MouseWheelListenerBase.java example

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ganttproject-master
/*
GanttProject is an opensource project management tool.
Copyright (C) 2011 GanttProject Team

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 3
of the License, or (at your option) any later version.

This program 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 for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package net.sourceforge.ganttproject.chart.mouse;

import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;

import net.sourceforge.ganttproject.gui.zoom.ZoomManager;

public class MouseWheelListenerBase implements MouseWheelListener {
  private final ZoomManager myZoomManager;

  public MouseWheelListenerBase(ZoomManager zoomManager) {
    myZoomManager = zoomManager;
  }

  @Override
  public void mouseWheelMoved(MouseWheelEvent e) {
    if (isRotationUp(e)) {
      fireZoomIn();
    } else {
      fireZoomOut();
    }
  }

  private void fireZoomIn() {
    if (myZoomManager.canZoomIn()) {
      myZoomManager.zoomIn();
    }
  }

  private void fireZoomOut() {
    if (myZoomManager.canZoomOut()) {
      myZoomManager.zoomOut();
    }
  }

  private boolean isRotationUp(MouseWheelEvent e) {
    return e.getWheelRotation() < 0;
  }
}