org.mapsforge.map.layer

Class Layer

java.lang.Object

org.mapsforge.map.layer.Layer

Direct Known Subclasses:

Circle, Grid, LabelLayer, Marker, Polygon, Polyline, TileCoordinatesLayer, TileGridLayer, TileLayer

public abstract class Layer
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
protected DisplayModel	displayModel

Constructor Summary

Constructors

Constructor and Description
Layer()

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	draw(BoundingBox boundingBox, byte zoomLevel, Canvas canvas, Point topLeftPoint) Draws this Layer on the given canvas.
LatLong	getPosition() Gets the geographic position of this layer element, if it exists.
boolean	isVisible()
protected void	onAdd() Called each time this Layer is added to a Layers list.
void	onDestroy()
boolean	onLongPress(LatLong tapLatLong, Point layerXY, Point tapXY) Handles a long press event.
protected void	onRemove() Called each time this Layer is removed from a Layers list.
boolean	onTap(LatLong tapLatLong, Point layerXY, Point tapXY) Handles a tap event.
void	requestRedraw() Requests an asynchronous redrawing of all layers.
void	setDisplayModel(DisplayModel displayModel) The DisplayModel comes from a MapView, so is generally not known when the layer itself is created.
void	setVisible(boolean visible) Sets the visibility flag of this Layer to the given value.
void	setVisible(boolean visible, boolean redraw) Sets the visibility flag of this Layer to the given value.

Methods inherited from class java.lang.Object

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

Field Detail

displayModel

protected DisplayModel displayModel

Constructor Detail

Layer

public Layer()

Method Detail

draw

public abstract void draw(BoundingBox boundingBox,
        byte zoomLevel,
        Canvas canvas,
        Point topLeftPoint)

Draws this Layer on the given canvas.

Parameters:

boundingBox - the geographical area which should be drawn.

zoomLevel - the zoom level at which this Layer should draw itself.

canvas - the canvas on which this Layer should draw itself.

topLeftPoint - the top-left pixel position of the canvas relative to the top-left map position.

getPosition

public LatLong getPosition()

Gets the geographic position of this layer element, if it exists.

The default implementation of this method returns null.

Returns:

the geographic position of this layer element, null otherwise

isVisible

public final boolean isVisible()

Returns:

true if this Layer is currently visible, false otherwise. The default value is true.

onDestroy

public void onDestroy()

onLongPress

public boolean onLongPress(LatLong tapLatLong,
                  Point layerXY,
                  Point tapXY)

Handles a long press event. A long press event is only triggered if the map was not moved. A return value of true indicates that the long press event has been handled by this overlay and stops its propagation to other overlays.

The default implementation of this method does nothing and returns false.

Parameters:

tapLatLong - the geographic position of the long press.

layerXY - the xy position of the layer element (if available)

tapXY - the xy position of the tap

Returns:

true if the long press event was handled, false otherwise.

onTap

public boolean onTap(LatLong tapLatLong,
            Point layerXY,
            Point tapXY)

Handles a tap event. A return value of true indicates that the tap event has been handled by this overlay and stops its propagation to other overlays.

The default implementation of this method does nothing and returns false.

Parameters:

tapLatLong - the the geographic position of the tap.

layerXY - the xy position of the layer element (if available)

tapXY - the xy position of the tap

Returns:

true if the tap event was handled, false otherwise.

requestRedraw

public final void requestRedraw()

Requests an asynchronous redrawing of all layers.

setDisplayModel

public void setDisplayModel(DisplayModel displayModel)

The DisplayModel comes from a MapView, so is generally not known when the layer itself is created. Maybe a better way would be to have a MapView as a parameter when creating a layer.

Parameters:

displayModel - the displayModel to use.

setVisible

public final void setVisible(boolean visible)

Sets the visibility flag of this Layer to the given value.

Note: By default a redraw will take place afterwards.

setVisible

public final void setVisible(boolean visible,
              boolean redraw)

Sets the visibility flag of this Layer to the given value.

onAdd

protected void onAdd()

Called each time this Layer is added to a Layers list.

onRemove

protected void onRemove()

Called each time this Layer is removed from a Layers list.