Package com.massifmaps.datasources

Class MBTilesTileDataSource

java.lang.Object

com.massifmaps.datasources.TileDataSource

com.massifmaps.datasources.MBTilesTileDataSource

public class MBTilesTileDataSource
extends TileDataSource

A tile data source that loads tiles from a local Sqlite database.
The database must contain table "tiles" with the following fields:
"zoom_level" (tile zoom level), "tile_column" (tile x coordinate),
"tile_row" (tile y coordinate), "tile_data" (compressed tile image).

Constructor Summary

Constructors

Constructor	Description
MBTilesTileDataSource(int minZoom, int maxZoom, String path)	Constructs a MBTilesTileDataSource object.
MBTilesTileDataSource(int minZoom, int maxZoom, String path, int scheme)	Constructs a MBTilesTileDataSource object with specified tile scheme.
MBTilesTileDataSource(String path)	Constructs a MBTilesTileDataSource object.

Method Summary

Modifier and Type	Method	Description
StringMap	getContainerMetaData()	Get data source metadata information. Possible parameters can be found in MBTiles specification.
String	getContainerMetaData(String key)	Reads one entry of the source's own metadata, when it has any - the MBTiles or PMTiles metadata table, for instance.
MapBounds	getDataExtent()	Returns the extent of the tiles in this data source. The bounds are in coordinate system of the projection of the data source.
int	getMaxZoom()	Returns the maximum zoom level supported by this data source.
int	getMinZoom()	Returns the minimum zoom level supported by this data source.
String	getTileMask()
TileData	loadTile(MapTile mapTile)	Loads the specified tile. Note: the tile coordinate system used here is vertically flipped relative to layer tile coordinate system.

Methods inherited from class com.massifmaps.datasources.TileDataSource

buildTagValues, containsMetaDataKey, getMaxOverzoomLevel, getMaxZoomWithOverzoom, getMetaData, getMetaDataElement, getProjection, isMaxOverzoomLevelSet, notifyTilesChanged, setMaxOverzoomLevel, setMetaData, setMetaDataElement

Methods inherited from class java.lang.Object

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

Constructor Details

MBTilesTileDataSource

public MBTilesTileDataSource(String path)
                      throws IOException

Constructs a MBTilesTileDataSource object. TMS tile scheme is used,
Min and max zoom levels are automatically detected.

Parameters:

path - The path to the local Sqlite database file.

Throws:

Exception - If the the file could not be opened.

IOException

MBTilesTileDataSource

public MBTilesTileDataSource(int minZoom,
 int maxZoom,
 String path)
                      throws IOException

Constructs a MBTilesTileDataSource object. TMS tile scheme is used.

Parameters:

minZoom - The minimum zoom level supported by this data source.

maxZoom - The maximum zoom level supported by this data source.

path - The path to the local Sqlite database file.

Throws:

Exception - If the the file could not be opened.

IOException

MBTilesTileDataSource

public MBTilesTileDataSource(int minZoom,
 int maxZoom,
 String path,
 int scheme)
                      throws IOException

Constructs a MBTilesTileDataSource object with specified tile scheme.

Parameters:

minZoom - The minimum zoom level supported by this data source.

maxZoom - The maximum zoom level supported by this data source.

path - The path to the local Sqlite database file.

scheme - Tile scheme to use.

Throws:

Exception - If the the file could not be opened.

IOException

Method Details

getContainerMetaData

public StringMap getContainerMetaData()

Get data source metadata information.
Possible parameters can be found in MBTiles specification.

Returns:

Map containing meta data information (parameter names mapped to parameter values).

getContainerMetaData

public String getContainerMetaData(String key)

Description copied from class: TileDataSource

Reads one entry of the source's own metadata, when it has any - the MBTiles or PMTiles
metadata table, for instance. Sources that carry none return an empty string, as do keys
they do not define. Unlike the meta data map above this is read-only and is NOT attached
to the loaded tiles: a container's metadata can be tens of kilobytes.

Overrides:

getContainerMetaData in class TileDataSource

Parameters:

key - The metadata key, as named by the container's specification.

Returns:

The value, or empty string if the source does not provide it.

getMinZoom

public int getMinZoom()

Description copied from class: TileDataSource

Returns the minimum zoom level supported by this data source.

Overrides:

getMinZoom in class TileDataSource

Returns:

The minimum zoom level supported (inclusive).

getMaxZoom

public int getMaxZoom()

Description copied from class: TileDataSource

Returns the maximum zoom level supported by this data source.

Overrides:

getMaxZoom in class TileDataSource

Returns:

The maximum zoom level supported (exclusive).

getDataExtent

public MapBounds getDataExtent()

Description copied from class: TileDataSource

Returns the extent of the tiles in this data source.
The bounds are in coordinate system of the projection of the data source.

Overrides:

getDataExtent in class TileDataSource

Returns:

The extent of the data source.

getTileMask

public String getTileMask()

loadTile

public TileData loadTile(MapTile mapTile)

Description copied from class: TileDataSource

Loads the specified tile.
Note: the tile coordinate system used here is vertically flipped relative to layer tile coordinate system.

Overrides:

loadTile in class TileDataSource

Parameters:

mapTile - The tile to load.

Returns:

The tile data. If the tile is not available, null may be returned.