ContextSystemOption.java

/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2003 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.openide.options;

import java.beans.beancontext.BeanContextProxy;
import java.beans.beancontext.BeanContextChild;
import java.beans.beancontext.BeanContext;
import java.beans.beancontext.BeanContextSupport;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Comparator;
import java.util.Arrays;

import org.openide.util.io.NbMarshalledObject;

/** Provides a group of system options with this as the parent.
* You must still implement {@link SystemOption#displayName}, at least.
* The suboptions are automatically saved as a group.
*
* @author Ales Novak
*/
public abstract class ContextSystemOption
            extends SystemOption
    implements BeanContextProxy {

    /** Reference to the bean context describing the structure of this option tree.
     * @deprecated To obtain bean context use {@link #getBeanContextProxy}.
     */
    protected BeanContext beanContext;
    
    /** beanContext property's key. */
    private static Object ctxt = new Object();

    private static final long serialVersionUID = -781528552645947127L;
    /** Default constructor. */
    public ContextSystemOption() {
        // backward compatability
        beanContext = getBeanContext();
    }

    /** Add a new option to the set.
    * @param so the option to add
    */
    public final void addOption(SystemOption so) {
        getBeanContext().add(so);
    }
    /** Remove an option from the set.
    * @param so the option to remove
    */
    public final void removeOption(SystemOption so) {
        getBeanContext().remove(so);
    }
    /** Get all options in the set.
    * @return the options
    */
    public final SystemOption[] getOptions() {
        // [WARNING] call to getBeanContext().toArray() can return either SystemOptions
        // or something of another type (I detected BeanContextSupport)
        // It requires deep investigation ...
        int i, j;
        SystemOption[] options;

        Object[] objs = getBeanContext().toArray();

        // filter out everything not SystemOption
        for(i = 0, j = 0; i < objs.length; i++) {
            if (objs[i] instanceof SystemOption) {
                if (i > j) objs[j] = objs[i];
                j++;
            }
        }
        options = new SystemOption[j];
        System.arraycopy(objs, 0, options, 0, j);
        return options;
    }

    /* Method from interface BeanContextProxy.
    * @return a BeanContext - tree of options
    */
    public final BeanContextChild getBeanContextProxy() {
        return getBeanContext();
    }
    
    private BeanContext getBeanContext() {
        return (BeanContext) getProperty(ctxt);
    }
    
    protected void initialize() {
        super.initialize();
        this.putProperty(ctxt, new OptionBeanContext(this));
    }
    
    /* Writes the beanContext variable to an ObjectOutput instance.
    * @param out
    */
    public void writeExternal(ObjectOutput out) throws IOException {
        super.writeExternal(out);

        Object objects[] =  getBeanContext().toArray();
        Arrays.sort(objects,new ClassComparator());
        for (int i = 0 ; i < objects.length ; i++) {
              out.writeObject(new NbMarshalledObject (objects[i]));
        }
        out.writeObject (null);
    }

    /* Reads the beanContext variable from an ObjectInpuit instance.
    * @param in
    */
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        super.readExternal(in);
        
        Object obj = in.readObject ();
        if (obj instanceof BeanContext) {
            // old version of serialization
            // XXX does this really work??
            beanContext = (BeanContext)obj;
        } else {
            // new version with safe serialization
            BeanContext c = getBeanContext();
            
            while (obj != null) {
                NbMarshalledObject m = (NbMarshalledObject)obj;
                // #18626 fix: deserialization of the context option should survive
                // deserialization of its children. They can belong to disabled
                // or removed modules.
                try {
                    c.add (m.get ());
                } catch (Exception e) {
                    org.openide.ErrorManager.getDefault().notify(
                        org.openide.ErrorManager.INFORMATIONAL, e);
                } catch (LinkageError e) {
                    org.openide.ErrorManager.getDefault().notify(
                        org.openide.ErrorManager.INFORMATIONAL, e);
                }
                // read next
                obj = in.readObject ();
            }
        }
    }

    
    /** Comparator of class names of objects. It is used in 
     *  <code>writeExternal</code>.
     */ 
    private static class ClassComparator implements Comparator {
	ClassComparator() {}
	
        /** It Compares name of classes of two objects */  
        public int compare (Object o1,Object o2) {
            return o1.getClass().getName().compareTo(
                    o2.getClass().getName());  
        }
    }
    
    /** A hierarchy of SystemOptions.
    * Allows add/remove SystemOption beans only.
    * @warning many methods throws UnsupportedOperationException like BeanContextSupport does.
    */
    private static class OptionBeanContext extends BeanContextSupport
        implements PropertyChangeListener {

        private ContextSystemOption parent = null;
        
        public OptionBeanContext (ContextSystemOption p) {
            parent = p;
        }
        
        private static final long serialVersionUID = 3532434266136225440L;
        /** Overridden from base class.
        * @exception IllegalArgumentException if not targetChild instanceof SystemOption
        */
        public boolean add(Object targetChild) {
            if (! (targetChild instanceof SystemOption)) throw new IllegalArgumentException("Not a SystemOption: " + targetChild); // NOI18N
            boolean b = super.add(targetChild);
            
            if (b) {
                ((SystemOption)targetChild).addPropertyChangeListener (this);
            }
            return b;
        }

        public boolean remove(Object targetChild) {
            if (! (targetChild instanceof SystemOption)) throw new IllegalArgumentException("Not a SystemOption: " + targetChild); // NOI18N
            boolean b = super.remove(targetChild);
            
            if (b) {
                ((SystemOption)targetChild).removePropertyChangeListener (this);
            }
            return b;
        }
        
        public void propertyChange (java.beans.PropertyChangeEvent evt) {
            if (parent != null) {
                parent.firePropertyChange (evt.getPropertyName (), evt.getOldValue (), evt.getNewValue ());
            }
        }
    }
}