uk.ac.starlink.table
Interface TableBuilder

All Known Implementing Classes:
FitsTableBuilder, TextTableBuilder, VOTableBuilder, WDCTableBuilder

public interface TableBuilder

Interface for objects which can construct a StarTable from a data resource.


Method Summary
 boolean canImport(DataFlavor flavor)
          Indicates whether this builder is able to turn a resource of media type indicated by flavor into a table.
 StarTable makeStarTable(DataSource datsrc, boolean wantRandom)
          Constructs a StarTable based on a given DataSource.
 

Method Detail

makeStarTable

public StarTable makeStarTable(DataSource datsrc,
                               boolean wantRandom)
                        throws IOException
Constructs a StarTable based on a given DataSource. If the source is not recognised or this builder does not know how to construct a table from it, then null should be returned. If this builder thinks it should be able to handle the source but an error occurs during processing, an IOException can be thrown.

The wantRandom parameter is used to indicate whether, ideally, a random-access table should be returned. There is no requirement for the builder to honour this request, but if it knows how to make both random and non-random tables, it can use this flag to decide which to return.

Parameters:
datsrc - the DataSource containing the table resource
wantRandom - whether, preferentially, a random access table should be returned
Returns:
a StarTable made out of datsrc, or null if this handler can't handle it
IOException

canImport

public boolean canImport(DataFlavor flavor)
Indicates whether this builder is able to turn a resource of media type indicated by flavor into a table. It should return true if it thinks that its makeStarTable(uk.ac.starlink.util.DataSource, boolean) method stands a reasonable chance of successfully constructing a StarTable from a DataSource whose input stream is described by the DataFlavor flavor. It will typically make this determination based on the flavor's MIME type.

For reasons of efficiency it is probably not a good idea to return true unless the flavor looks like it is targeted at this builder; for instance a builder which uses a text-based format should probably return false for a flavor which indicates a MIME type of text/plain.

This method is used in supporting drag and drop functionality (see StarTableFactory.canImport(java.awt.datatransfer.DataFlavor[])).

Parameters:
flavor - the DataFlavor whose suitability as stream input is to be assessed
Returns:
true iff this builder reckons it stands a good chance of turning a stream of type flavor into a StarTable

Copyright © 2004 CLRC: Central Laboratory of the Research Councils. All rights reserved.