org.eclipse.vex.ui/src/org/eclipse/vex/ui/internal/config/ConfigItem.java

/*******************************************************************************
 * Copyright (c) 2004, 2008 John Krasnay and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     John Krasnay - initial API and implementation
 *     Igor Jacy Lino Campista - Java 5 warnings fixed (bug 311325)
 *******************************************************************************/
package org.eclipse.vex.ui.internal.config;

import java.net.URI;

/**
 * Base class of all configurtion items such as document types and styles.
 */
public abstract class ConfigItem implements Comparable<ConfigItem> {

	/**
	 * Class constructor.
	 *
	 * @param config
	 *            VexConfiguration to which this item belongs.
	 */
	public ConfigItem(final ConfigSource config) {
		this.config = config;
	}

	@Override
	public int compareTo(final ConfigItem o) {
		return getName().compareTo(o.getName());
	}

	/**
	 * Generate a simple identifier for the item that is unique with its configuration.
	 */
	public String generateSimpleId() {
		final String base = "id"; //$NON-NLS-1$
		int i = 1;
		for (;;) {
			final String id = base + i;
			if (getConfig().getItem(id) == null) {
				return id;
			}
			i++;
		}
	}

	/**
	 * Returns the VexConfiguration to which this item belongs.
	 */
	public ConfigSource getConfig() {
		return config;
	}

	/**
	 * Returns the extension point ID of configuration item. This will be the same for all config items of a given type.
	 */
	public abstract String getExtensionPointId();

	/**
	 * Returns the simple ID of this item. This is a short string containing no periods.
	 */
	public String getSimpleId() {
		return id;
	}

	/**
	 * Returns the unique ID of this item. The unique ID is formed by concatenating the ID of the associated
	 * VexConfiguration, a period, and the simple ID of this item.
	 */
	public String getUniqueId() {
		return id == null ? null : getConfig().getUniqueIdentifer() + "." + id; //$NON-NLS-1$
	}

	/**
	 * Returns the human-readable name for this item.
	 */
	public String getName() {
		return name;
	}

	/**
	 * Returns the URI of the associated resource, if any, relative to the base directory of the associated
	 * VexConfiguration. Returns null if no resource is associated with this item.
	 */
	public URI getResourceUri() {
		return resourceUri;
	}

	/**
	 * Returns true if s is null or empty. Convenience method to be used in isValid().
	 *
	 * @param s
	 *            String to check.
	 */
	protected boolean isBlank(final String s) {
		return s == null || s.length() == 0;
	}

	/**
	 * Returns true if this item has sufficient information to be used as a configuration item. By default, the item
	 * must have a simple ID and a name. Subclasses should override and provide additional checks as necessary, after
	 * calling this base implementation.
	 */
	public boolean isValid() {
		return !isBlank(id) && !isBlank(name);
	}

	/**
	 * Sets the name for this item.
	 *
	 * @param name
	 *            New name for this item.
	 */
	public void setName(final String name) {
		this.name = name;
	}

	/**
	 * Sets the resource URI for this item.
	 *
	 * @param resourceUri
	 *            New resource URI for this item.
	 */
	public void setResourceUri(final URI resourceUri) {
		this.resourceUri = resourceUri;
	}

	/**
	 * Sets the simple ID for this item. The simple ID should only contain letters and numbers, and must not contain a
	 * period.
	 *
	 * @param id
	 *            New simple ID for this item.
	 */
	public void setSimpleId(final String id) {
		this.id = id;
	}

	@Override
	public String toString() {
		return getUniqueId();
	}

	// ==================================================== PRIVATE

	private String id;
	private String name;
	private URI resourceUri;
	private final ConfigSource config;

}