InputMap.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation. Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
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 * 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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packagejavax.swing;

importjava.io.IOException;
importjava.io.ObjectInputStream;
importjava.io.ObjectOutputStream;
importjava.io.Serial;
importjava.io.Serializable;
importjava.util.HashMap;

/**
 * {@code InputMap} provides a binding between an input event (currently only
 * {@code KeyStroke}s are used) and an {@code Object}. {@code InputMap}s are
 * usually used with an {@code ActionMap}, to determine an {@code Action} to
 * perform when a key is pressed. An {@code InputMap} can have a parent that
 * is searched for bindings not defined in the {@code InputMap}.
 * <p>As with {@code ActionMap} if you create a cycle, eg:
 * <pre>
 * InputMap am = new InputMap();
 * InputMap bm = new InputMap():
 * am.setParent(bm);
 * bm.setParent(am);
 * </pre>
 * some of the methods will cause a StackOverflowError to be thrown.
 *
 * @author Scott Violet
 * @since 1.3
 */
@SuppressWarnings("serial")
publicclassInputMapimplementsSerializable {
/** Handles the mapping between KeyStroke and Action name. */
privatetransientArrayTablearrayTable;
/** Parent that handles any bindings we don't contain. */
privateInputMapparent;


/**
 * Creates an {@code InputMap} with no parent and no mappings.
 */
publicInputMap() {
 }

/**
 * Sets this {@code InputMap}'s parent.
 *
 * @param map the {@code InputMap} that is the parent of this one
 */
publicvoidsetParent(InputMapmap) {
this.parent = map;
 }

/**
 * Gets this {@code InputMap}'s parent.
 *
 * @return map the {@code InputMap} that is the parent of this one,
 * or null if this {@code InputMap} has no parent
 */
publicInputMapgetParent() {
returnparent;
 }

/**
 * Adds a binding for {@code keyStroke} to {@code actionMapKey}.
 * If {@code actionMapKey} is null, this removes the current binding
 * for {@code keyStroke}.
 *
 * @param keyStroke a {@code KeyStroke}
 * @param actionMapKey an action map key
 */
publicvoidput(KeyStrokekeyStroke, ObjectactionMapKey) {
if (keyStroke == null) {
return;
 }
if (actionMapKey == null) {
remove(keyStroke);
 }
else {
if (arrayTable == null) {
arrayTable = newArrayTable();
 }
arrayTable.put(keyStroke, actionMapKey);
 }
 }

/**
 * Returns the binding for {@code keyStroke}, messaging the
 * parent {@code InputMap} if the binding is not locally defined.
 *
 * @param keyStroke the {@code KeyStroke} for which to get the binding
 * @return the binding for {@code keyStroke}
 */
publicObjectget(KeyStrokekeyStroke) {
if (arrayTable == null) {
InputMapparent = getParent();

if (parent != null) {
returnparent.get(keyStroke);
 }
returnnull;
 }
Objectvalue = arrayTable.get(keyStroke);

if (value == null) {
InputMapparent = getParent();

if (parent != null) {
returnparent.get(keyStroke);
 }
 }
returnvalue;
 }

/**
 * Removes the binding for {@code key} from this {@code InputMap}.
 *
 * @param key the {@code KeyStroke} for which to remove the binding
 */
publicvoidremove(KeyStrokekey) {
if (arrayTable != null) {
arrayTable.remove(key);
 }
 }

/**
 * Removes all the mappings from this {@code InputMap}.
 */
publicvoidclear() {
if (arrayTable != null) {
arrayTable.clear();
 }
 }

/**
 * Returns the {@code KeyStroke}s that are bound in this {@code InputMap}.
 *
 * @return an array of the {@code KeyStroke}s that are bound in this
 * {@code InputMap}
 */
publicKeyStroke[] keys() {
if (arrayTable == null) {
returnnull;
 }
KeyStroke[] keys = newKeyStroke[arrayTable.size()];
arrayTable.getKeys(keys);
returnkeys;
 }

/**
 * Returns the number of {@code KeyStroke} bindings.
 *
 * @return the number of {@code KeyStroke} bindings
 */
publicintsize() {
if (arrayTable == null) {
return0;
 }
returnarrayTable.size();
 }

/**
 * Returns an array of the {@code KeyStroke}s defined in this
 * {@code InputMap} and its parent. This differs from {@code keys()}
 * in that this method includes the keys defined in the parent.
 *
 * @return an array of the {@code KeyStroke}s defined in this
 * {@code InputMap} and its parent
 */
publicKeyStroke[] allKeys() {
intcount = size();
InputMapparent = getParent();

if (count == 0) {
if (parent != null) {
returnparent.allKeys();
 }
returnkeys();
 }
if (parent == null) {
returnkeys();
 }
KeyStroke[] keys = keys();
KeyStroke[] pKeys = parent.allKeys();

if (pKeys == null) {
returnkeys;
 }
if (keys == null) {
// Should only happen if size() != keys.length, which should only
// happen if mutated from multiple threads (or a bogus subclass).
returnpKeys;
 }

HashMap<KeyStroke, KeyStroke> keyMap = newHashMap<KeyStroke, KeyStroke>();
intcounter;

for (counter = keys.length - 1; counter >= 0; counter--) {
keyMap.put(keys[counter], keys[counter]);
 }
for (counter = pKeys.length - 1; counter >= 0; counter--) {
keyMap.put(pKeys[counter], pKeys[counter]);
 }

KeyStroke[] allKeys = newKeyStroke[keyMap.size()];

returnkeyMap.keySet().toArray(allKeys);
 }

@Serial
privatevoidwriteObject(ObjectOutputStreams) throwsIOException {
s.defaultWriteObject();

ArrayTable.writeArrayTable(s, arrayTable);
 }

@Serial
privatevoidreadObject(ObjectInputStreams) throwsClassNotFoundException,
IOException {
s.defaultReadObject();
for (intcounter = s.readInt() - 1; counter >= 0; counter--) {
put((KeyStroke)s.readObject(), s.readObject());
 }
 }
}