org.togglz.junit.vary.VariationSetBuilder Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of togglz-junit Show documentation
Togglz - JUnit integration
There is a newer version: 4.4.0
package org.togglz.junit.vary;

import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;

import org.togglz.core.Feature;
import org.togglz.core.util.Validate;

/**
 * Default implementation of {@link VariationSet} that allows to build the set dynamically.
 * 
 * @author Christian Kaltepoth
 * 
 * @param  The feature class
 */
public class VariationSetBuilder implements VariationSet
{

    public static  VariationSetBuilder create(Class featureClass)
    {
        return new VariationSetBuilder(featureClass);
    }

    private final Class featureClass;

    private final Set featuresToVary = new HashSet();
    private final Set featuresToEnable = new HashSet();
    private final Set featuresToDisable = new HashSet();

    private VariationSetBuilder(Class featureEnum)
    {
        Validate.notNull(featureEnum, "The featureEnum argument is required");
        Validate.isTrue(featureEnum.isEnum(), "This class only works with feature enums");
        this.featureClass = featureEnum;
    }

    /**
     * Vary this feature in the variation set.
     */
    public VariationSetBuilder vary(F f)
    {
        featuresToVary.add(f);
        featuresToEnable.remove(f);
        featuresToDisable.remove(f);
        return this;
    }

    /**
     * Enable this feature in the variation set.
     */
    public VariationSetBuilder enable(F f)
    {
        featuresToVary.remove(f);
        featuresToEnable.add(f);
        featuresToDisable.remove(f);
        return this;
    }

    /**
     * Disable this feature in the variation set.
     */
    public VariationSetBuilder disable(F f)
    {
        featuresToVary.remove(f);
        featuresToEnable.remove(f);
        featuresToDisable.add(f);
        return this;
    }

    /**
     * Enable all features in the variation set.
     */
    public VariationSetBuilder enableAll() {
        for (F f : featureClass.getEnumConstants()) {
            enable(f);
        }
        return this;
    }

    /**
     * Disable all features in the variation set.
     */
    public VariationSetBuilder disableAll() {
        for (F f : featureClass.getEnumConstants()) {
            disable(f);
        }
        return this;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.togglz.junit.vary.VariationSet#getVariants()
     */
    @Override
    public Set> getVariants()
    {

        // start with a single variant with all feature disabled
        Set> variantSet = new LinkedHashSet>();
        variantSet.add(new HashSet());

        for (F feature : featureClass.getEnumConstants()) {

            // enable the feature in all variants
            if (featuresToEnable.contains(feature)) {
                for (Set variant : variantSet) {
                    variant.add(feature);
                }
            }

            // disable the feature in all variants
            else if (featuresToDisable.contains(feature)) {
                for (Set variant : variantSet) {
                    variant.remove(feature);
                }
            }

            // copy the existing variants, enable the feature in the copy, and merge them
            else if (featuresToVary.contains(feature)) {
                Set> copy = deepCopy(variantSet);
                for (Set variant : copy) {
                    variant.add(feature);
                }
                variantSet.addAll(copy);
            }

        }

        return variantSet;

    }

    private Set> deepCopy(Set> src) {
        Set> copy = new HashSet>();
        for (Set variant : src) {
            copy.add(new HashSet(variant));
        }
        return copy;
    }

    public Class getFeatureClass()
    {
        return featureClass;
    }

}