<Swing Dev> [10] RFR JDK-8187957:Tab Size does not work correctly in JTextArea

[Sergey Bylokhov]

On 09/11/2017 01:56, Prasanta Sadhukhan wrote:
> So, I guess, as Semyon suggested, making the "result of the sentence 
> should be  truncated to int, not its members" should be the way to go.

Thank you for clarification, then this solution looks fine.

> 
> Lastly, could you please suggest as to how to automate this test?
> 
> Regards
> Prasanta
> On 11/9/2017 8:36 AM, semyon.sadetsky at oracle.com wrote:
>> On 11/8/17 12:24 PM, Sergey Bylokhov wrote:
>>
>>> On 08/11/2017 11:38, Semyon Sadetsky wrote:
>>>>> Yes "(int)+1" is also can be used for positive values, but the 
>>>>> "ceil()" is better since this purpose of this method, and in 
>>>>> general it works for negative values as well.
>>>> There may not be negative values here, so Math.ceil() is redundant.
>>>
>>> I do not see a reason why standard function can be redundant, and why 
>>> manual implementation is better. Since even in the first version of 
>>> the fix there is an issues in manual implementation.
>> I don't see it standard, just redundant in the case. What did you mean 
>> under "manual implementation"?
>>
>> --Semyon
>>>
>>>>
>>>> --Semyon
>>>>>
>>>>>>
>>>>>>
>>>>>> On 11/08/2017 10:24 AM, Sergey Bylokhov wrote:
>>>>>>> Hi, Prasanta.
>>>>>>> Is it possible that dropping the float part of "tabSize" and "x" 
>>>>>>> will cause Off-by-one error? For example:
>>>>>>>     float tabSize=3.99f;
>>>>>>>     float x=21.9f;
>>>>>>>     int tabBase=0;
>>>>>>>  649         int ntabs = ((int) x - tabBase) / (int)tabSize;
>>>>>>>  650         return tabBase + ((ntabs + 1) * tabSize);
>>>>>>>
>>>>>>> The result is: ntabs=7 -> 31.92 which is not correct.
>>>>>>>
>>>>>>> I guess you will need something like this:
>>>>>>>     int ntabs = (int) Math.ceil((x - tabBase) / tabSize);
>>>>>>>     return tabBase + ntabs * tabSize;
>>>>>>> The result is: ntabs=6 -> 23.94
>>>>>>>
>>>>>>>
>>>>>>> On 08/11/2017 03:25, Prasanta Sadhukhan wrote:
>>>>>>>> Hi All,
>>>>>>>>
>>>>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8187957
>>>>>>>> webrev: http://cr.openjdk.java.net/~psadhukhan/8187957/webrev.00/
>>>>>>>>
>>>>>>>> Please review a fix for an issue where it is seen string with 
>>>>>>>> "tab" in them are not aligned properly.
>>>>>>>> This is because while calculating tab stop postion, it is 
>>>>>>>> calculating number of tabs in float value (an aftereffect of 
>>>>>>>> JDK-8156217 <https://bugs.openjdk.java.net/browse/JDK-8156217>)
>>>>>>>> so next tab stop location is coming out wrong.
>>>>>>>> Fix is to use "number of tabs" as an integer value in order to 
>>>>>>>> calculate the tab position correctly.
>>>>>>>>
>>>>>>>> Regards
>>>>>>>> Prasanta
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
> 


-- 
Best regards, Sergey.