Added in API level 37

MathInfo

---

Kotlin |Java

class MathInfo : AccessibilityNodeInfo.StructuredDataInfo, Parcelable

kotlin.Any
↳	android.view.accessibility.AccessibilityNodeInfo.StructuredDataInfo
	↳	android.view.accessibility.AccessibilityNodeInfo.MathInfo

A class that holds information about a node that represents a mathematical expression.

This class's structure is based on the concepts and tags defined in the W3C MathML standard. An accessibility service can use this information to provide a richer experience for users interacting with mathematical content. For example, a screen reader could use the tag and attributes to correctly pronounce a fraction and allow the user to navigate between the numerator and the denominator.

To add math information to a node, create an instance of MathInfo, set its attributes using putAttribute(String,String), and then call setStructuredDataInfo(StructuredDataInfo) on the AccessibilityNodeInfo.

Summary

Constants
static String	MATH_ATTRIBUTE_ARG An attribute used to associate a child element with one of the arguments in its parent's MATH_ATTRIBUTE_INTENT value.
static String	MATH_ATTRIBUTE_INTENT An attribute that provides a semantic annotation for the element on which it is specified.
static String	MATH_TAG_FRACTION An element for creating fractions.
static String	MATH_TAG_IDENTIFIER An element for symbolic names or arbitrary text to be rendered as an identifier.
static String	MATH_TAG_MATH The top-level root element that encapsulates a MathML expression.
static String	MATH_TAG_MULTISCRIPTS An element for attaching any number of prescripts and postscripts to a base expression.
static String	MATH_TAG_NONE_SCRIPT Represents an empty element, often used as a placeholder in elements like mmultiscripts.
static String	MATH_TAG_NUMBER An element for a numeric literal.
static String	MATH_TAG_OPERATOR An element for an operator, fence, separator, or accent.
static String	MATH_TAG_OVER An element that attaches an accent or a limit over a base expression.
static String	MATH_TAG_PRESCRIPT_DELIMITER An empty element used within mmultiscripts to separate postscripts from prescripts.
static String	MATH_TAG_ROOT An element for radicals with an explicit index, such as a cube root.
static String	MATH_TAG_ROW An element for grouping sub-expressions horizontally.
static String	MATH_TAG_SQUARE_ROOT An element for a square root.
static String	MATH_TAG_STRING_LITERAL An element for representing string literals, often for computer algebra systems.
static String	MATH_TAG_SUB An element that attaches a subscript to a base expression.
static String	MATH_TAG_SUB_SUP An element that attaches both a subscript and a superscript to a base expression.
static String	MATH_TAG_SUP An element that attaches a superscript to a base expression.
static String	MATH_TAG_TABLE An element for creating tables or matrices.
static String	MATH_TAG_TABLE_CELL An element representing a single cell in a table or matrix.
static String	MATH_TAG_TABLE_ROW An element representing a single row in a a table or matrix.
static String	MATH_TAG_TEXT An element for arbitrary text to be rendered as itself, often used for commentary.
static String	MATH_TAG_UNDER An element that attaches an accent or a limit under a base expression.
static String	MATH_TAG_UNDER_OVER An element that attaches scripts both under and over a base expression.

Inherited constants

From class Parcelable Int CONTENTS_FILE_DESCRIPTOR Descriptor bit used with describeContents(): indicates that the Parcelable object's flattened representation includes a file descriptor. Int PARCELABLE_WRITE_RETURN_VALUE Flag for use with writeToParcel: the object being written is a return value, that is the result of a function such as "Parcelable someFunction()", "void someFunction(out Parcelable)", or "void someFunction(inout Parcelable)". Some implementations may want to release resources at this point.

Public constructors
MathInfo(tag: String) Creates a new MathInfo.

Public methods
Int	describeContents() Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.
String?	getAttribute(attributeKey: String) Gets the value of an attribute.
String	getTag()
Unit	putAttribute(attributeKey: String, value: String) Adds an attribute.
Unit	removeAttribute(attributeKey: String) Removes an attribute.
Unit	writeToParcel(dest: Parcel, flags: Int) Flatten this object in to a Parcel.

Inherited functions

From class StructuredDataInfo Boolean equals(other: Any?) Indicates whether some other object is "equal to" this one. The equals method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value x, x.equals(x) should return true. It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true. It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true. It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified. For any non-null reference value x, x.equals(null) should return false. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. MutableMap<String!, String!> getAttributes() Int hashCode() Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap. The general contract of hashCode is: Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Properties
static Parcelable.Creator<AccessibilityNodeInfo.MathInfo!>	CREATOR

Constants

MATH_ATTRIBUTE_ARG

Added in API level 37

static val MATH_ATTRIBUTE_ARG: String

An attribute used to associate a child element with one of the arguments in its parent's MATH_ATTRIBUTE_INTENT value.

The value of the arg attribute is a token that must match one of the argument names in the parent's intent value.

Use this attribute on a child node to explicitly link it to one of the argument placeholders in its parent's intent string. For example, if a parent node has intent="gcd($1, $2)", the child node representing the first parameter of the function should have its arg attribute set to "1".

Value: "arg"

MATH_ATTRIBUTE_INTENT

Added in API level 37

static val MATH_ATTRIBUTE_INTENT: String

An attribute that provides a semantic annotation for the element on which it is specified.

The intent attribute's value is a string that can be parsed to determine the meaning of the element and its children. An intent value is a string consisting of a single token, or a function-like expression.

Use this attribute on a container node to disambiguate mathematical notation. For example, the expression (a, b) is ambiguous; it could be a point, an open interval, or the greatest common divisor. By setting intent="open-interval($1, $2)" on the parent node, you provide a precise, machine-readable meaning that accessibility services can use to provide a better experience. The $1 and $2 are placeholders for the arguments, which are identified on child nodes using the MATH_ATTRIBUTE_ARG attribute.

Value: "intent"

MATH_TAG_FRACTION

Added in API level 37

static val MATH_TAG_FRACTION: String

An element for creating fractions.

Value: "mfrac"

MATH_TAG_IDENTIFIER

Added in API level 37

static val MATH_TAG_IDENTIFIER: String

An element for symbolic names or arbitrary text to be rendered as an identifier.

Value: "mi"

MATH_TAG_MATH

Added in API level 37

static val MATH_TAG_MATH: String

The top-level root element that encapsulates a MathML expression.

Value: "math"

MATH_TAG_MULTISCRIPTS

Added in API level 37

static val MATH_TAG_MULTISCRIPTS: String

An element for attaching any number of prescripts and postscripts to a base expression.

Value: "mmultiscripts"

MATH_TAG_NONE_SCRIPT

Added in API level 37

static val MATH_TAG_NONE_SCRIPT: String

Represents an empty element, often used as a placeholder in elements like mmultiscripts.

Value: "none"

MATH_TAG_NUMBER

Added in API level 37

static val MATH_TAG_NUMBER: String

An element for a numeric literal.

Value: "mn"

MATH_TAG_OPERATOR

Added in API level 37

static val MATH_TAG_OPERATOR: String

An element for an operator, fence, separator, or accent.

Value: "mo"

MATH_TAG_OVER

Added in API level 37

static val MATH_TAG_OVER: String

An element that attaches an accent or a limit over a base expression.

Value: "mover"

MATH_TAG_PRESCRIPT_DELIMITER

Added in API level 37

static val MATH_TAG_PRESCRIPT_DELIMITER: String

An empty element used within mmultiscripts to separate postscripts from prescripts.

Value: "mprescripts"

MATH_TAG_ROOT

Added in API level 37

static val MATH_TAG_ROOT: String

An element for radicals with an explicit index, such as a cube root.

Value: "mroot"

MATH_TAG_ROW

Added in API level 37

static val MATH_TAG_ROW: String

An element for grouping sub-expressions horizontally.

Value: "mrow"

MATH_TAG_SQUARE_ROOT

Added in API level 37

static val MATH_TAG_SQUARE_ROOT: String

An element for a square root.

Value: "msqrt"

MATH_TAG_STRING_LITERAL

Added in API level 37

static val MATH_TAG_STRING_LITERAL: String

An element for representing string literals, often for computer algebra systems.

Value: "ms"

MATH_TAG_SUB

Added in API level 37

static val MATH_TAG_SUB: String

An element that attaches a subscript to a base expression.

Value: "msub"

MATH_TAG_SUB_SUP

Added in API level 37

static val MATH_TAG_SUB_SUP: String

An element that attaches both a subscript and a superscript to a base expression.

Value: "msubsup"

MATH_TAG_SUP

Added in API level 37

static val MATH_TAG_SUP: String

An element that attaches a superscript to a base expression.

Value: "msup"

MATH_TAG_TABLE

Added in API level 37

static val MATH_TAG_TABLE: String

An element for creating tables or matrices.

Value: "mtable"

MATH_TAG_TABLE_CELL

Added in API level 37

static val MATH_TAG_TABLE_CELL: String

An element representing a single cell in a table or matrix.

Value: "mtd"

MATH_TAG_TABLE_ROW

Added in API level 37

static val MATH_TAG_TABLE_ROW: String

An element representing a single row in a a table or matrix.

Value: "mtr"

MATH_TAG_TEXT

Added in API level 37

static val MATH_TAG_TEXT: String

An element for arbitrary text to be rendered as itself, often used for commentary.

Value: "mtext"

MATH_TAG_UNDER

Added in API level 37

static val MATH_TAG_UNDER: String

An element that attaches an accent or a limit under a base expression.

Value: "munder"

MATH_TAG_UNDER_OVER

Added in API level 37

static val MATH_TAG_UNDER_OVER: String

An element that attaches scripts both under and over a base expression.

Value: "munderover"

Public constructors

MathInfo

Added in API level 37

MathInfo(tag: String)

Creates a new MathInfo.

Parameters

tag

String: The MathML tag for this node. Value is one of the following: MATH_TAG_MATH MATH_TAG_FRACTION MATH_TAG_IDENTIFIER MATH_TAG_MULTISCRIPTS MATH_TAG_NONE_SCRIPT MATH_TAG_NUMBER MATH_TAG_OPERATOR MATH_TAG_OVER MATH_TAG_PRESCRIPT_DELIMITER MATH_TAG_ROOT MATH_TAG_ROW MATH_TAG_SQUARE_ROOT MATH_TAG_STRING_LITERAL MATH_TAG_SUB MATH_TAG_SUB_SUP MATH_TAG_SUP MATH_TAG_TABLE MATH_TAG_TABLE_CELL MATH_TAG_TABLE_ROW MATH_TAG_TEXT MATH_TAG_UNDER MATH_TAG_UNDER_OVER . This value cannot be null.

Public methods

describeContents

Added in API level 37

fun describeContents(): Int

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(Parcel,int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.

Return
Int	a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or CONTENTS_FILE_DESCRIPTOR

getAttribute

Added in API level 37

fun getAttribute(attributeKey: String): String?

Gets the value of an attribute.

Parameters
attributeKey	String: Value is one of the following: MATH_ATTRIBUTE_INTENT MATH_ATTRIBUTE_ARG . This value cannot be null.

Return
String?	This value may be null.

getTag

Added in API level 37

fun getTag(): String

Return

String

This value cannot be null. Value is one of the following: MATH_TAG_MATH MATH_TAG_FRACTION MATH_TAG_IDENTIFIER MATH_TAG_MULTISCRIPTS MATH_TAG_NONE_SCRIPT MATH_TAG_NUMBER MATH_TAG_OPERATOR MATH_TAG_OVER MATH_TAG_PRESCRIPT_DELIMITER MATH_TAG_ROOT MATH_TAG_ROW MATH_TAG_SQUARE_ROOT MATH_TAG_STRING_LITERAL MATH_TAG_SUB MATH_TAG_SUB_SUP MATH_TAG_SUP MATH_TAG_TABLE MATH_TAG_TABLE_CELL MATH_TAG_TABLE_ROW MATH_TAG_TEXT MATH_TAG_UNDER MATH_TAG_UNDER_OVER

putAttribute

Added in API level 37

fun putAttribute(
    attributeKey: String, 
    value: String
): Unit

Adds an attribute.

Parameters
attributeKey	String: Value is one of the following: MATH_ATTRIBUTE_INTENT MATH_ATTRIBUTE_ARG . This value cannot be null.
value	String: This value cannot be null.

removeAttribute

Added in API level 37

fun removeAttribute(attributeKey: String): Unit

Removes an attribute.

Parameters
attributeKey	String: Value is one of the following: MATH_ATTRIBUTE_INTENT MATH_ATTRIBUTE_ARG . This value cannot be null.

writeToParcel

Added in API level 37

fun writeToParcel(
    dest: Parcel, 
    flags: Int
): Unit

Flatten this object in to a Parcel.

Parameters
dest	Parcel: This value cannot be null.
flags	Int: Additional flags about how the object should be written. May be 0 or PARCELABLE_WRITE_RETURN_VALUE. Value is either 0 or a combination of the following: PARCELABLE_WRITE_RETURN_VALUE

Properties

CREATOR

Added in API level 37

static val CREATOR: Parcelable.Creator<AccessibilityNodeInfo.MathInfo!>

See Also

• android.os.Parcelable.Creator