<AWT Dev> [9] Review Request: 8032187 [macosx] The fix for MACOSX_PORT-424 should be reworked

Anthony Petrov anthony.petrov at oracle.com
Wed Feb 5 13:26:44 PST 2014

[ adding back the awt-dev@ mailing list ]

Hi Sergey,

This all boils down to whether we want to deliver events related to our 
internal components to the user code or not. The fact that the 
MACOSX_PORT-424 was filed by an external developer suggests that this 
behavior may be unwanted. Also, common sense suggests that such events 
are useless for external consumers, and hence sending them just doesn't 
make any sense.

Could you please clarify again exactly what the problem is with the 
original fix for this issue? I do not quite like it myself (e.g. when I 
see "enableEvents(0xFFFFFFFF)" - this just looks fishy, and the 
setting/unsetting the listener looks like a hack, I agree), but I don't 
see any serious consequences that that fix could cause. Could you please 
elaborate on that?

If we see that there's some serious flows with the original solution, 
let's get rid of it. However, we'll need to file a new bug to deal with 
all the unwanted events, and implement it some other way then.

best regards,

On 2/5/2014 5:54 PM, Sergey Bylokhov wrote:
> On 05.02.2014 16:34, Anthony Petrov wrote:
>> I agree that the listener should receive all the events for compound
>> controls. They make sense because all the parts of compound controls
>> are accessible via our public API, so the app could just assign
>> listeners to specific sub-components if it needed to.
> Not necessary, for example for our text component in xawt. The user
> should filter out unnecessary events anyway, because they can belongs to
> a different application or some internal components(like SharedOwnerFrame).
>> However, this isn't true for our internal LWAWT components hierarchy.
>> This hierarchy is hidden from users (they can't access the underlying
>> Swing components via public API, and moreover, they shouldn't be able
>> to do so even if they want to). It is an implementation detail of the
>> LWAWT toolkit. And therefore, I don't see a reason to post events
>> related to this hidden hierarchy to a listener that can be installed
>> using the public API.
>> Can we find another way to filter the events out?
> Only if we will add additional checks to the places, where
> Toolkit.enabledOnToolkit is used.
>> --
>> best regards,
>> Anthony
>> On 2/5/2014 1:26 AM, Sergey Bylokhov wrote:
>>> On 04.02.2014 23:06, Anthony Petrov wrote:
>>>> Hi Sergey,
>>>> From the bug report:
>>>>> After discussion, it was decided to accept MACOSX_PORT-424 as not a
>>>>> defect
>>>> Are you saying that user code will start receiving hierarchy events
>>>> related to the internal hierarchy of our LWAWT peers? Why would anyone
>>>> want to process these events and why would we want to post them to
>>>> user code? Is there any way to filter them out?
>>> Documentation of Toolkit.addAWTEventListener() states:
>>>       * Adds an AWTEventListener to receive all AWTEvents dispatched
>>>       * system-wide that conform to the given <code>eventMask</code>.
>>> ....
>>>       * Note:  event listener use is not recommended for normal
>>>       * application use, but are intended solely to support special
>>>       * purpose facilities including support for accessibility,
>>>       * event record/playback, and diagnostic tracing.
>>> And components intentionally cannot filter them out. All our non trivial
>>> compound components posts lots of such events.
>>>> While I agree that using reflection is a bad idea, but is there any
>>>> other real problem with the original fix for MACOSX_PORT-424? I.e.
>>>> does that fix break anything? If not, can we simply replace usages of
>>>> reflection with AWTAccessor-like mechanism?
>>> The problem not in reflection but in replacing global list of listeners.
>>>> --
>>>> best regards,
>>>> Anthony
>>>> On 2/4/2014 3:52 PM, Sergey Bylokhov wrote:
>>>>> Hello.
>>>>> Please review the fix for jdk 9.
>>>>>   - Initial fix for MACOSX_PORT-424 was reverted back.
>>>>>   - delegate.addNotify(),because it was called from
>>>>> delegateContainer.addNotify();
>>>>>   - Testcase was updated to filter out events not from the Frame:
>>>>>    84             if (e.getSource() instanceof Frame) {
>>>>>    85                 counter++;
>>>>>    86                 notify();
>>>>>    87             }
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8032187
>>>>> Webrev can be found at:
>>>>> http://cr.openjdk.java.net/~serb/8032187/webrev.00

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