[Gambas-user] A random sort of listview

[Simonart Dominique]

jbskaggs a écrit :
> 
> I came up with a way to random sort listview.  (Iuse this for random
> shuffling card slots on games) But it isnt efficient some pointers if you
> dont mind?
> 
> I use two listviews one to sort from and one to sort to:
> 
> I first copy all the listitems from list 1 to list 2 EXCEPT the key for
> listview2 items = the integer from my for next loop
> 
> eg 
> for i = 0 to listview1.count -1 step 1
> listview2.add(i, listview1.item.text)
> next
> 
> then with a for next loop based on the length of list1 I copy the
> listview.item key to a string A and listview.item.text to second string B
> 
> Then I  calculate a random number the count of listview2 and add that to a
> integer C
>  thenadd it to listview2
> listview2.add("n"&A, B,,C)   "n"&A creates a key of n1, n2, etc ...
> 
> 
> AFter the loop ends
> 
> I run a second loop 
> 
> and run 
> for i = 0 to listview1.count -1 step 1
> listview.moveto(i)
> listview2.item.delete
> next
> 
> This gives me a random sorted list in viewlist2 of viewlist1 with no
> duplicates etc- 
> 
> But is there a more efficient way of doing this?
> 
> here is total code:
> 
> PUBLIC SUB button3_click()
> DIM a AS String
> DIM d AS Integer
> DIM e AS Integer
> DIM i AS Integer
> DIM c AS Integer
> listview1.Clear 'clears the list
> FOR i = 0 TO 199 STEP 1 'number of items to add
>   listview2.Add(i, "Slot" & i) 'adds items to sort to list
> NEXT 'next item
> i = 0
> 
> FOR i = 0 TO 199 STEP 1 'number of items
>  e = 0
>     listview1.MoveTo(i) 'goto item
>     a = listview1.Item.Text 'get text
>     PRINT a
>     d = listview1.Key 'get key
>     PRINT "old key", d
>     listview1.Item.Delete 'delete item (the cut part of cut and paste)
>        e = Round(Rnd(200)) ' make sure old key doesNOT equal NEW Key
>        PRINT e, "<<<< the randomimzed number"
>     
>     IF e >= 200 THEN e = 199
>         listview2.Add("n" & d, "n" & a,, e) 'adds cut items after randomly
> chosen item
>         listview3.Add("n" & d, "n" & a)
>             PRINT "new key", e
> NEXT   'next item down
> 
> FOR i = 0 TO 199 STEP 1 'number of items
> listview2.MoveTo(i)
>         listview2.Item.Delete
> NEXT 
> 
> ValueBox1.value = listview1.Count
> END
> 
> JB SKaggs
Hi,

Let say you want to populate an array with 0-199 randomly
(please note that I write this directly, so check carefully 
the syntax)

dim myArray as integer[200]
dim A as integer
dim i as integer

FOR i=0 to 199
    A=int(Rnd(200-i))
    ' I think we could use a Swap instruction
    ' instead of the 2 instructions below
    myArray[i]=A
    myArray[A]=i
NEXT

That's all
If these numbers was the keys of the initial Listview you 
just have to populate the second Listview in the new order

Hope this help
Dominique Simonart