org.subtlelib.poi.api.style.Styles Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of poi.builder Show documentation

Convenience library for apache poi-based xls documents creation

The newest version!

package org.subtlelib.poi.api.style;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

import java.util.ArrayList;
import java.util.List;

import org.subtlelib.poi.impl.style.CompositeStyle;

import com.google.common.collect.ImmutableList;

/**
 * Created on 10/04/13
 * @author d.serdiuk
 */
public class Styles {
    /**
     * Combine a list of additive styles into one. Styles with greater indexes may partially override
     * styles with lesser indexes.
     * @param styles not-null list that cannot contain null styles
     * @return a style that has the features of passed styles
     */
    public static AdditiveStyle combine(List styles) {
        checkNotNull(styles, "styles to combine cannot be null");
        checkArgument(styles.size() > 0, "cannot combine an empty list of styles");

        if (styles.size() == 1) {
            return styles.get(0);
        }

        List parts = new ArrayList();
        for (AdditiveStyle style : styles) {
            // can't use polymorphism in this case since we want to keep AdditiveStyle an interface so
            // that it can be implemented by user enums
            if (style instanceof CompositeStyle) {
                parts.addAll(((CompositeStyle) style).getStyles());
            } else {
                parts.add(style);
            }
        }
        return new CompositeStyle(parts);
    }

    /**
     * Combine an array of additive styles into one. Styles with greater indexes may partially override
     * styles with lesser indexes.
     * @param styles not-null list that cannot contain null styles
     * @return a style that has the features of passed styles
     */
    public static AdditiveStyle combine(AdditiveStyle... styles) {
        return Styles.combine(ImmutableList.copyOf(styles));
    }
}