// Created by plusminus on 20:32:01 - 27.09.2008
package org.mozilla.osmdroid.views.overlay;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Point;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.view.GestureDetector;
import android.view.KeyEvent;
import android.view.MotionEvent;
import org.mozilla.osmdroid.DefaultResourceProxyImpl;
import org.mozilla.osmdroid.ResourceProxy;
import org.mozilla.osmdroid.api.IMapView;
import org.mozilla.osmdroid.views.MapView;
import org.mozilla.osmdroid.views.util.constants.OverlayConstants;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Base class representing an overlay which may be displayed on top of a {@link MapView}. To add an
* overlay, subclass this class, create an instance, and add it to the list obtained from
* getOverlays() of {@link MapView}.
* <p/>
* This class implements a form of Gesture Handling similar to
* {@link android.view.GestureDetector.SimpleOnGestureListener} and
* {@link GestureDetector.OnGestureListener}. The difference is there is an additional argument for
* the item.
*
* @author Nicolas Gramlich
*/
public abstract class Overlay implements OverlayConstants {
// ===========================================================
// Constants
// ===========================================================
// From Google Maps API
protected static final float SHADOW_X_SKEW = -0.8999999761581421f;
protected static final float SHADOW_Y_SCALE = 0.5f;
private static final Rect mRect = new Rect();
// ===========================================================
// Fields
// ===========================================================
private static AtomicInteger sOrdinal = new AtomicInteger();
protected final ResourceProxy mResourceProxy;
protected final float mScale;
private boolean mEnabled = true;
// ===========================================================
// Constructors
// ===========================================================
public Overlay(final Context ctx) {
mResourceProxy = new DefaultResourceProxyImpl(ctx);
mScale = ctx.getResources().getDisplayMetrics().density;
}
public Overlay(final ResourceProxy pResourceProxy) {
mResourceProxy = pResourceProxy;
mScale = mResourceProxy.getDisplayMetricsDensity();
}
// ===========================================================
// Getter & Setter
// ===========================================================
/**
* Since the menu-chain will pass through several independent Overlays, menu IDs cannot be fixed
* at compile time. Overlays should use this method to obtain and store a menu id for each menu
* item at construction time. This will ensure that two overlays don't use the same id.
*
* @return an integer suitable to be used as a menu identifier
*/
protected final static int getSafeMenuId() {
return sOrdinal.getAndIncrement();
}
/**
* Similar to <see cref="getSafeMenuId" />, except this reserves a sequence of IDs of length
* <param name="count" />. The returned number is the starting index of that sequential list.
*
* @return an integer suitable to be used as a menu identifier
*/
protected final static int getSafeMenuIdSequence(final int count) {
return sOrdinal.getAndAdd(count);
}
/**
* Convenience method to draw a Drawable at an offset. x and y are pixel coordinates. You can
* find appropriate coordinates from latitude/longitude using the MapView.getProjection() method
* on the MapView passed to you in draw(Canvas, MapView, boolean).
*
* @param shadow If true, draw only the drawable's shadow. Otherwise, draw the drawable itself.
* @param aMapOrientation
*/
protected synchronized static void drawAt(final Canvas canvas, final Drawable drawable,
final int x, final int y, final boolean shadow,
final float aMapOrientation) {
canvas.save();
canvas.rotate(-aMapOrientation, x, y);
drawable.copyBounds(mRect);
drawable.setBounds(mRect.left + x, mRect.top + y, mRect.right + x, mRect.bottom + y);
drawable.draw(canvas);
drawable.setBounds(mRect);
canvas.restore();
}
/**
* Specifies if the Overlay is marked to be enabled. This should be checked before calling
* draw().
*
* @return true if the Overlay is marked enabled, false otherwise
*/
public boolean isEnabled() {
return this.mEnabled;
}
// ===========================================================
// Methods for SuperClass/Interfaces
// ===========================================================
/**
* Sets whether the Overlay is marked to be enabled. This setting does nothing by default, but
* should be checked before calling draw().
*/
public void setEnabled(final boolean pEnabled) {
this.mEnabled = pEnabled;
}
// ===========================================================
// Methods
// ===========================================================
/**
* Draw the overlay over the map. This will be called on all active overlays with shadow=true,
* to lay down the shadow layer, and then again on all overlays with shadow=false. Callers
* should check isEnabled() before calling draw(). By default, draws nothing.
*/
protected abstract void draw(final Canvas c, final MapView osmv, final boolean shadow);
/**
* Override to perform clean up of resources before shutdown. By default does nothing.
*/
public void onDetach(final MapView mapView) {
}
/**
* 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 MapView} has the chance to handle
* this event.
*/
public boolean onKeyDown(final int keyCode, final KeyEvent event, final MapView 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 MapView} has the chance to handle
* this event.
*/
public boolean onKeyUp(final int keyCode, final KeyEvent event, final MapView 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 MapView} has the chance to handle
* this event.
*/
public boolean onTouchEvent(final MotionEvent event, final MapView mapView) {
return false;
}
/** GestureDetector.OnDoubleTapListener **/
/**
* 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 MapView} has the chance to handle
* this event.
*/
public boolean onTrackballEvent(final MotionEvent event, final MapView 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 MapView} has the chance to handle
* this event.
*/
public boolean onDoubleTap(final MotionEvent e, final MapView 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 MapView} has the chance to handle
* this event.
*/
public boolean onDoubleTapEvent(final MotionEvent e, final MapView mapView) {
return false;
}
/** OnGestureListener **/
/**
* 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 MapView} has the chance to handle
* this event.
*/
public boolean onSingleTapConfirmed(final MotionEvent e, final MapView 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 MapView} has the chance to handle
* this event.
*/
public boolean onDown(final MotionEvent e, final MapView 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 MapView} has the chance to handle
* this event.
*/
public boolean onFling(final MotionEvent pEvent1, final MotionEvent pEvent2,
final float pVelocityX, final float pVelocityY, final MapView pMapView) {
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 MapView} has the chance to handle
* this event.
*/
public boolean onLongPress(final MotionEvent e, final MapView 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 MapView} has the chance to handle
* this event.
*/
public boolean onScroll(final MotionEvent pEvent1, final MotionEvent pEvent2,
final float pDistanceX, final float pDistanceY, final MapView pMapView) {
return false;
}
public void onShowPress(final MotionEvent pEvent, final MapView pMapView) {
return;
}
/**
* 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 MapView} has the chance to handle
* this event.
*/
public boolean onSingleTapUp(final MotionEvent e, final MapView mapView) {
return false;
}
// ===========================================================
// Inner and Anonymous Classes
// ===========================================================
/**
* Interface definition for overlays that contain items that can be snapped to (for example,
* when the user invokes a zoom, this could be called allowing the user to snap the zoom to an
* interesting point.)
*/
public interface Snappable {
/**
* Checks to see if the given x and y are close enough to an item resulting in snapping the
* current action (e.g. zoom) to the item.
*
* @param x The x in screen coordinates.
* @param y The y in screen coordinates.
* @param snapPoint To be filled with the the interesting point (in screen coordinates) that is
* closest to the given x and y. Can be untouched if not snapping.
* @param mapView The {@link MapView} that is requesting the snap. Use MapView.getProjection()
* to convert between on-screen pixels and latitude/longitude pairs.
* @return Whether or not to snap to the interesting point.
*/
boolean onSnapToItem(int x, int y, Point snapPoint, IMapView mapView);
}
}