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

Semyon Sadetsky semyon.sadetsky at oracle.com
Thu Nov 16 17:17:27 UTC 2017 

Hi Sergey,

On 11/15/2017 05:21 PM, Sergey Bylokhov wrote:
> 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.
But according to the layout constraints there enough space for preferred 
size. Why it shrinks to the minimum size?
>
>>>
>>>>
>>>> --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.
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>

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