Re: [platform-swt-dev] Providing SWT themeable scrollbars (onWindows)

[Fabio Zadrozny <fabiofz@xxxxxxxxx>]

On Mon, Feb 22, 2016 at 8:09 PM, Doug Schaefer <cdtdoug@xxxxxxxxx> wrote:

On Mon, Feb 22, 2016 at 3:32 PM, Aleksandar Kurtakov <akurtako@xxxxxxxxxx> wrote:

----- Original Message -----
> From: "Fabio Zadrozny" <fabiofz@xxxxxxxxx>
> To: "Eclipse Platform SWT component developers list." <platform-swt-dev@xxxxxxxxxxx>
> Sent: Monday, 22 February, 2016 9:56:47 PM
> Subject: Re: [platform-swt-dev] Providing SWT themeable scrollbars    (onWindows)
>
> Hi Tom,
>
> I must say that while I think that a qt-based or javafx-based backend may be
> a good alternative, I don't think I personally have enough diplomatic skills
> to make that work (i.e.: I can't envision the default Eclipse being based on
> SWT from one of those backends -- and not because of technical issues -- it
> seems many which would be more suitable than me have tried and failed in the
> past, so, I'm not thrilled in trying to pursue that path).

I would dare to say it's purely technical issues. A new port need someone dedicated to make it work fully compatible with current SWT API once it does and it proves to be more stable, better performance, better looking - changing the default wouldn't be an issue. The issue is that while making a port that would be >90% or even >95% compatible that's where things start to get ugly and one starts finding out that the two things just don't play well for design issues (scrollbar color anyone?) and it's not fine to change the default in this case as there is always code in the wild that will break.

+1. We went through this exercise when JavaFX was the latest cool thing. There are a lot of places where you get into trouble with backwards compatibility. Hell, we had a hard enough time just fitting Eclipse into the JavaFX startup.

At the time, I concluded, the only way to make significant changes to SWT is to blow up the entire stack and start over. Imagine an Eclipse where there was no SWT, only JavaFX. It would be pretty sweat. How that ever happens is a thing of dreams. It turns out Eclipse is good enough as it is and no one is willing to make that investment over again. At least I haven't met them yet.

It's easy to think of code changes that add in little features that would make things a lot better. It's a harder thing to see those changes and realize how much worse things will become. There's lots of experience on this list. I'm sure we'll make the right decisions.

​Well, I think there's been a lot of discussion in this list, so, I'd like to ask devs for a clear decision on whether they feel the work on the themed scrollbars should be done on SWT (on windows for now) or not.

To make it clear, I'd be nice having votes on (just copy/past with the answers on the list -- although if you feel the format is not appropriate I can create an online form).

1. Do you think SWT should support non-native theming of scrollbars? (yes/no)

1a. If you think it should be supported, do you think it's better to have "multiple methods" or a single method with a "CSS string"? 

3. Is the approach to incorporate element by element Ok? (i.e.: yes means it's Ok to do StyledText first and Tree/Table later, no means all has to land at once​ -- note that I appreciate all the warnings on the effort to make it work​).

​4. Do you use the dark theme on windows as your go-to theme? (yes/no) -- this is just because I'm curious as how many devs here ​​​actually struggle with that​ ;)

Best Regards,

Fabio​