SharpVectors.Css

The CSSCharsetRule interface represents a @charset rule in a CSS style sheet. The value of the encoding attribute does not affect the encoding of text data in the DOM objects; this encoding is always UTF-16. After a stylesheet is loaded, the value of the encoding attribute is the value found in the @charset rule. If there was no @charset in the original document, then no CSSCharsetRule is created. The value of the encoding attribute may also be used as a hint for the encoding used on serialization of the style sheet. The value of the @charset rule (and therefore of the CSSCharsetRule) may not correspond to the encoding the document actually came in; character encoding information e.g. in an HTTP header, has priority (see CSS document representation) but this is not reflected in the CSSCharsetRule.

The constructor for CssCharSetRule

The Regex match that found the charset rule The parent rule or parent stylesheet True if this instance is readonly An array of strings that have been replaced in the string used for matching. These needs to be put back use the DereplaceStrings method The type of CssStyleSheet

The encoding information used in this @charset rule

The type of the rule. The expectation is that binding-specific casting methods can be used to cast down from an instance of the CSSRule interface to the specific derived interface implied by the type.

Used internally to store collected properties.

The name of the property

The calculated specificity

The origin of the collected property.

The value of the property

The priority of the property, e.g. "important"

Used internally for collection of styles for a specific element

Returns the origin type of the collected property

The name of the property The origin type

Used to retrieve the priority of a CSS property (e.g. the "important" qualifier) if the property has been explicitly set in this declaration block.

The name of the CSS property. See the CSS property index. A string representing the priority (e.g. "important") if one exists. The empty string if none exists.

Used to retrieve the value of a CSS property if it has been explicitly set within this declaration block.

The number of properties that have been explicitly set in this declaration block. The range of valid indices is 0 to length-1 inclusive.

The parsable textual representation of the declaration block (excluding the surrounding curly braces). Setting this attribute will result in the parsing of the new value and resetting of all the properties in the declaration block including the removal or addition of properties.

SYNTAX_ERR: Raised if the specified CSS string value has a syntax error and is unparsable. NO_MODIFICATION_ALLOWED_ERR: Raised if this declaration is readonly or a property is readonly.

Used to retrieve the properties that have been explicitly set in this declaration block. The order of the properties retrieved using this method does not have to be the order in which they were set. This method can be used to iterate over all properties in this declaration block. The name of the property at this ordinal position. The empty string if no property exists at this position.

The RGB-Color interface is used to represent any RGB color value.

This interface reflects the values in the underlying style property. Hence, modifications made to the CSSPrimitiveValue objects modify the style property. A specified RGB color is not clipped (even if the number is outside the range 0-255 or 0%-100%). A computed RGB color is clipped depending on the device. Even if a style sheet can only contain an integer for a color value, the internal storage of this integer is a float, and this can be used as a float in the specified or the computed style. A color percentage value can always be converted to a number and vice versa.

Constructs a RgbColor based on the GDI color

Parses a constructs a RgbColor

String to parse to find the color

Gets a value which indicates whether the color is defined by custom properties.

This attribute is used for the red value of the RGB color

This attribute is used for the green value of the RGB color.

This attribute is used for the blue value of the RGB color

Converts HSL color (values from 0 to 1) to RGB color. Based on codes from: https://geekymonkey.com/Programming/CSharp/RGB2HSL_HSL2RGB.htm

hue saturation lightness alpha

The interface represents a @font-face rule in a CSS style sheet. The @font-face rule is used to hold a set of font descriptions.

The constructor for CssFontFaceRule

The parent rule or parent stylesheet True if this instance is readonly An array of strings that have been replaced in the string used for matching. These needs to be put back use the DereplaceStrings method The type of CssStyleSheet

The declaration-block of this rule.

The parsable textual representation of the rule. This reflects the current state of the rule and not its initial value.

Parses a string containging CSS and creates a CssFontFaceRule instance if found as the first content

The CSSImportRule interface represents a @import rule within a CSS style sheet. The @import rule is used to import style rules from other style sheets.

The constructor for CssImportRule

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

The style sheet referred to by this rule, if it has been loaded. The value of this attribute is null if the style sheet has not yet been loaded or if it will not be loaded (e.g. if the style sheet is for a media type not supported by the user agent).

A list of media types for which this style sheet may be used.

The location of the style sheet to be imported. The attribute will not contain the "url(...)" specifier around the URI

The CSSMediaRule interface represents a @media rule in a CSS style sheet. A @media rule can be used to delimit style rules for specific media types.

The constructor for CssMediaRule

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

Used to delete a rule from the media block.

The index within the media block's rule collection of the rule to remove. INDEX_SIZE_ERR: Raised if the specified index does not correspond to a rule in the media rule list. NO_MODIFICATION_ALLOWED_ERR: Raised if this media rule is readonly.

Used to insert a new rule into the media block

The parsable text representing the rule. For rule sets this contains both the selector and the style declaration. For at-rules, this specifies both the at-identifier and the rule content. The index within the media block's rule collection of the rule before which to insert the specified rule. If the specified index is equal to the length of the media blocks's rule collection, the rule will be added to the end of the media block. The index within the media block's rule collection of the newly inserted rule. HIERARCHY_REQUEST_ERR: Raised if the rule cannot be inserted at the specified index, e.g., if an @import rule is inserted after a standard rule set or other at-rule. INDEX_SIZE_ERR: Raised if the specified index is not a valid insertion point. NO_MODIFICATION_ALLOWED_ERR: Raised if this media rule is readonly SYNTAX_ERR: Raised if the specified rule has a syntax error and is unparsable

A list of all CSS rules contained within the media block.

A list of media types for this rule

The CSSPageRule interface represents a @page rule within a CSS style sheet. The @page rule is used to specify the dimensions, orientation, margins, etc. of a page box for paged media.

The constructor for CssPageRule

The parsable textual representation of the page selector for the rule.

SYNTAX_ERR: Raised if the specified CSS string value has a syntax error and is unparsable. NO_MODIFICATION_ALLOWED_ERR: Raised if this rule is readonly.

The declaration-block of this rule.

This implements the interface which represents a single CSS value.

This interface may be used to determine the value of a specific style property currently set in a block or to set a specific style property explicitly within the block. An instance of this interface might be obtained from the getPropertyCSSValue method of the CSSStyleDeclaration interface. A CSSPrimitiveValue object only occurs in a context of a CSS property. Conversions are allowed between absolute values (from millimeters to centimeters, from degrees to radians, and so on) but not between relative values. (For example, a pixel value cannot be converted to a centimeter value.) Percentage values can't be converted since they are relative to the parent value (or another property value). There is one exception for color percentage values: since a color percentage value is relative to the range 0-255, a color percentage value can be converted to a number; (see also the RGBColor interface).

Constructor called by CssValue.GetCssValue()

A Regex that matches a CssPrimitiveValue Specifiec if this instance is read-only

Only for internal use

A method to set the float value with a specified unit. If the property attached with this value can not accept the specified unit or the float value, the value will be unchanged and a will be raised.

A unit code as defined above. The unit code can only be a float unit type (i.e. CSS_NUMBER, CSS_PERCENTAGE, CSS_EMS, CSS_EXS, CSS_PX, CSS_CM, CSS_MM, CSS_IN, CSS_PT, CSS_PC, CSS_DEG, CSS_RAD, CSS_GRAD, CSS_MS, CSS_S, CSS_HZ, CSS_KHZ, CSS_DIMENSION). The new float value. INVALID_ACCESS_ERR: Raised if the CSS value doesn't contain a float value. NO_MODIFICATION_ALLOWED_ERR: Raised if this property is readonly.

This method is used to get a float value in a specified unit. If this CSS value doesn't contain a float value or can't be converted into the specified unit, a is raised

A unit code to get the float value. The unit code can only be a float unit type (i.e. CSS_NUMBER, CSS_PERCENTAGE, CSS_EMS, CSS_EXS, CSS_PX, CSS_CM, CSS_MM, CSS_IN, CSS_PT, CSS_PC, CSS_DEG, CSS_RAD, CSS_GRAD, CSS_MS, CSS_S, CSS_HZ, CSS_KHZ, CSS_DIMENSION). The float value in the specified unit. INVALID_ACCESS_ERR: Raised if the CSS value doesn't contain a float value.

A method to set the string value with the specified unit. If the property attached to this value can't accept the specified unit or the string value, the value will be unchanged and a will be raised.

A string code as defined above. The string code can only be a string unit type (i.e. CSS_STRING, CSS_URI, CSS_IDENT, and CSS_ATTR). The new string value INVALID_ACCESS_ERR: Raised if the CSS value doesn't contain a string value. NO_MODIFICATION_ALLOWED_ERR: Raised if this property is readonly.

This method is used to get the string value. If the CSS value doesn't contain a string value, a is raised. Note: Some properties (like 'font-family' or 'voice-family') convert a whitespace separated list of idents to a string.

The string value in the current unit. The current primitiveType can only be a string unit type (i.e. CSS_STRING, CSS_URI, CSS_IDENT and CSS_ATTR). INVALID_ACCESS_ERR: Raised if the CSS value doesn't contain a string value.

This method is used to get the Counter value. If this CSS value doesn't contain a counter value, a is raised. Modification to the corresponding style property can be achieved using the Counter interface

The Counter value. INVALID_ACCESS_ERR: Raised if the CSS value doesn't contain a Counter value (e.g. this is not CSS_COUNTER).

This method is used to get the Rect value. If this CSS value doesn't contain a rect value, a is raised. Modification to the corresponding style property can be achieved using the Rect interface.

The Rect value. INVALID_ACCESS_ERR: Raised if the CSS value doesn't contain a rect value.

This method is used to get the RGB color. If this CSS value doesn't contain a RGB color value, a is raised. Modification to the corresponding style property can be achieved using the RGBColor interface.

the RGB color value. INVALID_ACCESS_ERR: Raised if the CSS value doesn't contain a rgb value.

The type of the value as defined by the constants specified above.

The Rect interface is used to represent any rect value. This interface reflects the values in the underlying style property. Hence, modifications made to the CSSPrimitiveValue objects modify the style property.

Constructs a new Rect

The string to parse that contains the Rect structure Specifies if the Rect should be read-only

This attribute is used for the left of the rect.

This attribute is used for the bottom of the rect.

This attribute is used for the right of the rect.

This attribute is used for the top of the rect.

The origin stylesheet type of this rule

Specifies the read/write state of the instance

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

Finds the owner node of this rule

The owner XmlNode

The style sheet that contains this rule

If this rule is contained inside another rule (e.g. a style rule inside an @media block), this is the containing rule. If this rule is not nested inside any other rules, this returns null

The type of the rule, as defined above. The expectation is that binding-specific casting methods can be used to cast down from an instance of the CSSRule interface to the specific derived interface implied by the type.

The parsable textual representation of the rule. This reflects the current state of the rule and not its initial value.

The CSSRuleList interface provides the abstraction of an ordered collection of CSS rules. The items in the CSSRuleList are accessible via an integral index, starting from 0.

Constructor for CssRuleList

The parent rule or parent stylesheet The CSS text containing the rules that will be in this list An array of strings that have been replaced in the string used for matching. These needs to be put back use the DereplaceStrings method. The type of CssStyleSheet

Constructor for CssRuleList

The parent rule or parent stylesheet The CSS text containing the rules that will be in this list True if this instance is readonly An array of strings that have been replaced in the string used for matching. These needs to be put back use the DereplaceStrings method. The type of CssStyleSheet

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

Deletes a rule from the list

The index of the rule to delete NO_MODIFICATION_ALLOWED_ERR INDEX_SIZE_ERR

The number of CSSRules in the list. The range of valid child rule indices is 0 to length-1 inclusive.

Used to retrieve a CSS rule by ordinal index. The order in this collection represents the order of the rules in the CSS style sheet. If index is greater than or equal to the number of rules in the list, this returns null.

Internal class that stores a style in a declaration block

The type of the owner stylesheet

The property name

The value of the style

The priority of the style, e.g. "important"

The calculated specificity of the owner selector

The interface represents a single CSS declaration block. This interface may be used to determine the style properties currently set in a block or to set style properties explicitly within the block. While an implementation may not recognize all CSS properties within a CSS declaration block, it is expected to provide access to all specified properties in the style sheet through the interface. Furthermore, implementations that support a specific level of CSS should correctly handle CSS shorthand properties for that level. For a further discussion of shorthand properties, see the CSS2Properties interface. This interface is also used to provide a read-only access to the computed values of an element. See also the ViewCSS interface. Note: The CSS Object Model doesn't provide an access to the specified or actual values of the CSS cascade

The constructor used internally when collecting styles for a specified element

The constructor for CssStyleDeclaration

The string to parse for CSS The parent rule or parent stylesheet True if this instance is readonly The type of CssStyleSheet

Used to find matching style rules in the cascading order

Parsing CSS in C#: extracting all URLs

https://stackoverflow.com/questions/18262390/parsing-css-in-c-extracting-all-urls

Used to set a property value and priority within this declaration block

The name of the CSS property. See the CSS property index. The new value of the property. The new priority of the property (e.g. "important"). SYNTAX_ERR: Raised if the specified value has a syntax error and is unparsable. NO_MODIFICATION_ALLOWED_ERR: Raised if this declaration is readonly or the property is readonly.

Used to set a property value and priority within this declaration block

The name of the CSS property. See the CSS property index. The new value of the property. SYNTAX_ERR: Raised if the specified value has a syntax error and is unparsable. NO_MODIFICATION_ALLOWED_ERR: Raised if this declaration is readonly or the property is readonly.

Used to retrieve the priority of a CSS property (e.g. the "important" qualifier) if the property has been explicitly set in this declaration block.

The name of the CSS property. See the CSS property index. A string representing the priority (e.g. "important") if one exists. The empty string if none exists.

Used to remove a CSS property if it has been explicitly set within this declaration block.

The name of the CSS property. See the CSS property index. Returns the value of the property if it has been explicitly set for this declaration block. Returns the empty string if the property has not been set or the property name does not correspond to a known CSS property. NO_MODIFICATION_ALLOWED_ERR: Raised if this declaration is readonly or the property is readonly.

Used to retrieve the object representation of the value of a CSS property if it has been explicitly set within this declaration block. This method returns null if the property is a shorthand property. Shorthand property values can only be accessed and modified as strings, using the getPropertyValue and setProperty methods.

The name of the CSS property. See the CSS property index. Returns the value of the property if it has been explicitly set for this declaration block. Returns null if the property has not been set.

Used to retrieve the value of a CSS property if it has been explicitly set within this declaration block.

The CSS rule that contains this declaration block or null if this CSSStyleDeclaration is not attached to a CSSRule.

The number of properties that have been explicitly set in this declaration block. The range of valid indices is 0 to length-1 inclusive.

SYNTAX_ERR: Raised if the specified CSS string value has a syntax error and is unparsable. NO_MODIFICATION_ALLOWED_ERR: Raised if this declaration is readonly or a property is readonly.

The CSSStyleRule interface represents a single rule set in a CSS style sheet.

The constructor for CssStyleRule

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

The textual representation of the selector for the rule set. The implementation may have stripped out insignificant whitespace while parsing the selector.

SYNTAX_ERR: Raised if the specified CSS string value has a syntax error and is unparsable. NO_MODIFICATION_ALLOWED_ERR: Raised if this rule is readonly

The entire text of the CssStyleRule

The declaration-block of this rule set.

The interface is a concrete interface used to represent a CSS style sheet i.e., a style sheet whose content type is "text/css".

Constructor for CssStyleSheet

The XML processing instruction that references the stylesheet The type of stylesheet

Constructor for CssStyleSheet

The XML style element that references the stylesheet The type of stylesheet

Constructor for CssStyleSheet

The node that owns this stylesheet. E.g. used for getting the BaseUri The URL of the stylesheet The title of the stylesheet List of medias for the stylesheet The rule (e.g. ImportRule) that referenced this stylesheet The type of stylesheet

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

Used to delete a rule from the style sheet.

The index within the style sheet's rule list of the rule to remove. INDEX_SIZE_ERR: Raised if the specified index does not correspond to a rule in the style sheet's rule list. NO_MODIFICATION_ALLOWED_ERR: Raised if this style sheet is readonly.

Used to insert a new rule into the style sheet. The new rule now becomes part of the cascade.

The parsable text representing the rule. For rule sets this contains both the selector and the style declaration. For at-rules, this specifies both the at-identifier and the rule content. The index within the style sheet's rule list of the rule before which to insert the specified rule. If the specified index is equal to the length of the style sheet's rule collection, the rule will be added to the end of the style sheet. The index within the style sheet's rule collection of the newly inserted rule. INDEX_SIZE_ERR: Raised if the specified index does not correspond to a rule in the style sheet's rule list. NO_MODIFICATION_ALLOWED_ERR: Raised if this style sheet is readonly. HIERARCHY_REQUEST_ERR: Raised if the rule cannot be inserted at the specified index e.g. if an @import rule is inserted after a standard rule set or other at-rule. SYNTAX_ERR: Raised if the specified rule has a syntax error and is unparsable.

The list of all CSS rules contained within the style sheet. This includes both rule sets and at-rules.

If this style sheet comes from an @import rule, the ownerRule attribute will contain the CSSImportRule. In that case, the ownerNode attribute in the StyleSheet interface will be null. If the style sheet comes from an element or a processing instruction, the ownerRule attribute will be null and the ownerNode attribute will contain the Node.

The different types of CssStyleSheets

The stylesheet is a user agent stylesheet

The stylesheet is a author stylesheet

The stylesheet is a user stylesheet

The styles comes from a inline style attribute

Used internally for collection of styles for an element

Used internally for unknown properties

The CSSUnknownRule interface represents an at-rule not supported by this user agent.

The constructor for CssUnknownRule

This implements the interface, which represents a simple or a complex value. A object only occurs in a context of a CSS property.

Constructor for CssValue

The type of value The entire content of the value Specifies if the instance is read-only

Only for internal use

Detects what kind of value cssText contains and returns an instance of the correct CssValue class

The text to parse for a CSS value Specifies if this instance is read-only The correct type of CSS value

A string representation of the current value.

SYNTAX_ERR: Raised if the specified CSS string value has a syntax error (according to the attached property) or is unparsable. INVALID_MODIFICATION_ERR: Raised if the specified CSS string value represents a different type of values than the values allowed by the CSS property NO_MODIFICATION_ALLOWED_ERR: Raised if this value is readonly.

A code defining the type of the value as defined above

A XmlDocument with CSS support

Initializes a new instance of CssXmlDocument

The name table to use

Gets or sets a value indicating whether this handles DOM dynamic changes. Sometimes (when loading or rendering) this needs to be disabled. See for more information about use

true if static; otherwise, false.

All the stylesheets associated with this document

Loads a XML document, compare to XmlDocument.Load()

Adds a element type to be used as style elements (e.g. as in the HTML style element)

The namespace URI of the element The local-name of the element

Sets the user agent stylesheet for this document

The URI to the stylesheet

Sets the user stylesheet for this document

The URI to the stylesheet

This method is used to retrieve the override style declaration for a specified element and a specified pseudo-element.

The element whose style is to be modified. This parameter cannot be null. The pseudo-element or null if none. The override style declaration.

This method is used to get the computed style as it is defined in [CSS2].

The element whose style is to be computed. This parameter cannot be null. The pseudo-element or null if none. The computed style. The CSSStyleDeclaration is read-only and contains only absolute values.

Called when this element is changing in one of the following ways Text child added/removed/changed Element moved in the tree

Called when any parent element is changing. If an element is moved the CSS heirarchy for that element will need to change.

Called when any attribute is changing. This is typically triggered by calls to setAttribute() and should only be called from the CssXmlDocument.

This function allows each element to handle it's own behaviors for attribute changing. By default, the cached computed style is invalidated because most attributes refer to style properties.

The attribute that is changing.

Called when any child node is changing. If an element is moved the CSS heirarchy for that element will need to change. This is mainly useful when one of the child nodes parent is a referenced node (for example in a <use> element.

Only used for testing!

Creates a static section for a CssXmlDocument. Typical use: using(StaticSection.Use(doc)) { // blah blah }

Previous Static state

Document to be handled

Initializes a new instance of the class.

The CSS XML document.

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

Uses the specified CSS XML document with Static state to true.

The CSS XML document.

The MediaList interface provides the abstraction of an ordered collection of media, without defining or constraining how this collection is implemented. An empty list is the same as a list that contains the medium "all". The items in the MediaList are accessible via an integral index, starting from 0.

Compares this MediaList with another and see if the second fits this

The MediaList to compare True if this list fits the specified

Adds the medium newMedium to the end of the list. If the newMedium is already used, it is first removed.

The new medium to add. INVALID_CHARACTER_ERR: If the medium contains characters that are invalid in the underlying style language. NO_MODIFICATION_ALLOWED_ERR: Raised if this media list is readonly.

Deletes the medium indicated by oldMedium from the list.

The medium to delete in the media list. NOT_FOUND_ERR: Raised if oldMedium is not in the list. NO_MODIFICATION_ALLOWED_ERR: Raised if this media list is readonly.

The number of media in the list. The range of valid media is 0 to length-1 inclusive.

The parsable textual representation of the media list. This is a comma-separated list of media.

SYNTAX_ERR: Raised if the specified string value has a syntax error and is unparsable. NO_MODIFICATION_ALLOWED_ERR: Raised if this media list is readonly.

Returns the indexth in the list. If index is greater than or equal to the number of media in the list, this returns null.

The StyleSheet interface is the abstract base interface for any type of style sheet. It represents a single style sheet associated with a structured document. In HTML, the StyleSheet interface represents either an external style sheet, included via the HTML LINK element, or an inline STYLE element. In XML, this interface represents an external style sheet, included via a style sheet processing instruction.

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

The intended destination media for style information. The media is often specified in the ownerNode. If no media has been specified, the MediaList will be empty. See the media attribute definition for the LINK element in HTML 4.0, and the media pseudo-attribute for the XML style sheet processing instruction . Modifying the media list may cause a change to the attribute disabled.

The advisory title. The title is often specified in the ownerNode. See the title attribute definition for the LINK element in HTML 4.0, and the title pseudo-attribute for the XML style sheet processing instruction.

If the style sheet is a linked style sheet, the value of its attribute is its location. For inline style sheets, the value of this attribute is null. See the href attribute definition for the LINK element in HTML 4.0, and the href pseudo-attribute for the XML style sheet processing instruction.

The resolved absolute URL to the stylesheet

For style sheet languages that support the concept of style sheet inclusion, this attribute represents the including style sheet, if one exists. If the style sheet is a top-level style sheet, or the style sheet language does not support inclusion, the value of this attribute is null.

The node that associates this style sheet with the document. For HTML, this may be the corresponding LINK or STYLE element. For XML, it may be the linking processing instruction. For style sheets that are included by other style sheets, the value of this attribute is null.

false if the style sheet is applied to the document. true if it is not. Modifying this attribute may cause a new resolution of style for the document. A stylesheet only applies if both an appropriate medium definition is present and the disabled attribute is false. So, if the media doesn't apply to the current user agent, the disabled attribute is ignored.

This specifies the style sheet language for this style sheet. The style sheet language is specified as a content type (e.g. "text/css"). The content type is often specified in the ownerNode. Also see the type attribute definition for the LINK element in HTML 4.0, and the type pseudo-attribute for the XML style sheet processing instruction.

The StyleSheetList interface provides the abstraction of an ordered collection of style sheets. The items in the StyleSheetList are accessible via an integral index, starting from 0.

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for A CssStyleDeclaration that holds the collected styles

Used to find matching style rules in the cascading order

The element to find styles for The pseudo-element to find styles for The medialist that the document is using A CssStyleDeclaration that holds the collected styles

The number of StyleSheets in the list. The range of valid child stylesheet indices is 0 to length-1 inclusive.

Used to retrieve a style sheet by ordinal index. If index is greater than or equal to the number of style sheets in the list, this returns null.