content: /*******************************************************************************
   * Copyright (c) 2005, 2008 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 ts.eclipse.ide.jsdt.internal.ui.editor;
  
  import org.eclipse.core.runtime.ListenerList;
  import org.eclipse.core.runtime.preferences.IEclipsePreferences;
  import org.eclipse.core.runtime.preferences.IScopeContext;
  import org.eclipse.jface.preference.IPreferenceStore;
  import org.eclipse.jface.util.IPropertyChangeListener;
  import org.eclipse.jface.util.PropertyChangeEvent;
  import org.eclipse.swt.widgets.Display;
  import org.osgi.service.prefs.BackingStoreException;
  
  /**
   * Adapts an options {@link IEclipsePreferences} to {@link org.eclipse.jface.preference.IPreferenceStore}.
   * <p>
   * This preference store is read-only i.e. write access
   * throws an {@link java.lang.UnsupportedOperationException}.
   * </p>
   *
   * 
   */
  public class EclipsePreferencesAdapter implements IPreferenceStore {
  
  	/**
  	 * Preference change listener. Listens for events preferences
  	 * fires a {@link org.eclipse.jface.util.PropertyChangeEvent}
  	 * on this adapter with arguments from the received event.
  	 */
  	private class PreferenceChangeListener implements IEclipsePreferences.IPreferenceChangeListener {
  
  		/**
  		 * {@inheritDoc}
  		 */
  		public void preferenceChange(final IEclipsePreferences.PreferenceChangeEvent event) {
  			if (Display.getCurrent() == null) {
  				Display.getDefault().asyncExec(new Runnable() {
  					public void run() {
  						firePropertyChangeEvent(event.getKey(), event.getOldValue(), event.getNewValue());
  					}
  				});
  			} else {
  				firePropertyChangeEvent(event.getKey(), event.getOldValue(), event.getNewValue());
  			}
  		}
  	}
  
  	/** Listeners on on this adapter */
  	private ListenerList fListeners= new ListenerList(ListenerList.IDENTITY);
  
  	/** Listener on the node */
  	private IEclipsePreferences.IPreferenceChangeListener fListener= new PreferenceChangeListener();
  
  	/** wrapped node */
  	private final IScopeContext fContext;
  	private final String fQualifier;
  
  	/**
  	 * Initialize with the node to wrap
  	 *
  	 * @param context The context to access
  	 */
  	public EclipsePreferencesAdapter(IScopeContext context, String qualifier) {
  		fContext= context;
  		fQualifier= qualifier;
  	}
  
  	private IEclipsePreferences getNode() {
  		return fContext.getNode(fQualifier);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void addPropertyChangeListener(IPropertyChangeListener listener) {
  		if (fListeners.size() == 0)
  			getNode().addPreferenceChangeListener(fListener);
  		fListeners.add(listener);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void removePropertyChangeListener(IPropertyChangeListener listener) {
  		fListeners.remove(listener);
  		if (fListeners.size() == 0) {
  			getNode().removePreferenceChangeListener(fListener);
  		}
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public boolean contains(String name) {
  		return getNode().get(name, null) != null;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) {
  		PropertyChangeEvent event= new PropertyChangeEvent(this, name, oldValue, newValue);
  		Object[] listeners= fListeners.getListeners();
  		for (int i= 0; i < listeners.length; i++)
  			((IPropertyChangeListener) listeners[i]).propertyChange(event);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public boolean getBoolean(String name) {
  		return getNode().getBoolean(name, BOOLEAN_DEFAULT_DEFAULT);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public boolean getDefaultBoolean(String name) {
  		return BOOLEAN_DEFAULT_DEFAULT;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public double getDefaultDouble(String name) {
  		return DOUBLE_DEFAULT_DEFAULT;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public float getDefaultFloat(String name) {
  		return FLOAT_DEFAULT_DEFAULT;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public int getDefaultInt(String name) {
  		return INT_DEFAULT_DEFAULT;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public long getDefaultLong(String name) {
  		return LONG_DEFAULT_DEFAULT;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public String getDefaultString(String name) {
  		return STRING_DEFAULT_DEFAULT;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public double getDouble(String name) {
  		return getNode().getDouble(name, DOUBLE_DEFAULT_DEFAULT);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public float getFloat(String name) {
  		return getNode().getFloat(name, FLOAT_DEFAULT_DEFAULT);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public int getInt(String name) {
  		return getNode().getInt(name, INT_DEFAULT_DEFAULT);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public long getLong(String name) {
  		return getNode().getLong(name, LONG_DEFAULT_DEFAULT);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public String getString(String name) {
  		return getNode().get(name, STRING_DEFAULT_DEFAULT);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public boolean isDefault(String name) {
  		return false;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public boolean needsSaving() {
  		try {
  			return getNode().keys().length > 0;
  		} catch (BackingStoreException e) {
  			// ignore
  		}
  		return true;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void putValue(String name, String value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setDefault(String name, double value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setDefault(String name, float value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setDefault(String name, int value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setDefault(String name, long value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setDefault(String name, String defaultObject) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setDefault(String name, boolean value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setToDefault(String name) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setValue(String name, double value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setValue(String name, float value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setValue(String name, int value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setValue(String name, long value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setValue(String name, String value) {
  		throw new UnsupportedOperationException();
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	public void setValue(String name, boolean value) {
  		throw new UnsupportedOperationException();
  	}
  
  }
  