<Swing Dev> [10][JDK-8178430] JMenu in GridBagLayout flickers when label text shows "..." and is updated

Krishna Addepalli krishna.addepalli at oracle.com
Wed Nov 22 17:55:11 UTC 2017


Hi Semyon,

Thank you for reading through it. Please modify it as you see fit.

Krishna

-----Original Message-----
From: Semyon Sadetsky 
Sent: Wednesday, November 22, 2017 10:36 PM
To: Krishna Addepalli <krishna.addepalli at oracle.com>; swing-dev at openjdk.java.net
Subject: Re: <Swing Dev> [10][JDK-8178430] JMenu in GridBagLayout flickers when label text shows "..." and is updated

Hi Krishna,

I read the bug description you've created. It is not exactly what I meant.

It makes not a lot of sense to modify all existing components to avoid the flicker in the bug scenario.  It also would not possible because developers may have their own components, unless you are going to change specification to request the minimumSize to be always equal to the preferredSize.

--Semyon


On 11/19/2017 11:13 PM, Krishna Addepalli wrote:
> Hi Semyon,
> Created a bug : https://bugs.openjdk.java.net/browse/JDK-8191552
>
> Please add any more information that you feel is necessary.
>
> Thanks,
> Krishna
>
> -----Original Message-----
> From: Semyon Sadetsky
> Sent: Friday, November 17, 2017 9:39 PM
> To: Krishna Addepalli <krishna.addepalli at oracle.com>; Sergey Bylokhov 
> <sergey.bylokhov at oracle.com>; swing-dev at openjdk.java.net
> Subject: Re: <Swing Dev> [10][JDK-8178430] JMenu in GridBagLayout 
> flickers when label text shows "..." and is updated
>
> Can you create this bug send link to it to this thread?
>
> --Semyon
>
> On 11/17/17 1:45 AM, Krishna Addepalli wrote:
>> Hi Semyon,
>>
>> Yes, you are right about all the components exhibiting the same behavior. But, that would require more extensive analysis, and I feel should be addressed in its own bug - which can be linked to this.
>>
>> Thanks,
>> Krishna
>>
>> -----Original Message-----
>> From: Semyon Sadetsky
>> Sent: Thursday, November 16, 2017 10:42 PM
>> To: Krishna Addepalli <krishna.addepalli at oracle.com>; Sergey Bylokhov 
>> <sergey.bylokhov at oracle.com>; swing-dev at openjdk.java.net
>> Subject: Re: <Swing Dev> [10][JDK-8178430] JMenu in GridBagLayout 
>> flickers when label text shows "..." and is updated
>>
>> Hi Krishna,
>>
>> On 11/16/2017 03:38 AM, Krishna Addepalli wrote:
>>> Hi Semyon,
>>>
>>> 1. I have tried in my Ubuntu 17.04 VM and was able to see the test case fail before fix, and passing after the fix.
>>> 2. Regarding the minimum size, it is not related to any layout - the test fails across any Layout - I have verified this in debugging process. The only point is, whenever the label text / any other component rendering width is larger the window size, it requests all the components to report the minimum size. In the case of JMenu (which is a top level menu), it is better to return a preferred size rather than minimum size (which by the way is 1x1), so that the item is rendered correctly. Returning null from the fixed function will cause the layout class to return the default minimum value as per the layout class used. So, I didn’t see any reason to come up with arbitrary minimum values.
>> I don't see this bug as a Menu issue because any other component that has minimumSize != prefferredSize placed instead of the menu causes the same unexpected layout behavior.
>> The heights of all components should be preserved with the layout width change but the the upper component jumps to its minimum size after the width of the window reaches some value.
>>
>> --Semyon
>>> Thanks,
>>> Krishna
>>>
>>> -----Original Message-----
>>> From: Sergey Bylokhov
>>> Sent: Thursday, November 16, 2017 6:51 AM
>>> To: Semyon Sadetsky <semyon.sadetsky at oracle.com>; Krishna Addepalli 
>>> <krishna.addepalli at oracle.com>; swing-dev at openjdk.java.net
>>> Subject: Re: <Swing Dev> [10][JDK-8178430] JMenu in GridBagLayout 
>>> flickers when label text shows "..." and is updated
>>>
>>> On 15/11/2017 10:53, Semyon Sadetsky wrote:
>>>>> There are no such restrictions that getMinimumSize() must return 
>>>>> exact value of getPrefferredSize(). It should return some 
>>>>> reasonable value instead of null, which can be considered as 1x1 
>>>>> by some layout managers. In most cases the PrefferredSize is used for this purpose.
>>>> This doesn't correspond to what I see if add
>>>>
>>>> menu.setMinimumSize(new Dimension(2,2));
>>>>
>>>> After that the problem described in the bug comes back.
>>> This will not be a bug, if the application thinks that 2x2 or 200x200 are reasonable values for maximum/minimum/preferred sizes and will set it, then these values will be used.
>>>
>>>>>> --Semyon
>>>>>>
>>>>>>
>>>>>> On 11/15/2017 08:24 AM, Sergey Bylokhov wrote:
>>>>>>> Looks fine.
>>>>>>>
>>>>>>> On 15/11/2017 07:26, Krishna Addepalli wrote:
>>>>>>>> Hi Sergey,
>>>>>>>>
>>>>>>>> Per our conversation, I have added the volatile keyword to the 
>>>>>>>> Boolean flag. Here is the updated webrev:
>>>>>>>> http://cr.openjdk.java.net/~kaddepalli/8178430/webrev04/
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Krishna
>>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Krishna Addepalli
>>>>>>>> Sent: Wednesday, November 15, 2017 6:07 PM
>>>>>>>> To: Sergey Bylokhov <sergey.bylokhov at oracle.com>; 
>>>>>>>> swing-dev at openjdk.java.net
>>>>>>>> Subject: RE: <Swing Dev> [10][JDK-8178430] JMenu in 
>>>>>>>> GridBagLayout flickers when label text shows "..." and is 
>>>>>>>> updated
>>>>>>>>
>>>>>>>> Hi Sergey,
>>>>>>>>
>>>>>>>> I have modified the code as per your requests, and here is the 
>>>>>>>> updated webrev:
>>>>>>>> http://cr.openjdk.java.net/~kaddepalli/8178430/webrev03/
>>>>>>>>
>>>>>>>> However, I have a couple questions regarding the fix:
>>>>>>>> 1. Why was it considered good to fix it in BasicMenuUI rather 
>>>>>>>> than in BasicMenuUIItem?
>>>>>>>> 2. While using Robot.waitForIdle(), I came across the function 
>>>>>>>> "Suntoolkit.flushPendingEvents" function. But this is a private 
>>>>>>>> function and applications cannot use this. Is it expected that 
>>>>>>>> the applications should import the robot module to flush the 
>>>>>>>> events, considering that mostly it is used for testing purposes?
>>>>>>>> If this is the case, then "Suntoolkit.flushPendingEvents"
>>>>>>>> becomes a valuable tool, given that Swing rendering happens in 
>>>>>>>> an EDT that is separate from MainThread.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Krishna
>>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Sergey Bylokhov
>>>>>>>> Sent: Wednesday, November 15, 2017 2:23 AM
>>>>>>>> To: Krishna Addepalli <krishna.addepalli at oracle.com>; 
>>>>>>>> swing-dev at openjdk.java.net
>>>>>>>> Subject: Re: <Swing Dev> [10][JDK-8178430] JMenu in 
>>>>>>>> GridBagLayout flickers when label text shows "..." and is 
>>>>>>>> updated
>>>>>>>>
>>>>>>>> Hi, Krishna.
>>>>>>>> Small comments: I think that this code
>>>>>>>> "(JMenu)menuItem).isTopLevelMenu() == true"
>>>>>>>> can be simplified to
>>>>>>>> (JMenu)menuItem).isTopLevelMenu().
>>>>>>>>
>>>>>>>> In the test you create and dispose JFrame and other components 
>>>>>>>> outside of EDT thread. I suggest to use invokeAndWait() which 
>>>>>>>> will work synchronously. Instead of sleep() you van use 
>>>>>>>> Robot.waitForIdle();
>>>>>>>>
>>>>>>>>
>>>>>>>> On 12/11/2017 22:45, Krishna Addepalli wrote:
>>>>>>>>> Hi Sergey,
>>>>>>>>>
>>>>>>>>> Gentle reminder! Could you review the fix?
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Krishna
>>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: Krishna Addepalli
>>>>>>>>> Sent: Wednesday, November 8, 2017 8:22 PM
>>>>>>>>> To: Sergey Bylokhov <sergey.bylokhov at oracle.com>; 
>>>>>>>>> swing-dev at openjdk.java.net
>>>>>>>>> Subject: RE: <Swing Dev> [10][JDK-8178430] JMenu in 
>>>>>>>>> GridBagLayout flickers when label text shows "..." and is 
>>>>>>>>> updated
>>>>>>>>>
>>>>>>>>> Hi Sergey,
>>>>>>>>>
>>>>>>>>> Are the changes fine now?
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Krishna
>>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: Krishna Addepalli
>>>>>>>>> Sent: Monday, November 6, 2017 9:02 PM
>>>>>>>>> To: Sergey Bylokhov <sergey.bylokhov at oracle.com>; 
>>>>>>>>> swing-dev at openjdk.java.net
>>>>>>>>> Subject: RE: <Swing Dev> [10][JDK-8178430] JMenu in 
>>>>>>>>> GridBagLayout flickers when label text shows "..." and is 
>>>>>>>>> updated
>>>>>>>>>
>>>>>>>>> Hi Sergey,
>>>>>>>>>
>>>>>>>>> As per your recommendation I have done the following changes:
>>>>>>>>> 1. Moved the fix to BasicMenuUI.
>>>>>>>>> 2. Corrected the test to:
>>>>>>>>>        a. Access the UI elements only in the EDT.
>>>>>>>>>        b. Made sure that the main thread doesn't exit till the 
>>>>>>>>> test is complete.
>>>>>>>>>
>>>>>>>>> Here is the updated webrev:
>>>>>>>>> http://cr.openjdk.java.net/~kaddepalli/8178430/webrev02/
>>>>>>>>>
>>>>>>>>> However, I was wondering, why it is good to fix in BasicMenuUI?
>>>>>>>>> Also, while writing the testcase, I couldnot find any 
>>>>>>>>> functionality like "flush" on the event queue, which will 
>>>>>>>>> execute all the pending events. Is it by design?
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Krishna
>>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: Sergey Bylokhov
>>>>>>>>> Sent: Friday, November 3, 2017 11:24 PM
>>>>>>>>> To: Krishna Addepalli <krishna.addepalli at oracle.com>; 
>>>>>>>>> swing-dev at openjdk.java.net
>>>>>>>>> Subject: Re: <Swing Dev> [10][JDK-8178430] JMenu in 
>>>>>>>>> GridBagLayout flickets when label text shows "..." and is 
>>>>>>>>> updated
>>>>>>>>>
>>>>>>>>> Hi, Krishna.
>>>>>>>>> A few notes:
>>>>>>>>>        - Looks like the bug can be reproduced in JMenu only?
>>>>>>>>> Then it will be good to fix it in BasicMenuUI, moreover it is 
>>>>>>>>> already implemented a
>>>>>>>>> getMaximumSize() in a similar way as in your fix.
>>>>>>>>>        - In the test some of the Swing components are accessed 
>>>>>>>>> on non-EDT thread. Also note that when you start the Thread 
>>>>>>>>> you will exit
>>>>>>>>> invokeAndWait() and it is possible that the test will end 
>>>>>>>>> before the Thread complete(jtreg will kill the test when the 
>>>>>>>>> main thread is
>>>>>>>>> completed)
>>>>>>>>>
>>>>>>>>> On 31/10/2017 05:00, Krishna Addepalli wrote:
>>>>>>>>>> Hi Sergey,
>>>>>>>>>>
>>>>>>>>>> Thanks for pointing that out. Fixed the test case and created 
>>>>>>>>>> a new webrev here:
>>>>>>>>>> http://cr.openjdk.java.net/~kaddepalli/8178430/webrev01/
>>>>>>>>>>
>>>>>>>>>> Now, the testcase throws an exception and also after a few 
>>>>>>>>>> trials, closes on its own.
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Krishna
>>>>>>>>>>
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: Sergey Bylokhov
>>>>>>>>>> Sent: Tuesday, October 31, 2017 1:13 AM
>>>>>>>>>> To: Krishna Addepalli <krishna.addepalli at oracle.com>; 
>>>>>>>>>> swing-dev at openjdk.java.net
>>>>>>>>>> Subject: Re: <Swing Dev> [10][JDK-8178430] JMenu in 
>>>>>>>>>> GridBagLayout flickets when label text shows "..." and is 
>>>>>>>>>> updated
>>>>>>>>>>
>>>>>>>>>> Hi, Krishna.
>>>>>>>>>> Can you please clarify in what situation the test will stop 
>>>>>>>>>> working(it does not have any assertions)?
>>>>>>>>>>
>>>>>>>>>> On 27/10/2017 02:45, Krishna Addepalli wrote:
>>>>>>>>>>> Hi All,
>>>>>>>>>>>
>>>>>>>>>>> Please review the fix for bug:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Bug: JDK-8178430:
>>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8178430
>>>>>>>>>>>
>>>>>>>>>>> Webrev:
>>>>>>>>>>> http://cr.openjdk.java.net/~kaddepalli/8178430/webrev00/
>>>>>>>>>>>
>>>>>>>>>>> Summary:
>>>>>>>>>>>
>>>>>>>>>>> The issue is when the label text width is more than the
>>>>>>>>>>> container(JPanel) width, the container tries to render with 
>>>>>>>>>>> minimum width for all the components. In such case, the 
>>>>>>>>>>> JMenuItem, which is added to the JMenuBar also returns its 
>>>>>>>>>>> height dimension as 1 (the default minimum). The test case 
>>>>>>>>>>> alternates between the short text and long text on the 
>>>>>>>>>>> label, and it gives a flickering effect of the Menu.
>>>>>>>>>>> The fix is to return preferred size from JMenuItem, if its 
>>>>>>>>>>> parent is a JMenuBar, since JMenuBar is added to the top 
>>>>>>>>>>> level window.
>>>>>>>>>>>
>>>>>>>>>>> Thanks,
>>>>>>>>>>>
>>>>>>>>>>> Krishna
>>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Best regards, Sergey.
>>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Best regards, Sergey.
>>>>>>>>>
>>>>>>>> --
>>>>>>>> Best regards, Sergey.
>>>>>>>>
>>> --
>>> Best regards, Sergey.




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