On Thu, Apr 7, 2016 at 11:15 AM, Igor Stasenko <siguctua@gmail.com> wrote:

That may, indeed make accessing such properties like clipRect impossible to get, since clipped area cannot be represented by a simple rectangle anymore.
But then you could, perhaps instead provide a protocol to tell if given point/bounds/shape is fully outside currently clipped region(s) or not.
And thus, you don't have to worry about cliprect anymore.

In Sparta I use��cairo_clip_extents to get current clip rect in local coordinates. Together with��cairo_path_extents,��implementation of AthensCanvas#>>#isVisible: becomes trivial even for arbitrary path (+ assuming that Rectangle is polymorphic with Path).

Btw, for simple paths (circle, ellipse, text, rectangle) it is an overkill to ask cairo for path extent that is why it makes sense for optimisation to have subclasses of Path like EllipsePath, PolygonPath and calculate extent in Pharo. If user uses Factory than extent detection degrades to��cairo_path_extents.

So, in Sparta (now it is still BlPath) there is Path>>#bounds that by default uses��cairo_path_extents, still allowing user to override it and implement optimised Pharo version :)

Cheers,

Alex