org.osmdroid.views.overlay
Class Overlay

java.lang.Object
  org.osmdroid.views.overlay.Overlay

All Implemented Interfaces:

OverlayConstants

Direct Known Subclasses:

DirectedLocationOverlay, ItemizedOverlay, MyLocationOverlay, PathOverlay, ScaleBarOverlay, SimpleLocationOverlay, TilesOverlay

public abstract class Overlay
extends Object
implements OverlayConstants

Base class representing an overlay which may be displayed on top of a MapView. To add an overlay, subclass this class, create an instance, and add it to the list obtained from getOverlays() of MapView. This class implements a form of Gesture Handling similar to GestureDetector.SimpleOnGestureListener and GestureDetector.OnGestureListener. The difference is there is an additional argument for the item.

Author:

Nicolas Gramlich

Nested Class Summary

static interface

Overlay.Snappable 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.)

Field Summary

protected ResourceProxy	mResourceProxy
protected float	mScale
protected static float	SHADOW_X_SKEW
protected static float	SHADOW_Y_SCALE

Fields inherited from interface org.osmdroid.views.util.constants.OverlayConstants

DEBUGMODE, DEFAULT_ZOOMLEVEL_MINIMAP_DIFFERENCE, NOT_SET

Constructor Summary

Overlay(android.content.Context ctx)

Overlay(ResourceProxy pResourceProxy)

Method Summary

protected abstract void	draw(android.graphics.Canvas c, MapView osmv, boolean shadow) Draw the overlay over the map.
protected static void	drawAt(android.graphics.Canvas canvas, android.graphics.drawable.Drawable drawable, int x, int y, boolean shadow) Convenience method to draw a Drawable at an offset. x and y are pixel coordinates.
protected static int	getSafeMenuId() Since the menu-chain will pass through several independent Overlays, menu IDs cannot be fixed at compile time.
protected static int	getSafeMenuIdSequence(int count) Similar to , except this reserves a sequence of IDs of length .
boolean	isEnabled() Specifies if the Overlay is marked to be enabled.
void	onDetach(MapView mapView) Override to perform clean up of resources before shutdown.
boolean	onDoubleTap(android.view.MotionEvent e, MapView mapView) By default does nothing (return false).
boolean	onDoubleTapEvent(android.view.MotionEvent e, MapView mapView) By default does nothing (return false).
boolean	onDown(android.view.MotionEvent e, MapView mapView) By default does nothing (return false).
boolean	onFling(android.view.MotionEvent pEvent1, android.view.MotionEvent pEvent2, float pVelocityX, float pVelocityY, MapView pMapView) By default does nothing (return false).
boolean	onKeyDown(int keyCode, android.view.KeyEvent event, MapView mapView) By default does nothing (return false).
boolean	onKeyUp(int keyCode, android.view.KeyEvent event, MapView mapView) By default does nothing (return false).
boolean	onLongPress(android.view.MotionEvent e, MapView mapView) By default does nothing (return false).
boolean	onScroll(android.view.MotionEvent pEvent1, android.view.MotionEvent pEvent2, float pDistanceX, float pDistanceY, MapView pMapView) By default does nothing (return false).
void	onShowPress(android.view.MotionEvent pEvent, MapView pMapView)
boolean	onSingleTapConfirmed(android.view.MotionEvent e, MapView mapView) By default does nothing (return false).
boolean	onSingleTapUp(android.view.MotionEvent e, MapView mapView) By default does nothing (return false).
boolean	onTouchEvent(android.view.MotionEvent event, MapView mapView) You can prevent all(!)
boolean	onTrackballEvent(android.view.MotionEvent event, MapView mapView) By default does nothing (return false).
void	setEnabled(boolean pEnabled) Sets whether the Overlay is marked to be enabled.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SHADOW_X_SKEW

protected static final float SHADOW_X_SKEW

See Also:

Constant Field Values

SHADOW_Y_SCALE

protected static final float SHADOW_Y_SCALE

See Also:

Constant Field Values

mResourceProxy

protected final ResourceProxy mResourceProxy

mScale

protected final float mScale

Constructor Detail

Overlay

public Overlay(android.content.Context ctx)

Overlay

public Overlay(ResourceProxy pResourceProxy)

Method Detail

setEnabled

public void setEnabled(boolean pEnabled)

Sets whether the Overlay is marked to be enabled. This setting does nothing by default, but should be checked before calling draw().

isEnabled

public boolean isEnabled()

Specifies if the Overlay is marked to be enabled. This should be checked before calling draw().

Returns:

true if the Overlay is marked enabled, false otherwise

getSafeMenuId

protected static final int getSafeMenuId()

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.

Returns:

an integer suitable to be used as a menu identifier

getSafeMenuIdSequence

protected static final int getSafeMenuIdSequence(int count)

Similar to , except this reserves a sequence of IDs of length . The returned number is the starting index of that sequential list.

Returns:

an integer suitable to be used as a menu identifier

draw

protected abstract void draw(android.graphics.Canvas c,
                             MapView osmv,
                             boolean shadow)

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.

onDetach

public void onDetach(MapView mapView)

Override to perform clean up of resources before shutdown. By default does nothing.

onKeyDown

public boolean onKeyDown(int keyCode,
                         android.view.KeyEvent event,
                         MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onKeyUp

public boolean onKeyUp(int keyCode,
                       android.view.KeyEvent event,
                       MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onTouchEvent

public boolean onTouchEvent(android.view.MotionEvent event,
                            MapView mapView)

You can prevent all(!) other Touch-related events from happening!
By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onTrackballEvent

public boolean onTrackballEvent(android.view.MotionEvent event,
                                MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onDoubleTap

public boolean onDoubleTap(android.view.MotionEvent e,
                           MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onDoubleTapEvent

public boolean onDoubleTapEvent(android.view.MotionEvent e,
                                MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onSingleTapConfirmed

public boolean onSingleTapConfirmed(android.view.MotionEvent e,
                                    MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onDown

public boolean onDown(android.view.MotionEvent e,
                      MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onFling

public boolean onFling(android.view.MotionEvent pEvent1,
                       android.view.MotionEvent pEvent2,
                       float pVelocityX,
                       float pVelocityY,
                       MapView pMapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onLongPress

public boolean onLongPress(android.view.MotionEvent e,
                           MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onScroll

public boolean onScroll(android.view.MotionEvent pEvent1,
                        android.view.MotionEvent pEvent2,
                        float pDistanceX,
                        float pDistanceY,
                        MapView pMapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

onShowPress

public void onShowPress(android.view.MotionEvent pEvent,
                        MapView pMapView)

onSingleTapUp

public boolean onSingleTapUp(android.view.MotionEvent e,
                             MapView mapView)

By default does nothing (return false). If you handled the Event, return true, otherwise return false. If you returned true none of the following Overlays or the underlying MapView has the chance to handle this event.

drawAt

protected static void drawAt(android.graphics.Canvas canvas,
                             android.graphics.drawable.Drawable drawable,
                             int x,
                             int y,
                             boolean shadow)

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).

Parameters:

shadow - If true, draw only the drawable's shadow. Otherwise, draw the drawable itself.