uk.ac.starlink.topcat
Class TopcatUtils

java.lang.Object
  uk.ac.starlink.topcat.TopcatUtils

public class TopcatUtils
extends Object

Class containing miscellaneous static methods and constants for use in TOPCAT.

Since:

19 Aug 2004

Author:

Mark Taylor

Field Summary

static uk.ac.starlink.table.ValueInfo	ACTIVATORS_INFO Parameter key for storing an activation action for a table.
static uk.ac.starlink.table.ValueInfo	BASE_DESCRIPTION_INFO Column auxiliary metadata key identifying the description of columns which also have an expression (EXPR_INFO) entry.
static uk.ac.starlink.table.ValueInfo	COLID_INFO Column auxiliary metadata key identifying the uniqe column identifier for use in algebraic expressions.
static String	DEMO_LOCATION
static String	DEMO_NODES
static String	DEMO_TABLE
static uk.ac.starlink.table.ValueInfo	EXPR_INFO Column auxiliary metadata key identifying the text string which gives an expression for a synthetic column.
static uk.ac.starlink.table.ValueInfo	NUMERIC_CONVERTER_INFO Column auxiliary metadata key identifying an object which can convert from non-numeric cell values to numeric ones.
static String	STATUS_URL
static uk.ac.starlink.table.ValueInfo	TIME_INFO Data identifier for epoch-type data.
static String	VERSION_RESOURCE

Constructor Summary

TopcatUtils()

Method Summary

static boolean	canExec() Indicates whether we have System.exec permission.
static boolean	canJel() Indicates if it's possible to use JEL to compile algebraic expressions.
static boolean	canSog() Indicates whether there are enough classes to make SoG work at runtime.
static void	enquireLatestVersion() Ascertains the most recent release using an external connection, and reports through the logging system as appropriate.
static boolean	equals(Object o1, Object o2) Determines whether two objects are equal in the sense of Object.equals(java.lang.Object).
static String	formatLong(long num) Formats a long value for presentation as text.
static String[]	getAbout() Returns some lines of text describing this copy of the software including its version and versions of some important components.
static String	getApplicationName() Returns the name of this application.
static String	getBaseDescription(uk.ac.starlink.table.ColumnInfo info) Returns the 'base description' of a column info.
static String	getBaseName(String origName, String baseSuffix) Returns the base name of a column; that is one without any suffix based on baseSuffix.
static String	getDistinctName(ColumnList colList, String origName, String baseSuffix) Returns a column name based on a given one which is guaranteed distinct from any others in the column list.
static String	getExpression(uk.ac.starlink.table.ColumnInfo info) Returns the expression text for a column.
static String	getRevision() Returns the subversion revision number for TOPCAT and its dependencies.
static String	getSTILVersion() Returns the version string for the version of STIL being used here.
static String	getVersion() Returns the version string for this copy of TOPCAT.
static void	memoryError(OutOfMemoryError e) Alerts the user that the system has run out of memory, and provides the option of some useful tips.
static void	memoryErrorLater(OutOfMemoryError e) Queues a memoryError(java.lang.OutOfMemoryError) call for later execution on the event dispatch thread.
static void	setBaseDescription(uk.ac.starlink.table.ColumnInfo info, String desc) Sets the 'base description' of a column info.

Methods inherited from class java.lang.Object

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

Field Detail

DEMO_LOCATION

public static String DEMO_LOCATION

DEMO_TABLE

public static String DEMO_TABLE

DEMO_NODES

public static String DEMO_NODES

VERSION_RESOURCE

public static final String VERSION_RESOURCE

See Also:

Constant Field Values

STATUS_URL

public static final String STATUS_URL

See Also:

Constant Field Values

COLID_INFO

public static final uk.ac.starlink.table.ValueInfo COLID_INFO

Column auxiliary metadata key identifying the uniqe column identifier for use in algebraic expressions.

BASE_DESCRIPTION_INFO

public static final uk.ac.starlink.table.ValueInfo BASE_DESCRIPTION_INFO

Column auxiliary metadata key identifying the description of columns which also have an expression (EXPR_INFO) entry.

EXPR_INFO

public static final uk.ac.starlink.table.ValueInfo EXPR_INFO

Column auxiliary metadata key identifying the text string which gives an expression for a synthetic column.

NUMERIC_CONVERTER_INFO

public static final uk.ac.starlink.table.ValueInfo NUMERIC_CONVERTER_INFO

Column auxiliary metadata key identifying an object which can convert from non-numeric cell values to numeric ones.

ACTIVATORS_INFO

public static final uk.ac.starlink.table.ValueInfo ACTIVATORS_INFO

Parameter key for storing an activation action for a table.

TIME_INFO

public static final uk.ac.starlink.table.ValueInfo TIME_INFO

Data identifier for epoch-type data.

Constructor Detail

TopcatUtils

public TopcatUtils()

Method Detail

getBaseDescription

public static String getBaseDescription(uk.ac.starlink.table.ColumnInfo info)

Returns the 'base description' of a column info. This is the same as the description, except for synthetic columns, where it doesn't contain a respresentation of the algebraic expression.

Parameters:

info - column info

Returns:

base description of colinfo

setBaseDescription

public static void setBaseDescription(uk.ac.starlink.table.ColumnInfo info,
                                      String desc)

Sets the 'base description' of a column info. This sets the future result of calls to getBaseDescription(uk.ac.starlink.table.ColumnInfo) and also the description string itself (DefaultValueInfo.getDescription()).

Parameters:

info - column info to modify

desc - base description string (don't include expression text)

getExpression

public static String getExpression(uk.ac.starlink.table.ColumnInfo info)

Returns the expression text for a column. This should only have a non-null value for synthetic columns.

Parameters:

info - column info

Returns:

synthetic expression string

getBaseName

public static String getBaseName(String origName,
                                 String baseSuffix)

Returns the base name of a column; that is one without any suffix based on baseSuffix. This method is used in conjunction with getDistinctName(uk.ac.starlink.topcat.ColumnList, java.lang.String, java.lang.String).

Parameters:

origName - full name, possibly including bits of suffix

baseSuffix - the base suffix string

Returns:

name without any suffix-like elements of the sort specified by baseSuffix

getDistinctName

public static String getDistinctName(ColumnList colList,
                                     String origName,
                                     String baseSuffix)

Returns a column name based on a given one which is guaranteed distinct from any others in the column list. If the submitted origName is already unique, it may be returned. Otherwise a new name may be made which involves appending the given baseSuffix to it.

Parameters:

colList - column list within which distinct naming is required

origName - initial name

baseSuffix - suffix used for deduplication

Returns:

a name resembling origName which is not the same as any existing column names in colList

See Also:

getBaseName(java.lang.String, java.lang.String)

getApplicationName

public static String getApplicationName()

Returns the name of this application.

Returns:

"TOPCAT"

getAbout

public static String[] getAbout()

Returns some lines of text describing this copy of the software including its version and versions of some important components.

Returns:

lines of About text

memoryError

public static void memoryError(OutOfMemoryError e)

Alerts the user that the system has run out of memory, and provides the option of some useful tips.

Parameters:

e - exception, or null

memoryErrorLater

public static void memoryErrorLater(OutOfMemoryError e)

Queues a memoryError(java.lang.OutOfMemoryError) call for later execution on the event dispatch thread.

Parameters:

e - exception, or null

canSog

public static boolean canSog()

Indicates whether there are enough classes to make SoG work at runtime.

Returns:

true iff it's safe to use a SoG-based viewer

canExec

public static boolean canExec()

Indicates whether we have System.exec permission.

Returns:

true if it's possible to exec

canJel

public static boolean canJel()

Indicates if it's possible to use JEL to compile algebraic expressions. If the security manager does not permit creation of private class loaders, it will fail.

Returns:

true iff JEL epxression compilation will work

getVersion

public static String getVersion()

Returns the version string for this copy of TOPCAT.

Returns:

version number only

getRevision

public static String getRevision()

Returns the subversion revision number for TOPCAT and its dependencies.

Returns:

svn revision

getSTILVersion

public static String getSTILVersion()

Returns the version string for the version of STIL being used here.

Returns:

STIL version number

enquireLatestVersion

public static void enquireLatestVersion()

Ascertains the most recent release using an external connection, and reports through the logging system as appropriate.

equals

public static boolean equals(Object o1,
                             Object o2)

Determines whether two objects are equal in the sense of Object.equals(java.lang.Object). Unlike that method however, it returns true if both objects are null, and won't throw a NullPointerException.

Parameters:

o1 - first object

o2 - second object

Returns:

true if o1.equals(o2) or they're both null

formatLong

public static String formatLong(long num)

Formats a long value for presentation as text. This typically puts separators between groups of three numbers for improved visibility. TOPCAT policy is usually to do this only for numbers which are, or might be expected to be, quite large.

Parameters:

num - number to format

Returns:

formatted value