comparison src/samer/applet/JApplet.java @ 0:bf79fb79ee13

Initial Mercurial check in.

+/*
+ *	JApplet.java	
+ *
+ *	Copyright (c) 2000, 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.applet;
+import  samer.core.*;
+import  samer.core.util.heavy.*;
+import  java.applet.*;
+import  java.awt.*;
+import  java.net.*;
+import  java.io.*;
+
+
+/** Base class for applets that work with the JAppletShell framework.
+	Manages a border and scripts to run on create, destroy, init and term
+*/
+
+public class JApplet extends Applet
+{
+	private Border.Interface	border;
+	protected String			name, ondestroy;
+
+
+	public void setBorder( Border.Interface b) { border=b; }
+	public Border.Interface getBorder() { return border; }
+
+	public void init() 
+	{
+		JAppletShell.initialise(this);
+		name = getParameter("name");
+		if (name!=null && name.length()==0) name=null;
+
+		String args = getParameter("args");
+		if (args!=null && args.length()>0) {
+			try {
+				JAppletShell.instance.loadargs(new URL(getDocumentBase(), args));
+			}
+			catch (Exception ex) {
+				Shell.trace("JApplet: error loading "+args);
+			}
+		}
+
+		Shell.trace("JApplet init "+name); 
+		ondestroy=getParameter("ondestroy");
+		setup();
+	}
+
+	public void setup()
+	{
+		// create a new environment based on Shell top level
+		// with name equal to Applet name, using this applet
+		// as a Dictionary (String -> String mapping)
+
+		if (name!=null) { /* what? */ }
+		Node node= (name==null ? Shell.env().node() : new Node(name));
+		Environment env=new Environment(Shell.env(),node) {
+			public Datum datum(final String nm) {
+				final String vl=getParameter(nm);
+				if (vl==null) return parent.datum(nm);
+				return new Datum() {
+					public String name() { return nm; }
+					public int    score() { return 0; }
+					public Object get(Codec c, Object def) { return c.decode(vl); }
+					public void   get(Autocoder obj) { obj.decode(vl); }
+				};
+			}
+		};
+		// can't push global Environment because 
+		// applets may load mutli-threadedly.
+
+
+		// set up colours and fonts from properties
+		Color pageColour = X.color(env.datum("pagebg"), getBackground());
+		getParent().setBackground( pageColour);
+		setBackground( X.color(env.datum("background"), pageColour));
+		setForeground( X.color(env.datum("foreground"), getForeground()));
+		setFont((Font)(env.datum("font").get(X.FontCodec,"Helvetica-PLAIN-12")));
+
+		// create border using parameters from this applet
+
+		setBorder( Borders.createBorder(new Environment(env,"border")));
+
+		// "export" means  we should make this applets
+		// parameters globally visible as Shell properties 
+		synchronized (JAppletShell.instance) {
+			String export=getParameter("export"); // local search only!
+			if ("true".equals(export)) {
+				Shell.trace("Applet: "+name+" exporting properties");
+				Shell.push(env);
+				// ?? what happens when this applet goes away? 
+				// maybe implement Peers environement, consisting of
+				// a list (rather than a stack) of other environments
+			}
+		}
+	}
+
+	public void onStart() 
+	{
+		String oncreate=getParameter("oncreate");
+		if (oncreate!=null) {
+			Shell.trace("oncreate: "+oncreate);
+			Shell.interpret(new StringReader(oncreate));
+		}
+	}
+
+	public void onDestroy() 
+	{
+		if (ondestroy!=null) {
+			Shell.trace("ondestroy: "+ondestroy);
+			Shell.interpret(new StringReader(ondestroy));
+		}
+	}
+
+	public Insets getInsets() { 
+		if (border!=null) return border.getBorderInsets(this); 
+		else return new Insets(0,0,0,0);
+	}
+
+	public void paint(Graphics g)
+	{
+		// should paint border first, incase border erases bg
+		Dimension d=getSize();
+		border.paintBorder(this,g,0,0,d.width,d.height);
+		g.setColor( getForeground());
+	}
+
+	public void   setProperty(String nm,String vl) {}
+	public String getProperty(String nm) { return getParameter(nm); }
+
+	public void start() { Shell.trace("JApplet start"); onStart(); }
+	public void stop() { Shell.trace("JApplet stop"); }
+	public void destroy() { Shell.trace("JApplet destroy"); onDestroy(); }
+
+	protected void finalize() { Shell.trace("JApplet finalizing "+name); } 
+}