Re: Icon prelighting signals activation affordance incorrectly

[Havoc Pennington <hp redhat com>]

On Thu, Dec 05, 2002 at 03:40:25AM -0500, Alexander Larsson wrote:
> 
> That unfortunately shows off another issue, namely that you have to click 
> on a non-transparent part of an icon to select it. Without prelighting 
> that can be hard. Arguably that should be changed though.

It should definitely be changed at least for transparency "inside" the
icon. e.g. if my icon is a hollow circle clicking inside it should
work.

Surely it isn't hard to write a simple check for this.  A cheesy
algorithm that might work well enough is something like:

 - draw 4 lines at 0,90,180,270 degrees from the click point to the
   edge of the icon bounding box

 - if all 4 lines intersect a non-transparent pixel, 
   then the click is considered to be "inside" the icon

Then, file for a patent. ;-)

Havoc