/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * 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

 * particular file as subject to the "Classpath" exception as provided

 *

 * 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).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package javax.swing;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

import java.util.HashMap;

import java.util.Set;

/**

 * <code>InputMap</code> provides a binding between an input event

 * (currently only <code>KeyStroke</code>s are used)

 * and an <code>Object</code>. <code>InputMap</code>s

 * are usually used with an <code>ActionMap</code>,

 * to determine an <code>Action</code> to perform

 * when a key is pressed.

 * An <code>InputMap</code> can have a parent

 * that is searched for bindings not defined in the <code>InputMap</code>.

 * <p>As with <code>ActionMap</code> 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

 */

public class InputMap implements Serializable {

    /** Handles the mapping between KeyStroke and Action name. */

    private transient ArrayTable     arrayTable;

    /** Parent that handles any bindings we don't contain. */

    private InputMap                                parent;

    /**

     * Creates an <code>InputMap</code> with no parent and no mappings.

     */

    public InputMap() {

    }

    /**

     * Sets this <code>InputMap</code>'s parent.

     *

     * @param map  the <code>InputMap</code> that is the parent of this one

     */

    public void setParent(InputMap map) {

        this.parent = map;

    }

    /**

     * Gets this <code>InputMap</code>'s parent.

     *

     * @return map  the <code>InputMap</code> that is the parent of this one,

     *              or null if this <code>InputMap</code> has no parent

     */

    public InputMap getParent() {

        return parent;

    }

    /**

     * Adds a binding for <code>keyStroke</code> to <code>actionMapKey</code>.

     * If <code>actionMapKey</code> is null, this removes the current binding

     * for <code>keyStroke</code>.

     */

    public void put(KeyStroke keyStroke, Object actionMapKey) {

        if (keyStroke == null) {

            return;

        }

        if (actionMapKey == null) {

            remove(keyStroke);

        }

        else {

            if (arrayTable == null) {

                arrayTable = new ArrayTable();

            }

            arrayTable.put(keyStroke, actionMapKey);

        }

    }

    /**

     * Returns the binding for <code>keyStroke</code>, messaging the

     * parent <code>InputMap</code> if the binding is not locally defined.

     */

    public Object get(KeyStroke keyStroke) {

        if (arrayTable == null) {

            InputMap    parent = getParent();

            if (parent != null) {

                return parent.get(keyStroke);

            }

            return null;

        }

        Object value = arrayTable.get(keyStroke);

        if (value == null) {

            InputMap    parent = getParent();

            if (parent != null) {

                return parent.get(keyStroke);

            }

        }

        return value;

    }

    /**

     * Removes the binding for <code>key</code> from this

     * <code>InputMap</code>.

     */

    public void remove(KeyStroke key) {

        if (arrayTable != null) {

            arrayTable.remove(key);

        }

    }

    /**

     * Removes all the mappings from this <code>InputMap</code>.

     */

    public void clear() {

        if (arrayTable != null) {

            arrayTable.clear();

        }

    }

    /**

     * Returns the <code>KeyStroke</code>s that are bound in this <code>InputMap</code>.

     */

    public KeyStroke[] keys() {

        if (arrayTable == null) {

            return null;

        }

        KeyStroke[] keys = new KeyStroke[arrayTable.size()];

        arrayTable.getKeys(keys);

        return keys;

    }

    /**

     * Returns the number of <code>KeyStroke</code> bindings.

     */

    public int size() {

        if (arrayTable == null) {

            return 0;

        }

        return arrayTable.size();

    }

    /**

     * Returns an array of the <code>KeyStroke</code>s defined in this

     * <code>InputMap</code> and its parent. This differs from <code>keys()</code> in that

     * this method includes the keys defined in the parent.

     */

    public KeyStroke[] allKeys() {

        int             count = size();

        InputMap        parent = getParent();

        if (count == 0) {

            if (parent != null) {

                return parent.allKeys();

            }

            return keys();

        }

        if (parent == null) {

            return keys();

        }

        KeyStroke[]    keys = keys();

        KeyStroke[]    pKeys =  parent.allKeys();

        if (pKeys == null) {

            return keys;

        }

        if (keys == null) {

            // Should only happen if size() != keys.length, which should only

            // happen if mutated from multiple threads (or a bogus subclass).

            return pKeys;

        }

        HashMap<KeyStroke, KeyStroke> keyMap = new HashMap<KeyStroke, KeyStroke>();

        int            counter;

        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 = new KeyStroke[keyMap.size()];

        return keyMap.keySet().toArray(allKeys);

    }

    private void writeObject(ObjectOutputStream s) throws IOException {

        s.defaultWriteObject();

        ArrayTable.writeArrayTable(s, arrayTable);

    }

    private void readObject(ObjectInputStream s) throws ClassNotFoundException,

                                                 IOException {

        s.defaultReadObject();

        for (int counter = s.readInt() - 1; counter >= 0; counter--) {

            put((KeyStroke)s.readObject(), s.readObject());

        }

    }

}