Re: [MACTCL] Weird behaviour of Mac scrollbar

[Torsten B. <be...@ty...>]

Dear Kevin,

thanks for your response. I was suspecting it had to do with the scrollbar changes for Tk Cocoa 2.0 and I totally understand this is not an easy matter to deal with. If I had the skills and the time, I would give it a try myself. Still, it would be good to document this as a bug, don’t you think so?

I just wonder why no-one else has raised this issue before. This either means the number of Mac users is terribly small and no-one cares, or people are still using older versions of Tcl. What are you doing with the apps you released? Are you using Tcl 8.6.4 and newer for these and your users are not reporting anything? Then, there must be something wrong on my end somehow.

Torsten


> 
> On 3/30/17 5:22 AM, Torsten Berg wrote:
>> since quite some time I am experiencing a weird behaviour of the Tk scrollbar on the Mac. E.g. when I have a listbox (but this applies to all other widgets as well) and vertically scroll through it using the slider of the scrollbar, I need to click and hold the slider on the lower end in order to be able to move it. I can also click and hold below the slider, in the open space of the trough, it still moves. However, when I click on the upper part of the slider, the behaviour is as if I had clicked into the trough above the slider.
>> It seems as if the position where the mouse click occurs is not in sync with where the slider actually is.
> 
> I've seen this behavior, the slightly jumpy behavior of the scroller in 
> some situations, and I'm sure it's the result of the various changes I 
> committed; the changes to the scrollbar were my work. I am not certain 
> of how to address it. The redesign of the scrollbar essentially involved 
> rewriting the C-level code to remove all the Cocoa scrolling management, 
> which had all kinds of hidden issues, and use HITheme to draw the 
> scrollbar only, and delegate scrolling behavior to the Unix scripting 
> bindings. It's possible that there is a slight mismatch there somewhere, 
> but I do not know where to find it. Getting the scrollbar working took a 
> couple of months of work on my part--I quit when it was Basically Good 
> Enough--and I do not have that kind of time these days to re-investigate 
> it. Anyone else is welcome to take a look and I'll gladly review patches 
> that take it to higher level.
> 
> --Kevin