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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * particular file as subject to the "Classpath" exception as provided
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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,
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package javax.swing;

import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Enumeration;
import java.util.Hashtable;

/*
 * Private storage mechanism for Action key-value pairs.
 * In most cases this will be an array of alternating
 * key-value pairs.  As it grows larger it is scaled
 * up to a Hashtable.
 * <p>
 * This does no synchronization, if you need thread safety synchronize on
 * another object before calling this.
 *
 * @author Georges Saab
 * @author Scott Violet
 */
class ArrayTable implements Cloneable {
    // Our field for storage
    private Object table = null;
    private static final int ARRAY_BOUNDARY = 8;


    
Writes the passed in ArrayTable to the passed in ObjectOutputStream. The data is saved as an integer indicating how many key/value pairs are being archived, followed by the the key/value pairs. If table is null, 0 will be written to s.

This is a convenience method that ActionMap/InputMap and AbstractAction use to avoid having the same code in each class.

/** * Writes the passed in ArrayTable to the passed in ObjectOutputStream. * The data is saved as an integer indicating how many key/value * pairs are being archived, followed by the the key/value pairs. If * <code>table</code> is null, 0 will be written to <code>s</code>. * <p> * This is a convenience method that ActionMap/InputMap and * AbstractAction use to avoid having the same code in each class. */
static void writeArrayTable(ObjectOutputStream s, ArrayTable table) throws IOException { Object keys[]; if (table == null || (keys = table.getKeys(null)) == null) { s.writeInt(0); } else { // Determine how many keys have Serializable values, when // done all non-null values in keys identify the Serializable // values. int validCount = 0; for (int counter = 0; counter < keys.length; counter++) { Object key = keys[counter]; /* include in Serialization when both keys and values are Serializable */ if ( (key instanceof Serializable && table.get(key) instanceof Serializable) || /* include these only so that we get the appropriate exception below */ (key instanceof ClientPropertyKey && ((ClientPropertyKey)key).getReportValueNotSerializable())) { validCount++; } else { keys[counter] = null; } } // Write ou the Serializable key/value pairs. s.writeInt(validCount); if (validCount > 0) { for (Object key : keys) { if (key != null) { s.writeObject(key); s.writeObject(table.get(key)); if (--validCount == 0) { break; } } } } } } /* * Put the key-value pair into storage */ public void put(Object key, Object value){ if (table==null) { table = new Object[] {key, value}; } else { int size = size(); if (size < ARRAY_BOUNDARY) { // We are an array if (containsKey(key)) { Object[] tmp = (Object[])table; for (int i = 0; i<tmp.length-1; i+=2) { if (tmp[i].equals(key)) { tmp[i+1]=value; break; } } } else { Object[] array = (Object[])table; int i = array.length; Object[] tmp = new Object[i+2]; System.arraycopy(array, 0, tmp, 0, i); tmp[i] = key; tmp[i+1] = value; table = tmp; } } else { // We are a hashtable if ((size==ARRAY_BOUNDARY) && isArray()) { grow(); } ((Hashtable<Object,Object>)table).put(key, value); } } } /* * Gets the value for key */ public Object get(Object key) { Object value = null; if (table !=null) { if (isArray()) { Object[] array = (Object[])table; for (int i = 0; i<array.length-1; i+=2) { if (array[i].equals(key)) { value = array[i+1]; break; } } } else { value = ((Hashtable)table).get(key); } } return value; } /* * Returns the number of pairs in storage */ public int size() { int size; if (table==null) return 0; if (isArray()) { size = ((Object[])table).length/2; } else { size = ((Hashtable)table).size(); } return size; } /* * Returns true if we have a value for the key */ public boolean containsKey(Object key) { boolean contains = false; if (table !=null) { if (isArray()) { Object[] array = (Object[])table; for (int i = 0; i<array.length-1; i+=2) { if (array[i].equals(key)) { contains = true; break; } } } else { contains = ((Hashtable)table).containsKey(key); } } return contains; } /* * Removes the key and its value * Returns the value for the pair removed */ public Object remove(Object key){ Object value = null; if (key==null) { return null; } if (table !=null) { if (isArray()){ // Is key on the list? int index = -1; Object[] array = (Object[])table; for (int i = array.length-2; i>=0; i-=2) { if (array[i].equals(key)) { index = i; value = array[i+1]; break; } } // If so, remove it if (index != -1) { Object[] tmp = new Object[array.length-2]; // Copy the list up to index System.arraycopy(array, 0, tmp, 0, index); // Copy from two past the index, up to // the end of tmp (which is two elements // shorter than the old list) if (index < tmp.length) System.arraycopy(array, index+2, tmp, index, tmp.length - index); // set the listener array to the new array or null table = (tmp.length == 0) ? null : tmp; } } else { value = ((Hashtable)table).remove(key); } if (size()==ARRAY_BOUNDARY - 1 && !isArray()) { shrink(); } } return value; }
Removes all the mappings.
/** * Removes all the mappings. */
public void clear() { table = null; } /* * Returns a clone of the <code>ArrayTable</code>. */ public Object clone() { ArrayTable newArrayTable = new ArrayTable(); if (isArray()) { Object[] array = (Object[])table; for (int i = 0 ;i < array.length-1 ; i+=2) { newArrayTable.put(array[i], array[i+1]); } } else { Hashtable<?,?> tmp = (Hashtable)table; Enumeration<?> keys = tmp.keys(); while (keys.hasMoreElements()) { Object o = keys.nextElement(); newArrayTable.put(o,tmp.get(o)); } } return newArrayTable; }
Returns the keys of the table, or null if there are currently no bindings.
Params:
  • keys – array of keys
Returns:an array of bindings
/** * Returns the keys of the table, or <code>null</code> if there * are currently no bindings. * @param keys array of keys * @return an array of bindings */
public Object[] getKeys(Object[] keys) { if (table == null) { return null; } if (isArray()) { Object[] array = (Object[])table; if (keys == null) { keys = new Object[array.length / 2]; } for (int i = 0, index = 0 ;i < array.length-1 ; i+=2, index++) { keys[index] = array[i]; } } else { Hashtable<?,?> tmp = (Hashtable)table; Enumeration<?> enum_ = tmp.keys(); int counter = tmp.size(); if (keys == null) { keys = new Object[counter]; } while (counter > 0) { keys[--counter] = enum_.nextElement(); } } return keys; } /* * Returns true if the current storage mechanism is * an array of alternating key-value pairs. */ private boolean isArray(){ return (table instanceof Object[]); } /* * Grows the storage from an array to a hashtable. */ private void grow() { Object[] array = (Object[])table; Hashtable<Object, Object> tmp = new Hashtable<Object, Object>(array.length/2); for (int i = 0; i<array.length; i+=2) { tmp.put(array[i], array[i+1]); } table = tmp; } /* * Shrinks the storage from a hashtable to an array. */ private void shrink() { Hashtable<?,?> tmp = (Hashtable)table; Object[] array = new Object[tmp.size()*2]; Enumeration<?> keys = tmp.keys(); int j = 0; while (keys.hasMoreElements()) { Object o = keys.nextElement(); array[j] = o; array[j+1] = tmp.get(o); j+=2; } table = array; } }