Re: Tweaking default java.awt.Robot settings

[David Herron <David.Herron@Sun.COM>]

[resending because the mailing list thingy told me I had to use only 
plain text messages...]

Hmmm.. here's the meat of the test

  public void runTest(int code, char chr)
  {
    KeyEvent e = new KeyEvent(f, KeyEvent.KEY_PRESSED, 0, 0, code, chr, 
KeyEvent.KEY_LOCATION_STANDARD);
    f.dispatchEvent(e);
   
   
    f.setSize(200,200);
    f.show();
    r.mouseMove(60, 60);

    r.keyPress(code);
    r.keyRelease(code);
    h.check(key, (int) chr);
  }

I don't understand this.  If you're going to create a Java event why use 
Robot, or vice versa...?

It appears h.check is in gnu.testlet.TestHarness and that it simply does 
an immediate check with no waiting.  The dispatchEvent call is going to 
cause the listener to fire regardless of what's happening using Robot.

This looks like an incorrect test, and what I'd recommend is:-

a) ditch the two lines saying KeyEvent / dispatchEvent ... they are 
completely subverting the intent of the test

b) insert some code so the runTest method waits for the listener to be 
triggered.  Such as a wait and notify type of semaphor.

c) I don't know how the test guarantees runTest executes on the event 
dispatch thread.  Is the EDT as important to classpath as it is to Sun's 
Swing?

- David Herron


Steve McKay☄ wrote:
> So would you recommend I ignore the test, delete it, add a comment, ...?
>
> --steve
>
> On 9/24/07, David Herron <David.Herron@sun.com> wrote:
>   
>> Steve McKay☄ wrote:
>>     
>>> Hi All,
>>>
>>> I've noticed that at least some of the tests using java.awt.Robot are
>>> non-deterministic due to lags is the underlying window system. The
>>> java.awt.Component.keyPressTest, for example, fails some of the time
>>> (on linux, windows, linux+wine, ...). It looks like enabling
>>> autoWaitForIdle (waits for the awt EventQueue to be empty before
>>> adding new events to the queue), and setting autoDelay (pauses for an
>>> arbitrary period of time) to some magic number of millis well above
>>> zero (I use 100) significantly reduces failures. Would anyone object
>>> to configuring the Robot with settings like this by default? If no,
>>> should the config mechanism be updated to allow tweaking these
>>> settings?
>>>
>>>
>>>       
>> I don't know what the classpath implementation of Robot looks like, but
>> I do know what Sun's Linux/Unix implementation looks like (having
>> written the original version).
>>
>> Generally Robot has to request the OS or X11 to synthesize the event.
>> On Windows there's a direct API call, while on Unix/Linux there is a
>> child process which ends up calling XTEST extension methods.  In both
>> cases it means there is a nondeterministic delay due to the current
>> process scheduling characteristics of the given system.  In other words
>> it depends on an external entity, who Robot cannot coerce into
>> performing the request within a bounded set of time.
>>
>> I think that means depending on Robot doing it's thing within a given
>> period of time is an invalid test.
>>
>> Robot does not add events to EventQueue but it requests the OS to
>> synthesize an OS-level event.
>>
>> - David Herron
>>
>>
>>     
>
>
>