RFR: 8283493: Create an automated regression test for RFE 4231298 [v2]

[Sergey Bylokhov]

On Tue, 22 Mar 2022 15:41:19 GMT, Manukumar V S <mvs at openjdk.org> wrote:

>> Create a regression test for [JDK-4231298](https://bugs.openjdk.java.net/browse/JDK-4231298)
>> Issue:
>> When a JComboBox first drops down, the renderer is called for
>> every element in the list, even those elements that will not
>> actually be drawn on the screen.
>> 
>> Fix:
>> Introduced new API to JComboBox: get/setPrototypeDisplayValue(). This API allows the UI to calculate the display size using this prototype value rather than iterated over a large list of items. See RFE 4289100 which also addresses this problem.
>> 
>> Testing:
>> 1. Tested in Mach5, 10 times per platform(macos,linux and windows) and got all pass.
>> 
>> 2. Tested in JDK 1.3.0 and JDK 1.4.0 and the results are given below.
>> Java 1.3.0 -> Test Failed.
>> $ jdk1.3/bin/java JComboBoxPrototypeTest
>> getListCellRendererComponent index = -1, isSelected = false, cellHasFocus = false
>> Value of the Counter is 1
>> ....
>> getListCellRendererComponent index = -1, isSelected = false, cellHasFocus = false
>> Value of the Counter is 101
>> Test Failed
>> java.lang.RuntimeException: Custom Renderer got called 101 times, expected is maximum 6 times
>>         at JComboBoxPrototypeTestOld.main(JComboBoxPrototypeTest.java:107)
>> 
>> Java 1.4.0(added a call to setPrototypeDisplayValue()) -> Test Passed.
>> $ j2sdk1.4.0/bin/java JComboBoxPrototypeTest
>> getListCellRendererComponent index = -1, isSelected = false, cellHasFocus = false
>> Value of the Counter is 1
>> getListCellRendererComponent index = -1, isSelected = false, cellHasFocus = false
>> Value of the Counter is 2
>> getListCellRendererComponent index = -1, isSelected = false, cellHasFocus = false
>> Value of the Counter is 3
>> Test Passed
>
> Manukumar V S has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Removed unwanted comment text

Marked as reviewed by serb (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/7905