MapController.java :  » Tools » mapsforge » org » mapsforge » android » maps » Android Open Source

/*
 * Copyright 2010, 2011 mapsforge.org
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */
package org.mapsforge.android.maps;

import android.view.KeyEvent;
import android.view.View;

/**
 * A MapController is used to programmatically modify the position and zoom level of a map. Each
 * MapController is assigned to a single MapView instance. To retrieve a MapController for a
 * given MapView, call the {@link MapView#getController()} method.
 */
public final class MapController implements android.view.View.OnKeyListener {
  private final MapView mapView;

  /**
   * Constructs a new MapController for interacting with the given MapView.
   * 
   * @param mapView
   *            the MapView that should be controlled with this MapController.
   */
  MapController(MapView mapView) {
    this.mapView = mapView;
  }

  @Override
  public boolean onKey(View v, int keyCode, KeyEvent event) {
    if (event.getAction() == KeyEvent.ACTION_DOWN) {
      // forward the event to the MapView
      return this.mapView.onKeyDown(keyCode, event);
    } else if (event.getAction() == KeyEvent.ACTION_UP) {
      // forward the event to the MapView
      return this.mapView.onKeyUp(keyCode, event);
    }
    return false;
  }

  /**
   * Sets the center of the MapView without an animation to the given point.
   * 
   * @param point
   *            the new center point of the map.
   */
  public void setCenter(GeoPoint point) {
    this.mapView.setCenter(point);
  }

  /**
   * Sets the zoom level of the MapView.
   * 
   * @param zoomLevel
   *            the new zoom level. This value will be limited by the maximum and minimum
   *            possible zoom level.
   * @return the new zoom level.
   */
  public int setZoom(int zoomLevel) {
    this.mapView.zoom((byte) (zoomLevel - this.mapView.getZoomLevel()));
    return this.mapView.getZoomLevel();
  }

  /**
   * Increases the zoom level of the MapView, unless the maximum zoom level has been reached.
   * 
   * @return true if the zoom level has been changed, false otherwise.
   */
  public boolean zoomIn() {
    return this.mapView.zoom((byte) 1);
  }

  /**
   * Decreases the zoom level of the MapView, unless the minimum zoom level has been reached.
   * 
   * @return true if the zoom level has been changed, false otherwise.
   */
  public boolean zoomOut() {
    return this.mapView.zoom((byte) -1);
  }
}