/*

 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.

 * 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

 * 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.

 *

 * 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.lwawt;

import java.awt.*;

import java.awt.event.ItemEvent;

import java.awt.event.ItemListener;

import java.awt.peer.ChoicePeer;

import javax.accessibility.Accessible;

import javax.swing.*;

/**

 * Lightweight implementation of {@link ChoicePeer}. Delegates most of the work

 * to the {@link JComboBox}.

 */

final class LWChoicePeer extends LWComponentPeer<Choice, JComboBox<String>>

        implements ChoicePeer, ItemListener {

    /**

     * According to Choice specification item events are sent in response to

     * user input, but not in response to calls to select(). But JComboBox are

     * sent item events in both cases. Should be used under delegateLock.

     */

    private boolean skipPostMessage;

    LWChoicePeer(final Choice target,

                 final PlatformComponent platformComponent) {

        super(target, platformComponent);

    }

    @Override

    JComboBox<String> createDelegate() {

        return new JComboBoxDelegate();

    }

    @Override

    void initializeImpl() {

        super.initializeImpl();

        final Choice choice = getTarget();

        final JComboBox<String> combo = getDelegate();

        synchronized (getDelegateLock()) {

            final int count = choice.getItemCount();

            for (int i = 0; i < count; ++i) {

                combo.addItem(choice.getItem(i));

            }

            select(choice.getSelectedIndex());

            // NOTE: the listener must be added at the very end, otherwise it

            // fires events upon initialization of the combo box.

            combo.addItemListener(this);

        }

    }

    @Override

    public void itemStateChanged(final ItemEvent e) {

        // AWT Choice sends SELECTED event only whereas JComboBox

        // sends both SELECTED and DESELECTED.

        if (e.getStateChange() == ItemEvent.SELECTED) {

            synchronized (getDelegateLock()) {

                if (skipPostMessage) {

                    return;

                }

                getTarget().select(getDelegate().getSelectedIndex());

            }

            postEvent(new ItemEvent(getTarget(), ItemEvent.ITEM_STATE_CHANGED,

                                    e.getItem(), ItemEvent.SELECTED));

        }

    }

    @Override

    public void add(final String item, final int index) {

        synchronized (getDelegateLock()) {

            getDelegate().insertItemAt(item, index);

        }

    }

    @Override

    public void remove(final int index) {

        synchronized (getDelegateLock()) {

            // We shouldn't post event, if selected item was removed.

            skipPostMessage = true;

            getDelegate().removeItemAt(index);

            skipPostMessage = false;

        }

    }

    @Override

    public void removeAll() {

        synchronized (getDelegateLock()) {

            getDelegate().removeAllItems();

        }

    }

    @Override

    public void select(final int index) {

        synchronized (getDelegateLock()) {

            if (index != getDelegate().getSelectedIndex()) {

                skipPostMessage = true;

                getDelegate().setSelectedIndex(index);

                skipPostMessage = false;

            }

        }

    }

    @Override

    public boolean isFocusable() {

        return true;

    }

    @SuppressWarnings("serial")// Safe: outer class is non-serializable.

    private final class JComboBoxDelegate extends JComboBox<String> {

        // Empty non private constructor was added because access to this

        // class shouldn't be emulated by a synthetic accessor method.

        JComboBoxDelegate() {

            super();

        }

        @Override

        public boolean hasFocus() {

            return getTarget().hasFocus();

        }

        //Needed for proper popup menu location

        @Override

        public Point getLocationOnScreen() {

            return LWChoicePeer.this.getLocationOnScreen();

        }

        /**

         * We should post ITEM_STATE_CHANGED event when the same element is

         * reselected.

         */

        @Override

        public void setSelectedItem(final Object anObject) {

            final Object oldSelection = selectedItemReminder;

            if (oldSelection != null && oldSelection.equals(anObject)) {

                selectedItemChanged();

            }

            super.setSelectedItem(anObject);

        }

        @Override

        public void firePopupMenuWillBecomeVisible() {

            super.firePopupMenuWillBecomeVisible();

            SwingUtilities.invokeLater(() -> {

                JPopupMenu popupMenu = getPopupMenu();

                // Need to override the invoker for proper grab handling

                if (popupMenu != null

                        && popupMenu.isShowing()

                        && popupMenu.getInvoker() != getTarget()) {

                    // The popup is now visible with correct location

                    // Save it and restore after toggling visibility and changing invoker

                    Point loc = popupMenu.getLocationOnScreen();

                    SwingUtilities.convertPointFromScreen(loc, this);

                    popupMenu.setVisible(false);

                    popupMenu.show(getTarget(), loc.x, loc.y);

                }

            });

        }

        private JPopupMenu getPopupMenu() {

            for (int i = 0; i < getAccessibleContext().getAccessibleChildrenCount(); i++) {

                Accessible child = getAccessibleContext().getAccessibleChild(i);

                if (child instanceof JPopupMenu) {

                    return  (JPopupMenu) child;

                }

            }

            return null;

        }

    }

}