Resources.scala

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
*/

/* sbt -- Simple Build Tool
 * Copyright 2008, 2009  Mark Harrah
 */
package sbt

import java.io.File
import IO._
import Resources.error

object Resources
{
	def apply(basePath: String) =
	{
		require(basePath.startsWith("/"))
		val resource = getClass.getResource(basePath)
		if(resource == null)
			error("Resource base directory '" + basePath + "' not on classpath.")
		else
		{
			val file = toFile(resource)
			if(file.exists)
				new Resources(file)
			else
				error("Resource base directory '" + basePath + "' does not exist.")
		}
	}
	def error(msg: String) = throw new ResourcesException(msg)
	private val LoadErrorPrefix = "Error loading initial project: "
}
class ResourcesException(msg: String) extends Exception(msg)

class Resources(val baseDirectory: File)
{
	import Resources._
	// The returned directory is not actually read-only, but it should be treated that way
	def readOnlyResourceDirectory(group: String, name: String): File =
	{
		val groupDirectory = new File(baseDirectory, group)
		if(groupDirectory.isDirectory)
		{
			val resourceDirectory = new File(groupDirectory, name)
			if(resourceDirectory.isDirectory)
				resourceDirectory
			else
				error("Resource directory '" + name + "' in group '" + group + "' not found.")
		}
		else
			error("Group '" + group + "' not found.")
	}
	def readWriteResourceDirectory[T](group: String, name: String)(withDirectory: File => T): T =
	{
		val file = readOnlyResourceDirectory(group, name)
		readWriteResourceDirectory(file)(withDirectory)
	}

	def readWriteResourceDirectory[T](readOnly: File)(withDirectory: File => T): T =
	{
		require(readOnly.isDirectory)
		def readWrite(readOnly: File)(temporary: File): T =
		{
			val readWriteDirectory = new File(temporary, readOnly.getName)
			copyDirectory(readOnly, readWriteDirectory)
			withDirectory(readWriteDirectory)
		}
		withTemporaryDirectory(readWrite(readOnly))
	}
}