Package org.freedesktop.wayland.util

Class EnumUtil

java.lang.Object

org.freedesktop.wayland.util.EnumUtil

public class EnumUtil
extends Object

Constructor Summary

Constructors

Constructor	Description
EnumUtil()

Method Summary

Modifier and Type	Method	Description
static <E extends Enum<E>> Map<Integer,E>	buildEnumMap(Class<E> enumClass)
static <E extends Enum<E>> EnumSet<E>	decode(Class<E> enumClass, int mask)	Decodes an integer bitmask into an EnumSet of the specified enum type.
static <E extends Enum<E>> int	encode(EnumSet<E> set)	Encodes an EnumSet into an integer bitmask.
static <E extends Enum<E>> int	encodeWithReflection(EnumSet<E> set)	Encodes an EnumSet into an integer bitmask using reflection.
static <E extends Enum<E>> E	of(Class<E> type, Integer i)	Given an enum type from the generated code and an integer value returns the corresponding enum value for the integer.
static <E extends Enum<E>> void	register(Class<E> enumClass)

Methods inherited from class java.lang.Object

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

Constructor Details

EnumUtil

public EnumUtil()

Method Details

register

public static <E extends Enum<E>> void register(Class<E> enumClass)

buildEnumMap

public static <E extends Enum<E>> Map<Integer,E> buildEnumMap(Class<E> enumClass)

of

public static <E extends Enum<E>> E of(Class<E> type,
 Integer i)

Given an enum type from the generated code and an integer value returns the corresponding enum value for the integer.

Type Parameters:

E -

Parameters:

type - the enum type from the wayland-scanner generated code

i - the integer value

Returns:

the enum value

Throws:

NullPointerException - if enumClass is null or is not from the wayland-scanner generated code

decode

public static <E extends Enum<E>> EnumSet<E> decode(Class<E> enumClass,
 int mask)

Decodes an integer bitmask into an EnumSet of the specified enum type.

The function assumes that the enum constants are properly defined in the natural order of their bit positions. It iterates over the bits of the mask and adds the corresponding enum values to the resulting EnumSet.

Type Parameters:

E - the enum type

Parameters:

enumClass - the Class object representing the enum type

mask - the integer bitmask to decode

Returns:

an EnumSet containing the enum values corresponding to the set bits in the mask

Throws:

NullPointerException - if enumClass is null

IllegalArgumentException - if mask is negative or if the ordinal value of any enum constant exceeds the number of bits in an int

encode

public static <E extends Enum<E>> int encode(EnumSet<E> set)

Encodes an EnumSet into an integer bitmask.

The function assumes that the enum constants are defined in the order of powers of 2. It uses the ordinal values of the enum constants to set the appropriate bits in the bitmask.

Type Parameters:

E - the enum type

Parameters:

set - the EnumSet to be encoded

Returns:

an integer bitmask representing the encoded EnumSet

encodeWithReflection

public static <E extends Enum<E>> int encodeWithReflection(EnumSet<E> set)

Encodes an EnumSet into an integer bitmask using reflection.

Unlike encode(EnumSet), this method does not rely on the ordinal values of the enum constants. Instead, it uses reflection to invoke a getValue() method on each enum constant to obtain the corresponding bit value. The resulting bitmask is constructed by performing a bitwise OR operation on the obtained bit values.

The enum type must have a getValue() method that returns the desired bit value for each constant.

Type Parameters:

E - the enum type

Parameters:

set - the EnumSet to be encoded

Returns:

an integer bitmask representing the encoded EnumSet

Throws:

IllegalArgumentException - if the enum type does not have a getValue() method or if there is an exception during reflection