Re: [Goocanvas-devel] GooCanvas "in region" detection

[Damon C. <da...@ka...>]

On Fri, 2008-03-21 at 16:50 +0800, ZeeGeek wrote:
> Hi,
> 
> I'm reading the code of GooCanvas, and I'm interested in how you dealt
> with the in region detection of the mouse pointer. Does GooCanvas
> iterate over all the objects on the canvas and checks if the mouse
> pointer is in the region? Thank you.

Each item keeps a 'bounds' rectangle which describes the area that the
item (and any children) cover.

In the worst case scenario (with no groups) GooCanvas will iterate over
all the items. But if the canvas is split into groups of items it is
more efficient. (It is only a few double comparisons so it doesn't
matter too much unless there are thousands of items.)

Damon