view src/samer/core_/util/shell/AppShellBase.java @ 8:5e3cbbf173aa tip

Reorganise some more

/*
 *	AppShell.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.core.util.shell;
import  samer.core.util.*;
import  samer.core.*;
import  java.io.*;

public abstract class AppShellBase extends Properties
	implements Shell.Interface, Agent
{
	protected AgentManager		am;
	protected ViewableManager	vm;
	private   boolean registerAgents;
	private   boolean registerViewables;

	private static Environment baseEnvironment(String fname)
	{
		try {
			Shell.trace("loading user properties from " +fname);
			FileInputStream in=new FileInputStream(fname);

			try {
				Properties uprops=new Properties(Shell.env());
				uprops.load(in);
				uprops.setWritable(false);
				Shell.push(uprops);
				Shell.trace("user properties successfully loaded");
			} finally { in.close(); }
		} catch (Exception ex) {
			Shell.trace("failed to load user properties: "+ex);
		}
		return Shell.env();
	}

	protected static String getDefaultPropertiesFile() {
		return System.getProperty("user.home") + File.separator + "user.props";
	}

	protected AppShellBase() { this(getDefaultPropertiesFile());	}
	protected AppShellBase(String userPropsFile)
	{
		super(baseEnvironment(userPropsFile));

		try { execute("load",Shell.env()); }
		catch (Exception ex) { Shell.trace("failed to load local properties"); }

		Shell.push(this);
//		Shell.push(new FilteredEnvironment(new Properties(this), "bounds"));
		Shell.push(new HashMap(Shell.env()));

		am = new AgentManager();		registerAgent(am);
		vm = new ViewableManager();

		registerAgents=true;
		registerViewables=true;
	}

	public void enableAgentRegistry(boolean f) { registerAgents=f; }
	public void enableViewableRegistry(boolean f) { registerViewables=f; }

	public void getCommands(Agent.Registry r) {
		// r.add("set").add("get")
		r.add("load").add("save")
		 .add("expose").add("exit");
	}

	public void exit() { am.dispatch("exit",Shell.env()); }

	public void execute(String cmd, Environment env) throws Exception
	{
		if (cmd.equals("exit")) {
			try { execute("save",this); }
			catch (Exception ex) { Shell.trace(ex.toString()); }

			// not any more. Just exit and be done.
			// am.exitOnReturn(); // must let other agents respond before System.exit
			System.exit(0);
			
		} else if (cmd.equals("expose")) {
			if (!vm.hasViewerContainer()) {
				vm.exposeViewables(getViewerContainer());
			}

		} else if (cmd.equals("get")) { // get property
			String nm = X.string(env.datum());
			Shell.print("name: "+nm);
			try {
				Object val=X.object(datum(nm));
				Shell.print("value: "+val);
				env.add(val);
			} catch (Exception ex) { Shell.print("value: ** not bound **"); }

		} else if (cmd.equals("set")) {
			X.store(X.string(env.datum()),X.object(env.datum()));

		} else if (cmd.equals("load")) {
			String fname=X.string(env.datum("local.props"),"args");
			Shell.trace("loading properties from "+fname);
			InputStream in=new FileInputStream(fname);
			try { props.load(in); }
			finally { in.close(); }

		} else if (cmd.equals("save")) {
			String fname=X.string(env.datum("local.props"),"args");
			Shell.trace("saving properties to "+fname);

			try {
				File file=new File(fname);
				File old=new File(fname+".old");
				try { old.delete(); }
				catch (Exception ex) {}
				file.renameTo(old);
			} catch (Exception ex) {
				Shell.trace(ex.toString());
			}

			OutputStream out=new FileOutputStream(fname);
			try { props.store(out,"properties"); }
			finally { out.close(); }
		}
	}

	protected void put(Class a, Class b) { samer.core.Registry.put(a,b); }

	public void trace(String msg) { System.err.println(msg); }
//	public void trace(String string) {
//		System.err.println(" "+(System.currentTimeMillis() % 8192L)+": "+string);
//	}
	public void registerAgent(Agent a) { if (registerAgents) am.registerAgent(a); }
	public void deregisterAgent(Agent a) { am.deregisterAgent(a); }
	public void deregisterViewable(Viewable v) { vm.deregisterViewable(v); }
	public void registerViewable(Viewable v) { if (registerViewables) vm.registerViewable(v); }

	protected abstract ViewableManager.ViewerContainer getViewerContainer();
}