org.csstudio.data.values

Class ValueUtil

java.lang.Object

org.csstudio.data.values.ValueUtil

public final class ValueUtil
extends Object

Helper for decoding the data in a IValue, mostly for display purposes.

Author:

Kay Kasemir

Method Summary

Modifier and Type	Method and Description
static String	formatValueAndSeverity(IValue value) Formats the severity and status of the value.
static double	getDouble(IValue value) Try to get a double number from the Value.
static double	getDouble(IValue value, int index) Try to get a double-typed array element from the Value.
static double[]	getDoubleArray(IValue value) Try to get a double-typed array from the Value.
static String	getInfo(IValue value) Try to get an info string from the Value.
static int	getSize(IValue value) Measures the size of the data in number of elements.
static String	getString(IValue value) Converts the given value into a string representation.

Methods inherited from class java.lang.Object

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

Method Detail

getSize

public static int getSize(IValue value)

Measures the size of the data in number of elements.

Parameters:

value - the value, which provides the data that is measured

Returns:

Array length of the value. 1 for scalars

getDouble

public static double getDouble(IValue value)

Try to get a double number from the Value.

Some applications only deal with numeric data, so they want to interpret integer, enum and double values all the same.

Parameters:

value - The value to decode.

Returns:

A double, or Double.NaN in case the value type does not decode into a number, or Double.NEGATIVE_INFINITY if the value's severity indicates that there happens to be no useful value.

getDouble

public static double getDouble(IValue value,
                               int index)

Try to get a double-typed array element from the Value.

Parameters:

value - The value to decode.

index - The array index, 0 ... getSize()-1.

Returns:

A double, or Double.NaN in case the value type does not decode into a number, or Double.NEGATIVE_INFINITY if the value's severity indicates that there happens to be no useful value.

See Also:

getSize(IValue), getDouble(IValue)

getDoubleArray

public static double[] getDoubleArray(IValue value)

Try to get a double-typed array from the Value.

Parameters:

value - The value to decode.

Returns:

A double array, or an empty double array in case the value type does not decode into a number, or if the value's severity indicates that there happens to be no useful value.

See Also:

getSize(IValue), getDouble(IValue)

getInfo

public static String getInfo(IValue value)

Try to get an info string from the Value.

For numeric values, which is probably the vast majority of all values, this is the severity and status information.

For 'enum' type values, getDouble() will return the numeric value, and getInfo() returns the associated enumeration string, appended to a possible severity/status text.

For string type values, this is the string value and a possible severity/status text, while getDouble() will return NaN.

Parameters:

value - The value to decode.

Returns:

The info string, never null.

formatValueAndSeverity

public static String formatValueAndSeverity(IValue value)

Formats the severity and status of the value.

Parameters:

value - the value which provides the severity and status

Returns:

Non-null String for the value and its severity/status. Does not include the time stamp.

getString

public static String getString(IValue value)

Converts the given value into a string representation. For string values, returns the value. For numeric (double and long) values, returns a non-localised string representation. Double values use a point as the decimal separator. For other types of values, the value's IValue.format() method is called and its result returned.

Parameters:

value - the value.

Returns:

a string representation of the value.