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/OpenJDK 21

Interface AttributeSet

All Known Subinterfaces:
MutableAttributeSet, Style
All Known Implementing Classes:
AbstractDocument.AbstractElement, AbstractDocument.BranchElement, AbstractDocument.LeafElement, DefaultStyledDocument.SectionElement, HTMLDocument.BlockElement, HTMLDocument.RunElement, SimpleAttributeSet, StyleContext.NamedStyle, StyleContext.SmallAttributeSet 
public interface AttributeSet
A collection of unique attributes. This is a read-only, immutable interface. An attribute is basically a key and a value assigned to the key. The collection may represent something like a style run, a logical style, etc. These are generally used to describe features that will contribute to some graphical representation such as a font. The set of possible keys is unbounded and can be anything. Typically View implementations will respond to attribute definitions and render something to represent the attributes.

Attributes can potentially resolve in a hierarchy. If a key doesn't resolve locally, and a resolving parent exists, the key will be resolved through the parent.

See Also:

Nested Class Summary

Modifier and Type Interface Description
static interface  AttributeSet.CharacterAttribute
This interface is the type signature that is expected to be present on any attribute key that contributes to character level presentation.
static interface  AttributeSet.ColorAttribute
This interface is the type signature that is expected to be present on any attribute key that contributes to presentation of color.
static interface  AttributeSet.FontAttribute
This interface is the type signature that is expected to be present on any attribute key that contributes to the determination of what font to use to render some text.
static interface  AttributeSet.ParagraphAttribute
This interface is the type signature that is expected to be present on any attribute key that contributes to the paragraph level presentation.

Field Summary

Modifier and Type Field Description
static final Object NameAttribute
Attribute name used to name the collection of attributes.
static final Object ResolveAttribute
Attribute name used to identify the resolving parent set of attributes, if one is defined.

Method Summary

Modifier and Type Method Description
boolean containsAttribute(Object name, Object value)
Returns true if this set defines an attribute with the same name and an equal value.
boolean containsAttributes(AttributeSet attributes)
Returns true if this set defines all the attributes from the given set with equal values.
AttributeSet copyAttributes()
Returns an attribute set that is guaranteed not to change over time.
Object getAttribute(Object key)
Fetches the value of the given attribute.
int getAttributeCount()
Returns the number of attributes that are defined locally in this set.
Enumeration<?> getAttributeNames()
Returns an enumeration over the names of the attributes that are defined locally in the set.
AttributeSet getResolveParent()
Gets the resolving parent.
boolean isDefined(Object attrName)
Checks whether the named attribute has a value specified in the set without resolving through another attribute set.
boolean isEqual(AttributeSet attr)
Determines if the two attribute sets are equivalent.

Field Details

NameAttribute

static final Object NameAttribute
Attribute name used to name the collection of attributes.

ResolveAttribute

static final Object ResolveAttribute
Attribute name used to identify the resolving parent set of attributes, if one is defined.

Method Details

getAttributeCount

int getAttributeCount()
Returns the number of attributes that are defined locally in this set. Attributes that are defined in the parent set are not included.
Returns:
the number of attributes >= 0

isDefined

boolean isDefined(Object attrName)
Checks whether the named attribute has a value specified in the set without resolving through another attribute set.
Parameters:
attrName - the attribute name
Returns:
true if the attribute has a value specified

isEqual

boolean isEqual(AttributeSet attr)
Determines if the two attribute sets are equivalent.
Parameters:
attr - an attribute set
Returns:
true if the sets are equivalent

copyAttributes

AttributeSet copyAttributes()
Returns an attribute set that is guaranteed not to change over time.
Returns:
a copy of the attribute set

getAttribute

Object getAttribute(Object key)
Fetches the value of the given attribute. If the value is not found locally, the search is continued upward through the resolving parent (if one exists) until the value is either found or there are no more parents. If the value is not found, null is returned.
Parameters:
key - the non-null key of the attribute binding
Returns:
the value of the attribute, or null if not found

getAttributeNames

Enumeration<?> getAttributeNames()
Returns an enumeration over the names of the attributes that are defined locally in the set. Names of attributes defined in the resolving parent, if any, are not included. The values of the Enumeration may be anything and are not constrained to a particular Object type.

This method never returns null. For a set with no attributes, it returns an empty Enumeration.

Returns:
the names

containsAttribute

boolean containsAttribute(Object name, Object value)
Returns true if this set defines an attribute with the same name and an equal value. If such an attribute is not found locally, it is searched through in the resolving parent hierarchy.
Parameters:
name - the non-null attribute name
value - the value
Returns:
true if the set defines the attribute with an equal value, either locally or through its resolving parent
Throws:
NullPointerException - if either name or value is null

containsAttributes

boolean containsAttributes(AttributeSet attributes)
Returns true if this set defines all the attributes from the given set with equal values. If an attribute is not found locally, it is searched through in the resolving parent hierarchy.
Parameters:
attributes - the set of attributes to check against
Returns:
true if this set defines all the attributes with equal values, either locally or through its resolving parent
Throws:
NullPointerException - if attributes is null

getResolveParent

AttributeSet getResolveParent()
Gets the resolving parent.
Returns:
the parent

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Documentation extracted from Debian's OpenJDK Development Kit package.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/text/AttributeSet.html