Java EnumSet Usage rotateEnum(T ce, boolean backwards, EnumSet ValidOptions)

Description

rotate Enum

License

Open Source License

Declaration

public static <T extends Enum> T rotateEnum(T ce, boolean backwards, EnumSet ValidOptions) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.util.EnumSet;

public class Main {
    public static <T extends Enum> T rotateEnum(T ce, boolean backwards, EnumSet ValidOptions) {
        do {//ww  w .ja  v a  2s.c om
            if (backwards) {
                ce = prevEnum(ce);
            } else {
                ce = nextEnum(ce);
            }
        } while (!ValidOptions.contains(ce));
        return ce;
    }

    public static <T extends Enum> T prevEnum(T ce) {
        EnumSet valList = EnumSet.allOf(ce.getClass());
        int pLoc = ce.ordinal() - 1;
        if (pLoc < 0) {
            pLoc = valList.size() - 1;
        }
        if (pLoc < 0 || pLoc >= valList.size()) {
            pLoc = 0;
        }
        int pos = 0;
        for (Object g : valList) {
            if (pos == pLoc) {
                //noinspection unchecked
                return (T) g;
            }
            pos++;
        }
        return null;
    }

    public static <T extends Enum> T nextEnum(T ce) {
        EnumSet valList = EnumSet.allOf(ce.getClass());
        int pLoc = ce.ordinal() + 1;
        if (pLoc >= valList.size()) {
            pLoc = 0;
        }
        if (pLoc < 0 || pLoc >= valList.size()) {
            pLoc = 0;
        }
        int pos = 0;
        for (Object g : valList) {
            if (pos == pLoc) {
                //noinspection unchecked
                return (T) g;
            }
            pos++;
        }
        return null;
    }
}

Related

1. getDataInEnumClass(String enumClassName)
2. getEnumFromString(Class enumClass, String enumValue, boolean compareByValue)
3. nativeLoadEnumDefaultValues(Class enumType)
4. nextEnum(T ce)
5. possibilities(Class enumClass)
6. setOnly(EnumSet theSet, E flag)
7. valueOfIgnoreCase(String text, Class cls)
8. valueOfOrNull(Class enumType, String name)
9. valueOfOrNull(Class enumType, String name, boolean checkCase)