<AWT Dev> [13] JDK-8218917: KeyEvent.getModifiers() returns inconsistent values for ALT keys

[Sergey Bylokhov]

On 12/03/2019 12:28, Sergey Malenkov wrote:
> Hi Sergey,
> 
> 1. macOS uses a regular Alt key as "Alternate Character Key". This is
> the reason why JDK Toolkit defines Ctrl+Alt to select a mnemonic,
> instead of simple Alt. See
> https://sites.google.com/site/malenkov/java/141229

Right, but introducing this flag for the "left alt" could cause even more
issues, so this flag is set only for the right.

> 3. Regression was caused by adding AltGr to key processing on Mac. But
> I found more issues with inconsistent key processing on different
> platforms. See http://sites.google.com/site/malenkov/java/190312

Not sure that CAPS_LOCK is related.

> 
> 
> On Tue, Mar 12, 2019 at 4:17 AM Sergey Bylokhov
> <Sergey.Bylokhov at oracle.com> wrote:
>>
>> On 11/03/2019 17:37, Philip Race wrote:
>>> The debate is about AltGraph which an ancient MS-DOSism for
>>> asking for an ALTernate GRAPHics bitmap font - all pre-dates windows
>>> and I am sure has never been applicable to any MacOS.
>>
>> It also about the "right alt" which is also know as "AltGraph". I guess currently
>> it is implemented as "right alt" on Linux/macOS/windows.
>>
>> BTW on linux it is also named as "Alternative Characters Key":
>> https://help.ubuntu.com/community/ComposeKey
>>
>>> So someone needs to properly explain why we would claim a Mac keyboard
>>> is OK to generate a keycode it doesn't have and cause a slew of regressions
>>> in the process ...>
>>> If Mac doesn't distinguish these two, we should generate the same keycode for both.
>>
>> The macOS supports "right alt", otherwise it would not be possible to implement it in java:
>> https://developer.apple.com/library/archive/technotes/tn2450/_index.html
>>
>>
>>> One could suppose there is a difference else why two keys, but what is the right
>>> thing to do here  that fixes all the problems. What exactly WAS the problem
>>> with what was there in the first place ? And if changing it is correct why is it
>>> causing regressions ?
>>
>> Regressions were caused by the bugs in the fix implementation, or am I missed something?
>>
>>
>>>
>>> -phil.
>>>
>>>
>>>
>>> On 3/12/19, 5:34 AM, Sergey Bylokhov wrote:
>>>> Hi, Phil.
>>>> On 11/03/2019 07:43, Philip Race wrote:
>>>>> The reasoning that AltGraph might be useful to someone is a bit weak
>>>>> and I don't think I'd want to support it via system property or build options.
>>>>>
>>>>> If its not a platform keyboard key, why do we need it ?
>>>>
>>>> The "AltGraph" key is also commonly referred to as "Right Alt", and
>>>> it has been implemented on all platforms as a "Right Alt", it is convenient to
>>>> distinguish the left/right alts.
>>>>
>>
>>
>> --
>> Best regards, Sergey.
> 
> 
> 


-- 
Best regards, Sergey.