/*******************************************************************************
 * Copyright (c) 2012, 2014 Original authors and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Original authors and others - initial API and implementation
 *     Dirk Fauth <dirk.fauth@googlemail.com> - Bug 454909
 ******************************************************************************/
package org.eclipse.nebula.widgets.nattable.sort.command;

import org.eclipse.nebula.widgets.nattable.command.AbstractLayerCommandHandler;
import org.eclipse.nebula.widgets.nattable.sort.ISortModel;
import org.eclipse.nebula.widgets.nattable.sort.SortDirectionEnum;
import org.eclipse.nebula.widgets.nattable.sort.SortHeaderLayer;
import org.eclipse.nebula.widgets.nattable.sort.event.SortColumnEvent;
import org.eclipse.swt.custom.BusyIndicator;

/**
 * Command handler that handles {@link SortColumnCommand}s. Applies sorting via
 * the {@link ISortModel} corresponding to the information that are send via the
 * {@link SortColumnCommand}.
 *
 * @see SortHeaderLayer
 * @see SortColumnCommand
 */
public class SortCommandHandler<T> extends AbstractLayerCommandHandler<SortColumnCommand> {

    private final ISortModel sortModel;
    private final SortHeaderLayer<T> sortHeaderLayer;

    public SortCommandHandler(ISortModel sortModel, SortHeaderLayer<T> sortHeaderLayer) {
        this.sortModel = sortModel;
        this.sortHeaderLayer = sortHeaderLayer;
    }

    @Override
    public boolean doCommand(final SortColumnCommand command) {

        final int columnIndex = command.getLayer().getColumnIndexByPosition(command.getColumnPosition());
        final SortDirectionEnum newSortDirection =
                (command.getSortDirection()) != null ? command.getSortDirection() : this.sortModel.getSortDirection(columnIndex).getNextSortDirection();

        // Fire command - with busy indicator
        Runnable sortRunner = new Runnable() {
            @Override
            public void run() {
                SortCommandHandler.this.sortModel.sort(columnIndex, newSortDirection, command.isAccumulate());
            }
        };
        BusyIndicator.showWhile(null, sortRunner);

        // Fire event
        SortColumnEvent sortEvent = new SortColumnEvent(this.sortHeaderLayer, command.getColumnPosition());
        this.sortHeaderLayer.fireLayerEvent(sortEvent);

        return true;
    }

    @Override
    public Class<SortColumnCommand> getCommandClass() {
        return SortColumnCommand.class;
    }

}