BaseDirs.java

/***************************************************************************
 *   Copyright (C) 2007, 2009 by Kevin Krammer <kevin.krammer@gmx.at>      *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU Library General Public License as       *
 *   published by the Free Software Foundation; either version 2.1 of the  *
 *   License, or (at your option) any later version.                       *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this program; if not, write to the                 *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.         *
 ***************************************************************************/

package org.freedesktop.xdg;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.StringTokenizer;

/**
 * @author Kevin Krammer, <kevin.krammer@gmx.at>
 */
public class BaseDirs {
	public enum Resource {
		CONFIG("XDG_CONFIG_HOME", ".config", "XDG_CONFIG_DIRS", "/etc/xdg"),

		DATA("XDG_DATA_HOME", ".local/share", "XDG_DATA_DIRS",
				"/usr/local/share:/usr/share");

		Resource(String userPathProperty, String userPathDefault,
				String systemPathsProperty, String systemPathsDefault) {
			mUserPathProperty = userPathProperty;
			mUserPathDefault = userPathDefault;

			mSystemPathsProperty = systemPathsProperty;
			mSystemPathsDefault = systemPathsDefault;
		}

		public String getUserPathProperty() {
			return mUserPathProperty;
		}

		public String getUserPathDefault() {
			return mUserPathDefault;
		}

		public String getSystemPathsProperty() {
			return mSystemPathsProperty;
		}

		public String getSystemPathsDefault() {
			return mSystemPathsDefault;
		}

		private final String mUserPathProperty;
		private final String mUserPathDefault;
		private final String mSystemPathsProperty;
		private final String mSystemPathsDefault;
	}

	public BaseDirs() {
	}

	public String getUserPath(Resource resource) {
		if (mUserPaths == null)
			mUserPaths = new String[Resource.values().length];

		if (mUserPaths[resource.ordinal()] == null) {
			cacheHomePath(resource);
		}

		return mUserPaths[resource.ordinal()];
	}

	public String[] getSystemPaths(Resource resource) {
		if (mSystemPaths == null) {
			mSystemPaths = new String[Resource.values().length][];
		}

		if (mSystemPaths[resource.ordinal()] == null) {
			cacheSystemPaths(resource);
		}

		return mSystemPaths[resource.ordinal()];
	}

	public File findResourceFile(Resource resource, String relPath)
			throws FileNotFoundException {
		File file = new File(getUserPath(resource), relPath);
		if (file.exists() && file.isFile())
			return file;

		String[] paths = getSystemPaths(resource);
		for (int i = 0; i < paths.length; ++i) {
			file = new File(paths[i], relPath);
			if (file.exists() && file.isFile())
				return file;
		}

		throw new FileNotFoundException();
	}

	public File findResourceDirectory(Resource resource, String relPath)
			throws FileNotFoundException {
		File file = new File(getUserPath(resource), relPath);
		if (file.exists() && file.isDirectory())
			return file;

		String[] paths = getSystemPaths(resource);
		for (int i = 0; i < paths.length; ++i) {
			file = new File(paths[i], relPath);
			if (file.exists() && file.isDirectory())
				return file;
		}

		throw new FileNotFoundException();
	}

	public File getSaveDirectory(Resource resource, String relPath) {
		File file = new File(getUserPath(resource), relPath);

		if (file.exists()) {
			if (!file.isDirectory())
				return null; // exception?
		} else if (!file.mkdirs())
			return null; // exception?

		return file;
	}

	private void cacheHomePath(Resource resource) {
		String property = System.getenv(resource.getUserPathProperty());
		if (property == null || property.length() == 0) {
			property = resource.getUserPathDefault();
		}

		File file = new File(property);
		if (!file.isAbsolute()) {
			file = new File(System.getProperty("user.home"), property);

			mUserPaths[resource.ordinal()] = file.getAbsolutePath();
		} else {
			mUserPaths[resource.ordinal()] = property;
		}
	}

	private void cacheSystemPaths(Resource resource) {
		String property = System.getenv(resource.getSystemPathsProperty());
		if (property == null || property.length() == 0) {
			property = resource.getSystemPathsDefault();
		}

		StringTokenizer tokenizer = new StringTokenizer(property, ":");

		mSystemPaths[resource.ordinal()] = new String[tokenizer.countTokens()];

		for (int i = 0; tokenizer.hasMoreTokens(); ++i) {
			mSystemPaths[resource.ordinal()][i] = tokenizer.nextToken();
		}
	}

	private String[] mUserPaths = null;
	private String[][] mSystemPaths = null;
}