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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* published by the Free Software Foundation. Oracle designates this
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package javax.swing.text;
import java.util.Enumeration;
/**
* 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.
* <p>
* 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.
*
* @author Timothy Prinzing
* @see MutableAttributeSet
*/
public interface AttributeSet {
/**
* 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. This is not considered to be a closed set, the
* definition can change across version of the platform and can
* be amended by additional user added entries that
* correspond to logical settings that are specific to
* some type of content.
*/
public interface FontAttribute {
}
/**
* This interface is the type signature that is expected
* to be present on any attribute key that contributes to
* presentation of color.
*/
public interface ColorAttribute {
}
/**
* This interface is the type signature that is expected
* to be present on any attribute key that contributes to
* character level presentation. This would be any attribute
* that applies to a so-called <term>run</term> of
* style.
*/
public interface CharacterAttribute {
}
/**
* This interface is the type signature that is expected
* to be present on any attribute key that contributes to
* the paragraph level presentation.
*/
public interface ParagraphAttribute {
}
/**
* Returns the number of attributes that are defined locally in this set.
* Attributes that are defined in the parent set are not included.
*
* @return the number of attributes >= 0
*/
public int getAttributeCount();
/**
* Checks whether the named attribute has a value specified in
* the set without resolving through another attribute
* set.
*
* @param attrName the attribute name
* @return true if the attribute has a value specified
*/
public boolean isDefined(Object attrName);
/**
* Determines if the two attribute sets are equivalent.
*
* @param attr an attribute set
* @return true if the sets are equivalent
*/
public boolean isEqual(AttributeSet attr);
/**
* Returns an attribute set that is guaranteed not
* to change over time.
*
* @return a copy of the attribute set
*/
public AttributeSet copyAttributes();
/**
* 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.
*
* @param key the non-null key of the attribute binding
* @return the value of the attribute, or {@code null} if not found
*/
public Object getAttribute(Object key);
/**
* 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
* <code>Enumeration</code> may be anything and are not constrained to
* a particular <code>Object</code> type.
* <p>
* This method never returns {@code null}. For a set with no attributes, it
* returns an empty {@code Enumeration}.
*
* @return the names
*/
public Enumeration<?> getAttributeNames();
/**
* Returns {@code 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.
*
* @param name the non-null attribute name
* @param value the value
* @return {@code true} if the set defines the attribute with an
* equal value, either locally or through its resolving parent
* @throws NullPointerException if either {@code name} or
* {@code value} is {@code null}
*/
public boolean containsAttribute(Object name, Object value);
/**
* Returns {@code 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.
*
* @param attributes the set of attributes to check against
* @return {@code true} if this set defines all the attributes with equal
* values, either locally or through its resolving parent
* @throws NullPointerException if {@code attributes} is {@code null}
*/
public boolean containsAttributes(AttributeSet attributes);
/**
* Gets the resolving parent.
*
* @return the parent
*/
public AttributeSet getResolveParent();
/**
* Attribute name used to name the collection of
* attributes.
*/
public static final Object NameAttribute = StyleConstants.NameAttribute;
/**
* Attribute name used to identify the resolving parent
* set of attributes, if one is defined.
*/
public static final Object ResolveAttribute = StyleConstants.ResolveAttribute;
}