Module java.desktop
Package javax.swing.text

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:
MutableAttributeSet

  • Nested Class Summary

    Nested Classes 
    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

    Fields 
    Modifier and Type Field Description
    static Object NameAttribute
    Attribute name used to name the collection of attributes.
    static 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