Re: NS port horizontal scroll-bars

[YAMAMOTO Mitsuharu]

>>>>> On Tue, 26 Apr 2016 10:51:57 +0100, Alan Third <address@hidden> said:

> It's actually the other end of the process that I'm struggling
> with. I write pixel values for dragging the scroll-bar into an
> emacs_event struct (location of mouse in scroll-bar and total length
> of scroll-bar), and when that data pops back out in scroll-bar.el it
> doesn't seem to be any use to the standard scroll-bar functions.

Ah, that reminds me of something.  You can see how the Mac port
handles that (in the `work' branch based on Emacs 25.0.93 pretest).

https://bitbucket.org/mituharu/emacs-mac/src/472fe59bac472a9076cbb6e86e0ea92908f7b78d/src/macappkit.m?at=work&fileviewer=file-view-default#macappkit.m-6002

  6690        if (bar->horizontal && whole > 0)
  6691          {
  6692            /* The default horizontal scroll bar drag handler assumes
  6693               previously-set `whole' value to be preserved and doesn't
  6694               want overscrolling.  */
  6695            int position = lround (whole * minEdge / maximum);
  6696  
  6697            if (position > whole - portion)
  6698              position = whole - portion;
  6699            XSETINT (inputEvent.x, position);
  6700            XSETINT (inputEvent.y, whole);
  6701          }
  6702        else
  6703          {
  6704            XSETINT (inputEvent.x, minEdge);
  6705            XSETINT (inputEvent.y, maximum);
  6706          }
  6707      }

> The vertical scroll-bars in the NS port have their own functions
> defined in ns-win.el, rather than using the functions in
> scroll-bar.el. I think this is, at least in part, to enable clicking
> directional arrows in older versions of OS X (and GNUSTEP), but it's
> doing something different with dragging too.

The Mac port (and its predecessors) has been using the standard
toolkit scroll bar handler in scroll-bar.el as it is, and there has
been no problem even in the old OS X versions having the directional
arrows.

                                     YAMAMOTO Mitsuharu
                                address@hidden