Hello,
I am having a problem that I have spent days trying to figure out with no
success. My program includes a form with two lists, the options list and
the picked list. The options list is filled when the form loads and by
selecting items from the options list and clicking a button, the user can
fill their personal "picked list."
There is something slightly wrong with my function for adding to the picked
list however. If I use the function as is (shown below) I end up with a
number of memory leaks equivalent to the number of list items added after
the first item. (so I know that the leak is within the code in the
outermost Else clause of AddPickedItem). I thought that the problem was
that I was setting the list pointer equal to the pointer for a newly created
string, but never dealloating the memory that was held by the previous
version of the list. So I added a line (now commented) to free that memory.
However, when I add that line, my function ClearPickedList no longer works
upon closing the form. (It does however work when called at the beginning
of FillList each time a new item is added to the picked list.) I can an
unallocated chunk error. Any Ideas on this? My code is all below.
on a side note, when there are memory leaks, the emulator alerts me and
tells me that details can be found in "the log file." What log file?
thank you!
meg
***********************code*********************************
void AddPickedItem(char* itemToAdd) {
ListType *lstP;
UInt16 newSize;
char* newStringP;
char* oldP;
char* oldP2;
UInt16 addingSize;
UInt16 oldSize;
UInt16 i;
UInt16 length;
Boolean alreadyThere=false;
//grab pointer to picked list
lstP=(ListType *)GetObjectPtr(DetailHasslesPickedList);
//if picked list is currently empty
if (pickedListStringP.numItems==0) {
pickedListStringP.stringListP=itemToAdd;
}//if (pickedListStringP.numItems==0)
//if picked list already has items
else {
//calculate new size of string list
oldSize = MemPtrSize(pickedListStringP.stringListP);
addingSize=StrLen(itemToAdd);
newSize=oldSize+addingSize+1;
//create new string
newStringP=MemPtrNew(newSize);
//store old newString pointer
oldP=newStringP;
//store old picked list pointer
oldP2=pickedListStringP.stringListP;
//cycle through old items
for(i=0;i<pickedListStringP.numItems;i++) {
//find length of current item
length=StrLen(pickedListStringP.stringListP);
//copy old item into string
StrCopy(newStringP,pickedListStringP.stringListP);
//check to see if this item is not same as item being added
if (StrCompare(pickedListStringP.stringListP, itemToAdd)==0) {
//set flag
alreadyThere=true;
//alert user
FrmAlert(AlreadyInListAlert);
}//if (StrCompare(pickedListStringP.stringListP, itemToAdd)==0)
//add nullterminator
*(newStringP+length)='\0';
//move pointers
newStringP+=length+1;
pickedListStringP.stringListP+=length+1;
}//for(i=0;i<pickedListStringP.numItems;i++)
//if item is unique, add to list and reset pointer
if (!alreadyThere) {
//copy in new item
StrCopy(newStringP,itemToAdd);
}//if (!alreadyThere)
//reset pointers
newStringP=oldP;
//free memory used by old list
//if (oldP2)
// MemPtrFree(oldP2);
//set list pointer to point to new list
pickedListStringP.stringListP=newStringP;
}//else
//if item is unique
if (!alreadyThere) {
//update item count
pickedListStringP.numItems++;
//redraw list
FillPickedList(lstP,pickedListStringP.numItems,pickedListStringP.stringListP
);
LstDrawList(lstP);
LstSetSelection(lstP,LstGetNumberOfItems(lstP));
}//if (!alreadyThere)
}//AddPickedItem
void FillPickedList(ListType *lstP, UInt16 numItems, char *stringP) {
Char **itemList;
UInt16 i;
UInt16 length;
//first free old memory used by this list
ClearPickedList();
//set aside memory for array of list items
itemList = (Char **) MemPtrNew(numItems * sizeof(Char *));
//save so memory can be released later
hasslesPickedListChoices = itemList;
hasslesPickedListNumItems=numItems;
//for each list item
for(i=0;i<numItems; i++) {
length=StrLen(stringP);
//create space in array
itemList[i]=(char*)MemPtrNew(length+1);
//write to array
StrCopy(itemList[i], stringP);
//move pointer to next item in string
stringP+=(length+1);
}//for(i=0;i<numItems; i++)
//set list to reference array
LstSetListChoices(lstP, itemList, numItems);
}//FillPickedList
void ClearPickedList(void) {
//if there are still list items stored (from filling a list earlier)
if (hasslesPickedListChoices) {
UInt16 i;
//for each item
for(i=0;i<hasslesPickedListNumItems; i++) {
//free item's memory
MemPtrFree((MemPtr) hasslesPickedListChoices[i]);
}//for(i=0;i<hasslesPickedListNumItems; i++)
//free beginning pointer
MemPtrFree((MemPtr)hasslesPickedListChoices);
hasslesPickedListChoices=0;
}//if (hasslesPickedListChoices)
}//ClearPickedList
--
For information on using the Palm Developer Forums, or to unsubscribe, please see
http://www.palmos.com/dev/support/forums/
