com.luciad.format.sqlite.mbtiles

LuciadLightspeedClass TLcdMBTilesModelDecoder

java.lang.Object

com.luciad.format.sqlite.mbtiles.TLcdMBTilesModelDecoder

All Implemented Interfaces:

ILcdModelDecoder

@LcdService(service=ILcdModelDecoder.class,
            priority=20000)
public class TLcdMBTilesModelDecoder
extends Object
implements ILcdModelDecoder

A model decoder that decodes MBTiles files with image tiles.

Input Files

File	Required	Entry point	Description
*.mbtiles	X	X	The database file

Supported files

This model decoder supports MBTiles files with image tiles (tile data formats jpg or png). Files with vector tiles or grid tiles are not supported.

Supported file transfer protocols

• This model decoder supports all transfer protocols that are supported by java.io.File.

Model structure

• This model decoder creates a model per MBTiles file.

Model descriptor

• All models returned by this model decoder have an ILcdDataSourceModelDescriptor.
  • Model descriptors for image tiles datasets also implement the ILcdEarthModelDescriptor interface.

Model reference

• All models returned by this model decoder have a Web Mercator reference, aligned with the MBTiles specification.

Model elements

• Image tiles dataset:
  • A decoded model contains a single implementation of ALcdImage and ILcdEarthTileSet. The tiling structure of this tile set has world bounds defined in Web Mercator and a tile size of 256 by 256 pixels.

Thread safety

• Use TLcdLockUtil.readLock(Object) when accessing elements in the model.
• Use TLcdLockUtil.writeLock(Object) when changing elements in the model.

Sample code

Decoding MBTiles data and visualizing it on a Lightspeed map:

    //First create the model
    ILcdModelDecoder decoder =
        new TLcdCompositeModelDecoder(TLcdServiceLoader.getInstance(ILcdModelDecoder.class));
    ILcdModel model = decoder.decode(sourceName);

    //Create a layer for the model with default styling
    ILspLayer layer = TLspRasterLayerBuilder.newBuilder()
                                            .model(model)
                                            .build();

    //Add the layer to the Lightspeed view (an ILspView)
    view.addLayer(layer);

Decoding MBTiles data and visualizing it on a GXY map:

    //First create the model
    ILcdModelDecoder decoder =
        new TLcdCompositeModelDecoder(TLcdServiceLoader.getInstance(ILcdModelDecoder.class));
    ILcdModel model = decoder.decode(sourceName);

    //Create a layer for the model with default styling
    ILcdGXYLayer layer = TLcdGXYLayer.create(model);
    //Wrap the layer with an async layer wrapper to ensure
    //that the view remains responsive while data is being painted
    layer = ILcdGXYAsynchronousLayerWrapper.create(layer);

    //Add the async layer to the GXY view (an ILcdGXYView)
    view.addGXYLayer(layer);

Supported versions

• MBTiles, compliant with version 1.1, 1.2 or 1.3.

Since:

2020.1

Field Summary

Fields

Modifier and Type	Field and Description
static String	TYPE_NAME A general and human-readable type name for the MBTiles data format

Constructor Summary

Constructors

Constructor and Description
TLcdMBTilesModelDecoder() Creates a new MBTiles model decoder.

Method Summary

Modifier and Type	Method and Description
boolean	canDecodeSource(ILcdDataSource aDataSource) Checks whether the given data source can be decoded with this model decoder.
boolean	canDecodeSource(String aSource) Checks whether the given source can be decoded with this model decoder.
ILcdModel	decode(String aSource) Decodes the single dataset in an MBTiles file.
ILcdModel	decodeSource(ILcdDataSource aDataSource) Creates a model for the given data source.
List<TLcdMBTilesDataSource>	discoverDataSources(String aPath) Returns the single data source in the given MBTiles file.
String	getDisplayName() Returns a short, displayable name for the format that is decoded by this ILcdModelDecoder.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.luciad.model.ILcdModelDecoder

decodeModelMetadata, decodeModelMetadata

Field Detail

TYPE_NAME

public static final String TYPE_NAME

A general and human-readable type name for the MBTiles data format

See Also:

Constant Field Values

Constructor Detail

TLcdMBTilesModelDecoder

public TLcdMBTilesModelDecoder()

Creates a new MBTiles model decoder.

Method Detail

getDisplayName

public String getDisplayName()

Description copied from interface: ILcdModelDecoder

Returns a short, displayable name for the format that is decoded by this ILcdModelDecoder.

Specified by:

getDisplayName in interface ILcdModelDecoder

Returns:

the displayable name of this ILcdModelDecoder.

canDecodeSource

public boolean canDecodeSource(ILcdDataSource aDataSource)

Checks whether the given data source can be decoded with this model decoder.

This model decoder handles TLcdMBTilesDataSource data sources and TLcdDataSource data sources. The latter case delegates the source to the canDecodeSource(String) method.

Specified by:

canDecodeSource in interface ILcdModelDecoder

Parameters:

aDataSource - the dataset to be decoded.

Returns:

true if the data source is a TLcdMBTilesDataSource or a TLcdDataSource, false otherwise

See Also:

decodeSource(com.luciad.model.ILcdDataSource)

decodeSource

public ILcdModel decodeSource(ILcdDataSource aDataSource)
                       throws IOException

Creates a model for the given data source.

The data source must be a TLcdMBTilesDataSource, which represents one data set in the MBTiles file.

Specified by:

decodeSource in interface ILcdModelDecoder

Parameters:

aDataSource - the dataset to be decoded.

Returns:

A model with the structure described in the class javadoc

Throws:

IOException - if the dataset cannot be loaded.

See Also:

canDecodeSource(com.luciad.model.ILcdDataSource)

canDecodeSource

public boolean canDecodeSource(String aSource)

Checks whether the given source can be decoded with this model decoder.

This model decoder handles only .mbtiles files.

Specified by:

canDecodeSource in interface ILcdModelDecoder

Parameters:

aSource - the data source to be verified; typically a file name or a URL.

Returns:

true if the source has .mbtiles extension.

See Also:

decode(String)

decode

public ILcdModel decode(String aSource)
                 throws IOException

Decodes the single dataset in an MBTiles file.

Specified by:

decode in interface ILcdModelDecoder

Parameters:

aSource - the MBTiles file to be decoded.

Returns:

A model representing the dataset in the MBTiles file

Throws:

IOException - if the file cannot be loaded.

See Also:

canDecodeSource(String)

discoverDataSources

public List<TLcdMBTilesDataSource> discoverDataSources(String aPath)
                                                throws IOException

Returns the single data source in the given MBTiles file.

You can use decodeSource(com.luciad.model.ILcdDataSource) to create a model for an individual data source.

Specified by:

discoverDataSources in interface ILcdModelDecoder

Parameters:

aPath - A path to the data source to be decoded; typically a file name or a URL.

Returns:

the single data source in the given MBTiles file.

Throws:

IOException - if the file cannot be read