com.google.android.maps
public abstract class
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, create an implemention of this class and then pass it to add(Overlay, boolean) on the controller obtained from createOverlayController().
Nested Classes
| Overlay.PixelCalculator | An object capable of converting latitude, longitude into an on-screen pixel coordinate. |
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 | |
| int[] | sXYCoords | Coordinate pair for temporary use. | ||
Public Constructors
| Overlay() |
Public Methods
| boolean | draw(Canvas canvas, PixelCalculator calculator, boolean shadow, long when) | ||||
| Draw call for animated overlays. | |||||
| void | draw(Canvas canvas, PixelCalculator calculator, boolean shadow) | ||||
| Draw the overlay over the map. | |||||
| Point | getCenter() | ||||
| The overlay may suggest a new map center when it is loaded by overriding this method and returning a non-null Point. | |||||
| int | getLatSpanE6() | ||||
| int | getLonSpanE6() | ||||
| String | getTitle() | ||||
| If the overlay has a title, it can override this method to be listed in the overlay-switcher menu. | |||||
| final | boolean | isActive() | |||
| void | onDeactivate() | ||||
| This will be called before the overlay is deactivated or removed. | |||||
| boolean | onTap(DeviceType deviceType, Point p, PixelCalculator calculator) | ||||
| Handle a tap 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
protected static final int[] sXYCoords
Coordinate pair for temporary use.
Public Constructors
public Overlay()
Public Methods
public boolean draw(Canvas canvas, PixelCalculator calculator, boolean shadow, long when)
Draw call for animated overlays. By default, calls through to
draw(Canvas, PixelCalculator, boolean) and returns false.
Parameters
| 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, PixelCalculator calculator, 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.
public Point getCenter()
The overlay may suggest a new map center when it is loaded by overriding
this method and returning a non-null Point.
public int getLatSpanE6()
Returns
- a suggested latidunial map-span for optimal viewing of the overlay. By default, returns -1 to decline to request a span.
public int getLonSpanE6()
Returns
- a suggested longitudinal map-span for optimal viewing of the overlay. By default, returns -1 to decline to request a span.
public String getTitle()
If the overlay has a title, it can override this method to be listed
in the overlay-switcher menu.
public final boolean isActive()
public void onDeactivate()
This will be called before the overlay is deactivated or removed.
public boolean onTap(DeviceType deviceType, Point p, PixelCalculator calculator)
Handle a tap event.
By default does nothing and returns false.
Parameters
| deviceType | the type of the device that generated the tap |
|---|---|
| p | the point that has been tapped |
| calculator | maps lat/lon to screen coordinates. |
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 object in {@link #draw to call getPointXY(Point, int[]).
Parameters
| shadow | if true, draw only the drawable's shadow. Otherwise, draw the drawable itself. |
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