<AWT Dev> [9] Review request for 8044614: [macosx] Focus issue with 2 applets in firefox

dmitry markov dmitry.markov at oracle.com
Fri Jul 18 11:52:27 UTC 2014

Hi Alexandr,

Please find answer below.

On 17/07/2014 14:18, Alexander Scherbatiy wrote:
>   The pluginFocusedWindow is only updated after switching from one 
> browser to another (after WindowFocusEvent event).
>   Should it also be updated after switching from one applet to another 
> in the same browser (after FocusEvent)?
It is not necessary, since the pluginFocusedWindow stores information 
about the latest focused applet in the browser's window. This 
information is only used for focus restoring when the window becomes 
active again. So I think that is enough to update pluginFocusedWindow 
only in handleWindowFocusEvent() when the browser's window becomes inactive.

>   What happens if the focused applet is closed? Does the 
> pluginFocusedWindow  correctly updated in this case?
>   Does the closed applet receives handleFocusEvent(false) event?
The closing of an applet means that we closed the browser's window 
contained the applet or moved to another web-page. In this case we are 
not interesting in pluginFocusedWindow or focus events anymore, since 
all applets in the window are destroyed. If we go back to the applet's 
page, all applets will be started from scratch.
>    Thanks,
>   Alexandr.
> On 7/16/2014 4:08 PM, dmitry markov wrote:
>> Hi Alexandr,
>> I am sorry for the delay.
>> When a browser's window becomes active/inactive, the browser 
>> generates WindowFocusEvent and sends it to the applets via Java 
>> Plugin. So the order of the events is defined by the browser. I 
>> tested several browsers - all of them sends 
>> WindowFocusEvent(parentWindow=false) to the active window and then 
>> WindowFocusEvent(parentWindow=true) to inactive window during 
>> switching between two browser's windows. It looks like this is common 
>> practice for such operation. However, I did not find any docs which 
>> can confirm this behavior.
>> Please find new version of the fix here - 
>> http://cr.openjdk.java.net/~dmarkov/8044614/jdk9/webrev.02/
>> Changes:
>> - Made small refactoring: focusedWindow -> globalFocusedWindow, 
>> previousFocusedWindow -> pluginFocusedWindow, etc.
>> - Added manual test
>> Thanks,
>> Dmitry
>> On 04/07/2014 14:26, Alexander Scherbatiy wrote:
>>> On 7/3/2014 2:25 PM, Alexander Scherbatiy wrote:
>>>> On 7/3/2014 1:15 PM, dmitry markov wrote:
>>>>> Hi Alexandr,
>>>>> Thank you for review.
>>>>> For the use case you described - when we move back to the first 
>>>>> browser window with 3 applets, the first applet (not the second 
>>>>> one) will receive the focus. This behavior is incorrect, since the 
>>>>> second applet should receive the focus.
>>>>> I have updated the fix, please find new version here: 
>>>>> http://cr.openjdk.java.net/~dmarkov/8044614/jdk9/webrev.01/
>>>>> Now we store the information about focused applet when browser 
>>>>> window is deactivated and restore the focus to the previously 
>>>>> focused applet when browser window becomes active again
>>>>     The case can be more complicated with some browsers where each 
>>>> of them has several applets.
>>>>     It seems there should be a map between a browser and it's 
>>>> focused applet.
>>>    I see that your fix solves these cases.
>>>    One more problem can be with the WindowsFocusEvents order.
>>>    Is it guarantee that order of events WindowsFocusEvent 
>>> (parentwindow=false) to one browser and WindowsFocusEvent 
>>> (parentWindow=true)
>>>    for other browser can't be changed?
>>>   I would suggest to  do a small refactoring.
>>>   Something like focusedWindow to globalFocusedWindow, 
>>> previousFocusedWindow to pluginFocusedWindow, add method like 
>>> isPluginFocused(...)
>>>   and use conditional operator '?' for globalFocusedWindow setting.
>>>   Thanks,
>>>   Alexandr.
>>>>     Is it possible to add a manual test for the fix?
>>>>    Thanks,
>>>>    Alexandr.
>>>>> Thanks,
>>>>> Dmitry
>>>>> On 02/07/2014 16:36, Alexander Scherbatiy wrote:
>>>>>>  Let's assume one browser has 3 applets where the second applet 
>>>>>> has focus.
>>>>>>  I click on the second browser with an applet (the applet 
>>>>>> receives the focus) and then click on the first browser back.
>>>>>>  Should the second applet in the first browser receive the focus?
>>>>>>  Thanks,
>>>>>>  Alexandr.
>>>>>> On 7/2/2014 2:45 PM, dmitry markov wrote:
>>>>>>> Hello,
>>>>>>> Could you review the fix for jdk9, please?
>>>>>>>     bug: https://bugs.openjdk.java.net/browse/JDK-8044614
>>>>>>>     webrev: 
>>>>>>> http://cr.openjdk.java.net/~dmarkov/8044614/jdk9/webrev.00/
>>>>>>> Problem description: on Mac OSX when switching between several 
>>>>>>> applets running in separate browser's windows, the applet in 
>>>>>>> active window does not receive focus.
>>>>>>> Fix: the method CEmbeddedFrame.handleWindowFocusEvent() should 
>>>>>>> be modified. It has to detect the switching between browser's 
>>>>>>> windows and update focusedWindow field accordingly.
>>>>>>> Thanks,
>>>>>>> Dmitry

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