X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=cdc7e359d9630c89df119b173dcedda79d1db45c;hb=e8442c40f5b8c03a4e6993cbcc9ce64dddab6a90;hp=51929afcd099cfc260285db7d4a27cfc65aba487;hpb=9b9482f2939c8cb7526a8ca7ff43a7f2c2b5f97a;p=org.ibex.core.git diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java index 51929af..cdc7e35 100644 --- a/src/org/xwt/js/JS.java +++ b/src/org/xwt/js/JS.java @@ -1,55 +1,202 @@ -// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL] - +// Copyright 2003 Adam Megacz, see the COPYING file for licensing [GPL] + package org.xwt.js; import org.xwt.util.*; +import java.io.*; +import java.util.*; + +/** + * The public API for the JS engine. JS itself is actually a class + * implementing the absolute minimal amount of functionality for an + * Object which can be manipulated by JavaScript code. The static + * methods, fields, and inner classes of JS define the publicly + * visible API for the XWT JavaScript engine; code outside this + * package should never depend on anything not defined in this file. + */ +public abstract class JS { + + + // Public Helper Methods ////////////////////////////////////////////////////////////////////// + + /** parse and compile a function */ + public static CompiledFunction parse(String sourceName, int firstLine, Reader sourceCode) throws IOException { + return new CompiledFunction(sourceName, firstLine, sourceCode, null); + } + + /** coerce an object to a Boolean */ + public static boolean toBoolean(Object o) { + if (o == null) return false; + if (o instanceof Boolean) return ((Boolean)o).booleanValue(); + if (o instanceof Long) return ((Long)o).longValue() != 0; + if (o instanceof Integer) return ((Integer)o).intValue() != 0; + if (o instanceof Number) { + double d = ((Number) o).doubleValue(); + // NOTE: d == d is a test for NaN. It should be faster than Double.isNaN() + return d != 0.0 && d == d; + } + if (o instanceof String) return ((String)o).length() != 0; + return true; + } + + /** coerce an object to a Long */ + public static long toLong(Object o) { return toNumber(o).longValue(); } + + /** coerce an object to an Int */ + public static int toInt(Object o) { return toNumber(o).intValue(); } + + /** coerce an object to a Double */ + public static double toDouble(Object o) { return toNumber(o).doubleValue(); } + + /** coerce an object to a Number */ + public static Number toNumber(Object o) { + if (o == null) return new Long(0); + if (o instanceof Number) return ((Number)o); + // FIXME: There are about 3 pages of rules in ecma262 about string to number conversions + // We aren't even close to following all those rules + if (o instanceof String) try { return new Double((String)o); } catch (NumberFormatException e) { return new Double(Double.NaN); } + if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? new Long(1) : new Long(0); + if (o instanceof JS) return ((JS)o).coerceToNumber(); + throw new Error("toNumber() got object of type " + o.getClass().getName() + " which we don't know how to handle"); + } + + // Instance Methods //////////////////////////////////////////////////////////////////// -/** The public API for the JS engine */ -public interface JS { - - public Object get(Object key) throws JS.Exn; - public Object put(Object key, Object val) throws JS.Exn; - public Object[] enumerateProperties(); - public String coerceToString() throws JS.Exn; - /* - public Num coerceToNumber() throws JS.Exn; - public boolean coerceToBoolean() throws JS.Exn; - public Object call(Object[] args) throws JS.Exn; - */ - /** if JS calls a Java method, and the Java method throws an exception, it can only be caught by JS if it is a subclass of Exn. */ + public abstract Object get(Object key) throws JS.Exn; + public abstract void put(Object key, Object val) throws JS.Exn; + public abstract Object[] keys(); + public abstract Object callMethod(Object method, JS.Array args, boolean justChecking); + + public Number coerceToNumber() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a Number"); } + public String coerceToString() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a String"); } + public boolean coerceToBoolean() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a Boolean"); } + + public String typeName() { return "object"; } + + + // Inner Classes ///////////////////////////////////////////////////////////////////////// + + /** A sensible implementation of the abstract methods in the JS class */ + public static class Obj extends JS { + private Hash entries = new Hash(); + private boolean sealed = false; + public Obj() { this(false); } + public Obj(boolean sealed) { this.sealed = sealed; } + /** a sealed object cannot have its properties modified */ + public void setSeal(boolean sealed) { this.sealed = sealed; } + public void put(Object key, Object val) { if (!sealed) entries.put(key, val); } + public Object[] keys() { return(entries.keys()); } + public Object get(Object key) { + if(callMethod((String)key,null,true) == Boolean.TRUE) + return new Internal.CallableStub(this,key); + return entries.get(key); + } + public Object callMethod(Object method, JS.Array args, boolean checkOnly) throws JS.Exn { + if(checkOnly) return Boolean.FALSE; + Object o = get(method); + if(o instanceof JS.Callable) { + return ((JS.Callable)o).call(args); + } else if(o == null) { + throw new JS.Exn("Attempted to call non-existent method: " + method); + } else { + throw new JS.Exn("Attempted to call a non-method: " +method); + } + } + } + + /** An exception which can be thrown and caught by JavaScript code */ public static class Exn extends RuntimeException { - private Object js = null; - public Exn(Object js) { this.js = js; } - public Object getObject() { return js; } + private Object js = null; + public Exn(Object js) { this.js = js; } + public String toString() { return "JS.Exn: " + js; } + public String getMessage() { return toString(); } + public Object getObject() { return js; } } - + + /** The publicly-visible face of JavaScript Array objects */ + public static class Array extends ArrayImpl { + public Array() { } + public Array(int size) { super(size); } + public void setSize(int i) { super.setSize(i); } + public int length() { return super.length(); } + public Object elementAt(int i) { return super.elementAt(i); } + public void addElement(Object o) { super.addElement(o); } + public void setElementAt(Object o, int i) { super.setElementAt(o, i); } + public Object get(Object key) { return super._get(key); } + public void put(Object key, Object val) { super._put(key, val); } + } + /** Any object which becomes part of the scope chain must support this interface */ - public static interface Scope extends JS { - public boolean has(Object key); - public void declare(String s); - public JS getParentScope(); + public static class Scope extends ScopeImpl { + public Scope(Scope parentScope) { this(parentScope, false); } + public Scope(Scope parentScope, boolean sealed) { super(parentScope, sealed); } + /** transparent scopes are not returned by THIS */ + public boolean isTransparent() { return super.isTransparent(); } + public boolean has(Object key) { return super.has(key); } + public Object get(Object key) { return super._get(key); } + public void put(Object key, Object val) { super._put(key, val); } + public void declare(String s) { super.declare(s); } } + + /** anything that is callable with the () operator */ + public static abstract class Callable extends JS.Obj { + public abstract Object call(JS.Array args) throws JS.Exn; + } + + /** a Callable which was compiled from JavaScript code */ + public static class CompiledFunction extends CompiledFunctionImpl { + CompiledFunction(String sourceName, int firstLine, Reader sourceCode, Scope scope) throws IOException { + super(sourceName, firstLine, sourceCode, scope); + } + } + + /** a scope that is populated with js objects and functions normally found in the global scope */ + public static class GlobalScope extends GlobalScopeImpl { + public GlobalScope() { this(null); } + public GlobalScope(JS.Scope parent) { super(parent); } + } + + public static final JS Math = new org.xwt.js.Math(); - /** A mutable, boxed numeric value. These are recycled -- never duplicate references -- use duplicate() instead. */ - /* - public static class Num implements Cloneable, JS { - - private Num() { } - public boolean isDouble = false; - public long longVal = -1; - public double doubleVal = -1; - - private static Vec pool = new Vec(); - public static synchronized void recycle(Num n) { pool.push(n); } - public static synchronized Num getOne() { return (pool.size() > 0) ? (Num)pool.pop() : new Num(); } - - public Num duplicate() { try { return (Num)clone(); } catch (CloneNotSupportedException c) { throw new Error(c); } } - - public Object get(Object key) throws JS.Exn { return null; } - public Object put(Object key, Object val) throws JS.Exn { throw new JS.Exn("attempt to set a property on a Number"); } - public Object[] enumerateProperties() { return new Object[] { }; } - public String coerceToString() throws JS.Exn { return isDouble ? String.valueOf(doubleVal) : String.valueOf(longVal); } - public Num coerceToNumber() throws JS.Exn { return duplicate(); } - public Object call(Object[] args) throws JS.Exn { throw new JS.Exn("attempt to apply the () operator to a Number"); } - } - */ + /** encapsulates a single JavaScript thread; the JS.Thread->java.lang.Thread mapping is 1:1 */ + public static class Thread { + + CompiledFunction currentCompiledFunction = null; + Vec stack = new Vec(); + int pc; + + /** binds this thread to the current Java Thread */ + public void bindToCurrentJavaThread() { javaThreadToJSThread.put(java.lang.Thread.currentThread(), this); } + + /** returns the line of code that is currently executing */ + public int getLine() { return currentCompiledFunction == null ? -1 : currentCompiledFunction.getLine(pc); } + + /** returns the name of the source code file which declared the currently executing function */ + public String getSourceName() { return currentCompiledFunction == null ? null : currentCompiledFunction.getSourceName(); } + + /** fetches the currently-executing javascript function */ + public JS.CompiledFunction getCurrentCompiledFunction() { return currentCompiledFunction; } + + + // Statics /////////////////////////////////////////////////////////////////////// + + private static Hashtable javaThreadToJSThread = new Hashtable(); + + /** returns the JS thread for a given Java thread, creating one if necessary */ + public static JS.Thread fromJavaThread(java.lang.Thread t) { + JS.Thread ret = (JS.Thread)javaThreadToJSThread.get(t); + if (ret == null) { + ret = new JS.Thread(); + ret.bindToCurrentJavaThread(); + } + return ret; + } + + public static JS.Thread currentJSThread() { + return fromJavaThread(java.lang.Thread.currentThread()); + } + } } + + + +