org.mapsforge.map.layer

Class TileLayer<T extends Job>

java.lang.Object

org.mapsforge.map.layer.Layer

org.mapsforge.map.layer.TileLayer<T>

Direct Known Subclasses:

TileDownloadLayer, TileRendererLayer, TileStoreLayer

public abstract class TileLayer<T extends Job>
extends Layer

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	hasJobQueue
protected boolean	isTransparent
protected JobQueue<T>	jobQueue
protected TileCache	tileCache

Fields inherited from class org.mapsforge.map.layer.Layer

displayModel

Constructor Summary

Constructors

Constructor and Description
TileLayer(TileCache tileCache, MapViewPosition mapViewPosition, Matrix matrix, boolean isTransparent)
TileLayer(TileCache tileCache, MapViewPosition mapViewPosition, Matrix matrix, boolean isTransparent, boolean hasJobQueue)

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract T	createJob(Tile tile)
void	draw(BoundingBox boundingBox, byte zoomLevel, Canvas canvas, Point topLeftPoint) Draws this Layer on the given canvas.
TileCache	getTileCache()
protected abstract boolean	isTileStale(Tile tile, TileBitmap bitmap) Whether the tile is stale and should be refreshed.
protected void	retrieveLabelsOnly(T job)
void	setDisplayModel(DisplayModel displayModel) The DisplayModel comes from a MapView, so is generally not known when the layer itself is created.

Methods inherited from class org.mapsforge.map.layer.Layer

getPosition, isVisible, onAdd, onDestroy, onLongPress, onRemove, onTap, requestRedraw, setVisible, setVisible

Methods inherited from class java.lang.Object

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

Field Detail

hasJobQueue

protected final boolean hasJobQueue

isTransparent

protected final boolean isTransparent

jobQueue

protected JobQueue<T extends Job> jobQueue

tileCache

protected final TileCache tileCache

Constructor Detail

TileLayer

public TileLayer(TileCache tileCache,
         MapViewPosition mapViewPosition,
         Matrix matrix,
         boolean isTransparent)

TileLayer

public TileLayer(TileCache tileCache,
         MapViewPosition mapViewPosition,
         Matrix matrix,
         boolean isTransparent,
         boolean hasJobQueue)

Method Detail

draw

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

Description copied from class: Layer

Draws this Layer on the given canvas.

Specified by:

draw in class Layer

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.

setDisplayModel

public void setDisplayModel(DisplayModel displayModel)

Description copied from class: Layer

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.

Overrides:

setDisplayModel in class Layer

Parameters:

displayModel - the displayModel to use.

createJob

protected abstract T createJob(Tile tile)

isTileStale

protected abstract boolean isTileStale(Tile tile,
                  TileBitmap bitmap)

Whether the tile is stale and should be refreshed.

This method is called from draw(BoundingBox, byte, Canvas, Point) to determine whether the tile needs to be refreshed. Subclasses must override this method and implement appropriate checks to determine when a tile is stale.

Return false to use the cached copy without attempting to refresh it.

Return true to cause the layer to attempt to obtain a fresh copy of the tile. The layer will first display the tile referenced by bitmap and attempt to obtain a fresh copy in the background. When a fresh copy becomes available, the layer will replace is and update the cache. If a fresh copy cannot be obtained (e.g. because the tile is obtained from an online source which cannot be reached), the stale tile will continue to be used until another #draw(BoundingBox, byte, Canvas, Point) operation requests it again.

Parameters:

tile - A tile.

bitmap - The bitmap for tile currently held in the layer's cache.

retrieveLabelsOnly

protected void retrieveLabelsOnly(T job)

getTileCache

public TileCache getTileCache()