[webkit-dev] Table hit testing

[David Hyatt]

On May 20, 2010, at 3:38 PM, Fady Samuel wrote:

> So what are the rules for stacking here? do the cells stack in the order in which they appear in the HTML?
> 

Correct, although note that backgrounds paint behind foregrounds, and hit testing works the same way, so it's not as simple as saying that cell 7 is always above cell 5.  They're interleaved, so from bottom to top:

Cell 5 background
Cell 7 background
Cell 5 foreground (the number "5" in this example)
Cell 7 foreground (the number "7" in this example)

That's why if you hover over the actual number 5 in that example it will light up, but if you're in the background area overlap, the number 7 will light up.

http://www.w3.org/TR/CSS21/zindex.html

Therefore you do have to know about all the cells at the position, since when you're in the "foreground" phase of hit testing, cell 7 will say "Nope, you're not inside my foreground", and so you then need to check cell 5, which will say "Yes, you are inside my foreground."

The grid structure just isn't expressive enough.  It needs to be patched to track all cells in a given row/column instead of just the first one.

dave
(hyatt at apple.com)