/*

 * 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 javax.swing.*;

import javax.swing.event.*;

import java.awt.*;

import java.awt.event.*;

import java.awt.peer.ListPeer;

import java.util.Arrays;

/**

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

 * the {@link JList}, which is placed inside {@link JScrollPane}.

 */

final class LWListPeer extends LWComponentPeer<List, LWListPeer.ScrollableJList>

        implements ListPeer {

    /**

     * The default number of visible rows.

     */

    private static final int DEFAULT_VISIBLE_ROWS = 4; // From java.awt.List,

    /**

     * This text is used for cell bounds calculation.

     */

    private static final String TEXT = "0123456789abcde";

    LWListPeer(final List target, final PlatformComponent platformComponent) {

        super(target, platformComponent);

        if (!getTarget().isBackgroundSet()) {

            getTarget().setBackground(SystemColor.text);

        }

    }

    @Override

    ScrollableJList createDelegate() {

        return new ScrollableJList();

    }

    @Override

    void initializeImpl() {

        super.initializeImpl();

        setMultipleMode(getTarget().isMultipleMode());

        final int[] selectedIndices = getTarget().getSelectedIndexes();

        synchronized (getDelegateLock()) {

            getDelegate().setSkipStateChangedEvent(true);

            getDelegate().getView().setSelectedIndices(selectedIndices);

            getDelegate().setSkipStateChangedEvent(false);

        }

    }

    @Override

    public boolean isFocusable() {

        return true;

    }

    @Override

    Component getDelegateFocusOwner() {

        return getDelegate().getView();

    }

    @Override

    public int[] getSelectedIndexes() {

        synchronized (getDelegateLock()) {

            return getDelegate().getView().getSelectedIndices();

        }

    }

    @Override

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

        synchronized (getDelegateLock()) {

            getDelegate().getModel().add(index, item);

            revalidate();

        }

    }

    @Override

    public void delItems(final int start, final int end) {

        synchronized (getDelegateLock()) {

            getDelegate().getModel().removeRange(start, end);

            revalidate();

        }

    }

    @Override

    public void removeAll() {

        synchronized (getDelegateLock()) {

            getDelegate().getModel().removeAllElements();

            revalidate();

        }

    }

    @Override

    public void select(final int index) {

        synchronized (getDelegateLock()) {

            getDelegate().setSkipStateChangedEvent(true);

            getDelegate().getView().setSelectedIndex(index);

            getDelegate().setSkipStateChangedEvent(false);

        }

    }

    @Override

    public void deselect(final int index) {

        synchronized (getDelegateLock()) {

            getDelegate().getView().getSelectionModel().

                    removeSelectionInterval(index, index);

        }

    }

    @Override

    public void makeVisible(final int index) {

        synchronized (getDelegateLock()) {

            getDelegate().getView().ensureIndexIsVisible(index);

        }

    }

    @Override

    public void setMultipleMode(final boolean m) {

        synchronized (getDelegateLock()) {

            getDelegate().getView().setSelectionMode(m ?

                    ListSelectionModel.MULTIPLE_INTERVAL_SELECTION

                    : ListSelectionModel.SINGLE_SELECTION);

        }

    }

    @Override

    public Dimension getPreferredSize() {

        return getMinimumSize();

    }

    @Override

    public Dimension getMinimumSize() {

        return getMinimumSize(DEFAULT_VISIBLE_ROWS);

    }

    @Override

    public Dimension getPreferredSize(final int rows) {

        return getMinimumSize(rows);

    }

    @Override

    public Dimension getMinimumSize(final int rows) {

        synchronized (getDelegateLock()) {

            final Dimension size = getCellSize();

            size.height *= rows;

            // Always take vertical scrollbar into account.

            final JScrollBar vbar = getDelegate().getVerticalScrollBar();

            size.width += vbar != null ? vbar.getMinimumSize().width : 0;

            // JScrollPane and JList insets

            final Insets pi = getDelegate().getInsets();

            final Insets vi = getDelegate().getView().getInsets();

            size.width += pi.left + pi.right + vi.left + vi.right;

            size.height += pi.top + pi.bottom + vi.top + vi.bottom;

            return size;

        }

    }

    private Dimension getCellSize() {

        final JList<String> jList = getDelegate().getView();

        final ListCellRenderer<? super String> cr = jList.getCellRenderer();

        final Component cell = cr.getListCellRendererComponent(jList, TEXT, 0,

                                                               false, false);

        return cell.getPreferredSize();

    }

    private void revalidate() {

        synchronized (getDelegateLock()) {

            getDelegate().getView().invalidate();

            getDelegate().validate();

        }

    }

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

    final class ScrollableJList extends JScrollPane implements ListSelectionListener {

        private boolean skipStateChangedEvent;

        private final DefaultListModel<String> model =

                new DefaultListModel<String>() {

                    @Override

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

                        if (index == -1) {

                            addElement(element);

                        } else {

                            super.add(index, element);

                        }

                    }

                };

        private int[] oldSelectedIndices = new int[0];

        ScrollableJList() {

            getViewport().setScrollMode(JViewport.SIMPLE_SCROLL_MODE);

            final JList<String> list = new JListDelegate();

            list.addListSelectionListener(this);

            getViewport().setView(list);

            // Pull the items from the target.

            final String[] items = getTarget().getItems();

            for (int i = 0; i < items.length; i++) {

                model.add(i, items[i]);

            }

        }

        public boolean isSkipStateChangedEvent() {

            return skipStateChangedEvent;

        }

        public void setSkipStateChangedEvent(boolean skipStateChangedEvent) {

            this.skipStateChangedEvent = skipStateChangedEvent;

        }

        @Override

        @SuppressWarnings("unchecked")

        public void valueChanged(final ListSelectionEvent e) {

            if (!e.getValueIsAdjusting() && !isSkipStateChangedEvent()) {

                final JList<?> source = (JList<?>) e.getSource();

                for(int i = 0 ; i < source.getModel().getSize(); i++) {

                    final boolean wasSelected = Arrays.binarySearch(oldSelectedIndices, i) >= 0;

                    final boolean isSelected = source.isSelectedIndex(i);

                    if (wasSelected == isSelected) {

                        continue;

                    }

                    final int state = !wasSelected && isSelected ? ItemEvent.SELECTED: ItemEvent.DESELECTED;

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

                            i, state));

                }

                oldSelectedIndices = source.getSelectedIndices();

            }

        }

        @SuppressWarnings("unchecked")

        public JList<String> getView() {

            return (JList<String>) getViewport().getView();

        }

        public DefaultListModel<String> getModel() {

            return model;

        }

        @Override

        public void setEnabled(final boolean enabled) {

            getView().setEnabled(enabled);

            super.setEnabled(enabled);

        }

        @Override

        public void setOpaque(final boolean isOpaque) {

            super.setOpaque(isOpaque);

            if (getView() != null) {

                getView().setOpaque(isOpaque);

            }

        }

        @Override

        public void setFont(Font font) {

            super.setFont(font);

            if (getView() != null) {

                getView().setFont(font);

                LWListPeer.this.revalidate();

            }

        }

        private final class JListDelegate extends JList<String> {

            JListDelegate() {

                super(model);

            }

            @Override

            public boolean hasFocus() {

                return getTarget().hasFocus();

            }

            @Override

            protected void processMouseEvent(final MouseEvent e) {

                super.processMouseEvent(e);

                if (e.getID() == MouseEvent.MOUSE_CLICKED && e.getClickCount() == 2) {

                    final int index = locationToIndex(e.getPoint());

                    if (0 <= index && index < getModel().getSize()) {

                        LWListPeer.this.postEvent(new ActionEvent(getTarget(), ActionEvent.ACTION_PERFORMED,

                            getModel().getElementAt(index), e.getWhen(), e.getModifiers()));

                    }

                }

            }

            @Override

            protected void processKeyEvent(final KeyEvent e) {

                super.processKeyEvent(e);

                if (e.getID() == KeyEvent.KEY_PRESSED && e.getKeyCode() == KeyEvent.VK_ENTER) {

                    final String selectedValue = getSelectedValue();

                    if(selectedValue != null){

                        LWListPeer.this.postEvent(new ActionEvent(getTarget(), ActionEvent.ACTION_PERFORMED,

                            selectedValue, e.getWhen(), e.getModifiers()));

                    }

                }

            }

            //Needed for Autoscroller.

            @Override

            public Point getLocationOnScreen() {

                return LWListPeer.this.getLocationOnScreen();

            }

        }

    }

}