com.tomtom.speedtools.tilemap

Class TileMap<T>

java.lang.Object

com.tomtom.speedtools.tilemap.TileMap<T>

Direct Known Subclasses:

CachedTileMap

public abstract class TileMap<T>
extends Object

This class represents an (abstract) cacheable map. The type parameter T is the image tile type. It is parametrized to allow retrieving tiles in different internal formats, such as AWT Image objects, or Processing PImage objects.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	TileMap.ViewportTileProcessor<T> Callback function for viewport tile processing.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TileMap()
protected	TileMap(int bufferColumns, int bufferRows)

Method Summary

Modifier and Type	Method and Description
void	cacheTile(TileKey key) Buffer a map tile which is not shown in the viewport, given a map tile key.
Collection<ViewportTile<T>>	collectViewportTiles(int widthPixels, int heightPixels, GeoPoint mapCenter, int zoomLevel) Get all tiles for a specific viewport.
static TileOffset	convertLatLonToTileOffset(GeoPoint point, int zoomLevel) Convert a lat/lon coordinate to a map tile with an offset within the tile.
static Tuple<Integer,Integer>	convertLatLonToViewportXY(GeoPoint point, int width, int height, int zoomLevel, GeoPoint mapCenter) Given a viewport calculate the (x, y) position of a lat/lon.
static GeoPoint	convertTileOffsetToLatLon(TileOffset tileOffset) Convert a map tile with zoomlevel and offset to a lat/lon coordinate.
static GeoPoint	convertViewportXYToLatLon(int posX, int posY, int width, int height, int zoomLevel, GeoPoint mapCenter) Convert a (X, Y) position on a screen to a latitude and longitude, given the center of the map and the zoomLevel.
static Tuple<Integer,GeoPoint>	findZoomLevelAndMapCenter(int width, int height, int borderWidth, Collection<GeoPoint> points) Given a set of points, a viewport width/height and the border width, return a zoomlevel and map center that will contain the specific viewport.
abstract T	getTile(TileKey key) Get a map tile, given a map tile key.
boolean	isCacheEnabled() Returns if the map supports caching.
boolean	isPreCacheEnabled() Returns if the map supports pre-caching of additional non-visible tiles.
static GeoPoint	moveLatLonByViewportXY(int deltaX, int deltaY, int zoomLevel, GeoPoint mapCenter) Calculate a new map center, given a delta in pixels.
void	processViewportTiles(int widthPixels, int heightPixels, GeoPoint mapCenter, int zoomLevel, TileMap.ViewportTileProcessor<T> processor) Process all tiles for a specific viewport.
void	setPreCachingHint(boolean preCaching) Set pre-caching on or off, if possible.

Methods inherited from class java.lang.Object

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

Constructor Detail

TileMap

protected TileMap()

TileMap

protected TileMap(int bufferColumns,
                  int bufferRows)

Method Detail

getTile

@Nullable
public abstract T getTile(@Nonnull
                                    TileKey key)

Get a map tile, given a map tile key. This function is implemented by the user of the tile.

Parameters:

key - Tile key.

Returns:

Tile, or null if missing.

isCacheEnabled

public boolean isCacheEnabled()

Returns if the map supports caching.

Returns:

True if the map supports caching (does not say anything about the cache size).

setPreCachingHint

public void setPreCachingHint(boolean preCaching)

Set pre-caching on or off, if possible. Pre-caching means fetching tiles that might be useful later. This may speed up or slow down the application, depending on network performance. Pre-caching can only be set if caching is enabled. Setting the value to true does not always mean pre-caching will be enabled. The cache itself must support it.

Parameters:

preCaching - True of pre-caching is enabled.

isPreCacheEnabled

public boolean isPreCacheEnabled()

Returns if the map supports pre-caching of additional non-visible tiles.

Returns:

True if the map supports pre-caching (does not say anything about the cache size).

cacheTile

public void cacheTile(@Nonnull
                      TileKey key)

Buffer a map tile which is not shown in the viewport, given a map tile key. This function can be used to preload image tiles for caching maps. Note that this function ALWAYS gets called, so only buffer the image if you do not already have it.

Parameters:

key - Tile key.

processViewportTiles

public void processViewportTiles(int widthPixels,
                                 int heightPixels,
                                 @Nonnull
                                 GeoPoint mapCenter,
                                 int zoomLevel,
                                 @Nonnull
                                 TileMap.ViewportTileProcessor<T> processor)

Process all tiles for a specific viewport. For every tile a callback function 'process()' is called. This function can either immediately draw the image, or for example store it in a collection.

Parameters:

widthPixels - Width of viewport in pixels.

heightPixels - Height of viewport in pixels.

mapCenter - Center of map, as lat/lon.

zoomLevel - Zoomlevel (from 0..LbsConst.MapConst.MAXIMUM_ZOOM).

processor - Viewport processor.

collectViewportTiles

@Nonnull
public Collection<ViewportTile<T>> collectViewportTiles(int widthPixels,
                                                                 int heightPixels,
                                                                 @Nonnull
                                                                 GeoPoint mapCenter,
                                                                 int zoomLevel)

Get all tiles for a specific viewport.

Parameters:

widthPixels - Width of viewport in pixels.

heightPixels - Height of viewport in pixels.

mapCenter - Center of map, as lat/lon.

zoomLevel - Zoomlevel (from 0..LbsConst.MapConst.MAXIMUM_ZOOM).

Returns:

The returned value is a collection of viewport images. Every viewport image element is contains an image to be plotted, the position from the top-left of the viewport and the crop area to plot from the image. This makes it easy to crop the images at the edges correctly.

convertLatLonToTileOffset

@Nonnull
public static TileOffset convertLatLonToTileOffset(@Nonnull
                                                            GeoPoint point,
                                                            int zoomLevel)

Convert a lat/lon coordinate to a map tile with an offset within the tile.

Parameters:

point - Coordinate.

zoomLevel - Zoom level.

Returns:

Map tile with zoomlevel and offset.

convertTileOffsetToLatLon

@Nonnull
public static GeoPoint convertTileOffsetToLatLon(@Nonnull
                                                          TileOffset tileOffset)

Convert a map tile with zoomlevel and offset to a lat/lon coordinate.

Parameters:

tileOffset - Map tile with zoomlevel and offset within tile.

Returns:

Coordinate.

convertViewportXYToLatLon

@Nonnull
public static GeoPoint convertViewportXYToLatLon(int posX,
                                                          int posY,
                                                          int width,
                                                          int height,
                                                          int zoomLevel,
                                                          @Nonnull
                                                          GeoPoint mapCenter)

Convert a (X, Y) position on a screen to a latitude and longitude, given the center of the map and the zoomLevel.

Parameters:

posX - Offset in pixels from left.

posY - Offset in pixels from top.

width - Width in pixels.

height - Height in pixels.

zoomLevel - Zoom level.

mapCenter - Latitude and longitude of center of map.

Returns:

Latitude and longitude of XY position.

convertLatLonToViewportXY

@Nullable
public static Tuple<Integer,Integer> convertLatLonToViewportXY(@Nonnull
                                                                         GeoPoint point,
                                                                         int width,
                                                                         int height,
                                                                         int zoomLevel,
                                                                         @Nonnull
                                                                         GeoPoint mapCenter)

Given a viewport calculate the (x, y) position of a lat/lon. If the lat or the lon is not displayed in the viewport, null is returned for that value.

Parameters:

point - Lat/lon.

width - Width of viewport.

height - Height of viewport.

zoomLevel - Zoomlevel of viewport.

mapCenter - Latitude and longitude of center of map.

Returns:

Returns (x, y) position in viewport. 0 <= x < width and 0 <= y < height, or null if either of the values is out of range, if the lat or lon is not positioned within the viewport.

findZoomLevelAndMapCenter

@Nonnull
public static Tuple<Integer,GeoPoint> findZoomLevelAndMapCenter(int width,
                                                                         int height,
                                                                         int borderWidth,
                                                                         @Nonnull
                                                                         Collection<GeoPoint> points)

Given a set of points, a viewport width/height and the border width, return a zoomlevel and map center that will contain the specific viewport.

Parameters:

width - Width of viewport.

height - Height of viewport.

borderWidth - Border width (in pixels) inside viewport to keep points clear from.

points - Points to fit in viewport (but not in border).

Returns:

Zoom level and map center of map to display.

moveLatLonByViewportXY

@Nonnull
public static GeoPoint moveLatLonByViewportXY(int deltaX,
                                                       int deltaY,
                                                       int zoomLevel,
                                                       @Nonnull
                                                       GeoPoint mapCenter)

Calculate a new map center, given a delta in pixels.

Parameters:

deltaX - Delta in pixels to left.

deltaY - Delta in pixels to bottom.

zoomLevel - Zoom level.

mapCenter - Latitude and longitude of center of map.

Returns:

Latitude and longitude of XY position.