uk.ac.starlink.ttools.plot2.layer

Interface MultiPointReader

@Equality
public interface MultiPointReader

Defines data reading behaviour for use by a MultiPointForm.

Since:

8 Feb 2023

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	MultiPointReader.ExtrasReader Reads the non-central data positions for a MultiPointCoordSet.

Method Summary

Modifier and Type	Method and Description
MultiPointReader.ExtrasReader	createExtrasReader(DataGeom geom, Span sizeSpan) Returns a reader for the non-central parts of the MultiPointCoordSet.
AuxReader	createSizeReader(DataGeom geom) Returns an AuxReader that can obtain the characteristic size of the shapes to be plotted with the data from this reader.
double	getBaseScale(Surface surface, Span sizeSpan) Returns the base size scaling value.
MultiPointCoordSet	getExtraCoordSet() Returns the coord set defining the non-central coordinates used with this reader.
boolean	isAutoscale() Indicates whether autoscaling should be applied.

Method Detail

getExtraCoordSet

MultiPointCoordSet getExtraCoordSet()

Returns the coord set defining the non-central coordinates used with this reader.

Returns:

extra positions coordSet

isAutoscale

boolean isAutoscale()

Indicates whether autoscaling should be applied. If true, before plotting is carried out a scan of all the data values is performed to determine the range of values, and the supplied offsets are scaled accordingly, so that the largest ones are a reasonable size on the screen.

Returns:

true for autoscaling, false to use raw values

createExtrasReader

MultiPointReader.ExtrasReader createExtrasReader(DataGeom geom,
                                                 Span sizeSpan)

Returns a reader for the non-central parts of the MultiPointCoordSet.

If isAutoscale() returns true, the sizeSpan argument will contain a characterisation of the sizes of the items to be plotted, as calculated by an earlier call to the createSizeReader(uk.ac.starlink.ttools.plot2.DataGeom) method.

Parameters:

geom - data geometry used to interpret coordinate values

sizeSpan - characteristic size in case of autoscaling, otherwise null

Returns:

coordinate reader

createSizeReader

AuxReader createSizeReader(DataGeom geom)

Returns an AuxReader that can obtain the characteristic size of the shapes to be plotted with the data from this reader. The returned AuxReader will be used iff isAutoscale() returns true.

Parameters:

geom - data geometry used to interpret coordinate values

Returns:

multipoint shape size reader

getBaseScale

double getBaseScale(Surface surface,
                    Span sizeSpan)

Returns the base size scaling value. Manual adjustment may be applied on top of this value.

Parameters:

surface - plot surface

sizeSpan - size range calculated from data by request, null if autoscale is not in effect