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

[semyon.sadetsky at oracle.com]

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
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>