Resizable DataGrid Question

[zryip theSlug]

On Thu, Oct 20, 2011 at 12:34 AM, Mike Doub <Mike at doub.com> wrote:
> I am not sure that you can assume that the indexes always going to
> correspond to the display order.  This is why I decided to use dgIndex
> function as it returns the indexes in the display order.   I do plan on
> having multiple sorting options.

Indeed, we can't assume that the dgIndex and the dgLine will return
the same value after sorting the list. And that was exactly the reason
I chosen to use dgLine instead of dgData after testing.

Why? Let's explore a small array of three names and their respective indexes:

[firstname][1] = "Mike"
[firstname][2] = "zryip"
[firstname][3] = "Dave"

Indexes for the firstname column are : 1,2,3

Now apply an ascending sort to our column firstname. The result is:

[firstname][3] = "Dave"
[firstname][1] = "Mike"
[firstname][2] = "Zryip"

Indexes for the firstname column are now : 3,1,2

Now we can explore your code:

 put the dgIndexes of me into tList
 -- Here tList for our sorting column will contain indexes in their
current order: 3,1,2

 -- Considering we are currently filling data for the second row, the
dgIndex for row 2 is 1

 put itemoffset(tIndex,tList) into toff -- itemoffset(1,"3,1,2")

-- will return 2, which is actually the number of our second row.

 put item (toff -1) of tList into tpreIndex --find the current index
in the ordered list

-- The previous index of index (2 - 1) in the dgIndexes is 3.


By using this code:
put the dgIndexes of me into tList
put itemoffset(tIndex,tList) into toff
put item (toff -1) of tList into tpreIndex

You are in fact searching the location of the previous dgIndex in the
rows order, so you are doing something equivalent to:
put (the dgLine of me - 1) into tThePreviousLine

In conclusion using your code or using dgLine - 1 to get the previous
value linked to the array index, have an equivalent result.


Best regards,
--
-Zryip TheSlug- wish you the best! 8)
http://www.aslugontheroad.co.cc