OSMMapViewOverlay.java :  » UnTagged » andnav » org » andnav2 » osm » views » overlay » Android Open Source

// Created by plusminus on 20:32:01 - 27.09.2008
package org.andnav2.osm.views.overlay;

import org.andnav2.osm.util.constants.OSMConstants;
import org.andnav2.osm.views.OSMMapView;

import android.graphics.Canvas;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;


/**
 * Base class representing an overlay which may be displayed on top of a {@link OSMMapView}. To add an overlay, subclass this class, create an instance, and add it to the list obtained from getOverlays() of {@link OSMMapView}.
 * @author Nicolas Gramlich
 */
public abstract class OSMMapViewOverlay implements OSMConstants {
  // ===========================================================
  // Constants
  // ===========================================================

  // ===========================================================
  // Fields
  // ===========================================================

  private boolean mVisible = true;

  // ===========================================================
  // Constructors
  // ===========================================================

  // ===========================================================
  // Getter & Setter
  // ===========================================================

  public void setVisible(final boolean pVisible){
    this.mVisible = pVisible;
  }

  public boolean isVisible(){
    return this.mVisible;
  }

  // ===========================================================
  // Methods for SuperClass/Interfaces
  // ===========================================================

  /**
   * Managed Draw calls gives Overlays the possibility to first draw manually and after that do a final draw. This is very useful, i sth. to be drawn needs to be <b>topmost</b>.
   */
  public void onManagedDraw(final Canvas c, final OSMMapView osmv){
    try{
      if(this.mVisible){
        onDraw(c, osmv);
        onDrawFinished(c, osmv);
      }
    }catch(final Throwable t){
      Log.e(DEBUGTAG, "Error in onManagedDraw();", t);
    }
  }

  protected abstract void onDraw(final Canvas c, final OSMMapView osmv);

  protected abstract void onDrawFinished(final Canvas c, final OSMMapView osmv);

  public abstract void release();

  // ===========================================================
  // Methods
  // ===========================================================

  /**
   * By default does nothing (<code>return false</code>). If you handled the Event, return <code>true</code>, otherwise return <code>false</code>.
   * If you returned <code>true</code> none of the following Overlays or the underlying {@link OSMMapView} has the chance to handle this event.
   */
  public boolean onKeyDown(final int keyCode, final KeyEvent event, final OSMMapView mapView) {
    return false;
  }

  /**
   * By default does nothing (<code>return false</code>). If you handled the Event, return <code>true</code>, otherwise return <code>false</code>.
   * If you returned <code>true</code> none of the following Overlays or the underlying {@link OSMMapView} has the chance to handle this event.
   */
  public boolean onKeyUp(final int keyCode, final KeyEvent event, final OSMMapView mapView) {
    return false;
  }

  /**
   * <b>You can prevent all(!) other Touch-related events from happening!</b><br />
   * By default does nothing (<code>return false</code>). If you handled the Event, return <code>true</code>, otherwise return <code>false</code>.
   * If you returned <code>true</code> none of the following Overlays or the underlying {@link OSMMapView} has the chance to handle this event.
   */
  public boolean onTouchEvent(final MotionEvent event, final OSMMapView mapView) {
    return false;
  }

  /**
   * By default does nothing (<code>return false</code>). If you handled the Event, return <code>true</code>, otherwise return <code>false</code>.
   * If you returned <code>true</code> none of the following Overlays or the underlying {@link OSMMapView} has the chance to handle this event.
   */
  public boolean onTrackballEvent(final MotionEvent event, final OSMMapView mapView) {
    return false;
  }

  /**
   * By default does nothing (<code>return false</code>). If you handled the Event, return <code>true</code>, otherwise return <code>false</code>.
   * If you returned <code>true</code> none of the following Overlays or the underlying {@link OSMMapView} has the chance to handle this event.
   */
  public boolean onSingleTapUp(final MotionEvent e, final OSMMapView openStreetMapView) {
    return false;
  }

  /**
   * By default does nothing (<code>return false</code>). If you handled the Event, return <code>true</code>, otherwise return <code>false</code>.
   * If you returned <code>true</code> none of the following Overlays or the underlying {@link OSMMapView} has the chance to handle this event.
   */
  public boolean onLongPress(final MotionEvent e, final OSMMapView openStreetMapView) {
    return false;
  }

  // ===========================================================
  // Inner and Anonymous Classes
  // ===========================================================
}