comparison src/samer/core_/util/Properties.java @ 0:bf79fb79ee13

Initial Mercurial check in.

+/*
+ *	Properties.java	
+ *
+ *	Copyright (c) 2001, Samer Abdallah, King's College London.
+ *	All rights reserved.
+ *
+ *	This software is provided AS IS and WITHOUT ANY WARRANTY; 
+ *	without even the implied warranty of MERCHANTABILITY or 
+ *	FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+package	samer.core.util;
+import	samer.core.*;
+import	java.io.*;
+
+public class Properties extends Environment
+{
+	protected java.util.Properties	props;
+	protected boolean	writable;
+
+	public Properties(Environment parent) { 
+		this(parent,parent.node(),new java.util.Properties());
+	}
+	public Properties(Environment parent, java.util.Properties pr) {
+		this(parent,parent.node(),pr);
+	}
+	public Properties(Environment parent, Node n) {
+		this(parent,n,new java.util.Properties());
+	}
+	public Properties(Environment parent, Node n, java.util.Properties pr) {
+		super(parent,n); props=pr; writable=true;
+	}
+
+	public void save(OutputStream out) throws Exception { props.store(out,"properties"); }
+	public void load(InputStream in) throws Exception { props.load(in); }
+	public void setWritable(boolean f) { writable=f; }
+	protected class Property implements Binding
+	{
+		String	nm;
+		String	vl;
+		int		sc;
+
+		Property(String n, String v, int s) { 
+			nm=n; sc=s;
+			vl = v.equals("~default") ? null : v;
+		}
+
+		public String	name() { return abs(nm); }		
+		public int		score() { return sc; }
+
+		public Object	get() { return vl; }
+		public Object	get(Codec c, Object def) { return c.decode(vl==null?def:vl); }
+		public void		get(Autocoder obj) { obj.decode(vl); }
+
+		public void		set(Object obj) { props.put(nm,(String)obj); }
+		public void		remove() { props.remove(nm); }
+	}
+
+	public void store(String name, Autocoder o) {
+		if (writable && belongs(name)) props.put(rel(name),o.string());
+		else parent.store(name,o);
+	}
+	public void store(String name, Object o, Codec c) {
+		if (writable && belongs(name)) props.put(rel(name),c.string(o));
+		else parent.store(name,o,c);
+	}
+
+	public Datum datum(String name) 
+	{
+		Datum local=localFind(rel(name)); // localised name
+
+		if (local.score()>0) { 
+			// if match is less than perfect, get parent's best match
+			Datum inherited=parent.datum(abs(name));
+			if (inherited.score()<local.score()) return inherited;
+		}
+		return local;
+	}
+
+	public Binding binding(String name) 
+	{
+		Binding local=localFind(rel(name)); // localised name
+
+		if (local.score()>0) { 
+			Binding inherited=parent.binding(abs(name));
+			if (inherited.score()<local.score()) return inherited;
+		}
+		return local;
+	}
+
+	public Iterator data()
+	{
+		return new CompoundIterator( new Iterator() {
+			java.util.Enumeration enu=props.keys();
+			public boolean hasNext() { return enu.hasMoreElements(); }
+			public Datum next() {
+				String key=(String)enu.nextElement();
+				return new Property(key,props.getProperty(key),0);
+		} }, parent.data() );
+	}
+
+	public Binding localFind(String key) 
+	{
+		String	val, pname = '.'+key;
+
+		for (int i=0, s=0; i>=0; s++) {
+			pname = pname.substring(i+1);
+			val=props.getProperty(pname); 
+			if (val!=null) return new Property(pname,val,s);
+			i = pname.indexOf('.');
+		}
+		return Null;
+	}
+}
+