bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceStore.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation 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:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jface.preference;

 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.PrintStream;
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.Properties;

 import org.eclipse.core.commands.common.EventManager;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.util.Assert;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.jface.util.SafeRunnable;

 /**
  * A concrete preference store implementation based on an internal
  * <code>java.util.Properties</code> object, with support for persisting the
  * non-default preference values to files or streams.
  * <p>
  * This class was not designed to be subclassed.
  * </p>
  *
  * @see IPreferenceStore
  */
 public class PreferenceStore extends EventManager implements
 		IPersistentPreferenceStore {

     /**
      * The mapping from preference name to preference value (represented as
      * strings).
      */
     private Properties properties;

     /**
      * The mapping from preference name to default preference value (represented
      * as strings); <code>null</code> if none.
      */
     private Properties defaultProperties;

     /**
      * Indicates whether a value as been changed by <code>setToDefault</code>
      * or <code>setValue</code>; initially <code>false</code>.
      */
     private boolean dirty = false;

     /**
      * The file name used by the <code>load</code> method to load a property
      * file. This filename is used to save the properties file when
      * <code>save</code> is called.
      */
     private String filename;

     /**
      * Creates an empty preference store.
      * <p>
      * Use the methods <code>load(InputStream)</code> and
      * <code>save(InputStream)</code> to load and store this preference store.
      * </p>
      *
      * @see #load(InputStream)
      * @see #save(OutputStream, String)
      */
     public PreferenceStore() {
         defaultProperties = new Properties();
         properties = new Properties(defaultProperties);
     }

     /**
      * Creates an empty preference store that loads from and saves to the a
      * file.
      * <p>
      * Use the methods <code>load()</code> and <code>save()</code> to load
      * and store this preference store.
      * </p>
      *
      * @param filename
      *            the file name
      * @see #load()
      * @see #save()
      */
     public PreferenceStore(String filename) {
         this();
         Assert.isNotNull(filename);
         this.filename = filename;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void addPropertyChangeListener(IPropertyChangeListener listener) {
         addListenerObject(listener);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public boolean contains(String name) {
         return (properties.containsKey(name) || defaultProperties
                 .containsKey(name));
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void firePropertyChangeEvent(String name, Object oldValue,
             Object newValue) {
         final Object[] finalListeners = getListeners();
         // Do we need to fire an event.
         if (finalListeners.length > 0
                 && (oldValue == null || !oldValue.equals(newValue))) {
             final PropertyChangeEvent pe = new PropertyChangeEvent(this, name,
                     oldValue, newValue);
             for (int i = 0; i < finalListeners.length; ++i) {
                 final IPropertyChangeListener l = (IPropertyChangeListener) finalListeners[i];
                 SafeRunnable.run(new SafeRunnable(JFaceResources.getString("PreferenceStore.changeError")) { //$NON-NLS-1$
                 		public void run() {
   			                l.propertyChange(pe);
                 		}
                 });
             }
         }
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public boolean getBoolean(String name) {
         return getBoolean(properties, name);
     }

     /**
      * Helper function: gets boolean for a given name.
      *
      * @param p
      * @param name
      * @return boolean
      */
     private boolean getBoolean(Properties p, String name) {
         String value = p != null ? p.getProperty(name) : null;
         if (value == null)
             return BOOLEAN_DEFAULT_DEFAULT;
         if (value.equals(IPreferenceStore.TRUE))
             return true;
         return false;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public boolean getDefaultBoolean(String name) {
         return getBoolean(defaultProperties, name);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public double getDefaultDouble(String name) {
         return getDouble(defaultProperties, name);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public float getDefaultFloat(String name) {
         return getFloat(defaultProperties, name);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public int getDefaultInt(String name) {
         return getInt(defaultProperties, name);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public long getDefaultLong(String name) {
         return getLong(defaultProperties, name);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public String getDefaultString(String name) {
         return getString(defaultProperties, name);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public double getDouble(String name) {
         return getDouble(properties, name);
     }

     /**
      * Helper function: gets double for a given name.
      *
      * @param p
      * @param name
      * @return double
      */
     private double getDouble(Properties p, String name) {
         String value = p != null ? p.getProperty(name) : null;
         if (value == null)
             return DOUBLE_DEFAULT_DEFAULT;
         double ival = DOUBLE_DEFAULT_DEFAULT;
         try {
             ival = new Double(value).doubleValue();
         } catch (NumberFormatException e) {
         }
         return ival;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public float getFloat(String name) {
         return getFloat(properties, name);
     }

     /**
      * Helper function: gets float for a given name.
      * @param p
      * @param name
      * @return float
      */
     private float getFloat(Properties p, String name) {
         String value = p != null ? p.getProperty(name) : null;
         if (value == null)
             return FLOAT_DEFAULT_DEFAULT;
         float ival = FLOAT_DEFAULT_DEFAULT;
         try {
             ival = new Float(value).floatValue();
         } catch (NumberFormatException e) {
         }
         return ival;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public int getInt(String name) {
         return getInt(properties, name);
     }

     /**
      * Helper function: gets int for a given name.
      * @param p
      * @param name
      * @return int
      */
     private int getInt(Properties p, String name) {
         String value = p != null ? p.getProperty(name) : null;
         if (value == null)
             return INT_DEFAULT_DEFAULT;
         int ival = 0;
         try {
             ival = Integer.parseInt(value);
         } catch (NumberFormatException e) {
         }
         return ival;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public long getLong(String name) {
         return getLong(properties, name);
     }

     /**
      * Helper function: gets long for a given name.
      * @param p
      * @param name
      * @return
      */
     private long getLong(Properties p, String name) {
         String value = p != null ? p.getProperty(name) : null;
         if (value == null)
             return LONG_DEFAULT_DEFAULT;
         long ival = LONG_DEFAULT_DEFAULT;
         try {
             ival = Long.parseLong(value);
         } catch (NumberFormatException e) {
         }
         return ival;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public String getString(String name) {
         return getString(properties, name);
     }

     /**
      * Helper function: gets string for a given name.
      * @param p
      * @param name
      * @return
      */
     private String getString(Properties p, String name) {
         String value = p != null ? p.getProperty(name) : null;
         if (value == null)
             return STRING_DEFAULT_DEFAULT;
         return value;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public boolean isDefault(String name) {
         return (!properties.containsKey(name) && defaultProperties
                 .containsKey(name));
     }

     /**
      * Prints the contents of this preference store to the given print stream.
      *
      * @param out
      *            the print stream
      */
     public void list(PrintStream out) {
         properties.list(out);
     }

     /**
      * Prints the contents of this preference store to the given print writer.
      *
      * @param out
      *            the print writer
      */
     public void list(PrintWriter out) {
         properties.list(out);
     }

     /**
      * Loads this preference store from the file established in the constructor
      * <code>PreferenceStore(java.lang.String)</code> (or by
      * <code>setFileName</code>). Default preference values are not affected.
      *
      * @exception java.io.IOException
      *                if there is a problem loading this store
      */
     public void load() throws IOException {
         if (filename == null)
             throw new IOException("File name not specified");//$NON-NLS-1$
         FileInputStream in = new FileInputStream(filename);
         load(in);
         in.close();
     }

     /**
      * Loads this preference store from the given input stream. Default
      * preference values are not affected.
      *
      * @param in
      *            the input stream
      * @exception java.io.IOException
      *                if there is a problem loading this store
      */
     public void load(InputStream in) throws IOException {
         properties.load(in);
         dirty = false;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public boolean needsSaving() {
         return dirty;
     }

     /**
      * Returns an enumeration of all preferences known to this store which have
      * current values other than their default value.
      *
      * @return an array of preference names
      */
     public String[] preferenceNames() {
         ArrayList list = new ArrayList();
         Enumeration it = properties.propertyNames();
         while (it.hasMoreElements()) {
             list.add(it.nextElement());
         }
         return (String[]) list.toArray(new String[list.size()]);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void putValue(String name, String value) {
         String oldValue = getString(name);
         if (oldValue == null || !oldValue.equals(value)) {
             setValue(properties, name, value);
             dirty = true;
         }
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void removePropertyChangeListener(IPropertyChangeListener listener) {
         removeListenerObject(listener);
     }

     /**
      * Saves the non-default-valued preferences known to this preference store
      * to the file from which they were originally loaded.
      *
      * @exception java.io.IOException
      *                if there is a problem saving this store
      */
     public void save() throws IOException {
         if (filename == null)
             throw new IOException("File name not specified");//$NON-NLS-1$
         FileOutputStream out = null;
         try {
             out = new FileOutputStream(filename);
             save(out, null);
         } finally {
             if (out != null)
                 out.close();
         }
     }

     /**
      * Saves this preference store to the given output stream. The given string
      * is inserted as header information.
      *
      * @param out
      *            the output stream
      * @param header
      *            the header
      * @exception java.io.IOException
      *                if there is a problem saving this store
      */
     public void save(OutputStream out, String header) throws IOException {
         properties.store(out, header);
         dirty = false;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setDefault(String name, double value) {
         setValue(defaultProperties, name, value);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setDefault(String name, float value) {
         setValue(defaultProperties, name, value);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setDefault(String name, int value) {
         setValue(defaultProperties, name, value);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setDefault(String name, long value) {
         setValue(defaultProperties, name, value);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setDefault(String name, String value) {
         setValue(defaultProperties, name, value);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setDefault(String name, boolean value) {
         setValue(defaultProperties, name, value);
     }

     /**
      * Sets the name of the file used when loading and storing this preference
      * store.
      * <p>
      * Afterward, the methods <code>load()</code> and <code>save()</code>
      * can be used to load and store this preference store.
      * </p>
      *
      * @param name the file name
      * @see #load()
      * @see #save()
      */
     public void setFilename(String name) {
         filename = name;
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setToDefault(String name) {
         Object oldValue = properties.get(name);
         properties.remove(name);
         dirty = true;
         Object newValue = null;
         if (defaultProperties != null)
             newValue = defaultProperties.get(name);
         firePropertyChangeEvent(name, oldValue, newValue);
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setValue(String name, double value) {
         double oldValue = getDouble(name);
         if (oldValue != value) {
             setValue(properties, name, value);
             dirty = true;
             firePropertyChangeEvent(name, new Double(oldValue), new Double(
                     value));
         }
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setValue(String name, float value) {
         float oldValue = getFloat(name);
         if (oldValue != value) {
             setValue(properties, name, value);
             dirty = true;
             firePropertyChangeEvent(name, new Float(oldValue), new Float(value));
         }
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setValue(String name, int value) {
         int oldValue = getInt(name);
         if (oldValue != value) {
             setValue(properties, name, value);
             dirty = true;
             firePropertyChangeEvent(name, new Integer(oldValue), new Integer(
                     value));
         }
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setValue(String name, long value) {
         long oldValue = getLong(name);
         if (oldValue != value) {
             setValue(properties, name, value);
             dirty = true;
             firePropertyChangeEvent(name, new Long(oldValue), new Long(value));
         }
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setValue(String name, String value) {
         String oldValue = getString(name);
         if (oldValue == null || !oldValue.equals(value)) {
             setValue(properties, name, value);
             dirty = true;
             firePropertyChangeEvent(name, oldValue, value);
         }
     }

     /*
      * (non-Javadoc) Method declared on IPreferenceStore.
      */
     public void setValue(String name, boolean value) {
         boolean oldValue = getBoolean(name);
         if (oldValue != value) {
             setValue(properties, name, value);
             dirty = true;
             firePropertyChangeEvent(name, new Boolean(oldValue), new Boolean(
                     value));
         }
     }

     /**
      * Helper method: sets value for a given name.
      * @param p
      * @param name
      * @param value
      */
     private void setValue(Properties p, String name, double value) {
         Assert.isTrue(p != null);
         p.put(name, Double.toString(value));
     }

     /**
      * Helper method: sets value for a given name.
      * @param p
      * @param name
      * @param value
      */
     private void setValue(Properties p, String name, float value) {
         Assert.isTrue(p != null);
         p.put(name, Float.toString(value));
     }

     /**
      * Helper method: sets value for a given name.
      * @param p
      * @param name
      * @param value
      */
     private void setValue(Properties p, String name, int value) {
         Assert.isTrue(p != null);
         p.put(name, Integer.toString(value));
     }

     /**
      * Helper method: sets the value for a given name.
      * @param p
      * @param name
      * @param value
      */
     private void setValue(Properties p, String name, long value) {
         Assert.isTrue(p != null);
         p.put(name, Long.toString(value));
     }

     /**
      * Helper method: sets the value for a given name.
      * @param p
      * @param name
      * @param value
      */
     private void setValue(Properties p, String name, String value) {
         Assert.isTrue(p != null && value != null);
         p.put(name, value);
     }

     /**
      * Helper method: sets the value for a given name.
      * @param p
      * @param name
      * @param value
      */
     private void setValue(Properties p, String name, boolean value) {
         Assert.isTrue(p != null);
         p.put(name, value == true ? IPreferenceStore.TRUE
                 : IPreferenceStore.FALSE);
     }
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2005 IBM Corporation 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:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jface.preference;

	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.io.PrintStream;
	import java.io.PrintWriter;
	import java.util.ArrayList;
	import java.util.Enumeration;
	import java.util.Properties;

	import org.eclipse.core.commands.common.EventManager;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.util.Assert;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.jface.util.SafeRunnable;

	/**
	* A concrete preference store implementation based on an internal
	* <code>java.util.Properties</code> object, with support for persisting the
	* non-default preference values to files or streams.
	* <p>
	* This class was not designed to be subclassed.
	* </p>
	*
	* @see IPreferenceStore
	*/
	public class PreferenceStore extends EventManager implements
	IPersistentPreferenceStore {

	/**
	* The mapping from preference name to preference value (represented as
	* strings).
	*/
	private Properties properties;

	/**
	* The mapping from preference name to default preference value (represented
	* as strings); <code>null</code> if none.
	*/
	private Properties defaultProperties;

	/**
	* Indicates whether a value as been changed by <code>setToDefault</code>
	* or <code>setValue</code>; initially <code>false</code>.
	*/
	private boolean dirty = false;

	/**
	* The file name used by the <code>load</code> method to load a property
	* file. This filename is used to save the properties file when
	* <code>save</code> is called.
	*/
	private String filename;

	/**
	* Creates an empty preference store.
	* <p>
	* Use the methods <code>load(InputStream)</code> and
	* <code>save(InputStream)</code> to load and store this preference store.
	* </p>
	*
	* @see #load(InputStream)
	* @see #save(OutputStream, String)
	*/
	public PreferenceStore() {
	defaultProperties = new Properties();
	properties = new Properties(defaultProperties);
	}

	/**
	* Creates an empty preference store that loads from and saves to the a
	* file.
	* <p>
	* Use the methods <code>load()</code> and <code>save()</code> to load
	* and store this preference store.
	* </p>
	*
	* @param filename
	* the file name
	* @see #load()
	* @see #save()
	*/
	public PreferenceStore(String filename) {
	this();
	Assert.isNotNull(filename);
	this.filename = filename;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void addPropertyChangeListener(IPropertyChangeListener listener) {
	addListenerObject(listener);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public boolean contains(String name) {
	return (properties.containsKey(name) \|\| defaultProperties
	.containsKey(name));
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void firePropertyChangeEvent(String name, Object oldValue,
	Object newValue) {
	final Object[] finalListeners = getListeners();
	// Do we need to fire an event.
	if (finalListeners.length > 0
	&& (oldValue == null \|\| !oldValue.equals(newValue))) {
	final PropertyChangeEvent pe = new PropertyChangeEvent(this, name,
	oldValue, newValue);
	for (int i = 0; i < finalListeners.length; ++i) {
	final IPropertyChangeListener l = (IPropertyChangeListener) finalListeners[i];
	SafeRunnable.run(new SafeRunnable(JFaceResources.getString("PreferenceStore.changeError")) { //$NON-NLS-1$
	public void run() {
	l.propertyChange(pe);
	}
	});
	}
	}
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public boolean getBoolean(String name) {
	return getBoolean(properties, name);
	}

	/**
	* Helper function: gets boolean for a given name.
	*
	* @param p
	* @param name
	* @return boolean
	*/
	private boolean getBoolean(Properties p, String name) {
	String value = p != null ? p.getProperty(name) : null;
	if (value == null)
	return BOOLEAN_DEFAULT_DEFAULT;
	if (value.equals(IPreferenceStore.TRUE))
	return true;
	return false;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public boolean getDefaultBoolean(String name) {
	return getBoolean(defaultProperties, name);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public double getDefaultDouble(String name) {
	return getDouble(defaultProperties, name);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public float getDefaultFloat(String name) {
	return getFloat(defaultProperties, name);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public int getDefaultInt(String name) {
	return getInt(defaultProperties, name);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public long getDefaultLong(String name) {
	return getLong(defaultProperties, name);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public String getDefaultString(String name) {
	return getString(defaultProperties, name);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public double getDouble(String name) {
	return getDouble(properties, name);
	}

	/**
	* Helper function: gets double for a given name.
	*
	* @param p
	* @param name
	* @return double
	*/
	private double getDouble(Properties p, String name) {
	String value = p != null ? p.getProperty(name) : null;
	if (value == null)
	return DOUBLE_DEFAULT_DEFAULT;
	double ival = DOUBLE_DEFAULT_DEFAULT;
	try {
	ival = new Double(value).doubleValue();
	} catch (NumberFormatException e) {
	}
	return ival;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public float getFloat(String name) {
	return getFloat(properties, name);
	}

	/**
	* Helper function: gets float for a given name.
	* @param p
	* @param name
	* @return float
	*/
	private float getFloat(Properties p, String name) {
	String value = p != null ? p.getProperty(name) : null;
	if (value == null)
	return FLOAT_DEFAULT_DEFAULT;
	float ival = FLOAT_DEFAULT_DEFAULT;
	try {
	ival = new Float(value).floatValue();
	} catch (NumberFormatException e) {
	}
	return ival;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public int getInt(String name) {
	return getInt(properties, name);
	}

	/**
	* Helper function: gets int for a given name.
	* @param p
	* @param name
	* @return int
	*/
	private int getInt(Properties p, String name) {
	String value = p != null ? p.getProperty(name) : null;
	if (value == null)
	return INT_DEFAULT_DEFAULT;
	int ival = 0;
	try {
	ival = Integer.parseInt(value);
	} catch (NumberFormatException e) {
	}
	return ival;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public long getLong(String name) {
	return getLong(properties, name);
	}

	/**
	* Helper function: gets long for a given name.
	* @param p
	* @param name
	* @return
	*/
	private long getLong(Properties p, String name) {
	String value = p != null ? p.getProperty(name) : null;
	if (value == null)
	return LONG_DEFAULT_DEFAULT;
	long ival = LONG_DEFAULT_DEFAULT;
	try {
	ival = Long.parseLong(value);
	} catch (NumberFormatException e) {
	}
	return ival;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public String getString(String name) {
	return getString(properties, name);
	}

	/**
	* Helper function: gets string for a given name.
	* @param p
	* @param name
	* @return
	*/
	private String getString(Properties p, String name) {
	String value = p != null ? p.getProperty(name) : null;
	if (value == null)
	return STRING_DEFAULT_DEFAULT;
	return value;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public boolean isDefault(String name) {
	return (!properties.containsKey(name) && defaultProperties
	.containsKey(name));
	}

	/**
	* Prints the contents of this preference store to the given print stream.
	*
	* @param out
	* the print stream
	*/
	public void list(PrintStream out) {
	properties.list(out);
	}

	/**
	* Prints the contents of this preference store to the given print writer.
	*
	* @param out
	* the print writer
	*/
	public void list(PrintWriter out) {
	properties.list(out);
	}

	/**
	* Loads this preference store from the file established in the constructor
	* <code>PreferenceStore(java.lang.String)</code> (or by
	* <code>setFileName</code>). Default preference values are not affected.
	*
	* @exception java.io.IOException
	* if there is a problem loading this store
	*/
	public void load() throws IOException {
	if (filename == null)
	throw new IOException("File name not specified");//$NON-NLS-1$
	FileInputStream in = new FileInputStream(filename);
	load(in);
	in.close();
	}

	/**
	* Loads this preference store from the given input stream. Default
	* preference values are not affected.
	*
	* @param in
	* the input stream
	* @exception java.io.IOException
	* if there is a problem loading this store
	*/
	public void load(InputStream in) throws IOException {
	properties.load(in);
	dirty = false;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public boolean needsSaving() {
	return dirty;
	}

	/**
	* Returns an enumeration of all preferences known to this store which have
	* current values other than their default value.
	*
	* @return an array of preference names
	*/
	public String[] preferenceNames() {
	ArrayList list = new ArrayList();
	Enumeration it = properties.propertyNames();
	while (it.hasMoreElements()) {
	list.add(it.nextElement());
	}
	return (String[]) list.toArray(new String[list.size()]);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void putValue(String name, String value) {
	String oldValue = getString(name);
	if (oldValue == null \|\| !oldValue.equals(value)) {
	setValue(properties, name, value);
	dirty = true;
	}
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void removePropertyChangeListener(IPropertyChangeListener listener) {
	removeListenerObject(listener);
	}

	/**
	* Saves the non-default-valued preferences known to this preference store
	* to the file from which they were originally loaded.
	*
	* @exception java.io.IOException
	* if there is a problem saving this store
	*/
	public void save() throws IOException {
	if (filename == null)
	throw new IOException("File name not specified");//$NON-NLS-1$
	FileOutputStream out = null;
	try {
	out = new FileOutputStream(filename);
	save(out, null);
	} finally {
	if (out != null)
	out.close();
	}
	}

	/**
	* Saves this preference store to the given output stream. The given string
	* is inserted as header information.
	*
	* @param out
	* the output stream
	* @param header
	* the header
	* @exception java.io.IOException
	* if there is a problem saving this store
	*/
	public void save(OutputStream out, String header) throws IOException {
	properties.store(out, header);
	dirty = false;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setDefault(String name, double value) {
	setValue(defaultProperties, name, value);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setDefault(String name, float value) {
	setValue(defaultProperties, name, value);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setDefault(String name, int value) {
	setValue(defaultProperties, name, value);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setDefault(String name, long value) {
	setValue(defaultProperties, name, value);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setDefault(String name, String value) {
	setValue(defaultProperties, name, value);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setDefault(String name, boolean value) {
	setValue(defaultProperties, name, value);
	}

	/**
	* Sets the name of the file used when loading and storing this preference
	* store.
	* <p>
	* Afterward, the methods <code>load()</code> and <code>save()</code>
	* can be used to load and store this preference store.
	* </p>
	*
	* @param name the file name
	* @see #load()
	* @see #save()
	*/
	public void setFilename(String name) {
	filename = name;
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setToDefault(String name) {
	Object oldValue = properties.get(name);
	properties.remove(name);
	dirty = true;
	Object newValue = null;
	if (defaultProperties != null)
	newValue = defaultProperties.get(name);
	firePropertyChangeEvent(name, oldValue, newValue);
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setValue(String name, double value) {
	double oldValue = getDouble(name);
	if (oldValue != value) {
	setValue(properties, name, value);
	dirty = true;
	firePropertyChangeEvent(name, new Double(oldValue), new Double(
	value));
	}
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setValue(String name, float value) {
	float oldValue = getFloat(name);
	if (oldValue != value) {
	setValue(properties, name, value);
	dirty = true;
	firePropertyChangeEvent(name, new Float(oldValue), new Float(value));
	}
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setValue(String name, int value) {
	int oldValue = getInt(name);
	if (oldValue != value) {
	setValue(properties, name, value);
	dirty = true;
	firePropertyChangeEvent(name, new Integer(oldValue), new Integer(
	value));
	}
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setValue(String name, long value) {
	long oldValue = getLong(name);
	if (oldValue != value) {
	setValue(properties, name, value);
	dirty = true;
	firePropertyChangeEvent(name, new Long(oldValue), new Long(value));
	}
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setValue(String name, String value) {
	String oldValue = getString(name);
	if (oldValue == null \|\| !oldValue.equals(value)) {
	setValue(properties, name, value);
	dirty = true;
	firePropertyChangeEvent(name, oldValue, value);
	}
	}

	/*
	* (non-Javadoc) Method declared on IPreferenceStore.
	*/
	public void setValue(String name, boolean value) {
	boolean oldValue = getBoolean(name);
	if (oldValue != value) {
	setValue(properties, name, value);
	dirty = true;
	firePropertyChangeEvent(name, new Boolean(oldValue), new Boolean(
	value));
	}
	}

	/**
	* Helper method: sets value for a given name.
	* @param p
	* @param name
	* @param value
	*/
	private void setValue(Properties p, String name, double value) {
	Assert.isTrue(p != null);
	p.put(name, Double.toString(value));
	}

	/**
	* Helper method: sets value for a given name.
	* @param p
	* @param name
	* @param value
	*/
	private void setValue(Properties p, String name, float value) {
	Assert.isTrue(p != null);
	p.put(name, Float.toString(value));
	}

	/**
	* Helper method: sets value for a given name.
	* @param p
	* @param name
	* @param value
	*/
	private void setValue(Properties p, String name, int value) {
	Assert.isTrue(p != null);
	p.put(name, Integer.toString(value));
	}

	/**
	* Helper method: sets the value for a given name.
	* @param p
	* @param name
	* @param value
	*/
	private void setValue(Properties p, String name, long value) {
	Assert.isTrue(p != null);
	p.put(name, Long.toString(value));
	}

	/**
	* Helper method: sets the value for a given name.
	* @param p
	* @param name
	* @param value
	*/
	private void setValue(Properties p, String name, String value) {
	Assert.isTrue(p != null && value != null);
	p.put(name, value);
	}

	/**
	* Helper method: sets the value for a given name.
	* @param p
	* @param name
	* @param value
	*/
	private void setValue(Properties p, String name, boolean value) {
	Assert.isTrue(p != null);
	p.put(name, value == true ? IPreferenceStore.TRUE
	: IPreferenceStore.FALSE);
	}
	}