/*

 * Copyright (c) 2011, 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;

final class LWListPeer

        extends LWComponentPeer<List, LWListPeer.ScrollableJList>

        implements ListPeer {

    LWListPeer(final List target, final PlatformComponent platformComponent) {

        super(target, platformComponent);

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

            getTarget().setBackground(SystemColor.text);

        }

    }

    @Override

    protected 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

    protected 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(final int rows) {

        return getMinimumSize(rows);

    }

    @Override

    public Dimension getMinimumSize(final int rows) {

        synchronized (getDelegateLock()) {

            final int margin = 2;

            final int space = 1;

            // TODO: count ScrollPane's scrolling elements if any.

            final FontMetrics fm = getFontMetrics(getFont());

            final int itemHeight = (fm.getHeight() - fm.getLeading()) + (2 * space);

            return new Dimension(20 + (fm == null ? 10 * 15 : fm.stringWidth("0123456789abcde")),

                    (fm == null ? 10 : itemHeight) * rows + (2 * margin));

        }

    }

    private void revalidate() {

        synchronized (getDelegateLock()) {

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

            getDelegate().validate();

        }

    }

    final class ScrollableJList extends JScrollPane implements ListSelectionListener {

        private boolean skipStateChangedEvent;

        private DefaultListModel<Object> model =

                new DefaultListModel<Object>() {

                    @Override

                    public void add(final int index, final Object 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<Object> 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

        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();

            }

        }

        public JList getView() {

            return (JList) getViewport().getView();

        }

        public DefaultListModel<Object> 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<Object> {

            JListDelegate() {

                super(ScrollableJList.this.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).toString(), 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 Object selectedValue = getSelectedValue();

                    if(selectedValue != null){

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

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

                    }

                }

            }

            //Needed for Autoscroller.

            @Override

            public Point getLocationOnScreen() {

                return LWListPeer.this.getLocationOnScreen();

            }

        }

    }

}