scriptableobject.java

這是一個javascript 的 interpreter是了解 web browser的好材料

                      "msg.zero.arg.ctor", clazz.getName());
        }

        Scriptable proto = (Scriptable) protoCtor.newInstance(ScriptRuntime.emptyArgs);
        String className = proto.getClassName();

        // Set the prototype's prototype, trying to map Java inheritance to JS
        // prototype-based inheritance if requested to do so.
        Scriptable superProto = null;
        if (mapInheritance) {
            Class superClass = clazz.getSuperclass();
            if (ScriptRuntime.ScriptableClass.isAssignableFrom(superClass)
                    && !Modifier.isAbstract(superClass.getModifiers())) {
                String name = ScriptableObject.defineClass(scope, superClass, sealed, mapInheritance);
                if (name != null) {
                    superProto = ScriptableObject.getClassPrototype(scope, name);
                }
            }
        }
        if (superProto == null) {
            superProto = ScriptableObject.getObjectPrototype(scope);
        }
        proto.setPrototype(superProto);

        // Find out whether there are any methods that begin with
        // "js". If so, then only methods that begin with special
        // prefixes will be defined as JavaScript entities.
        final String functionPrefix = "jsFunction_";
        final String staticFunctionPrefix = "jsStaticFunction_";
        final String getterPrefix = "jsGet_";
        final String setterPrefix = "jsSet_";
        final String ctorName = "jsConstructor";

        Member ctorMember = FunctionObject.findSingleMethod(methods, ctorName);

        if (ctorMember == null) {
            if (ctors.length == 1) {
                ctorMember = ctors[0];
            } else if (ctors.length == 2) {
                if (ctors[0].getParameterTypes().length == 0)
                    ctorMember = ctors[1];
                else if (ctors[1].getParameterTypes().length == 0)
                    ctorMember = ctors[0];
            }
            if (ctorMember == null) {
                throw Context.reportRuntimeError1(
                          "msg.ctor.multiple.parms", clazz.getName());
            }
        }

        FunctionObject ctor = new FunctionObject(className, ctorMember, scope);
        if (ctor.isVarArgsMethod()) {
            throw Context.reportRuntimeError1
                ("msg.varargs.ctor", ctorMember.getName());
        }
        ctor.initAsConstructor(scope, proto);

        Method finishInit = null;
        for (int i=0; i < methods.length; i++) {
            if (methods[i] == ctorMember) {
                continue;
            }
            String name = methods[i].getName();
            if (name.equals("finishInit")) {
                Class[] parmTypes = methods[i].getParameterTypes();
                if (parmTypes.length == 3 &&
                    parmTypes[0] == ScriptRuntime.ScriptableClass &&
                    parmTypes[1] == FunctionObject.class &&
                    parmTypes[2] == ScriptRuntime.ScriptableClass &&
                    Modifier.isStatic(methods[i].getModifiers()))
                {
                    finishInit = methods[i];
                    continue;
                }
            }
            // ignore any compiler generated methods.
            if (name.indexOf('$') != -1)
                continue;
            if (name.equals(ctorName))
                continue;

            String prefix = null;
            if (name.startsWith(functionPrefix)) {
                prefix = functionPrefix;
            } else if (name.startsWith(staticFunctionPrefix)) {
                prefix = staticFunctionPrefix;
                if (!Modifier.isStatic(methods[i].getModifiers())) {
                    throw Context.reportRuntimeError(
                        "jsStaticFunction must be used with static method.");
                }
            } else if (name.startsWith(getterPrefix)) {
                prefix = getterPrefix;
            } else if (name.startsWith(setterPrefix)) {
                prefix = setterPrefix;
            } else {
                continue;
            }
            name = name.substring(prefix.length());
            if (prefix == setterPrefix)
                continue;   // deal with set when we see get
            if (prefix == getterPrefix) {
                if (!(proto instanceof ScriptableObject)) {
                    throw Context.reportRuntimeError2(
                        "msg.extend.scriptable",
                        proto.getClass().toString(), name);
                }
                Method setter = FunctionObject.findSingleMethod(
                                    methods,
                                    setterPrefix + name);
                int attr = ScriptableObject.PERMANENT |
                           ScriptableObject.DONTENUM  |
                           (setter != null ? 0
                                           : ScriptableObject.READONLY);
                ((ScriptableObject) proto).defineProperty(name, null,
                                                          methods[i], setter,
                                                          attr);
                continue;
            }

            FunctionObject f = new FunctionObject(name, methods[i], proto);
            if (f.isVarArgsConstructor()) {
                throw Context.reportRuntimeError1
                    ("msg.varargs.fun", ctorMember.getName());
            }
            Scriptable dest = prefix == staticFunctionPrefix
                              ? ctor
                              : proto;
            defineProperty(dest, name, f, DONTENUM);
            if (sealed) {
                f.sealObject();
            }
        }

        // Call user code to complete initialization if necessary.
        if (finishInit != null) {
            Object[] finishArgs = { scope, ctor, proto };
            finishInit.invoke(null, finishArgs);
        }

        // Seal the object if necessary.
        if (sealed) {
            ctor.sealObject();
            if (proto instanceof ScriptableObject) {
                ((ScriptableObject) proto).sealObject();
            }
        }

        return ctor;
    }

    /**
     * Define a JavaScript property.
     *
     * Creates the property with an initial value and sets its attributes.
     *
     * @param propertyName the name of the property to define.
     * @param value the initial value of the property
     * @param attributes the attributes of the JavaScript property
     * @see org.mozilla.javascript.Scriptable#put(String, Scriptable, Object)
     */
    public void defineProperty(String propertyName, Object value,
                               int attributes)
    {
        checkNotSealed(propertyName, 0);
        put(propertyName, this, value);
        setAttributes(propertyName, attributes);
    }

    /**
     * Utility method to add properties to arbitrary Scriptable object.
     * If destination is instance of ScriptableObject, calls
     * defineProperty there, otherwise calls put in destination
     * ignoring attributes
     */
    public static void defineProperty(Scriptable destination,
                                      String propertyName, Object value,
                                      int attributes)
    {
        if (!(destination instanceof ScriptableObject)) {
            destination.put(propertyName, destination, value);
            return;
        }
        ScriptableObject so = (ScriptableObject)destination;
        so.defineProperty(propertyName, value, attributes);
    }

    /**
     * Utility method to add properties to arbitrary Scriptable object.
     * If destination is instance of ScriptableObject, calls
     * defineProperty there, otherwise calls put in destination
     * ignoring attributes
     */
    public static void defineConstProperty(Scriptable destination,
                                           String propertyName)
    {
        if (destination instanceof ConstProperties) {
            ConstProperties cp = (ConstProperties)destination;
            cp.defineConst(propertyName, destination);
        } else
            defineProperty(destination, propertyName, Undefined.instance, CONST);
    }

    /**
     * Define a JavaScript property with getter and setter side effects.
     *
     * If the setter is not found, the attribute READONLY is added to
     * the given attributes. <p>
     *
     * The getter must be a method with zero parameters, and the setter, if
     * found, must be a method with one parameter.<p>
     *
     * @param propertyName the name of the property to define. This name
     *                    also affects the name of the setter and getter
     *                    to search for. If the propertyId is "foo", then
     *                    <code>clazz</code> will be searched for "getFoo"
     *                    and "setFoo" methods.
     * @param clazz the Java class to search for the getter and setter
     * @param attributes the attributes of the JavaScript property
     * @see org.mozilla.javascript.Scriptable#put(String, Scriptable, Object)
     */
    public void defineProperty(String propertyName, Class clazz,
                               int attributes)
    {
        int length = propertyName.length();
        if (length == 0) throw new IllegalArgumentException();
        char[] buf = new char[3 + length];
        propertyName.getChars(0, length, buf, 3);
        buf[3] = Character.toUpperCase(buf[3]);
        buf[0] = 'g';
        buf[1] = 'e';
        buf[2] = 't';
        String getterName = new String(buf);
        buf[0] = 's';
        String setterName = new String(buf);

        Method[] methods = FunctionObject.getMethodList(clazz);
        Method getter = FunctionObject.findSingleMethod(methods, getterName);
        Method setter = FunctionObject.findSingleMethod(methods, setterName);
        if (setter == null)
            attributes |= ScriptableObject.READONLY;
        defineProperty(propertyName, null, getter,
                       setter == null ? null : setter, attributes);
    }

    /**
     * Define a JavaScript property.
     *
     * Use this method only if you wish to define getters and setters for
     * a given property in a ScriptableObject. To create a property without
     * special getter or setter side effects, use
     * <code>defineProperty(String,int)</code>.
     *
     * If <code>setter</code> is null, the attribute READONLY is added to
     * the given attributes.<p>
     *
     * Several forms of getters or setters are allowed. In all cases the
     * type of the value parameter can be any one of the following types:
     * Object, String, boolean, Scriptable, byte, short, int, long, float,
     * or double. The runtime will perform appropriate conversions based
     * upon the type of the parameter (see description in FunctionObject).
     * The first forms are nonstatic methods of the class referred to
     * by 'this':
     * <pre>
     * Object getFoo();
     * void setFoo(SomeType value);</pre>
     * Next are static methods that may be of any class; the object whose
     * property is being accessed is passed in as an extra argument:
     * <pre>
     * static Object getFoo(Scriptable obj);
     * static void setFoo(Scriptable obj, SomeType value);</pre>
     * Finally, it is possible to delegate to another object entirely using
     * the <code>delegateTo</code> parameter. In this case the methods are
     * nonstatic methods of the class delegated to, and the object whose
     * property is being accessed is passed in as an extra argument:
     * <pre>
     * Object getFoo(Scriptable obj);
     * void setFoo(Scriptable obj, SomeType value);</pre>
     *
     * @param propertyName the name of the property to define.
     * @param delegateTo an object to call the getter and setter methods on,
     *                   or null, depending on the form used above.
     * @param getter the method to invoke to get the value of the property
     * @param setter the method to invoke to set the value of the property
     * @param attributes the attributes of the JavaScript property
     */
    public void defineProperty(String propertyName, Object delegateTo,
                               Method getter, Method setter, int attributes)
    {
        MemberBox getterBox = null;
        if (getter != null) {
            getterBox = new MemberBox(getter);

            boolean delegatedForm;
            if (!Modifier.isStatic(getter.getModifiers())) {
                delegatedForm = (delegateTo != null);
                getterBox.delegateTo = delegateTo;
            } else {
                delegatedForm = true;
                // Ignore delegateTo for static getter but store
                // non-null delegateTo indicator.
                getterBox.delegateTo = Void.TYPE;
            }

            String errorId = null;
            Class[] parmTypes = getter.getParameterTypes();
            if (parmTypes.length == 0) {
                if (delegatedForm) {
                    errorId = "msg.obj.getter.parms";
                }
            } else if (parmTypes.length == 1) {
                Object argType = parmTypes[0];
                // Allow ScriptableObject for compatibility
                if (!(argType == ScriptRuntime.ScriptableClass ||
                      argType == ScriptRuntime.ScriptableObjectClass))
                {
                    errorId = "msg.bad.getter.parms";
                } else if (!delegatedForm) {
                    errorId = "msg.bad.getter.parms";
                }
            } else {
                errorId = "msg.bad.getter.parms";
            }
            if (errorId != null) {
                throw Context.reportRuntimeError1(errorId, getter.toString());
            }
        }

        MemberBox setterBox = null;
        if (setter != null) {
            if (setter.getReturnType() != Void.TYPE)
                throw Context.reportRuntimeError1("msg.setter.return",
                                                  setter.toString());

            setterBox = new MemberBox(setter);

            boolean delegatedForm;
            if (!Modifier.isStatic(setter.getModifiers())) {
                delegatedForm = (delegateTo != null);
                setterBox.delegateTo = delegateTo;
            } else {
                delegatedForm = true;
                // Ignore delegateTo for static setter but store
                // non-null delegateTo indicator.
                setterBox.delegateTo = Void.TYPE;
            }

            String errorId = null;
            Class[] parmTypes = setter.getParameterTypes();