Simpler scrollbar behaviour [Demo available]

[yahvuu <yahvuu gmail com>]

Hi all,

currently, it is not possible to scroll beyond the image border by
using the scrollbars. Instead, you are forced to use the middle-button
or space bar for that purpose.

When doing so, the scrollbars' handles unexpectedly change their size.
Which breaks the convention to indicate which fraction of the
"whole thing" is visible inside the view port.


Please try [1] for a Flash, or [2] for a HTML5 prototype of a simpler
and IMHO better model. Conceptually:

  - the image is placed in the center of a gray workspace, such that
    the image is surrounded by a frame of gray. The workspace size
    depends on both image and viewport size (current behaviour)
  - the frame is big enough such that at least half of the image can
    be scrolled outside the viewport (current behaviour)
  - the frame's border size is at least half the viewport size
    (current behaviour) *)
  - the size of a scrollbar's handle indicates which fraction of the
    _workspace_ is visible inside the viewport (new proposal)


In other words, the proposal is to consistently use the dimensions of
the workspace as "the whole thing", instead of using the image size
plus some exceptions when zooming out. Just KISS.


On a sidenote, the minimum frame size as of *) may be discussed:
when zooming in, the scrollbar handles remain bigger if the border is
clamped to a smaller, fixed value. For example, 25 pixels. Just try it.


best regards,
yahvuu



[1] 
https://sites.google.com/site/yahvuu/stuff/wscroll.lzx.swf8.swf?attredirects=0&d=1
[2] 
https://sites.google.com/site/yahvuu/stuff/wscroll_deploy_html5.zip?attredirects=0&d=1
[3] 
https://sites.google.com/site/yahvuu/stuff/wscroll_deploy_flash8.zip?attredirects=0&d=1