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stadidas
Jan 28, 2007, 07:43 PM
Hi everybody.

I've been having a small issue getting a new feature in a program I've made to work correctly.
Currently the methods do exactly what I want them to, and when I hit undo, the action is undone as I would expect. However, when I try to redo the action, nothing happens. Hopefully this will be an easy problem to solve that I just can't see, even Aaron Hillegas says the UndoManager makes his head spin! Anyway, here's the troublesome code:

- (void)add:(double)d:(NSString *)s
{
Log *l = [[Log alloc] init];
[l setDescription:s];
[l setAmount:d];
[self doAdd:d:s:l];
[l release];
}

- (void)addAmount:(double)d
{
double tempBalance = [myBalance doubleValue];
double newBalance = tempBalance + d;
[detailsController setMyBalance:newBalance];
}

- (void)doAdd:(double)d:(NSString *)s:(Log *)l
{
[self addAmount:d];
[self addLog:l];
[tableView reloadData];

NSUndoManager *undo = [self undoManager];
[[undo prepareWithInvocationTarget:self]
removeLog:l];

[[undo prepareWithInvocationTarget:self]
subtractAmount:d];

if (![undo isUndoing]) {
[undo setActionName:@"Add to Balance"];
}
}

- (void)subtract:(double)d:(NSString *)s
{
Log *l = [[Log alloc] init];
double inverseD = - d;
[l setDescription:s];
[l setAmount:inverseD];
[self doSubtract:d:s:l];
[l release];
}

- (void)subtractAmount:(double)d
{
double tempBalance = [myBalance doubleValue];
double newBalance = tempBalance - d;
[detailsController setMyBalance:newBalance];
}

- (void)doSubtract:(double)d:(NSString *)s:(Log *)l
{
[self subtractAmount:d];
[self addLog:l];
[tableView reloadData];

NSUndoManager *undo = [self undoManager];
[[undo prepareWithInvocationTarget:self]
removeLog:l];

[[undo prepareWithInvocationTarget:self]
addAmount:d];

if (![undo isUndoing]) {
[undo setActionName:@"Subtract From Balance"];
}

}


I hacked this code out a few nights ago, so I'm sure it's probably just a fault from trying several different approaches and maybe not thinking it through correctly.
As always any help is very much appreciated!



stadidas
Jan 30, 2007, 01:11 PM
No-one has any ideas? :(