/*

 * 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.Adjustable;

import java.awt.Scrollbar;

import java.awt.event.AdjustmentEvent;

import java.awt.event.AdjustmentListener;

import java.awt.peer.ScrollbarPeer;

import javax.swing.JScrollBar;

/**

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

 * work to the {@link JScrollBar}.

 */

final class LWScrollBarPeer extends LWComponentPeer<Scrollbar, JScrollBar>

        implements ScrollbarPeer, AdjustmentListener {

    // JScrollBar fires two changes with firePropertyChange (one for old value

    // and one for new one.

    // We save the last value and don't fire event if not changed.

    private int currentValue;

    LWScrollBarPeer(final Scrollbar target,

                    final PlatformComponent platformComponent) {

        super(target, platformComponent);

    }

    @Override

    JScrollBar createDelegate() {

        return new JScrollBar();

    }

    @Override

    void initializeImpl() {

        super.initializeImpl();

        final Scrollbar target = getTarget();

        setLineIncrement(target.getUnitIncrement());

        setPageIncrement(target.getBlockIncrement());

        setValues(target.getValue(), target.getVisibleAmount(),

                  target.getMinimum(), target.getMaximum());

        final int orientation = target.getOrientation();

        final JScrollBar delegate = getDelegate();

        synchronized (getDelegateLock()) {

            delegate.setOrientation(orientation == Scrollbar.HORIZONTAL

                                    ? Adjustable.HORIZONTAL

                                    : Adjustable.VERTICAL);

            delegate.addAdjustmentListener(this);

        }

    }

    @Override

    public void setValues(final int value, final int visible, final int minimum,

                          final int maximum) {

        synchronized (getDelegateLock()) {

            currentValue = value;

            getDelegate().setValues(value, visible, minimum, maximum);

        }

    }

    @Override

    public void setLineIncrement(final int l) {

        synchronized (getDelegateLock()) {

            getDelegate().setUnitIncrement(l);

        }

    }

    @Override

    public void setPageIncrement(final int l) {

        synchronized (getDelegateLock()) {

            getDelegate().setBlockIncrement(l);

        }

    }

    // Peer also registered as a listener for ComponentDelegate component

    @Override

    public void adjustmentValueChanged(final AdjustmentEvent e) {

        final int value = e.getValue();

        synchronized (getDelegateLock()) {

            if (currentValue == value) {

                return;

            }

            currentValue = value;

        }

        getTarget().setValueIsAdjusting(e.getValueIsAdjusting());

        getTarget().setValue(value);

        postEvent(new AdjustmentEvent(getTarget(), e.getID(),

                e.getAdjustmentType(), value,

                e.getValueIsAdjusting()));

    }

}