uk.ac.starlink.table
Class URLValueInfo

java.lang.Object
  uk.ac.starlink.table.URLValueInfo

All Implemented Interfaces:

ValueInfo

public class URLValueInfo
extends java.lang.Object
implements ValueInfo

ValueInfo for URL values.

Since:

16 Sep 2004

Constructor Summary

URLValueInfo(java.lang.String name, java.lang.String description)
Constructs a new URLValueInfo.

Method Summary

java.lang.String	formatValue(java.lang.Object value, int maxLength) Returns a string representation of a given value described by this ValueInfo.
javax.swing.table.TableCellRenderer	getCellRenderer()
java.lang.Class	getContentClass() Returns the java class of the values described by this object.
java.lang.String	getDescription() Returns a description of the values described by this object.
DomainMapper[]	getDomainMappers() Returns an array of objects which may be able to convert from the values described by this info to a particular target value domain.
int	getElementSize() May indicate the size of a value element stored as the value of this info.
java.lang.String	getName() Returns the name of this object.
int[]	getShape() Returns the shape associated with array value types.
java.lang.String	getUCD() Returns the Unified Column Descriptor string applying to the values described by this object.
java.lang.String	getUnitString() Returns a string representing the units of the values described by this object.
java.lang.String	getUtype() Returns the Utype string applying to the values described by this object.
boolean	isArray() Indicates whether the values described by this object are java arrays.
boolean	isNullable() Indicates whether values returned described by this object may have the value null.
java.lang.Object	unformatString(java.lang.String rep) Returns an object of the sort described by this ValueInfo represented by the given string rep.

Methods inherited from class java.lang.Object

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

Constructor Detail

URLValueInfo

public URLValueInfo(java.lang.String name,
                    java.lang.String description)

Constructs a new URLValueInfo.

Parameters:

name - info name

description - info description

Method Detail

getName

public java.lang.String getName()

Description copied from interface: ValueInfo

Returns the name of this object.

Specified by:

getName in interface ValueInfo

Returns:

the name

getDescription

public java.lang.String getDescription()

Description copied from interface: ValueInfo

Returns a description of the values described by this object. It may contain a short or long textual description of the kind of information represented by the value.

Specified by:

getDescription in interface ValueInfo

Returns:

a textual description, or the empty string "" if there is nothing to be said

getUnitString

public java.lang.String getUnitString()

Description copied from interface: ValueInfo

Returns a string representing the units of the values described by this object. The syntax and conventions should ideally match those adopted by VOTable, as defined by CDS.

Specified by:

getUnitString in interface ValueInfo

Returns:

a string giving the units, or null if units are unknown

See Also:

Standards for Astronomical Catalogues: Units, CDS Strasbourg

getUCD

public java.lang.String getUCD()

Description copied from interface: ValueInfo

Returns the Unified Column Descriptor string applying to the values described by this object.

Specified by:

getUCD in interface ValueInfo

Returns:

the UCD, or null if none is known

See Also:

Unified Column Descriptor scheme, UCD

getUtype

public java.lang.String getUtype()

Description copied from interface: ValueInfo

Returns the Utype string applying to the values described by this object. Utype is a string which references a data model. It is used pervasively within IVOA standards; probably an official IVOA definition of Utype syntax and semantics will arise one day.

Specified by:

getUtype in interface ValueInfo

Returns:

the Utype, or null if none is known

getContentClass

public java.lang.Class getContentClass()

Description copied from interface: ValueInfo

Returns the java class of the values described by this object. The intention is that any Object described by this ValueInfo will be an instance of the returned class or one of its subclasses. Note therefore that it must not return one of the primitive class objects (int.class et al.); the appropriate wrapper classes must be used instead (Integer.class etc).

The class returned should not under normal circumstances be an array of arrays; to express multidimensionality of arrays you should store an array of non-array objects or of primitives and provide shape information via the getShape method. There is nothing to stop you describing arrays of arrays with a ValueInfo, but some other elements of the tables infrastructure and applications may work on the assumption that such objects are not present.

Note that to store sets of more than 2³¹ items it will be necessary to use some custom object, since java arrays are indexed by type int.

Specified by:

getContentClass in interface ValueInfo

Returns:

the java class

isArray

public boolean isArray()

Description copied from interface: ValueInfo

Indicates whether the values described by this object are java arrays. This convenience method should return the same as

     getContentClass().getComponentType()!=null
 

Specified by:

isArray in interface ValueInfo

Returns:

true iff the values described by this object are java arrays

getShape

public int[] getShape()

Description copied from interface: ValueInfo

Returns the shape associated with array value types. If the class returned by ValueInfo.getContentClass() is a java array type, the return from this method may contain information about the shape of the rectangular array which this represents. The dimensions of the array are given in the elements of the return value of this method, fastest varying first. All elements of the array should be positive, except that the last (slowest varying) element may be <=0 (conventionally -1) to indicate that the number of (shape.length-1)-dimensional slices contained in the value is not known. If nothing is known about the shape of the array values, then a 1-element array whose only element is <=0 should be returned.

If getContentClass does not give an array type (hence isArray returns false) the return value for this method is undefined (but should probably be null).

Specified by:

getShape in interface ValueInfo

Returns:

the shape of the array value

getElementSize

public int getElementSize()

Description copied from interface: ValueInfo

May indicate the size of a value element stored as the value of this info. The total size of the value will in this case be the return value of this method multiplied by the number of elements, as indicated by ValueInfo.getShape() (or by 1, if getShape is null).

The exact meaning of the value returned is dependent on this ValueInfo. This method was introduced to return the maximum number of characters in a String-class ValueInfo; this information is necessary for writing out to certain formats (FITS). Other ValueInfo types however may use it for their own purposes.

ValueInfo instances which decline to supply this information should return -1 from this method.

Specified by:

getElementSize in interface ValueInfo

Returns:

notional size of each element an array of values described by this info

isNullable

public boolean isNullable()

Description copied from interface: ValueInfo

Indicates whether values returned described by this object may have the value null. In general this should return true, which implies no assertion about the return values (they may or may not be null). But if the values are known never to be null, it may return false.

Specified by:

isNullable in interface ValueInfo

Returns:

false if values are guaranteed non-null

getDomainMappers

public DomainMapper[] getDomainMappers()

Description copied from interface: ValueInfo

Returns an array of objects which may be able to convert from the values described by this info to a particular target value domain. This can used for non-obvious representations of certain coordinates such as time and angular position. In most cases the returned array will be empty, since the target domain is obvious (e.g. numeric values). In the (unusual) case that the returned array contains multiple entries, it should have no more than one for any given target domain, and the first entry may be considered "primary" in some sense. Absence of a mapper for a given target domain does not necessarily indicate that the described values cannot be used in that domain.

Specified by:

getDomainMappers in interface ValueInfo

Returns:

array of domain mappers for the values described by this info

formatValue

public java.lang.String formatValue(java.lang.Object value,
                                    int maxLength)

Description copied from interface: ValueInfo

Returns a string representation of a given value described by this ValueInfo. The returned string should be no longer than a given maximum length.

Specified by:

formatValue in interface ValueInfo

Parameters:

value - the value to represent

maxLength - the maximum number of characters in the returned string

unformatString

public java.lang.Object unformatString(java.lang.String rep)

Description copied from interface: ValueInfo

Returns an object of the sort described by this ValueInfo represented by the given string rep.

Specified by:

unformatString in interface ValueInfo

Parameters:

rep - the string representation of a value described by this ValueInfo

Returns:

the Object value represented by rep; must match this info's content class (or be null)

getCellRenderer

public javax.swing.table.TableCellRenderer getCellRenderer()