ShortenedJavaNameRenderer.java

package fr.openwide.core.wicket.more.rendering;

import java.util.Locale;

/**
 * A renderer that shortens Java names, such as package names, class names or fully-qualified attribute names,
 * by replacing the least-significant (e.g. leftmost) components by their first letter. 
 */
public class ShortenedJavaNameRenderer extends Renderer<String> {
	
	private static final long serialVersionUID = 1L;

	private static final String JAVA_SEPARATOR_REGEXP = "\\.";
	
	private static final String JAVA_SEPARATOR = ".";
	
	private static final ShortenedJavaNameRenderer INSTANCE = new ShortenedJavaNameRenderer(5);

	public static Renderer<String> get() {
		return INSTANCE;
	}

	private final int maximumFullComponents;
	
	/**
	 * @param maximumFullComponents Maximum number of components in the package name that will be
	 * displayed in their full form.
	 */
	public ShortenedJavaNameRenderer(int maximumFullComponents) {
		this.maximumFullComponents = maximumFullComponents;
	}
	
	@Override
	public String render(String value, Locale locale) {
		String[] packages = value.split(JAVA_SEPARATOR_REGEXP);
		StringBuilder displayStringBuilder = new StringBuilder();
		int packagesCount = packages.length;
		for (int cpt=0; cpt < packagesCount; cpt++) {
			if (cpt > 0) {
				displayStringBuilder.append(JAVA_SEPARATOR);
			}
			String p = packages[cpt];
			if (cpt < packagesCount - maximumFullComponents) {
				displayStringBuilder.append(p, 0, 1);
			} else {
				displayStringBuilder.append(p);
			}
		}
		return displayStringBuilder.toString();
	}

}