plugins/org.eclipse.dltk.javascript.rhino.dbgp/src/org/eclipse/dltk/rhino/dbgp/DBGPStackManager.java

package org.eclipse.dltk.rhino.dbgp;

import java.util.ArrayList;
import java.util.Observer;
import java.util.WeakHashMap;

import org.mozilla.javascript.Context;

public class DBGPStackManager {

	protected static WeakHashMap map = new WeakHashMap();

	private ArrayList stack = new ArrayList();

	private static boolean breakpointsThreadLocal;

	private boolean needSuspend;

	private DBGPDebugger observer;

	private BreakPointManager manager = null;

	private static BreakPointManager gmanager = null;

	private boolean suspendOnExit;

	private boolean suspendOnEntry;

	private boolean suspenOnChangeLine;

	public BreakPointManager getManager() {
		return manager;
	}

	private DBGPStackManager() {
		if (isBreakpointsThreadLocal()) {
			manager = new BreakPointManager();
		} else {
			synchronized (DBGPStackManager.class) {
				if (gmanager == null)
					gmanager = new BreakPointManager();
			}
			manager = gmanager;
		}
	}

	public static DBGPStackManager getManager(Context cx) {
		DBGPStackManager object = (DBGPStackManager) map.get(cx);
		if (object != null)
			return object;
		object = new DBGPStackManager();
		map.put(cx, object);
		return object;
	}

	public static void removeManager(Context cx) {
		map.remove(cx);
	}

	public void enter(DBGPDebugFrame debugFrame) {
		stack.add(debugFrame);
		String sn = debugFrame.getWhere();

		if (sn != null) {
			BreakPoint hit = manager.hitEnter(sn);
			if (hit != null)
				checkBreakpoint(debugFrame, hit);
		}

		if (suspendOnEntry) {
			if (debugFrame.getWhere().equals("module")) {
				observer.update(null, this);
				waitForContinuation();
			} else
				suspenOnChangeLine = true;
		}
	}

	public void exit(DBGPDebugFrame debugFrame) {
		if (needSuspend || suspendOnExit) {

			observer.update(null, this);
			waitForContinuation();
		}
		String sn = debugFrame.getWhere();

		if (sn != null) {
			BreakPoint hit = manager.hitExit(sn);
			if (hit != null)
				checkBreakpoint(debugFrame, hit);
		}
		stack.remove(debugFrame);

	}

	public void changeLine(DBGPDebugFrame frame, int lineNumber) {
		if (suspenOnChangeLine) {
			suspenOnChangeLine = false;
			observer.update(null, this);
			waitForContinuation();
		}
		if (frame.isSuspend()) {
			needSuspend = true;
		}
		BreakPoint hit = manager.hit(frame.getSourceName(), lineNumber);
		checkBreakpoint(frame, hit);
	}

	private synchronized void waitForContinuation() {
		try {
			this.wait();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	private void continueExecution() {
		this.notify();
	}

	private void checkBreakpoint(DBGPDebugFrame frame, BreakPoint hit) {

		if (hit != null) {
			if (hit.isEnabled()) {
				if (hit.expression != null) {
					Object eval = frame.eval(hit.expression);
					if (eval != null) {
						if (eval.equals(Boolean.TRUE)) {
							needSuspend = true;
						} else
							needSuspend = false;
					} else
						needSuspend = false;
				} else
					needSuspend = true;
				// observer.update(null, hit);
			}
		}
		if (needSuspend) {
			observer.update(null, this);
			waitForContinuation();
		}
	}

	public void exceptionThrown(Throwable ex) {

	}

	public void suspend() {
		needSuspend = true;
	}

	public int getStackDepth() {
		return stack.size();
	}

	public DBGPDebugFrame getStackFrame(int parseInt) {
		int stackCounter = stack.size() - parseInt - 1;
		if (stackCounter >= 0) {
			return (DBGPDebugFrame) stack.get(stackCounter);
		}
		return null;
	}

	public int getLineNumber(String level) {
		return getStackFrame(0).getLineNumber();
	}

	public void registerBreakPoint(BreakPoint p) {
		manager.addBreakPoint(p);
	}

	public void setDebugger(DBGPDebugger debugger) {
		this.observer = debugger;
	}

	public synchronized void resume() {
		this.needSuspend = false;
		for (int a = 0; a < this.getStackDepth(); a++) {
			this.getStackFrame(a).setSuspend(false);
		}
		continueExecution();
	}

	public synchronized void stepOver() {
		getStackFrame(0).setSuspend(true);
		if (this.getStackDepth() > 1) {
			getStackFrame(1).setSuspend(true);
		}
		this.needSuspend = false;
		continueExecution();
	}

	public synchronized void stepIn() {
		this.needSuspend = true;
		continueExecution();
	}

	public synchronized void stepOut() {
		getStackFrame(0).setSuspend(false);
		this.needSuspend = false;
		if (this.getStackDepth() > 1) {
			getStackFrame(1).setSuspend(true);
		}
		continueExecution();
	}

	public void waitForNotify() {
		waitForContinuation();
	}

	public void removeBreakpoint(String id) {
		this.manager.removeBreakPoint(id);
	}

	public void updateBreakpoint(String id, String newState, String newLine,
			String hitValue, String hitCondition, String condExpr) {
		this.manager.updateBreakpoint(id, newState, newLine, hitValue,
				hitCondition, condExpr);
	}

	public Observer getObserver() {
		return observer;
	}

	public BreakPoint getBreakpoint(String id) {
		return this.manager.getBreakpoint(id);
	}

	public void setSuspendOnExit(boolean parseBoolean) {
		this.suspendOnExit = parseBoolean;
	}

	public void setSuspendOnEntry(boolean parseBoolean) {
		this.suspendOnEntry = parseBoolean;
	}

	public static boolean isBreakpointsThreadLocal() {
		return breakpointsThreadLocal;
	}

	public static void setBreakpointsThreadLocal(boolean breakpointsThreadLocal) {
		DBGPStackManager.breakpointsThreadLocal = breakpointsThreadLocal;
	}

}