Well, this is something I do a lot of in every one of my applications. If
the data needs be sorted, I always use a linked list. This has the
advantage of sorting 100+ items instantaneously. It's a little complex,
however.
typedef struct bob_t {
// Put the data you wish to list here... VFS attributes, etc.
Char *caption;
struct bob_t *next;
} BobType, *BobPtr;
Once you have the data structure (note the *next pointer pointing to the
same structure...) down pat, you need a global head pointer and some
functions. If you wish to be able to add or remove an element anywhere in
the list, you'll need a doubly-linked list. That's a little more complex,
but is a simple extension of the following.
BobPtr head; // A pointer to the first item in the list... always.
UInt32 count; // A running count of the items in the list.
BobPtr *sorted; // The sorted array of items.
BobPtr addNode(Char *caption) {
BobPtr p = MemPtrNew(sizeof(BobType));
if ( !p ) return NULL; // error...
count++;
p->next = head; // the next item used to be the first...
head = p; // make the new item the head.
// Note: this effectively reverses the sort.
if ( caption ) {
p->caption = MemPtrNew(sizeof(Char) * (StrLen(caption)+1));
StrCopy(p->caption, caption);
}
}
// allow you to use different heads...
void deleteNodes(BobPtr head) {
BobPtr p = head, q;
while ( p ) {
q = p->next;
if ( p->caption ) MemPtrFree(p->caption);
MemPtrFree(p);
p = q;
}
count = 0;
}
// This function is called by QuickSort... sort by caption.
Int16 captionSortCallback(void *p1, void *p2, Int32 other) {
BobPtr i = *(BobPtr *)p1,
j = *(BobPtr *)p2;
return StrCompare(i->caption, j->caption);
}
// Sorting is a whole other matter...
void sortNodes(void) {
BobPtr p, **r;
if ( sorted ) MemPtrFree(sorted);
sorted = MemPtrNew(sizeof(BobPtr) * count + 1);
if ( !sorted ) return; // error!
MemSet(sorted, MemPtrSize(sorted), 0); // just to be safe.
// This is the magic that creates the array of pointers.
for ( r = sorted, p = head; p; p = p->next, r++ ) *r = p;
SysQSort(sorted, count, sizeof(BobPtr *), &captionSortCallback, NULL);
}
// Now you can address the sorted list like this:
// sorted[20]->caption // returns the 21'st caption.
This, of course, may be more than you are looking for. Trust me, though,
when I say linked lists are the way to go - they're blinding fast when
adding, removing, and sorting items. In fact, with multiple sorted pointer
arrays, you can pre-cache multiple sorts, combine them, etc.
> -----Original Message-----
> From: Roberto Pedrozo Mendes [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, June 22, 2004 10:30 AM
> To: Palm Developer Forum
> Subject: creating list dinamically
>
> Hi
> How can I to create a list dinamically in my aplication ?
> Thanks
>
> =====
> Roberto Pedrozo Mendes
> Arquiteto Sistemas
> HST - CPqD - Campinas
> [EMAIL PROTECTED]
>
>
>
>
> ______________________________________________________________________
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