfully loaded
web font.

Parameters
Name Type Description
font (optional) FontFace The web font that has loaded.

CSS.mediaQueryResultChanged

Fires whenever a MediaQuery result changes (for example, after a browser window has been
resized.) The current implementation considers only viewport-dependent media features.

CSS.styleSheetAdded

Fired whenever an active document stylesheet is added.

Parameters
Name Type Description
header CSSStyleSheetHeader Added stylesheet metainfo.

CSS.styleSheetChanged

Fired whenever a stylesheet is changed as a result of the client operation.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId

CSS.styleSheetRemoved

Fired whenever an active document stylesheet is removed.

Parameters
Name Type Description
styleSheetId DOM.StyleSheetId Identifier of the removed stylesheet.

CSS.computedStyleUpdated

Experimental
Parameters
Name Type Description
nodeId DOM.NodeId The node id that has updated computed styles.

Types

StyleSheetOrigin

(string)

Stylesheet type: "injected" for stylesheets injected via extension, "user-agent" for user-agent
stylesheets, "inspector" for stylesheets created by the inspector (i.e. those holding the "via
inspector" rules), "regular" for regular stylesheets.

Allowed Values
  • injected
  • user-agent
  • inspector
  • regular

PseudoElementMatches

(object)

CSS rule collection for a single pseudo style.

Properties
Name Type Description
pseudoType DOM.PseudoType Pseudo element type.
pseudoIdentifier (optional) string Pseudo element custom ident.
matches array<RuleMatch> Matches of CSS rules applicable to the pseudo style.

CSSAnimationStyle

(object)

CSS style coming from animations with the name of the animation.

Properties
Name Type Description
name (optional) string The name of the animation.
style CSSStyle The style coming from the animation.

InheritedStyleEntry

(object)

Inherited CSS rule collection from ancestor node.

Properties
Name Type Description
inlineStyle (optional) CSSStyle The ancestor node's inline style, if any, in the style inheritance chain.
matchedCSSRules array<RuleMatch> Matches of CSS rules matching the ancestor node in the style inheritance chain.

InheritedAnimatedStyleEntry

(object)

Inherited CSS style collection for animated styles from ancestor node.

Properties
Name Type Description
animationStyles (optional) array<CSSAnimationStyle> Styles coming from the animations of the ancestor, if any, in the style inheritance chain.
transitionsStyle (optional) CSSStyle The style coming from the transitions of the ancestor, if any, in the style inheritance chain.

InheritedPseudoElementMatches

(object)

Inherited pseudo element matches from pseudos of an ancestor node.

Properties
Name Type Description
pseudoElements array<PseudoElementMatches> Matches of pseudo styles from the pseudos of an ancestor node.

RuleMatch

(object)

Match data for a CSS rule.

Properties
Name Type Description
rule CSSRule CSS rule in the match.
matchingSelectors array<integer> Matching selector indices in the rule's selectorList selectors (0-based).

Value

(object)

Data for a simple selector (these are delimited by commas in a selector list).

Properties
Name Type Description
text string Value text.
range (optional) SourceRange Value range in the underlying resource (if available).
specificity (optional) Experimental Specificity Specificity of the selector.

Specificity

(object) Experimental

Specificity:
https://drafts.csswg.org/selectors/#specificity-rules

Properties
Name Type Description
a integer The a component, which represents the number of ID selectors.
b integer The b component, which represents the number of class selectors, attributes selectors, and
pseudo-classes.
c integer The c component, which represents the number of type selectors and pseudo-elements.

SelectorList

(object)

Selector list data.

Properties
Name Type Description
selectors array<Value> Selectors in the list.
text string Rule selector text.

CSSStyleSheetHeader

(object)

CSS stylesheet metainformation.

Properties
Name Type Description
styleSheetId DOM.StyleSheetId The stylesheet identifier.
frameId Page.FrameId Owner frame identifier.
sourceURL string Stylesheet resource URL. Empty if this is a constructed stylesheet created using
new CSSStyleSheet() (but non-empty if this is a constructed stylesheet imported
as a CSS module script).
sourceMapURL (optional) string URL of source map associated with the stylesheet (if any).
origin StyleSheetOrigin Stylesheet origin.
title string Stylesheet title.
ownerNode (optional) DOM.BackendNodeId The backend id for the owner node of the stylesheet.
disabled boolean Denotes whether the stylesheet is disabled.
hasSourceURL (optional) boolean Whether the sourceURL field value comes from the sourceURL comment.
isInline boolean Whether this stylesheet is created for STYLE tag by parser. This flag is not set for
document.written STYLE tags.
isMutable boolean Whether this stylesheet is mutable. Inline stylesheets become mutable
after they have been modified via CSSOM API.
`<link>` element's stylesheets become mutable only if DevTools modifies them.
Constructed stylesheets (new CSSStyleSheet()) are mutable immediately after creation.
isConstructed boolean True if this stylesheet is created through new CSSStyleSheet() or imported as a
CSS module script.
startLine number Line offset of the stylesheet within the resource (zero based).
startColumn number Column offset of the stylesheet within the resource (zero based).
length number Size of the content (in characters).
endLine number Line offset of the end of the stylesheet within the resource (zero based).
endColumn number Column offset of the end of the stylesheet within the resource (zero based).
loadingFailed (optional) Experimental boolean If the style sheet was loaded from a network resource, this indicates when the resource failed to load

CSSRule

(object)

CSS rule representation.

Properties
Name Type Description
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
selectorList SelectorList Rule selector data.
nestingSelectors (optional) Experimental array<string> Array of selectors from ancestor style rules, sorted by distance from the current rule.
origin StyleSheetOrigin Parent stylesheet's origin.
style CSSStyle Associated style declaration.
originTreeScopeNodeId (optional) Experimental DOM.BackendNodeId The BackendNodeId of the DOM node that constitutes the origin tree scope of this rule.
media (optional) array<CSSMedia> Media list array (for rules involving media queries). The array enumerates media queries
starting with the innermost one, going outwards.
containerQueries (optional) Experimental array<CSSContainerQuery> Container query list array (for rules involving container queries).
The array enumerates container queries starting with the innermost one, going outwards.
supports (optional) Experimental array<CSSSupports> @supports CSS at-rule array.
The array enumerates @supports at-rules starting with the innermost one, going outwards.
layers (optional) Experimental array<CSSLayer> Cascade layer array. Contains the layer hierarchy that this rule belongs to starting
with the innermost layer and going outwards.
scopes (optional) Experimental array<CSSScope> @scope CSS at-rule array.
The array enumerates @scope at-rules starting with the innermost one, going outwards.
ruleTypes (optional) Experimental array<CSSRuleType> The array keeps the types of ancestor CSSRules from the innermost going outwards.
startingStyles (optional) Experimental array<CSSStartingStyle> @starting-style CSS at-rule array.
The array enumerates @starting-style at-rules starting with the innermost one, going outwards.
navigations (optional) Experimental array<CSSNavigation> @navigation CSS at-rule array.
The array enumerates @navigation at-rules starting with the innermost one, going outwards.

CSSRuleType

(string) Experimental

Enum indicating the type of a CSS rule, used to represent the order of a style rule's ancestors.
This list only contains rule types that are collected during the ancestor rule collection.

Allowed Values
  • MediaRule
  • SupportsRule
  • ContainerRule
  • LayerRule
  • ScopeRule
  • StyleRule
  • StartingStyleRule
  • NavigationRule

RuleUsage

(object)

CSS coverage information.

Properties
Name Type Description
styleSheetId DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
startOffset number Offset of the start of the rule (including selector) from the beginning of the stylesheet.
endOffset number Offset of the end of the rule body from the beginning of the stylesheet.
used boolean Indicates whether the rule was actually used by some element in the page.

SourceRange

(object)

Text range within a resource. All numbers are zero-based.

Properties
Name Type Description
startLine integer Start line of range.
startColumn integer Start column of range (inclusive).
endLine integer End line of range
endColumn integer End column of range (exclusive).

ShorthandEntry

(object)
Properties
Name Type Description
name string Shorthand name.
value string Shorthand value.
important (optional) boolean Whether the property has "!important" annotation (implies `false` if absent).

CSSComputedStyleProperty

(object)
Properties
Name Type Description
name string Computed style property name.
value string Computed style property value.

ComputedStyleExtraFields

(object) Experimental
Properties
Name Type Description
isAppearanceBase boolean Returns whether or not this node is being rendered with base appearance,
which happens when it has its appearance property set to base/base-select
or it is in the subtree of an element being rendered with base appearance.

CSSStyle

(object)

CSS style representation.

Properties
Name Type Description
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
cssProperties array<CSSProperty> CSS properties in the style.
shorthandEntries array<ShorthandEntry> Computed values for all shorthands found in the style.
cssText (optional) string Style declaration text (if available).
range (optional) SourceRange Style declaration range in the enclosing stylesheet (if available).

CSSProperty

(object)

CSS property declaration data.

Properties
Name Type Description
name string The property name.
value string The property value.
important (optional) boolean Whether the property has "!important" annotation (implies `false` if absent).
implicit (optional) boolean Whether the property is implicit (implies `false` if absent).
text (optional) string The full property text as specified in the style.
parsedOk (optional) boolean Whether the property is understood by the browser (implies `true` if absent).
disabled (optional) boolean Whether the property is disabled by the user (present for source-based properties only).
range (optional) SourceRange The entire property range in the enclosing style declaration (if available).
longhandProperties (optional) Experimental array<CSSProperty> Parsed longhand components of this property if it is a shorthand.
This field will be empty if the given property is not a shorthand.

CSSMedia

(object)

CSS media rule descriptor.

Properties
Name Type Description
text string Media query text.
source string Source of the media query: "mediaRule" if specified by a @media rule, "importRule" if
specified by an @import rule, "linkedSheet" if specified by a "media" attribute in a linked
stylesheet's LINK tag, "inlineSheet" if specified by a "media" attribute in an inline
stylesheet's STYLE tag.
sourceURL (optional) string URL of the document containing the media query description.
range (optional) SourceRange The associated rule (@media or @import) header range in the enclosing stylesheet (if
available).
styleSheetId (optional) DOM.StyleSheetId Identifier of the stylesheet containing this object (if exists).
mediaList (optional) array<MediaQuery> Array of media queries.

MediaQuery

(object)

Media query descriptor.

Properties
Name Type Description
expressions array<MediaQueryExpression> Array of media query expressions.
active boolean Whether the media query condition is satisfied.

MediaQueryExpression

(object)

Media query expression descriptor.

Properties
Name Type Description
value number Media query expression value.
unit string Media query expression units.
feature string Media query expression feature.
valueRange (optional) SourceRange The associated range of the value text in the enclosing stylesheet (if available).
computedLength (optional) number Computed length of media query expression (if applicable).

CSSContainerQuery

(object) Experimental

CSS container query rule descriptor.

Properties
Name Type Description
text string Container query text.
range (optional) SourceRange The associated rule header range in the enclosing stylesheet (if
available).
styleSheetId (optional) DOM.StyleSheetId Identifier of the stylesheet containing this object (if exists).
name (optional) string Optional name for the container.
physicalAxes (optional) DOM.PhysicalAxes Optional physical axes queried for the container.
logicalAxes (optional) DOM.LogicalAxes Optional logical axes queried for the container.
queriesScrollState (optional) boolean true if the query contains scroll-state() queries.
queriesAnchored (optional) boolean true if the query contains anchored() queries.

CSSSupports

(object) Experimental

CSS Supports at-rule descriptor.

Properties
Name Type Description
text string Supports rule text.
active boolean Whether the supports condition is satisfied.
range (optional) SourceRange The associated rule header range in the enclosing stylesheet (if
available).
styleSheetId (optional) DOM.StyleSheetId Identifier of the stylesheet containing this object (if exists).

CSSNavigation

(object) Experimental

CSS Navigation at-rule descriptor.

Properties
Name Type Description
text string Navigation rule text.
active (optional) boolean Whether the navigation condition is satisfied.
range (optional) SourceRange The associated rule header range in the enclosing stylesheet (if
available).
styleSheetId (optional) DOM.StyleSheetId Identifier of the stylesheet containing this object (if exists).

CSSScope

(object) Experimental

CSS Scope at-rule descriptor.

Properties
Name Type Description
text string Scope rule text.
range (optional) SourceRange The associated rule header range in the enclosing stylesheet (if
available).
styleSheetId (optional) DOM.StyleSheetId Identifier of the stylesheet containing this object (if exists).

CSSLayer

(object) Experimental

CSS Layer at-rule descriptor.

Properties
Name Type Description
text string Layer name.
range (optional) SourceRange The associated rule header range in the enclosing stylesheet (if
available).
styleSheetId (optional) DOM.StyleSheetId Identifier of the stylesheet containing this object (if exists).

CSSStartingStyle

(object) Experimental

CSS Starting Style at-rule descriptor.

Properties
Name Type Description
range (optional) SourceRange The associated rule header range in the enclosing stylesheet (if
available).
styleSheetId (optional) DOM.StyleSheetId Identifier of the stylesheet containing this object (if exists).

CSSLayerData

(object) Experimental

CSS Layer data.

Properties
Name Type Description
name string Layer name.
subLayers (optional) array<CSSLayerData> Direct sub-layers
order number Layer order. The order determines the order of the layer in the cascade order.
A higher number has higher priority in the cascade order.

PlatformFontUsage

(object)

Information about amount of glyphs that were rendered with given font.

Properties
Name Type Description
familyName string Font's family name reported by platform.
postScriptName string Font's PostScript name reported by platform.
isCustomFont boolean Indicates if the font was downloaded or resolved locally.
glyphCount number Amount of glyphs that were rendered with this font.

FontVariationAxis

(object)

Information about font variation axes for variable fonts

Properties
Name Type Description
tag string The font-variation-setting tag (a.k.a. "axis tag").
name string Human-readable variation name in the default language (normally, "en").
minValue number The minimum value (inclusive) the font supports for this tag.
maxValue number The maximum value (inclusive) the font supports for this tag.
defaultValue number The default value.

FontFace

(object)

Properties of a web font: https://www.w3.org/TR/2008/REC-CSS2-20080411/fonts.html#font-descriptions
and additional information such as platformFontFamily and fontVariationAxes.

Properties
Name Type Description
fontFamily string The font-family.
fontStyle string The font-style.
fontVariant string The font-variant.
fontWeight string The font-weight.
fontStretch string The font-stretch.
fontDisplay string The font-display.
unicodeRange string The unicode-range.
src string The src.
platformFontFamily string The resolved platform font family
fontVariationAxes (optional) array<FontVariationAxis> Available variation settings (a.k.a. "axes").

CSSTryRule

(object)

CSS try rule representation.

Properties
Name Type Description
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
origin StyleSheetOrigin Parent stylesheet's origin.
style CSSStyle Associated style declaration.

CSSPositionTryRule

(object)

CSS @position-try rule representation.

Properties
Name Type Description
name Value The prelude dashed-ident name
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
origin StyleSheetOrigin Parent stylesheet's origin.
style CSSStyle Associated style declaration.
active boolean

CSSKeyframesRule

(object)

CSS keyframes rule representation.

Properties
Name Type Description
animationName Value Animation name.
keyframes array<CSSKeyframeRule> List of keyframes.

CSSPropertyRegistration

(object)

Representation of a custom property registration through CSS.registerProperty

Properties
Name Type Description
propertyName string
initialValue (optional) Value
inherits boolean
syntax string

CSSAtRule

(object)

CSS generic @rule representation.

Properties
Name Type Description
type string Type of at-rule.
subsection (optional) string Subsection of font-feature-values, if this is a subsection.
name (optional) Value LINT.ThenChange(//third_party/blink/renderer/core/inspector/inspector_style_sheet.cc:FontVariantAlternatesFeatureType,//third_party/blink/renderer/core/inspector/inspector_css_agent.cc:FontVariantAlternatesFeatureType)
Associated name, if applicable.
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
origin StyleSheetOrigin Parent stylesheet's origin.
style CSSStyle Associated style declaration.

CSSPropertyRule

(object)

CSS property at-rule representation.

Properties
Name Type Description
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
origin StyleSheetOrigin Parent stylesheet's origin.
propertyName Value Associated property name.
style CSSStyle Associated style declaration.

CSSFunctionParameter

(object)

CSS function argument representation.

Properties
Name Type Description
name string The parameter name.
type string The parameter type.

CSSFunctionConditionNode

(object)

CSS function conditional block representation.

Properties
Name Type Description
media (optional) CSSMedia Media query for this conditional block. Only one type of condition should be set.
containerQueries (optional) CSSContainerQuery Container query for this conditional block. Only one type of condition should be set.
supports (optional) CSSSupports @supports CSS at-rule condition. Only one type of condition should be set.
navigation (optional) CSSNavigation @navigation condition. Only one type of condition should be set.
children array<CSSFunctionNode> Block body.
conditionText string The condition text.

CSSFunctionNode

(object)

Section of the body of a CSS function rule.

Properties
Name Type Description
condition (optional) CSSFunctionConditionNode A conditional block. If set, style should not be set.
style (optional) CSSStyle Values set by this node. If set, condition should not be set.

CSSFunctionRule

(object)

CSS function at-rule representation.

Properties
Name Type Description
name Value Name of the function.
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
origin StyleSheetOrigin Parent stylesheet's origin.
parameters array<CSSFunctionParameter> List of parameters.
children array<CSSFunctionNode> Function body.

CSSKeyframeRule

(object)

CSS keyframe rule representation.

Properties
Name Type Description
styleSheetId (optional) DOM.StyleSheetId The css style sheet identifier (absent for user agent stylesheet and user-specified
stylesheet rules) this rule came from.
origin StyleSheetOrigin Parent stylesheet's origin.
keyText Value Associated key text.
style CSSStyle Associated style declaration.

StyleDeclarationEdit

(object)

A descriptor of operation to mutate style declaration text.

Properties
Name Type Description
styleSheetId DOM.StyleSheetId The css style sheet identifier.
range SourceRange The range of the style text in the enclosing stylesheet.
text string New style text.

Summary