Android
com.google.android.maps
public abstract class

com.google.android.maps.Overlay

java.lang.Object
com.google.android.maps.Overlay

Base class representing an overlay which may be displayed on top of a map. To add an overlay, subclass this class, create an instance, and add it to the list obtained from getOverlays().

Known Direct Subclasses

Summary

Constants

      Value  
float  SHADOW_X_SKEW  X Skew value for creating a marker shadow in perspective.  -0.9 
float  SHADOW_Y_SCALE  Y Scale value for creating a marker shadow in perspective.  0.5 

Public Constructors

            Overlay()

Public Methods

          boolean  draw(Canvas canvas, MapView mapView, boolean shadow, long when)
Draw call for animated overlays.
          void  draw(Canvas canvas, MapView mapView, boolean shadow)
Draw the overlay over the map.
          boolean  onKeyDown(int keyCode, KeyEvent event, MapView mapView)
Handle a key down event.
          boolean  onKeyUp(int keyCode, KeyEvent event, MapView mapView)
Handle a key up event.
          boolean  onTap(GeoPoint p, MapView mapView)
Handle a "tap" event.
          boolean  onTouchEvent(MotionEvent e, MapView mapView)
Handle a touch event.
          boolean  onTrackballEvent(MotionEvent event, MapView mapView)
Handle a trackball event.

Protected Methods

      static    void  drawAt(Canvas canvas, Drawable drawable, int x, int y, boolean shadow)
Convenience method to draw a Drawable at an offset.
Methods inherited from class java.lang.Object

Details

Constants

protected static final float SHADOW_X_SKEW

X Skew value for creating a marker shadow in perspective.
Constant Value: -0.9

protected static final float SHADOW_Y_SCALE

Y Scale value for creating a marker shadow in perspective.
Constant Value: 0.5

Public Constructors

public Overlay()

Public Methods

public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when)

Draw call for animated overlays. By default, calls through to draw(Canvas, MapView, boolean) and returns false.

Parameters

canvas The Canvas upon which to draw. Note that this may already have a transformation applied, so be sure to leave it the way you found it.
mapView the MapView that requested the draw. Use getProjection() to convert between on-screen pixels and latitude/longitude pairs.
shadow If true, draw the shadow layer. If false, draw the overlay contents.
when The timestamp of the draw.

Returns

  • True if you need to be drawn again right away; false otherwise. Default implementation returns false.

public void draw(Canvas canvas, MapView mapView, 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. By default, draws nothing.

Parameters

canvas The Canvas upon which to draw. Note that this may already have a transformation applied, so be sure to leave it the way you found it.
mapView the MapView that requested the draw. Use getProjection() to convert between on-screen pixels and latitude/longitude pairs.
shadow If true, draw the shadow layer. If false, draw the overlay contents.

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

Handle a key down event. By default does nothing and returns false.

Parameters

keyCode The key code.
event The key event.
mapView the MapView that generated the key event

Returns

  • True If the tap was handled by this overlay.

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

Handle a key up event. By default does nothing and returns false.

Parameters

keyCode The key code
event The key event
mapView the MapView that generated the key event

Returns

  • True if the tap was handled by this overlay.

public boolean onTap(GeoPoint p, MapView mapView)

Handle a "tap" event. This can be either a touchscreen tap anywhere on the map, or a trackball click on the center of the map. By default does nothing and returns false.

Parameters

p The point that has been tapped.
mapView the MapView that generated the tap event

Returns

  • True if the tap was handled by this overlay.

public boolean onTouchEvent(MotionEvent e, MapView mapView)

Handle a touch event. By default does nothing and returns false.

Parameters

e The motion event.
mapView the MapView that generated the touch event

Returns

  • True if the tap was handled by this overlay.

public boolean onTrackballEvent(MotionEvent event, MapView mapView)

Handle a trackball event. By default does nothing and returns false.

Parameters

event The motion event.
mapView the MapView that generated the trackball event

Returns

  • True if the tap was handled by this overlay.

Protected Methods

protected static void drawAt(Canvas canvas, 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 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.
Copyright 2007 Google Inc. Build 0.9_r1-98467 - 14 Aug 2008 18:56