/*

 * 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.ChangeListener;

import javax.swing.event.ChangeEvent;

import java.awt.*;

import java.awt.event.MouseWheelEvent;

import java.awt.peer.ScrollPanePeer;

import java.util.List;

/**

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

 * work to the {@link JScrollPane}.

 */

final class LWScrollPanePeer extends LWContainerPeer<ScrollPane, JScrollPane>

        implements ScrollPanePeer, ChangeListener {

    LWScrollPanePeer(final ScrollPane target,

                     final PlatformComponent platformComponent) {

        super(target, platformComponent);

    }

    @Override

    JScrollPane createDelegate() {

        final JScrollPane sp = new JScrollPane();

        final JPanel panel = new JPanel();

        panel.setOpaque(false);

        panel.setVisible(false);

        sp.getViewport().setView(panel);

        sp.setBorder(BorderFactory.createEmptyBorder());

        sp.getViewport().addChangeListener(this);

        return sp;

    }

    @Override

    public void handleEvent(AWTEvent e) {

        if (e instanceof MouseWheelEvent) {

            MouseWheelEvent wheelEvent = (MouseWheelEvent) e;

            //java.awt.ScrollPane consumes the event

            // in case isWheelScrollingEnabled() is true,

            // forcibly send the consumed event to the delegate

            if (getTarget().isWheelScrollingEnabled() && wheelEvent.isConsumed()) {

                sendEventToDelegate(wheelEvent);

            }

        } else {

            super.handleEvent(e);

        }

    }

    @Override

    public void stateChanged(final ChangeEvent e) {

        SwingUtilities.invokeLater(new Runnable() {

            @Override

            public void run() {

                final LWComponentPeer<?, ?> viewPeer = getViewPeer();

                if (viewPeer != null) {

                    final Rectangle r;

                    synchronized (getDelegateLock()) {

                        r = getDelegate().getViewport().getView().getBounds();

                    }

                    viewPeer.setBounds(r.x, r.y, r.width, r.height, SET_BOUNDS,

                                       true, true);

                }

            }

        });

    }

    @Override

    void initializeImpl() {

        super.initializeImpl();

        final int policy = getTarget().getScrollbarDisplayPolicy();

        synchronized (getDelegateLock()) {

            getDelegate().getViewport().setScrollMode(JViewport.SIMPLE_SCROLL_MODE);

            getDelegate().setVerticalScrollBarPolicy(convertVPolicy(policy));

            getDelegate().setHorizontalScrollBarPolicy(convertHPolicy(policy));

        }

    }

    LWComponentPeer<?, ?> getViewPeer() {

        final List<LWComponentPeer<?, ?>> peerList = getChildren();

        return peerList.isEmpty() ? null : peerList.get(0);

    }

    @Override

    Rectangle getContentSize() {

        Rectangle viewRect = getDelegate().getViewport().getViewRect();

        return new Rectangle(viewRect.width, viewRect.height);

    }

    @Override

    public void layout() {

        super.layout();

        synchronized (getDelegateLock()) {

            final LWComponentPeer<?, ?> viewPeer = getViewPeer();

            if (viewPeer != null) {

                Component view = getDelegate().getViewport().getView();

                view.setBounds(viewPeer.getBounds());

                view.setPreferredSize(viewPeer.getPreferredSize());

                view.setMinimumSize(viewPeer.getMinimumSize());

                getDelegate().invalidate();

                getDelegate().validate();

                viewPeer.setBounds(view.getBounds());

            }

        }

    }

    @Override

    public void setScrollPosition(int x, int y) {

    }

    @Override

    public int getHScrollbarHeight() {

        synchronized (getDelegateLock()) {

            return getDelegate().getHorizontalScrollBar().getHeight();

        }

    }

    @Override

    public int getVScrollbarWidth() {

        synchronized (getDelegateLock()) {

            return getDelegate().getVerticalScrollBar().getWidth();

        }

    }

    @Override

    public void childResized(int w, int h) {

        synchronized (getDelegateLock()) {

            getDelegate().invalidate();

            getDelegate().validate();

        }

    }

    @Override

    public void setUnitIncrement(Adjustable adj, int u) {

    }

    @Override

    public void setValue(Adjustable adj, int v) {

    }

    private static int convertHPolicy(final int policy) {

        switch (policy) {

            case ScrollPane.SCROLLBARS_NEVER:

                return ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER;

            case ScrollPane.SCROLLBARS_ALWAYS:

                return ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS;

            default:

                return ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED;

        }

    }

    private static int convertVPolicy(final int policy) {

        switch (policy) {

            case ScrollPane.SCROLLBARS_NEVER:

                return ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER;

            case ScrollPane.SCROLLBARS_ALWAYS:

                return ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS;

            default:

                return ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED;

        }

    }

}