samer@0: /*
samer@0:  *	X.java	
samer@0:  *
samer@0:  *	Copyright (c) 2001, Samer Abdallah, King's College London.
samer@0:  *	All rights reserved.
samer@0:  *
samer@0:  *	This software is provided AS IS and WITHOUT ANY WARRANTY; 
samer@0:  *	without even the implied warranty of MERCHANTABILITY or
samer@0:  *	FITNESS FOR A PARTICULAR PURPOSE.
samer@0:  */
samer@0: 
samer@0: package samer.core;
samer@0: import  java.io.StringWriter;
samer@0: import  java.util.StringTokenizer;
samer@0: import  java.awt.Font;
samer@0: import  java.awt.Rectangle;
samer@0: import  java.awt.Color;
samer@0: import  java.awt.SystemColor;
samer@0: 
samer@0: import  samer.core.Environment.Datum;
samer@0: import  samer.core.Environment.Codec;
samer@0: import  samer.core.Environment.Autocoder;
samer@0: 
samer@0: /**
samer@0: 	Static methods for converting objects and extracting correctly typed
samer@0: 	values from Environments. Short name
samer@0: 	because of expected frequent use! Also, contains
samer@0: 	several Codec classes.
samer@0: 	@see samer.core.Environment
samer@0: 	@see samer.core.Environment.Datum
samer@0: 	@see samer.core.Environment.Autocoder
samer@0:  */
samer@0: 
samer@0: public class X
samer@0: {
samer@0: 	/** Tries to extract an Object from the given Datum, throws Exception in failure */
samer@0: 	public static Object object(Datum b) throws Exception {
samer@0: 		Object ret=b.get(ObjectCodec,null);
samer@0: 		if (ret==null) throw new Exception("no data");
samer@0: 		return ret;
samer@0: 	}
samer@0: 
samer@0: 	/** Tries to extract a String given Datum */
samer@0: 	public static String string(Datum b) throws Exception {
samer@0: 		String ret=(String)b.get(StringCodec,null);
samer@0: 		if (ret==null) throw new Exception("datum has no value");
samer@0: 		return ret;
samer@0: 	}
samer@0: 
samer@0: 	/** Tries to extract a Font given Datum. If this fails, tries
samer@0: 		to decode def using FontCodec. def can be a Font or a String. */
samer@0: 	public static Font font(Datum b, Object def) {
samer@0: 		return (Font)b.get(FontCodec,def);
samer@0: 	}
samer@0: 
samer@0: 	/** Tries to extract a Rectangle from given Datum. If this fails, tries
samer@0: 		to decode def as a rectangle. */
samer@0: 	public static Rectangle rect(Datum b, Rectangle def) {
samer@0: 		return (Rectangle)b.get(RectangleCodec,def);
samer@0: 	}
samer@0: 
samer@0: 	/** Get String from Datum, returning def if this fails */
samer@0: 	public static String string(Datum b,String def) {
samer@0: 		return (String)b.get(StringCodec,def);
samer@0: 	}
samer@0: 
samer@0: 	/** Get Color from Datum, decoding def if this fails. def can
samer@0: 		be a Color or a String. See ColorCodec. */
samer@0: 	public static Color	color(Datum b, Object def) {
samer@0: 		return (Color)b.get(ColorCodec,def);
samer@0: 	}
samer@0: 
samer@0: 	/** Extract int from Datum */
samer@0: 	public static int _int(Datum b,int def) {
samer@0: 		return ((Integer)b.get(IntegerCodec,new Integer(def))).intValue();
samer@0: 	}
samer@0: 	/** Extract double from Datum */
samer@0: 	public static double _double(Datum b,double def) {
samer@0: 		return ((Double)b.get(DoubleCodec,new Double(def))).doubleValue();
samer@0: 	}
samer@0: 	/** Extract boolean from Datum */
samer@0: 	public static boolean _bool(Datum b,boolean def) {
samer@0: 		return ((Boolean)b.get(BooleanCodec,new Boolean(def))).booleanValue();
samer@0: 	}
samer@0: 
samer@0: 	/** store given object to current environment */
samer@0: 	public static void store(String name, Object value) {
samer@0: 		Shell.env().store(name,value,codec(value));
samer@0: 	}
samer@0: 
samer@0: 	/** Extracts an integer array from a string. Valid strings are, eg
samer@0: 		"(1,2,3)", "(4 5 6)", "7 8 9", "10, 11, 12" */
samer@0: 	public static int[] parseIntArray(String s, int n)
samer@0: 	{
samer@0: 		StringTokenizer token = new StringTokenizer(s,"(), ");
samer@0: 		int[] a=new int[n];
samer@0: 
samer@0: 		for (int i=0; i<n; i++) {
samer@0: 			a[i]=Integer.parseInt(token.nextToken());
samer@0: 		}
samer@0: 		return a;
samer@0: 	}
samer@0: 
samer@0: 	/** @see samer.core.X.parseIntArray */
samer@0: 	public static double[] doubleArray(String s, int n)
samer@0: 	{
samer@0: 		StringTokenizer token = new StringTokenizer(s,"(), ");
samer@0: 		double[] a=new double[n];
samer@0: 
samer@0: 		for (int i=0; i<n; i++) {
samer@0: 			a[i]=parseDouble(token.nextToken());
samer@0: 		}
samer@0: 		return a;
samer@0: 	}
samer@0: 
samer@0: 	/** Sets each integer in the int array to the numeric value of the corresponding
samer@0: 		Objects in the Object array (they have to be subclasses of Numbe).
samer@0: 	 */
samer@0: 	public static void setIntArray(int[] a, Object[] b) {
samer@0: 		for (int i=0; i<a.length; i++)
samer@0: 			a[i]=((Number)b[i]).intValue();
samer@0: 	}
samer@0: 
samer@0: 	/** Base class for objects that can convert some type to and from String or
samer@0: 		Object. @see samer.core.Environment.Codec */
samer@0: 	public static class BaseCodec implements Codec
samer@0: 	{
samer@0: 		public Class targetClass() { return Object.class; }
samer@0: 
samer@0: 		/** convert to string using object's toString() method (a reasonable default) */
samer@0: 		public String string(Object o) { return o.toString(); }
samer@0: 
samer@0: 		/** Convert to object by returning original object. This might be OK for
samer@0: 		 *  immutable objects, but should be overriden for mutable ones, perhaps
samer@0: 		 *	returning a clone of the original or an object of a different class altogether.
samer@0: 		 */
samer@0: 		public Object object(Object o) { return o; }
samer@0: 
samer@0: 		/** Decode given object to by return it the given object itself. */
samer@0: 		public Object decode(Object o) {	return o; }
samer@0: 	};
samer@0: 
samer@0: 	public static Codec ObjectCodec = new BaseCodec();
samer@0: 
samer@0: 	/** Can decode numbers in Integer, Number, or String form */
samer@0: 	public static Codec IntegerCodec = new BaseCodec()
samer@0: 	{
samer@0: 		public Class targetClass() { return Integer.class; }
samer@0: 
samer@0: 		/** If given object is any subclass of java.lang.Number, then its
samer@0: 			numerical value is returned as an Integer. If it is a string,
samer@0: 			the string is parsed to extract an integer value. Any other
samer@0: 			class will probably cause this function to barf.
samer@0: 		*/
samer@0: 		
samer@0: 		public Object decode(Object o) {
samer@0: //			if (o==null) return null;
samer@0: 			if (o instanceof Integer) return o;
samer@0: 			if (o instanceof String)  return Integer.decode(o.toString());
samer@0: 			return new Integer(((Number)o).intValue());
samer@0: 		}
samer@0: 	};
samer@0: 
samer@0: 	private static DoubleFormat fmt=new DoubleFormat(3);
samer@0: 
samer@0: 	/** Convert double to string using the (private) current DoubleFormat object */
samer@0: 	public static String string(double v) { return fmt._format(v); }
samer@0: 
samer@0: 	/** Convert string to double */
samer@0: 	public static double parseDouble(String s) {
samer@0: 		return Double.valueOf(s).doubleValue();
samer@0: 	}
samer@0: 
samer@0: 	/** Can decode numbers in Double, Number, or String form */
samer@0: 	public static Codec DoubleCodec = new BaseCodec()
samer@0: 	{
samer@0: 		public Class targetClass() { return Double.class; }
samer@0: 
samer@0: 		public String string(Object o) { return fmt._format(((Number)o).doubleValue()); }
samer@0: 
samer@0: 		/** Can decode String or any subclass of Number */
samer@0: 		public Object decode(Object o) {
samer@0: //			if (o==null) return null;
samer@0: 			if (o instanceof Double) return o;
samer@0: 			if (o instanceof String) return Double.valueOf(o.toString());
samer@0: 			return new Double(((Number)o).doubleValue());
samer@0: 		}
samer@0: 
samer@0: 	};
samer@0: 
samer@0: 	/** Can decode Boolean or String ("true" or "false") form */
samer@0: 	public static Codec BooleanCodec = new BaseCodec()
samer@0: 	{
samer@0: 		public Class  targetClass() { return Boolean.class; }
samer@0: 		public Object decode(Object o) {
samer@0: //			if (o==null) return null;
samer@0: 			if (o instanceof Boolean) return o;
samer@0: 			return Boolean.valueOf(o.toString());
samer@0: 		}
samer@0: 	};
samer@0: 
samer@0: 	public static Codec StringCodec = new BaseCodec()
samer@0: 	{
samer@0: 		public Class  targetClass() { return String.class; }
samer@0: 		public Object decode(Object o) {
samer@0: //			if (o==null) return null;
samer@0: 			if (o instanceof String) return o;
samer@0: 			else return o.toString();
samer@0: 		}
samer@0: 	};
samer@0: 
samer@0: 
samer@0: 	/** Can decode Color or String form
samer@0: 		String can be "#rrggbb" where rrggbb are hex,
samer@0: 		or "(r,g,b)" or "(r g b)" where r, g, b are integers,
samer@0: 		or "$bg", which evaluates to SystemColor.control, the
samer@0: 		default background color for components,
samer@0: 		or "$fg", which evaluates to SystemColor.controlText,
samer@0: 		the default foreground color.
samer@0: 	*/
samer@0: 
samer@0: 	public static Codec ColorCodec = new Codec()
samer@0: 	{
samer@0: 		public Class  targetClass() { return Color.class; }
samer@0: 		public Object object(Object o) { return o; }
samer@0: 		public String string(Object o) {
samer@0: 			StringBuffer buf=new StringBuffer("#");
samer@0: 			buf.append(Integer.toHexString(((Color)o).getRGB() & 0xffffff));
samer@0: 			return buf.toString();
samer@0: 		}
samer@0: 		public Object decode(Object o) {	
samer@0: //			if (o==null) return null;
samer@0: 			if (o instanceof Color) return o;
samer@0: 
samer@0: 			String s=o.toString();
samer@0: 			if (s.startsWith("(")) {
samer@0: 				int[] a=parseIntArray(s,3);
samer@0: 				return new Color(a[0],a[1],a[2]);
samer@0: 			}
samer@0: 			if (s.equals("$bg"))	return SystemColor.control;
samer@0: 			if (s.equals("$fg"))	return SystemColor.controlText;
samer@0: 			return Color.decode(s);
samer@0: 		}
samer@0: 	};
samer@0: 
samer@0: 	/** Can decode Font or String, using Font.decode(),
samer@0: 		eg "Helvetica-PLAIN-12" */
samer@0: 	public static Codec FontCodec = new Codec()
samer@0: 	{
samer@0: 		public Class  targetClass() { return Font.class; }
samer@0: 		public Object object(Object o) { return o; }
samer@0: 		public String string(Object o) { return o.toString(); }
samer@0: 		public Object decode(Object o) {
samer@0: //			if (o==null) return null;
samer@0: 			if (o instanceof Font)   return o;
samer@0: 			return Font.decode(o.toString());
samer@0: 		}
samer@0: 	};
samer@0: 
samer@0: 	public static Codec RectangleCodec = new Codec()
samer@0: 	{
samer@0: 		public Class  targetClass() { return Font.class; }
samer@0: 		public Object object(Object o) { return o; }
samer@0: 		public String string(Object o) {
samer@0: 			Rectangle      r=(Rectangle)o;
samer@0: 			StringBuffer	buf=new StringBuffer();
samer@0: 
samer@0: 			buf.append('(');
samer@0: 			buf.append(String.valueOf(r.x));			buf.append(',');
samer@0: 			buf.append(String.valueOf(r.y));			buf.append(',');
samer@0: 			buf.append(String.valueOf(r.width));	buf.append(',');
samer@0: 			buf.append(String.valueOf(r.height));
samer@0: 			buf.append(')');
samer@0: 			return buf.toString();
samer@0: 		}
samer@0: 
samer@0: 		public Object decode(Object o) {
samer@0: //			if (o==null) return null;
samer@0: 			if (o instanceof Rectangle) return o;
samer@0: 
samer@0: 			int[] a=parseIntArray(o.toString(),4);
samer@0: 			return new Rectangle(a[0],a[1],a[2],a[3]);
samer@0: 		}
samer@0: 	};
samer@0: 
samer@0: 	public static Codec codec(Object o) { return codec(o.getClass()); }
samer@0: 	public static Codec codec(Class c)
samer@0: 	{
samer@0: 		for (int i=classes.length-1; i>0; i--) {
samer@0: 			if (classes[i].isAssignableFrom(c)) return codecs[i];
samer@0: 		}
samer@0: 		return codecs[0];
samer@0: 	}
samer@0: 
samer@0: 	private static Class[] classes = {
samer@0: 		Object.class,
samer@0: 		Font.class,
samer@0: 		Rectangle.class,
samer@0: 		Color.class,
samer@0: 		String.class,
samer@0: 		Boolean.class,
samer@0: 		Integer.class,
samer@0: 		Double.class
samer@0: 	};
samer@0: 
samer@0: 	private static Codec[] codecs = {
samer@0: 		ObjectCodec,
samer@0: 		FontCodec,
samer@0: 		RectangleCodec,
samer@0: 		ColorCodec,
samer@0: 		StringCodec,
samer@0: 		BooleanCodec,
samer@0: 		IntegerCodec,
samer@0: 		DoubleCodec
samer@0: 	};
samer@0: }
samer@0: