* Was intermittent on * system/host/tinman/windows.xht, both IE and Firefox. * Different failure modes, including crash of browser. * Probable concurrency bug in the underlying JSObject bridge. *
* Moved to Java 1.6, and added memory to that * Windows box. * Bug has not recurred. *
* * @see LiveConnect documentation * @see JSObject in the LiveConnect API * @see JSObject as implmented for the Java Plug-In */ public @ThreadSafe class Rhinohide { // Thread-safety really depends on the JSObject implementation. // JavaScript itself is naturally single threaded. // The doubt therefore falls on the Java side. But neither LiveConnect docs, // nor Plug-In's JSObject docs say anything about thread-safety/concurrency. /** Constructs a Rhinohide. * * @param window global object * @param jsObject bridge to underlying JavaScript object, per {@linkplain #jsObject() jsObject}() */ public Rhinohide( RhiWindow window, JSObject jsObject ) { if( window == null || jsObject == null ) throw new NullPointerException(); this.window = window; this.jsObject = jsObject; } protected Rhinohide( JSObject jsObject ) // for RhiWindow { if( jsObject == null ) throw new NullPointerException(); this.jsObject = jsObject; } // ------------------------------------------------------------------------------------ /** @return the same object * @throws StunnedRhinoException if the object is null * * @see #callV(String,Object...) * @see #evalV(String) * @see #getMemberV(String) */ public static Object checkV( Object object ) { if( object == null ) throw new StunnedRhinoException(); return object; } /** Bridge to underlying JavaScript object. It is never null. ** Ordinary clients ought not to call methods * of the underlying JavaScript object directly. * Instead, they ought to call the equivalent methods of this Rhinohide wrapper. *
*/ public final JSObject jsObject() { return jsObject; } private final JSObject jsObject; /** @return rhinohide.jsObject(); or null if rhinohide is null */ public static JSObject toJSObject( Rhinohide rhinohide ) { final JSObject jsObject; if( rhinohide == null ) return null; else jsObject = rhinohide.jsObject(); return jsObject; } /** The global object. */ public RhiWindow window() { return window; } protected RhiWindow window; // final after subclass init // - J - S - O b j e c t -------------------------------------------------------------- /** Calls a method on the underlying JavaScript object, via the bridge. * Equivalent to {@linkplain #jsObject() jsObject}().call(). * Equivalent to JavaScript: *
* object.methodName( arguments );
*
*/
public Object call( String methodName, Object... arguments )
{
try
{
return jsObject.call( methodName, arguments );
}
catch( JSException xJS ) { throw convertedException( xJS ); }
}
/** Same as {@linkplain #checkV(Object) checkV}({@linkplain #call(String,Object...) call}(methodName, arguments)).
*
* @throws StunnedRhinoException if the result is null
*/
public Object callV( String methodName, Object... arguments )
{
return checkV( call( methodName, arguments ));
}
/** Evaluates an expression in the context of the underlying JavaScript object, via the bridge.
* Equivalent to {@linkplain #jsObject() jsObject}().eval().
* Similar to JavaScript:
*
* object.eval( expression );
*
* * Repeatable on * system/host/tinman/windows.xht#firefox. * JSObject.eval() and call() fail, after a time. * Failure may occur some time into applet initialization; * or after interruption by an alert box. * It consistently occurs on that host for all post-init access, * e.g. via RMI worker threads, or the AWT event dispatch thread. *
** On failure, JSObject.eval() calls no longer have effect, and always return null. * And JSObject.call(method) always returns null for custom methods; * those defined in page content scripts, * as well as those defined in previous calls to eval(). *
*/ public Object eval( String expression ) { try { return jsObject.eval( expression ); } catch( JSException xJS ) { throw convertedException( xJS ); } } /** Same as {@linkplain #checkV(Object) checkV}({@linkplain #eval(String) eval}(expression)). * * @throws StunnedRhinoException if the result is null */ public Object evalV( String expression ) { return checkV( eval( expression )); } /** Returns a property of the underlying JavaScript object, via the bridge. * Equivalent to {@linkplain #jsObject() jsObject}().getMember(). * Similar to JavaScript: *
* object.name;
*
*/
public Object getMember( String name )
{
try
{
return jsObject.getMember( name );
}
catch( JSException xJS ) { throw convertedException( xJS ); }
}
/** Same as {@linkplain #checkV(Object) checkV}({@linkplain #getMember(String) getMember}(name)).
*
* @throws StunnedRhinoException if the result is null
*/
public Object getMemberV( String name ) { return checkV( getMember( name )); }
/** Sets a property of the underlying JavaScript object, via the bridge.
* Equivalent to {@linkplain #jsObject() jsObject}().setMember().
* Equivalent to JavaScript:
*
* object.name = value;
*
*/
public void setMember( String name, Object value )
{
try
{
jsObject.setMember( name, value );
}
catch( JSException xJS ) { throw convertedException( xJS ); }
}
// /** Removes a property of the underlying JavaScript object, via the bridge.
// * Equivalent to {@linkplain #jsObject() jsObject}().removeMember().
// * Equivalent (presumeably) to JavaScript:
// * // * delete object.name; // *// */ // public void removeMember( String name ) { jsObject.removeMember( name ); } // // // // // public Object getSlot( int index ) { return jsObject.getSlot( index ); } // // // public void setSlot( int index, Object value ) { jsObject.setSlot( index, value ); } // // ///// but these methods disavowed by Sun, per warning in: http://java.sun.com/j2se/1.5.0/docs/guide/plugin/developer_guide/java_js.html // - O b j e c t ---------------------------------------------------------------------- /** Returns true iff o is a Rhinohide, * and has an 'equal' {@linkplain #jsObject() JSObject bridge}. */ public @Override boolean equals( Object o ) { if( !(o instanceof Rhinohide )) return false; Rhinohide that = (Rhinohide)o; return this.jsObject.equals( that.jsObject ); } /** Defers to the bridge, returning {@linkplain #jsObject() jsObject}.hashCode(). */ public @Override int hashCode() { return jsObject.hashCode(); } /** Defers to the bridge, returning {@linkplain #jsObject() jsObject}.toString(). */ public @Override String toString() { return jsObject.toString(); } // disavowed as for removeMember(), but how could it fail? //// P r i v a t e /////////////////////////////////////////////////////////////////////// /** @return same exception, or an unwrapped equivalent */ private static RuntimeException convertedException( final JSException xJS ) { // try // { // final Object xWrappedObject = xJS.getWrappedException(); //System.out.println( "R xWrappedObject=" + xWrappedObject ); // if( xWrappedObject instanceof JSObject ) // { // final JSObject xWrappedJSO = (JSObject)xWrappedObject; // Object codeObject = xWrappedJSO.getMember( "code" ); // FIX, this is an imprecise check. Do an eval instead, and use JS typeof and instanceof operators to ensure that it really is a DOMException. // if( codeObject instanceof Number ) // { // LoggerX.i(Rhinohide.class).info("untested code is running"); // Untested because neither Firefox nor IE behave as expected. See textbender.a.b.rhinohideDemo._.Rhinohide_1.domException(). But if that's ever fixed, then remember to add a note to javadocs of call, eval, etc. above, stating that DOMException etc. are auto-unwrapped. // return new DOMException // ( ((Number)codeObject).shortValue(), xWrappedJSO.toString() ); // } // } // } // catch( ThreadDeath d ) { throw d; } // always let it die // catch( Error e ) { throw e; } // catch( Throwable t ) // normal code does not catch Throwable, but this is not normal code // { // try // { // LoggerX.i(Rhinohide.class).log( LoggerX.WARNING, /*message*/"", t ); // } // catch( ThreadDeath d2 ) { throw d2; } // always let it die // catch( Error e2 ) { throw e2; } // catch( Throwable t2 ) {} // } ///// no point, per 'Untested' above return xJS; } }