PrefFile.java

/**
 * 
 */
package ecologylab.appframework.types.prefs;

import java.io.File;

import ecologylab.appframework.EnvironmentGeneric;
import ecologylab.appframework.PropertiesAndDirectories;
import ecologylab.serialization.annotations.simpl_inherit;
import ecologylab.serialization.annotations.simpl_scalar;

/**
 * Pref indicating a File. Stores a value that indicates either an absolute path, or one relative to
 * the code base or application data dir for the application using the Pref.
 * 
 * @author ross
 * @author Zachary O. Toups (zach@ecologylab.net)
 * 
 */
@simpl_inherit
public class PrefFile extends Pref<File>
{
	/** Path associated with this preference. */
	@simpl_scalar
	String									value;

	/**
	 * Context indicating the type of path specified by value. Possible values are ABSOLUTE_PATH,
	 * CODE_BASE, or APP_DATA_DIR.
	 */
	@simpl_scalar
	int											pathContext		= ABSOLUTE_PATH;

	/** Indicates that value is an absolute path. */
	public static final int	ABSOLUTE_PATH	= 0;

	/**
	 * Indicates that value is a path relative to the codebase of the application using this Pref.
	 */
	public static final int	CODE_BASE			= 1;

	/**
	 * Indicates that value is a path relative to the data directory associated with the application
	 * using this Pref.
	 */
	public static final int	APP_DATA_DIR	= 2;

	/**
	 * The cached File object that goes with this Pref; lazilly evaluated. fileValue should NEVER be
	 * directly referenced, it should only be accessed through the file() method.
	 */
	File										fileValue			= null;

	/** No-argument constructor for XML translation. */
	public PrefFile()
	{
		super();
	}

	public PrefFile(String name, String value, int pathContext)
	{
		this.name = name;
		this.value = value;
		this.pathContext = pathContext;
	}

	/**
	 * Instantiate Pref to value
	 * 
	 * @param value
	 */
	public PrefFile(File value)
	{
		super();
		this.setValue(value);
	}

	/**
	 * Get the value of the Pref. If this's file path includes '$FIND_PATH', then this builds a file
	 * based upon the pathname provided by the App Framework.
	 * 
	 * @return The value of the Pref
	 */
	@Override
	protected File getValue()
	{
		return file();
	}

	/**
	 * Sets up this Pref object to be associated with newValue as an absolute path.
	 * 
	 * @see ecologylab.appframework.types.prefs.Pref#setValue(java.lang.Object)
	 */
	@Override
	public void setValue(File newValue)
	{
		this.value = newValue.getAbsolutePath();

		this.prefChanged();
	}

	/**
	 * Sets up this Pref object to be associated with newValue as a path indicated by pathContext.
	 * 
	 * @param newValue
	 * @param pathContext
	 */
	public void setValue(String newValue, int pathContext)
	{
		this.value = newValue;
		this.pathContext = pathContext;

		this.prefChanged();
	}

	private final File file()
	{
		if (fileValue == null)
		{
			switch (pathContext)
			{
			case (CODE_BASE):
				this.fileValue = new File(EnvironmentGeneric.codeBase().file(), value);
				break;
			case (APP_DATA_DIR):
				this.fileValue = new File(PropertiesAndDirectories.applicationDataDir(), value);
				break;
			default:
				this.fileValue = new File(value);
			}
		}

		return fileValue;
	}

	/**
	 * @see ecologylab.appframework.types.prefs.Pref#clone()
	 */
	@Override
	public Pref<File> clone()
	{
		return new PrefFile(this.name, this.value, this.pathContext);
	}
}