uk.ac.starlink.ttools.cone

Class MocCoverage

java.lang.Object

uk.ac.starlink.ttools.cone.MocCoverage

All Implemented Interfaces:

Coverage

Direct Known Subclasses:

AsciiMocCoverage, ConeQueryCoverage, UrlMocCoverage

public abstract class MocCoverage
extends Object
implements Coverage

Abstract superclass for Coverage implementations based on MOC (HEALPix Multi-Order Coverage) objects.

Since:

9 Jan 2012

Author:

Mark Taylor

Nested Class Summary

Nested classes/interfaces inherited from interface uk.ac.starlink.ttools.cone.Coverage

Coverage.Amount

Field Summary

Fields

Modifier and Type	Field and Description
static cds.moc.HealpixImpl	DFLT_HPI Default Healpix implementation.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MocCoverage() Constructs a MocCoverage with default HEALPix implementation.
protected	MocCoverage(cds.moc.HealpixImpl hpi) Constructs a MocCoverage with specified HEALPix implementation.

Method Summary

Modifier and Type	Method and Description
protected abstract cds.moc.SMoc	createMoc() Constructs the MOC which will define this object's coverage.
boolean	discOverlaps(double alphaDeg, double deltaDeg, double radiusDeg) Indicates whether a given disc on the sphere overlaps, or may overlap with this coverage.
Coverage.Amount	getAmount() Returns the amount category for coverage.
cds.moc.SMoc	getMoc() Returns the MOC object associated with this footprint.
void	initCoverage() Must be called before any of the query methods are used.

Methods inherited from class java.lang.Object

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

Field Detail

DFLT_HPI

public static final cds.moc.HealpixImpl DFLT_HPI

Default Healpix implementation.

Constructor Detail

MocCoverage

protected MocCoverage()

Constructs a MocCoverage with default HEALPix implementation.

MocCoverage

protected MocCoverage(cds.moc.HealpixImpl hpi)

Constructs a MocCoverage with specified HEALPix implementation.

Parameters:

hpi - HEALPix implementation to use for calculations

Method Detail

createMoc

protected abstract cds.moc.SMoc createMoc()
                                   throws IOException

Constructs the MOC which will define this object's coverage. This method, which may be time-consuming, will be called a maximum of once by the initCoverage() method of MocCoverage, and should not be called by anyone else.

Returns:

new MOC defining footprint, or null

Throws:

IOException

initCoverage

public void initCoverage()
                  throws IOException

Description copied from interface: Coverage

Must be called before any of the query methods are used. May be time consuming (it may contact an external service). It is legal to call this method multiple times from the same or different threads. If Coverage.getAmount() returns non-null, this method will return directly. Following a successful or error return of this method, Coverage.getAmount() will return non-null.

Specified by:

initCoverage in interface Coverage

Throws:

IOException

getAmount

public Coverage.Amount getAmount()

Description copied from interface: Coverage

Returns the amount category for coverage. If the footprint is not ready for use, null is returned. In that case, Coverage.initCoverage() must be called before use.

Specified by:

getAmount in interface Coverage

Returns:

coverage amount category

discOverlaps

public boolean discOverlaps(double alphaDeg,
                            double deltaDeg,
                            double radiusDeg)

Description copied from interface: Coverage

Indicates whether a given disc on the sphere overlaps, or may overlap with this coverage. False positives are permitted.

Specified by:

discOverlaps in interface Coverage

Parameters:

alphaDeg - central longitude in degrees

deltaDeg - central latitude in degrees

radiusDeg - radius in degrees

Returns:

false if the given disc definitely does not overlap this footprint; otherwise true

getMoc

public cds.moc.SMoc getMoc()

Returns the MOC object associated with this footprint.

Returns:

moc