diff options
Diffstat (limited to 'libjava/classpath/javax/swing/text/SimpleAttributeSet.java')
| -rw-r--r-- | libjava/classpath/javax/swing/text/SimpleAttributeSet.java | 195 |
1 files changed, 182 insertions, 13 deletions
diff --git a/libjava/classpath/javax/swing/text/SimpleAttributeSet.java b/libjava/classpath/javax/swing/text/SimpleAttributeSet.java index 0c9f607b196..8dbcb0c6a14 100644 --- a/libjava/classpath/javax/swing/text/SimpleAttributeSet.java +++ b/libjava/classpath/javax/swing/text/SimpleAttributeSet.java @@ -1,5 +1,5 @@ /* SimpleAttributeSet.java -- - Copyright (C) 2004, 2005 Free Software Foundation, Inc. + Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc. This file is part of GNU Classpath. @@ -42,33 +42,67 @@ import java.io.Serializable; import java.util.Enumeration; import java.util.Hashtable; +/** + * A set of attributes. + */ public class SimpleAttributeSet implements MutableAttributeSet, Serializable, Cloneable { /** The serialization UID (compatible with JDK1.5). */ private static final long serialVersionUID = 8267656273837665219L; + /** An empty attribute set. */ public static final AttributeSet EMPTY = new SimpleAttributeSet(); + /** Storage for the attributes. */ Hashtable tab; + /** + * Creates a new attribute set that is initially empty. + */ public SimpleAttributeSet() { - this(null); + tab = new Hashtable(); } + /** + * Creates a new <code>SimpleAttributeSet</code> with the same attributes + * and resolve parent as the specified set. + * + * @param a the attributes (<code>null</code> not permitted). + * + * @throws NullPointerException if <code>a</code> is <code>null</code>. + */ public SimpleAttributeSet(AttributeSet a) { tab = new Hashtable(); - if (a != null) - addAttributes(a); + addAttributes(a); } + /** + * Adds an attribute with the given <code>name</code> and <code>value</code> + * to the set. If the set already contains an attribute with the given + * <code>name</code>, the attribute value is updated. + * + * @param name the attribute name (<code>null</code> not permitted). + * @param value the value (<code>null</code> not permitted). + * + * @throws NullPointerException if either argument is <code>null</code>. + */ public void addAttribute(Object name, Object value) { tab.put(name, value); } + /** + * Adds all the attributes from <code>attributes</code> to this set. + * + * @param attributes the set of attributes to add (<code>null</code> not + * permitted). + * + * @throws NullPointerException if <code>attributes</code> is + * <code>null</code>. + */ public void addAttributes(AttributeSet attributes) { Enumeration e = attributes.getAttributeNames(); @@ -80,6 +114,11 @@ public class SimpleAttributeSet } } + /** + * Returns a clone of the attribute set. + * + * @return A clone of the attribute set. + */ public Object clone() { SimpleAttributeSet s = new SimpleAttributeSet(); @@ -97,9 +136,18 @@ public class SimpleAttributeSet */ public boolean containsAttribute(Object name, Object value) { - return (tab.containsKey(name) && tab.get(name).equals(value)) || - (getResolveParent() != null && getResolveParent(). - containsAttribute(name, value)); + if (value == null) + throw new NullPointerException("Null 'value' argument."); + if (tab.containsKey(name)) + return tab.get(name).equals(value); + else + { + AttributeSet p = getResolveParent(); + if (p != null) + return p.containsAttribute(name, value); + else + return false; + } } /** @@ -115,6 +163,15 @@ public class SimpleAttributeSet && tab.get(name).equals(value); } + /** + * Returns <code>true</code> of this <code>AttributeSet</code> contains all + * of the specified <code>attributes</code>. + * + * @param attributes the requested attributes + * + * @return <code>true</code> of this <code>AttributeSet</code> contains all + * of the specified <code>attributes</code> + */ public boolean containsAttributes(AttributeSet attributes) { Enumeration e = attributes.getAttributeNames(); @@ -128,11 +185,24 @@ public class SimpleAttributeSet return true; } + /** + * Creates and returns a copy of this <code>AttributeSet</code>. + * + * @return a copy of this <code>AttributeSet</code> + */ public AttributeSet copyAttributes() { return (AttributeSet) clone(); } + /** + * Checks this set for equality with an arbitrary object. + * + * @param obj the object (<code>null</code> permitted). + * + * @return <code>true</code> if this set is equal to <code>obj</code>, and + * <code>false</code> otherwise. + */ public boolean equals(Object obj) { return @@ -140,44 +210,95 @@ public class SimpleAttributeSet && this.isEqual((AttributeSet) obj); } + /** + * Returns the value of the specified attribute, or <code>null</code> if + * there is no attribute with that name. If the attribute is not defined + * directly in this set, the parent hierarchy (if there is one) will be + * used. + * + * @param name the attribute (<code>null</code> not permitted). + * + * @throws NullPointerException if <code>name</code> is <code>null</code>. + */ public Object getAttribute(Object name) { Object val = tab.get(name); if (val != null) return val; - Object p = getResolveParent(); - if (p != null && p instanceof AttributeSet) - return (((AttributeSet)p).getAttribute(name)); + AttributeSet p = getResolveParent(); + if (p != null) + return p.getAttribute(name); return null; } + /** + * Returns the number of attributes stored in this set, plus 1 if a parent + * has been specified (the reference to the parent is stored as a special + * attribute). The attributes stored in the parent do NOT contribute + * to the count. + * + * @return The attribute count. + */ public int getAttributeCount() { return tab.size(); } + /** + * Returns an enumeration of the attribute names. + * + * @return An enumeration of the attribute names. + */ public Enumeration getAttributeNames() { return tab.keys(); } + /** + * Returns the resolving parent. + * + * @return The resolving parent (possibly <code>null</code>). + * + * @see #setResolveParent(AttributeSet) + */ public AttributeSet getResolveParent() { return (AttributeSet) tab.get(ResolveAttribute); } + /** + * Returns a hash code for this instance. + * + * @return A hash code. + */ public int hashCode() { return tab.hashCode(); } + /** + * Returns <code>true</code> if the given attribute is defined in this set, + * and <code>false</code> otherwise. The parent attribute set is not + * checked. + * + * @param attrName the attribute name (<code>null</code> not permitted). + */ public boolean isDefined(Object attrName) { return tab.containsKey(attrName); } + /** + * Returns <code>true</code> if the set contains no attributes, and + * <code>false</code> otherwise. Note that the resolving parent is + * stored as an attribute, so this method will return <code>false</code> if + * a resolving parent is set. + * + * @return <code>true</code> if the set contains no attributes, and + * <code>false</code> otherwise. + */ public boolean isEmpty() { return tab.isEmpty(); @@ -186,7 +307,13 @@ public class SimpleAttributeSet /** * Returns true if the given set has the same number of attributes * as this set and <code>containsAttributes(attr)</code> returns - * true. + * <code>true</code>. + * + * @param attr the attribute set (<code>null</code> not permitted). + * + * @return A boolean. + * + * @throws NullPointerException if <code>attr</code> is <code>null</code>. */ public boolean isEqual(AttributeSet attr) { @@ -194,6 +321,15 @@ public class SimpleAttributeSet && this.containsAttributes(attr); } + /** + * Removes the attribute with the specified <code>name</code>, if this + * attribute is defined. This method will only remove an attribute from + * this set, not from the resolving parent. + * + * @param name the attribute name (<code>null</code> not permitted). + * + * @throws NullPointerException if <code>name</code> is <code>null</code>. + */ public void removeAttribute(Object name) { tab.remove(name); @@ -202,7 +338,12 @@ public class SimpleAttributeSet /** * Removes attributes from this set if they are found in the * given set. Only attributes whose key AND value are removed. - * Removes attributes only from this set, not from the resolving parent. + * Removes attributes only from this set, not from the resolving parent. + * Since the resolving parent is stored as an attribute, if + * <code>attributes</code> has the same resolving parent as this set, the + * parent will be removed from this set. + * + * @param attributes the attributes (<code>null</code> not permitted). */ public void removeAttributes(AttributeSet attributes) { @@ -216,6 +357,14 @@ public class SimpleAttributeSet } } + /** + * Removes the attributes listed in <code>names</code>. + * + * @param names the attribute names (<code>null</code> not permitted). + * + * @throws NullPointerException if <code>names</code> is <code>null</code> + * or contains any <code>null</code> values. + */ public void removeAttributes(Enumeration names) { while (names.hasMoreElements()) @@ -224,11 +373,31 @@ public class SimpleAttributeSet } } + /** + * Sets the reolving parent for this set. When looking up an attribute, if + * it is not found in this set, then the resolving parent is also used for + * the lookup. + * <p> + * Note that the parent is stored as an attribute, and will contribute 1 to + * the count returned by {@link #getAttributeCount()}. + * + * @param parent the parent attribute set (<code>null</code> not permitted). + * + * @throws NullPointerException if <code>parent</code> is <code>null</code>. + * + * @see #setResolveParent(AttributeSet) + */ public void setResolveParent(AttributeSet parent) { addAttribute(ResolveAttribute, parent); } - + + /** + * Returns a string representation of this instance, typically used for + * debugging purposes. + * + * @return A string representation of this instance. + */ public String toString() { return tab.toString(); |