org.mozilla.javascript

Class IdScriptableObject

public abstract class IdScriptableObject extends ScriptableObject implements IdFunctionCall

Base class for native object implementation that uses IdFunctionObject to export its methods to script via .prototype object. Any descendant should implement at least the following methods: findInstanceIdInfo getInstanceIdName execIdCall methodArity To define non-function properties, the descendant should override getInstanceIdValue setInstanceIdValue to get/set property value and provide its default attributes. To customize initializition of constructor and protype objects, descendant may override scopeInit or fillConstructorProperties methods.

Constructor Summary
	IdScriptableObject()
	IdScriptableObject(Scriptable scope, Scriptable prototype)

Method Summary
void	activatePrototypeMap(int maxPrototypeId)
protected void	addIdFunctionProperty(Scriptable obj, Object tag, int id, String name, int arity)
protected Object	defaultGet(String name)
protected void	defaultPut(String name, Object value)
void	delete(String name)
Object	execIdCall(IdFunctionObject f, Context cx, Scriptable scope, Scriptable thisObj, Object[] args) 'thisObj' will be null if invoked as constructor, in which case instance of Scriptable should be returned.
IdFunctionObject	exportAsJSClass(int maxPrototypeId, Scriptable scope, boolean sealed)
protected void	fillConstructorProperties(IdFunctionObject ctor)
protected int	findInstanceIdInfo(String name) Map name to id of instance property.
protected int	findPrototypeId(String name)
Object	get(String name, Scriptable start)
int	getAttributes(String name)
protected String	getInstanceIdName(int id) Map id back to property name it defines.
protected Object	getInstanceIdValue(int id) Get id value.
protected int	getMaxInstanceId() Get maximum id findInstanceIdInfo can generate.
boolean	has(String name, Scriptable start)
boolean	hasPrototypeMap()
protected static EcmaError	incompatibleCallError(IdFunctionObject f) Utility method to construct type error to indicate incompatible call when converting script thisObj to a particular type is not possible.
void	initPrototypeConstructor(IdFunctionObject f)
protected void	initPrototypeId(int id)
void	initPrototypeMethod(Object tag, int id, String name, int arity)
void	initPrototypeValue(int id, String name, Object value, int attributes)
protected static int	instanceIdInfo(int attributes, int id)
void	put(String name, Scriptable start, Object value)
void	setAttributes(String name, int attributes)
protected void	setInstanceIdValue(int id, Object value) Set or delete id value.

Constructor Detail

IdScriptableObject

public IdScriptableObject()

IdScriptableObject

public IdScriptableObject(Scriptable scope, Scriptable prototype)

Method Detail

activatePrototypeMap

public final void activatePrototypeMap(int maxPrototypeId)

addIdFunctionProperty

protected void addIdFunctionProperty(Scriptable obj, Object tag, int id, String name, int arity)

defaultGet

protected final Object defaultGet(String name)

defaultPut

protected final void defaultPut(String name, Object value)

delete

public void delete(String name)

execIdCall

public Object execIdCall(IdFunctionObject f, Context cx, Scriptable scope, Scriptable thisObj, Object[] args)

'thisObj' will be null if invoked as constructor, in which case instance of Scriptable should be returned.

exportAsJSClass

public final IdFunctionObject exportAsJSClass(int maxPrototypeId, Scriptable scope, boolean sealed)

fillConstructorProperties

protected void fillConstructorProperties(IdFunctionObject ctor)

findInstanceIdInfo

protected int findInstanceIdInfo(String name)

Map name to id of instance property. Should return 0 if not found or the result of IdScriptableObject.

findPrototypeId

protected int findPrototypeId(String name)

get

public Object get(String name, Scriptable start)

getAttributes

public int getAttributes(String name)

getInstanceIdName

protected String getInstanceIdName(int id)

Map id back to property name it defines.

getInstanceIdValue

protected Object getInstanceIdValue(int id)

Get id value. If id value is constant, descendant can call cacheIdValue to store value in the permanent cache. Default implementation creates IdFunctionObject instance for given id and cache its value

getMaxInstanceId

protected int getMaxInstanceId()

Get maximum id findInstanceIdInfo can generate.

has

public boolean has(String name, Scriptable start)

hasPrototypeMap

public final boolean hasPrototypeMap()

incompatibleCallError

protected static EcmaError incompatibleCallError(IdFunctionObject f)

Utility method to construct type error to indicate incompatible call when converting script thisObj to a particular type is not possible. Possible usage would be to have a private function like realThis:

  private static NativeSomething realThis(Scriptable thisObj,
                                          IdFunctionObject f)
  {
      if (!(thisObj instanceof NativeSomething))
          throw incompatibleCallError(f);
      return (NativeSomething)thisObj;
 }

Note that although such function can be implemented universally via java.lang.Class.isInstance(), it would be much more slower.

Parameters: readOnly specify if the function f does not change state of object.

Returns: Scriptable object suitable for a check by the instanceof operator.

Throws: RuntimeException if no more instanceof target can be found